ORCID Profile
0000-0003-3141-8410
Current Organisations
University of Western Australia
,
University of Sydney
,
University of Georgia
,
Wuhan Institute of Virology
,
Australian National University
,
Sichuan Agricultural University - Chengdu Campus
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Publisher: Proceedings of the National Academy of Sciences
Date: 22-05-2001
Abstract: We inoculated BALB/c mice deficient in STAT6 (STAT6 −/− ) and their wild-type (wt) littermates (STAT6 +/+ ) with the natural mouse pathogen, ectromelia virus (EV). STAT6 −/− mice exhibited increased resistance to generalized infection with EV when compared with STAT6 +/+ mice. In the spleens and lymph nodes of STAT6 −/− mice, T helper 1 (Th1) cytokines were induced at earlier time points and at higher levels postinfection when compared with those in STAT6 +/+ mice. Elevated levels of NO were evident in plasma and splenocyte cultures of EV-infected STAT6 −/− mice in comparison with STAT6 +/+ mice. The induction of high levels of Th1 cytokines in the mutant mice correlated with a strong natural killer cell response. We demonstrate in genetically susceptible BALB/c mice that the STAT6 locus is critical for progression of EV infection. Furthermore, in the absence of this transcription factor, the immune system defaults toward a protective Th1-like response, conferring pronounced resistance to EV infection and disease progression.
Publisher: Elsevier BV
Date: 02-2012
Publisher: Springer Science and Business Media LLC
Date: 10-04-2018
DOI: 10.1038/S41467-018-03640-Y
Abstract: Despite anti-TNF therapy advancements for inflammatory diseases such as rheumatoid arthritis, the burden of diseases remains high. An 11-mer TNF peptide, TNF 70–80 , is known to stimulate selective functional responses compared to the parent TNF molecule. Here, we show that TNF 70–80 binds to the TNF receptor, activating p38 MAP kinase through TNF receptor-associated factor 2. Using truncated TNFR mutants, we identify the sequence in TNFRI which enables p38 activation by TNF 70–80 . Peptides with this TNFRI sequence, such as TNFRI 206–211 bind to TNF and inhibit TNF-induced p38 activation, respiratory burst, cytokine production and adhesion receptor expression but not F-Met-Leu-Phe-induced respiratory burst in neutrophils. TNFRI 206–211 does not prevent TNF binding to TNFRI or TNF-induced stimulation of ERK, JNK and NF-κB. TNFRI 206–211 inhibits bacterial lipopolysaccharide-induced peritonitis, carrageenan-induced and antigen-induced paw inflammation, and respiratory syncytial virus-induced lung inflammation in mice. Our findings suggest a way of targeting TNF-p38 pathway to treat chronic inflammatory disorders.
Publisher: American Chemical Society (ACS)
Date: 09-09-2009
DOI: 10.1021/JM900652E
Publisher: American Chemical Society (ACS)
Date: 23-10-2013
DOI: 10.1021/JM400460D
Abstract: Chikungunya virus is an emerging arbovirus that is widespread in tropical regions and is spreading quickly to temperate climates with recent epidemics in Africa and Asia and documented outbreaks in Europe and the Americas. It is having an increasingly major impact on humankind, with potentially life-threatening and debilitating arthritis. There is no treatment available, and only in the past 24 months have lead compounds for development as potential therapeutics been reported. This Perspective discusses the chikungunya virus as a significant, new emerging topic for medicinal chemistry, highlighting the key viral target proteins and their molecular functions that can be used in drug design, as well as the most important ongoing developments for anti-chikungunya virus research. It represents a complete picture of the current medicinal chemistry of chikungunya, supporting the development of chemotherapeutics through drug discovery and design targeting this virus.
Publisher: Public Library of Science (PLoS)
Date: 12-08-2013
Publisher: American Society for Microbiology
Date: 15-04-2016
DOI: 10.1128/JVI.03192-15
Abstract: The alphaviral 6k gene region encodes the two structural proteins 6K protein and, due to a ribosomal frameshift event, the transframe protein (TF). Here, we characterized the role of the 6k proteins in the arthritogenic alphavirus Ross River virus (RRV) in infected cells and in mice, using a novel 6k in-frame deletion mutant. Comprehensive microscopic analysis revealed that the 6k proteins were predominantly localized at the endoplasmic reticulum of RRV-infected cells. RRV virions that lack the 6k proteins 6K and TF [RRV-(Δ6K)] were more vulnerable to changes in pH, and the corresponding virus had increased sensitivity to a higher temperature. While the 6k deletion did not reduce RRV particle production in BHK-21 cells, it affected virion release from the host cell. Subsequent in vivo studies demonstrated that RRV-(Δ6K) caused a milder disease than wild-type virus, with viral titers being reduced in infected mice. Immunization of mice with RRV-(Δ6K) resulted in a reduced viral load and accelerated viral elimination upon secondary infection with wild-type RRV or another alphavirus, chikungunya virus (CHIKV). Our results show that the 6k proteins may contribute to alphaviral disease manifestations and suggest that manipulation of the 6k gene may be a potential strategy to facilitate viral vaccine development. IMPORTANCE Arthritogenic alphaviruses, such as chikungunya virus (CHIKV) and Ross River virus (RRV), cause epidemics of debilitating rheumatic disease in areas where they are endemic and can emerge in new regions worldwide. RRV is of considerable medical significance in Australia, where it is the leading cause of arboviral disease. The mechanisms by which alphaviruses persist and cause disease in the host are ill defined. This paper describes the phenotypic properties of an RRV 6k deletion mutant. The absence of the 6k gene reduced virion release from infected cells and also reduced the severity of disease and viral titers in infected mice. Immunization with the mutant virus protected mice against viremia not only upon exposure to RRV but also upon challenge with CHIKV. These findings could lead to the development of safer and more immunogenic alphavirus vectors for vaccine delivery.
Publisher: American Society for Microbiology
Date: 08-2015
DOI: 10.1128/JVI.00224-15
Abstract: Arthritogenic alphaviruses such as Ross River virus (RRV) and chikungunya virus (CHIKV) cause large-scale epidemics of severe musculoskeletal disease and have been progressively expanding their global distribution. Since its introduction in July 2014, CHIKV now circulates in the United States. The hallmark of alphavirus disease is crippling pain and inflammation of the joints, a similar immunopathology to rheumatoid arthritis. The use of glycans as novel therapeutics is an area of research that has increased in recent years. Here, we describe the promising therapeutic potential of the glycosaminoglycan (GAG)-like molecule pentosan polysulfate (PPS) to alleviate virus-induced arthritis. Mouse models of RRV and CHIKV disease were used to characterize the extent of cartilage damage in infection and investigate the potential of PPS to treat disease. This was assessed using histological analysis, real-time PCR, and fluorescence-activated cell sorting (FACS). Alphaviral infection resulted in cartilage destruction, the severity of which was alleviated by PPS therapy during RRV and CHIKV clinical disease. The reduction in cartilage damage corresponded with a significant reduction in immune infiltrates. Using multiplex bead arrays, PPS treatment was found to have significantly increased the anti-inflammatory cytokine interleukin-10 and reduced proinflammatory cytokines, typically correlated with disease severity. Furthermore, we reveal that the severe RRV-induced joint pathology, including thinning of articular cartilage and loss of proteoglycans in the cartilage matrix, was diminished with treatment. PPS is a promising new therapy for alphavirus-induced arthritis, acting to preserve the cartilage matrix, which is damaged during alphavirus infection. Overall, the data demonstrate the potential of glycotherapeutics as a new class of treatment for infectious arthritis. IMPORTANCE The hallmark of alphavirus disease is crippling pain and joint arthritis, which often has an extended duration. In the past year, CHIKV has expanded into the Americas, with approximately 1 million cases reported to date, whereas RRV continues to circulate in the South Pacific. Currently, there is no licensed specific treatment for alphavirus disease, and the increasing spread of infection highlights an urgent need for therapeutic intervention strategies. Pentosan polysulfate (PPS) is a glycan derivative that is orally bioavailable, has few toxic side effects, and is currently licensed under the name Elmiron for the treatment of cystitis in the United States. Our findings show that RRV infection damages the articular cartilage, including a loss of proteoglycans within the joint. Furthermore, treatment with PPS reduced the severity of both RRV- and CHIKV-induced musculoskeletal disease, including a reduction in inflammation and joint swelling, suggesting that PPS is a promising candidate for drug repurposing for the treatment of alphavirus-induced arthritis.
Publisher: Proceedings of the National Academy of Sciences
Date: 14-04-2014
Abstract: Persistent polyarthritis, which occurs in 30–40% of alphavirus-infected patients, has been proposed to be caused by proinflammatory mediators such as IL-6. In the present study we investigated the susceptibility and response of primary human osteoblasts to Ross River virus (RRV) infection and determined whether infection could result in bone pathology. RRV infection of osteoblasts resulted in increased receptor activator of nuclear factor-kappaB ligand (RANKL) but decreased osteoprotegerin (OPG). We are the first to report that alphavirus infection results in bone loss in an established RRV murine model and that this bone loss is prevented by IL-6 inhibition. These findings reveal that RRV can disrupt bone homeostasis and that osteoblasts play an important role in alphavirus-induced arthritis by regulating IL-6 and contribute to bone loss by disrupting the RANKL/OPG balance.
Publisher: Centers for Disease Control and Prevention (CDC)
Date: 08-2013
Publisher: Wiley
Date: 23-03-2018
DOI: 10.1002/ART.40403
Abstract: In the past decade, arboviruses-arthropod-borne viruses-have been the focus of public health institutions worldwide following a spate of devastating outbreaks. Chikungunya virus, an arbovirus that belongs to the alphavirus genus, is a reemerging arthritogenic virus that has caused explosive outbreaks since 2006, notably on Réunion Island, and more recently in the Caribbean, South America, India, and Southeast Asia. The severity of arthritic disease caused by chikungunya virus has prompted public health authorities in affected countries to develop specific guidelines to tackle this pathogen. Chikungunya virus disease manifests first as an acute stage of severe joint inflammation and febrile illness, which later progresses to a chronic stage, during which patients may experience debilitating and persisting articular pain for extended periods. This review aims to provide a broad perspective on current knowledge of chikungunya virus pathogenesis by identifying key clinical and experimental studies that have contributed to our understanding of chikungunya virus to date. In addition, the review explores the practical aspects of treatment and management of both acute and chronic chikungunya virus based on clinical experience during chikungunya virus outbreaks. Finally, recent findings on potential therapeutic solutions-from antiviral agents to immunomodulators-are reviewed to provide both viral immunologists and clinical rheumatologists with a balanced perspective on the nature of a reemerging arboviral disease of significant public health concern, and insight into future therapeutic approaches to better address the treatment and management of chikungunya virus.
Publisher: F1000 Research Ltd
Date: 17-08-2020
DOI: 10.12688/F1000RESEARCH.25998.1
Abstract: COVID-19 emerged in late 2019 and has rapidly spread through many countries globally. The causative SARS-CoV-2 virus was not known until recently, and there is little or no natural immunity in human populations. There is an urgent need for vaccines and drugs to combat this new pandemic. In just a few months, huge efforts and resources by government, academia, and industry have been thrown into the race to develop a vaccine. This brief review summarizes and discusses the array of technologies being applied to vaccine development, highlighting the strengths and weaknesses of the various approaches.
Publisher: Elsevier BV
Date: 03-2013
Publisher: American Society for Microbiology
Date: 27-10-2021
Abstract: Mouse models that accurately replicate the immunopathogenesis and clinical disease of alphavirus infection are vital to the preclinical development of therapeutic strategies that target alphavirus infection and disease. Current models rely on subjective scoring made through experienced observation of infected mice.
Publisher: Microbiology Society
Date: 06-01-2010
Abstract: Human metapneumovirus (hMPV) is a major cause of upper and lower respiratory-tract infection in infants, the elderly and immunocompromised in iduals. Virus-directed cellular immunity elicited by hMPV infection is poorly understood, in contrast to the phylogenetically and clinically related pathogen human respiratory syncytial virus (hRSV). In a murine model of acute lower respiratory-tract infection with hMPV, we demonstrate the accumulation of gamma interferon (IFN-gamma)-producing CD8+ T cells in the airways and lungs at day 7 post-infection (p.i.), associated with cytotoxic T lymphocytes (CTLs) directed to an epitope of the M2-1 protein. This CTL immunity was accompanied by increased pulmonary expression of Th1 cytokines IFN-gamma and interleukin (IL)-12 and antiviral cytokines (IFN-beta), as well as chemokines Mip-1alpha, Mip-1beta, Mig, IP-10 and CX3CL1. There was also a moderate increase in Th2-type cytokines IL-4 and IL-10 compared with uninfected mice. At 21 days p.i., a strong CTL response could be recalled from the spleen. A similar pattern of CTL induction to the homologous M2-1 CTL epitope of hRSV, and of cytokine/chemokine induction, was observed following infection with hRSV, highlighting similarities in the cellular immune response to the two related pathogens.
Publisher: Elsevier BV
Date: 02-2013
DOI: 10.1016/J.PHARMTHERA.2012.10.007
Abstract: Dengue virus (DV) is the most widespread arbovirus, being endemic in over 100 countries, and is estimated to cause 50 million infections annually. Viral factors, such as the genetic composition of the virus strain can play a role in determining the virus virulence and subsequent clinical disease severity. Virus vector competence plays an integral role in virus transmission and is a critical factor in determining the severity and impact of DV outbreaks. Host genetic variations in immune-related genes, including the human leukocyte antigen, have also been shown to correlate with clinical disease and thus may play a role in regulating disease severity. The host's immune system, however, appears to be the primary factor in DV pathogenesis with the delicate interplay of innate and acquired immunity playing a crucial role. Although current research of DV pathogenesis has been limited by the lack of an appropriate animal model, the development of DV therapeutics has been a primary focus of research groups around the world. In the past decade advances in both the development of vaccines and anti-virals have increased in dramatically. This review summarises the current understanding of viral, vector and host factors which contribute to dengue virus pathogenesis and how this knowledge is critically important in the development of pharmaceutical interventions.
Publisher: American Society for Microbiology
Date: 15-09-2000
DOI: 10.1128/JVI.74.18.8376-8381.2000
Abstract: Ross River virus (RRV) is an indigenous Australian arthropod-borne alphavirus responsible for epidemic polyarthritis (EPA), myalgia, and lethargy in humans. Macrophages and monocytes have been associated with human RRV disease, and previous studies have shown that RRV is capable of infecting macrophages via both a natural virus receptor and by Fc receptor-mediated antibody-dependent enhancement (ADE). Similar to other viruses, such as human immunodeficiency virus and dengue virus, ADE infection results in dramatic RRV growth increases for in vitro macrophage cultures. This study demonstrates that RRV could resist lipopolysaccharide (LPS)-induced antiviral activity in macrophage cultures when infection was via the ADE pathway. Investigation of this infection pathway found that RRV was able to suppress the transcription and translation of key antiviral genes (tumor necrosis factor and inducible nitric oxide synthase) in LPS-stimulated macrophages by disrupting the transcription into mRNA of the genes coding for the associated transcription factors IRF-1 and NF-κB. The transcription of non-antiviral control genes was not perturbed by RRV-ADE infection, and de novo protein synthesis also was not significantly affected in RRV-ADE infected cells. The ADE pathway of infection allowed RRV to specifically target antiviral genes in macrophages, resulting in unrestricted virus replication. As ADE has been observed for several virus families and associated with disease and adverse vaccination outcomes, these findings may have broad relevance to viral disease formation and antiviral vaccination strategies.
Publisher: American Society for Microbiology
Date: 23-02-2021
Abstract: COVID-19 has plagued the world since it was first identified in December 2019. Previous systematic reviews and meta-analysis were limited by various factors such as the usage of non-peer reviewed data and were also limited by the lack of clinical data on a global scale.
Publisher: Wiley
Date: 28-01-2011
DOI: 10.1002/ART.30112
Abstract: Mosquito-borne alphaviruses such as chikungunya virus, o'nyong-nyong virus, and Ross River virus (RRV) cause sporadic, sometimes large, outbreaks of rheumatic disease worldwide. This study was designed to test the effect of treating RRV-induced arthritis using the anti-tumor necrosis factor (anti-TNF) drug etanercept in a mouse model of rheumatic disease. Mice were infected with RRV and treated with etanercept. Weight gain was measured, tissue viral titers were determined, and histologic changes in muscle and joint tissues were assessed. RRV-infected mice treated with etanercept showed decreased weight gain, higher viral titers in muscle, joints, and blood, and more tissue damage and inflammatory cell recruitment than RRV-infected mice without treatment. Anti-TNF therapy is unlikely to be useful in treating alphaviral arthritides. During alphaviral epidemics, careful monitoring of patients being treated with anti-TNF agents may be warranted.
Publisher: Springer Science and Business Media LLC
Date: 12-12-2022
DOI: 10.1038/S41467-022-35225-1
Abstract: Although ocular manifestations are reported in patients with COVID-19, consensus on ocular tropism of SARS-CoV-2 is lacking. Here, we infect K18-hACE2 transgenic mice with SARS-CoV-2 using various routes. We observe ocular manifestation and retinal inflammation with production of pro-inflammatory cytokines in the eyes of intranasally (IN)-infected mice. Intratracheal (IT) infection results in dissemination of the virus from the lungs to the brain and eyes via trigeminal and optic nerves. Ocular and neuronal invasions are confirmed using intracerebral (IC) infection. Notably, the eye-dropped (ED) virus does not cause lung infection and becomes undetectable with time. Ocular and neurotropic distribution of the virus in vivo is evident in fluorescence imaging with an infectious clone of SARS-CoV-2-mCherry. The ocular tropic and neuroinvasive characteristics of SARS-CoV-2 are confirmed in wild-type Syrian hamsters. Our data can improve the understanding regarding viral transmission and clinical characteristics of SARS-CoV-2 and help in improving COVID-19 control procedures.
Publisher: Elsevier BV
Date: 10-2012
Publisher: American Society for Microbiology
Date: 02-1999
DOI: 10.1128/JVI.73.2.1479-1491.1999
Abstract: MuMig (murine monokine induced by gamma interferon) and Crg-2 (cytokine responsive gene 2) are two murine chemokines of the CXC family that are induced by the interferons (IFNs): MuMig specifically by IFN-γ and Crg-2 by IFN-α, IFN-β, and IFN-γ. To investigate the biological roles of these chemokines, recombinant vaccinia viruses (rVVs) encoding either MuMig or Crg-2 were constructed. In vitro, the chemokine-encoding rVVs replicated to similar levels to the control virus. Athymic nude mice inoculated with 10 5 PFU or less of VV-HA-Mig or VV-HA–Crg-2 resolved the infection successfully whereas mice given a similar dose of the control virus VV-HA-TK died from generalized infection. At higher doses, there was mortality in all groups but death was significantly delayed in mice infected with either chemokine-encoding rVV compared with those infected with the control virus. Virus-encoded MuMig and Crg-2 enhanced the cytolytic activity of NK cells and splenic cellularity by two- to threefold and resulted in significant increases in mononuclear cell infiltration in the livers of mice. Using specific neutralizing or depleting antibodies, we have established that the control of rVV replication in athymic nude mice, as a consequence of virus-expressed MuMig and Crg-2, requires NK cells and IFN-α, IFN-β, and IFN-γ.
Publisher: Public Library of Science (PLoS)
Date: 10-02-2022
DOI: 10.1371/JOURNAL.PPAT.1010185
Abstract: Arthritogenic alphaviruses are mosquito-borne viruses that are a major cause of infectious arthropathies worldwide, and recent outbreaks of chikungunya virus and Ross River virus (RRV) infections highlight the need for robust intervention strategies. Alphaviral arthritis can persist for months after the initial acute disease, and is mediated by cellular immune responses. A common strategy to limit inflammation and pathology is to d en the overwhelming inflammatory responses by modulating proinflammatory cytokine pathways. Here, we investigate the contribution of interleukin-17 (IL-17), a cytokine involved in arthropathies such as rheumatoid arthritis, in the development RRV-induced arthritis and myositis. IL-17 was quantified in serum from RRV-infected patients, and mice were infected with RRV and joints and muscle tissues collected to analyse cellular infiltrates, tissue mRNA, cytokine expression, and joint and muscle histopathology. IL-17 expression was increased in musculoskeletal tissues and serum of RRV-infected mice and humans, respectively. IL-17–producing T cells and neutrophils contributed to the cellular infiltrate in the joint and muscle tissue during acute RRV disease in mice. Blockade of IL-17A/F using a monoclonal antibody (mAb) reduced disease severity in RRV-infected mice and led to decreased proinflammatory proteins, cellular infiltration in synovial tissues and cartilage damage, without affecting viral titers in inflamed tissues. IL-17A/F blockade triggered a shift in transcriptional profile of both leukocyte infiltrates and musculoskeletal stromal cells by downregulating proinflammatory genes. This study highlights a previously uncharacterized role for an effector cytokine in alphaviral pathology and points towards potential therapeutic benefit in targeting IL-17 to treat patients presenting with RRV-induced arthropathy.
Publisher: American Society for Microbiology
Date: 27-04-2021
Abstract: To develop COVID-19 countermeasures, powerful research tools are essential. We produced a SARS-COV-2 reverse genetic (RG) infectious clone toolkit that will benefit a variety of investigations.
Publisher: American Society for Microbiology
Date: 08-2011
DOI: 10.1128/JVI.00563-11
Abstract: The C3-V4 region is a major target of autologous neutralizing antibodies in HIV-1 subtype C infection. We previously identified a Center for AIDS Program of Research in South Africa (CAPRISA) participant, CAP88, who developed a potent neutralizing-antibody response within 3 months of infection that targeted an epitope in the C3 region of the HIV-1 envelope (P. L. Moore et al., PLoS Pathog. 5:e1000598, 2009). Here we showed that these type-specific antibodies could be adsorbed using recombinant gp120 from the transmitted/founder virus from CAP88 but not by gp120 made from other isolates. Furthermore, this activity could be depleted using a chimeric gp120 protein that contained only the C3 region from the CAP88 viral envelope engrafted onto the unrelated CAP63 viral envelope (called 63-88C3). On the basis of this, a differential sorting of memory B cells was performed using gp120s made from 63-88C3 and CAP63 labeled with different fluorochromes as positive and negative probes, respectively. This strategy resulted in the isolation of a highly specific monoclonal antibody (MAb), called CAP88-CH06, that neutralized the CAP88 transmitted/founder virus and viruses from acute infection but was unable to neutralize CAP88 viruses isolated at 6 and 12 months postinfection. The latter viruses contained 2 amino acid changes in the alpha-2 helix of C3 that mediated escape from this MAb. One of these changes involved the introduction of an N-linked glycan at position 339 that occluded the epitope, while the other mutation (either E343K or E350K) was a charge change. Our data validate the use of differential sorting to isolate a MAb targeting a specific epitope in the envelope glycoprotein and provided insights into the mechanisms of autologous neutralization escape.
Publisher: Bentham Science Publishers Ltd.
Date: 06-2011
DOI: 10.2174/138945011795677836
Abstract: Animal models, which mimic human disease, are invaluable tools for understanding the mechanisms of disease pathogenesis and development of treatment strategies. In particular, animal models play important roles in the area of infectious arthritis. Alphaviruses, including Ross River virus (RRV), o'nyong-nyong virus, chikungunya virus (CHIKV), mayaro virus, Semliki Forest virus and sindbis virus, are globally distributed and cause transient illness characterized by fever, rash, myalgia, arthralgia and arthritis in humans. Severe forms of the disease result in chronic incapacitating arthralgia and arthritis. The mechanisms of how these viruses cause musculoskeletal disease are ill defined. In recent years, the use of a mouse model for RRV-induced disease has assisted in unraveling the pathobiology of infection and in discovering novel drugs to ameliorate disease. RRV as an infection model has the potential to provide key insights into such disease processes, particularly as many viruses, other than alphaviruses, are known to cause infectious arthritides. The emergence and outbreak of CHIKV in many parts of the world has necessitated the need to develop animal models of CHIKV disease. The development of non-human primate models of CHIKV disease has given insights into viral tropism and disease pathogenesis and facilitated the development of new treatment strategies. This review highlights the application of animal models of alphaviral diseases in the fundamental understanding of the mechanisms that contribute to disease and for defining the role that the immune response may have on disease pathogenesis, with the view of providing the foundation for new treatments.
Publisher: Public Library of Science (PLoS)
Date: 21-09-2022
Publisher: Wiley
Date: 06-06-2019
DOI: 10.1002/ART.40856
Publisher: Springer Science and Business Media LLC
Date: 10-07-2012
Abstract: Human metapneumovirus (hMPV) is a significant viral respiratory pathogen of infants and children, the elderly and immunocompromised in iduals. Disease associated with hMPV infection resembles that of human respiratory syncytial virus (RSV) and includes bronchiolitis and pneumonia. The glycosylated G attachment protein of hMPV is required for viral entry in vivo and has also been identified as an inhibitor of innate immune responses. We designed and validated two siRNA molecules against the G gene using A549 cells and demonstrated consistent 88-92% knock-down for one siRNA molecule, which was used in subsequent experiments. Significant reduction of G mRNA in A549 cells infected with hMPV did not result in a reduction in viral growth, nor did it significantly increase the production of type I interferon (α/β) in response to infection. However, there was a moderate increase in IFN-β mRNA expression in response to infection in siG-transfected cells compared to untransfected and si-mismatch-transfected cells. Expression of G by recombinant adenovirus did not affect type I IFN expression. G has been previously described as a type I interferon antagonist, although our findings suggest it may not be a significant antagonist.
Publisher: Oxford University Press (OUP)
Date: 25-05-2012
Publisher: Oxford University Press (OUP)
Date: 26-03-2008
DOI: 10.1111/J.1753-4887.2008.00022.X
Abstract: There is strong evidence that a diet high in whole grains is associated with lower body mass index, smaller waist circumference, and reduced risk of being overweight that a diet high in whole grains and legumes can help reduce weight gain and that significant weight loss is achievable with energy-controlled diets that are high in cereals and legumes. There is weak evidence that high intakes of refined grains may cause small increases in waist circumference in women. There is no evidence that low-carbohydrate diets that restrict cereal intakes offer long-term advantages for sustained weight loss. There is insufficient evidence to make clear conclusions about the protective effect of legumes on weight.
Publisher: American Society for Microbiology
Date: 25-04-2023
Abstract: Previous studies have shown the importance of the cell surface protein MXRA8 as an entry receptor for several different prominent alphaviruses such as CHIKV, RRV, MAYV, and ONNV. In particular, the role of MXRA8 in the tissue tropism, viral pathogenesis, and immune response of a CHIKV mouse model have already been briefly characterized.
Publisher: Proceedings of the National Academy of Sciences
Date: 05-07-2011
Abstract: Arthrogenic alphaviruses, such as Ross River virus (RRV), chikungunya, Sindbis, mayaro and o'nyong-nyong viruses circulate endemically worldwide, frequently causing outbreaks of polyarthritis. The exact mechanisms of how alphaviruses induce polyarthritis remain ill defined, although macrophages are known to play a key role. Macrophage migration inhibitory factor (MIF) is an important cytokine involved in rheumatoid arthritis pathogenesis. Here, we characterize the role of MIF in alphavirus–induced arthritides using a mouse model of RRV-induced arthritis, which has many characteristics of RRV disease in humans. RRV-infected WT mice developed severe disease associated with up-regulated MIF expression in serum and tissues, which corresponded to severe inflammation and tissue damage. MIF-deficient (MIF −/− ) mice developed mild disease accompanied by a reduction in inflammatory infiltrates and muscle destruction in the tissues, despite having viral titers similar to WT mice. In addition, reconstitution of MIF into MIF −/− mice exacerbated RRV disease and treatment of mice with MIF antagonist ameliorated disease in WT mice. Collectively, these findings suggest that MIF plays a critical role in determining the clinical severity of alphavirus–induced musculoskeletal disease and may provide a target for the development of antiviral pharmaceuticals. The prospect being that early treatment with MIF-blocking pharmaceuticals may curtail the debilitating arthritis associated with alphaviral infections.
Publisher: American Society for Microbiology
Date: 05-09-2018
Abstract: Infection with Ross River virus (RRV) causes debilitating polyarthritis and arthralgia in in iduals. Alphaviruses are highly sensitive to type I interferon (IFN). Mutations at the conserved P3 position of the cleavage site between nonstructural protein 1 (nsP1) and nsP2 (1/2 site) modulate type I IFN induction for both RRV and Sindbis virus (SINV). We constructed and characterized RRV-T48 A534V , a mutant harboring an A534V substitution in the P1 position of the 1/2 site, and compared it to parental RRV-T48 and to RRV-T48 A532V , SINV I538 and SINV T538 harboring different substitutions in the same region. A534V substitution resulted in impaired processing of RRV nonstructural polyprotein and in elevated production of replicase-generated pathogen-associated molecular pattern (PAMP) RNAs that induce expression of type I IFN. Both A532V and A534V substitutions affected synthesis of viral RNAs, though the effects of these closely located mutations were drastically different affecting mostly either the viral negative-strand RNA or genomic and subgenomic RNA levels, respectively. Synthesis of PAMP RNAs was also observed for SINV replicase, and it was increased by I538T substitution. In comparison to RRV-T48, RRV-T48 A534V was attenuated in vitro and in vivo . Interestingly, when type I IFN-deficient cells and type I IFN receptor-deficient mice were infected with RRV-T48 or RRV-T48 A534V , differences between these viruses were no longer apparent. Compared to RRV-T48, RRV-T48 A534V infection was associated with increased upregulation of type I IFN signaling proteins. We demonstrate novel mechanisms by which the A534V mutation affect viral nonstructural polyprotein processing that can impact PAMP RNA production, type I IFN induction/sensitivity, and disease. IMPORTANCE This study gives further insight into mechanisms of type I IFN modulation by the medically important alphaviruses Ross River virus (RRV) and Sindbis virus (SINV). By characterizing attenuated RRV mutants, the crucial role of amino acid residues in P1 and P3 positions (the first and third amino acid residues preceding the scissile bond) of the cleavage site between nsP1 and nsP2 regions was highlighted. The study uncovers a unique relationship between alphavirus nonstructural polyprotein processing, RNA replication, production of different types of pathogen-associated molecular pattern (PAMP) RNAs, type I IFN induction, and disease pathogenesis. This study also highlights the importance of the host innate immune response in RRV infections. The viral determinants of type I IFN modulation provide potential drug targets for clinical treatment of alphaviral disease and offer new approaches for rational attenuation of alphaviruses for construction of vaccine candidates.
Publisher: Oxford University Press (OUP)
Date: 08-2011
Publisher: Oxford University Press (OUP)
Date: 10-2011
Abstract: Chikungunya virus (CHIKV) is associated with outbreaks of infectious rheumatic disease in humans. Using a mouse model of CHIKV arthritis and myositis, we show that tumor necrosis factor-α, interferon-γ, and monocyte chemotactic protein 1 (MCP-1) were dramatically induced in tissues from infected mice. The same factors were detected in the serum of patients with CHIKV-induced polyarthralgia and polyarthritis, with MCP-1 levels being particularly elevated. Bindarit (MCP inhibitor) treatment ameliorated CHIKV disease in mice. Histological analysis of muscle and joint tissues showed a reduction in inflammatory infiltrate in infected mice treated with bindarit. These results suggest that bindarit may be useful in treating CHIKV-induced arthritides in humans.
Publisher: Oxford University Press (OUP)
Date: 06-2008
DOI: 10.1086/587841
Abstract: Alphaviruses, such as chikungunya virus and Ross River virus (RRV), are associated with outbreaks of infectious rheumatic disease in humans worldwide. Using an established mouse model of disease that mimics RRV disease in humans, we showed that macrophage-derived factors are critical in the development of striated muscle and joint tissue damage. Histologic analyses of muscle and ankle joint tissues demonstrated a substantial reduction in inflammatory infiltrates in infected mice depleted of macrophages (i.e., "macrophage-depleted mice"). Levels of the proinflammatory factors tumor necrosis factor-alpha, interferon-gamma, and macrophage chemoattractant protein-1 were also dramatically reduced in tissue s les obtained from infected macrophage-depleted mice, compared with s les obtained from infected mice without macrophage depletion. These factors were also detected in the synovial fluid of patients with RRV-induced polyarthritis. Neutralization of these factors reduced the severity of disease in mice, whereas blocking nuclear factor kappaB by treatment with sulfasalazine ameliorated RRV inflammatory disease and tissue damage. To our knowledge, these findings are the first to demonstrate that macrophage-derived products play important roles in the development of arthritis and myositis triggered by alphavirus infection.
Publisher: Elsevier BV
Date: 12-2009
DOI: 10.1016/J.PHARMTHERA.2009.09.005
Abstract: A large range of human viruses are associated with the development of arthritis or arthralgia. Although there are many parallels with autoimmune arthritides, there is little evidence that viral arthritides lead to autoimmune disease. In humans viral arthritides usually last from weeks to months, can be debilitating, and are usually treated with non-steroidal anti-inflammatory drugs, but with variable success. Viral arthritides likely arise from immunopathological inflammatory responses directed at viruses and/or their products residing and/or replicating within joint tissues. Macrophages recruited by monocyte chemoattractant protein-1 (MCP-1/CCL2) and activated by interferon, and proinflammatory mediators like tumour necrosis factor alpha, interferon gamma, interleukin-6 and interleukin-1beta appear to be common elements in this group of diseases. The challenge for new treatments is to target excessive inflammation without compromising anti-viral immunity. Recent evidence from mouse models suggests targeting MCP-1 or complement may emerge as viable new treatment options for viral arthritides.
Publisher: American Society for Microbiology
Date: 2015
DOI: 10.1128/JVI.02034-14
Abstract: The recent global resurgence of arthritogenic alphaviruses, in particular chikungunya virus (CHIKV), highlights an urgent need for the development of therapeutic intervention strategies. While there has been significant progress in defining the pathophysiology of alphaviral disease, relatively little is known about the mechanisms involved in CHIKV-induced arthritis or potential therapeutic options to treat the severe arthritic symptoms associated with infection. Here, we used microcomputed tomographic (μCT) and histomorphometric analyses to provide previously undescribed evidence of reduced bone volume in the proximal tibial epiphysis of CHIKV-infected mice compared to the results for mock controls. This was associated with a significant increase in the receptor activator of nuclear factor-κB ligand/osteoprotegerin (RANKL/OPG) ratio in infected murine joints and in the serum of CHIKV patients. The expression levels of the monocyte chemoattractant proteins (MCPs), including MCP-1/CCL2, MCP-2/CCL8, and MCP-3/CCL7, were also highly elevated in joints of CHIKV-infected mice, accompanied by increased cellularity within the bone marrow in tibial epiphysis and ankle joints. Both this effect and CHIKV-induced bone loss were significantly reduced by treatment with the MCP inhibitor bindarit. Collectively, these findings demonstrate a unique role for MCPs in promoting CHIKV-induced osteoclastogenesis and bone loss during disease and suggest that inhibition of MCPs with bindarit may be an effective therapy for patients affected with alphavirus-induced bone loss. IMPORTANCE Arthritogenic alphaviruses, including chikungunya virus (CHIKV) and Ross River virus (RRV), cause worldwide outbreaks of polyarthritis, which can persist in patients for months following infection. Previous studies have shown that host proinflammatory soluble factors are associated with CHIKV disease severity. Furthermore, it is established that chemokine (C-C motif) ligand 2 (CCL2/MCP-1) is important in cellular recruitment and inducing bone-resorbing osteoclast (OC) formation. Here, we show that CHIKV replicates in bone and triggers bone loss by increasing the RANKL/OPG ratio. CHIKV infection results in MCP-induced cellular infiltration in the inflamed joints, and bone loss can be ameliorated by treatment with an MCP-inhibiting drug, bindarit. Taken together, our data reveal a previously undescribed role for MCPs in CHIKV-induced bone loss: one of recruiting monocytes/OC precursors to joint sites and thereby favoring a pro-osteoclastic microenvironment. This suggests that bindarit may be an effective treatment for alphavirus-induced bone loss and arthritis in humans.
Publisher: Springer Science and Business Media LLC
Date: 26-10-2023
Publisher: Public Library of Science (PLoS)
Date: 25-02-2021
DOI: 10.1371/JOURNAL.PBIO.3001091
Abstract: The recent emergence of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), the underlying cause of Coronavirus Disease 2019 (COVID-19), has led to a worldwide pandemic causing substantial morbidity, mortality, and economic devastation. In response, many laboratories have redirected attention to SARS-CoV-2, meaning there is an urgent need for tools that can be used in laboratories unaccustomed to working with coronaviruses. Here we report a range of tools for SARS-CoV-2 research. First, we describe a facile single plasmid SARS-CoV-2 reverse genetics system that is simple to genetically manipulate and can be used to rescue infectious virus through transient transfection (without in vitro transcription or additional expression plasmids). The rescue system is accompanied by our panel of SARS-CoV-2 antibodies (against nearly every viral protein), SARS-CoV-2 clinical isolates, and SARS-CoV-2 permissive cell lines, which are all openly available to the scientific community. Using these tools, we demonstrate here that the controversial ORF10 protein is expressed in infected cells. Furthermore, we show that the promising repurposed antiviral activity of apilimod is dependent on TMPRSS2 expression. Altogether, our SARS-CoV-2 toolkit, which can be directly accessed via our website at mrcppu-covid.bio/ , constitutes a resource with considerable potential to advance COVID-19 vaccine design, drug testing, and discovery science.
Publisher: American Society for Microbiology
Date: 28-06-2022
Abstract: SARS-CoV-2 variants, with the threat of increased transmissibility, infectivity, and immune escape, continue to emerge as the COVID-19 pandemic progresses. Detailing the pathogenesis of disease caused by SARS-CoV-2 variants, such as Delta, is essential to better understand the clinical threat caused by emerging variants and associated disease.
Publisher: Elsevier BV
Date: 10-2010
Publisher: Proceedings of the National Academy of Sciences
Date: 03-10-2002
Abstract: Subneutralizing concentrations of antibody may enhance virus infection by bringing the virus–antibody complex into contact with the cell surface Fc receptors this interaction facilitates entry of virus into the cell and is referred to as antibody-dependent enhancement (ADE) of infection. Northern analysis of macrophage RNA demonstrated that ADE infection by the indigenous Australian alphavirus Ross River (RRV-ADE) ablated or diminished message for tumor necrosis factor α (TNF-α), nitric-oxide synthase 2 (NOS2), and IFN regulatory factor 1 (IRF-1), as well as for IFN-inducible protein 10 (IP-10) and IFN-β the transcription of a control gene was unaffected. Additionally, electrophoretic mobility-shift assay (EMSA) studies showed that transcription factor IFN-α-activated factor (AAF), IFN-stimulated gene factor 3 (ISGF3), and nuclear factor-κB (NF-κB) complex formation in macrophage nuclear extracts were specifically suppressed post-RRV-ADE infection, emphasizing the capacity for ADE infections to compromise antiviral responses at the transcriptional level. The suppression of antiviral transcription factor complexes was shown to depend on replicating virus and was not simply a result of general antibody–Fc–receptor interaction. Although only a minority of cells (≈15%) were shown to be positive for RRV by immunostaining techniques post ADE, molecular (RT-PCR) analysis showed that unstained cells carried RRV-RNA, indicating a higher level of viral infectivity than previously suspected. Electron microscopy studies confirmed this observation. Furthermore, levels of cellular IL-10 protein were dramatically elevated in RRV-ADE cultures. This evidence demonstrates that RRV can potently disrupt the activation of specific antiviral pathways via ADE infection pathways, and may suggest a significant mechanism in the infection and pathogenesis of other ADE viruses.
Publisher: American Chemical Society (ACS)
Date: 22-06-2020
Publisher: Microbiology Society
Date: 06-2020
DOI: 10.1099/JGV.0.001416
Abstract: Zika virus (ZIKV) has recently emerged as an important human pathogen due to the strong evidence that it causes disease of the central nervous system, particularly microcephaly and Guillain–Barré syndrome. The pathogenesis of disease, including mechanisms of neuroinvasion, may include both invasion via the blood–brain barrier and via peripheral (including cranial) nerves. Cellular responses to infection are also poorly understood. This study characterizes the in vitro infection of laboratory-adapted ZIKV African MR766 and two Asian strains of (1) brain endothelial cells (hCMEC/D3 cell line) and (2) olfactory ensheathing cells (OECs) (the neuroglia populating cranial nerve I and the olfactory bulb both human and mouse OEC lines) in comparison to kidney epithelial cells (Vero cells, in which ZIKV infection is well characterized). Readouts included infection kinetics, intracellular virus localization, viral persistence and cytokine responses. Although not as high as in Vero cells, viral titres exceeded 10 4 plaque-forming units (p.f.u.) ml −1 in the endothelial/neuroglial cell types, except hOECs. Despite these substantial titres, a relatively small proportion of neuroglial cells were primarily infected. Immunolabelling of infected cells revealed localization of the ZIKV envelope and NS3 proteins in the cytoplasm NS3 staining overlapped with that of dsRNA replication intermediate and the endoplasmic reticulum (ER). Infected OECs and endothelial cells produced high levels of pro-inflammatory chemokines. Nevertheless, ZIKV was also able to establish persistent infection in hOEC and hCMEC/D3 cells. Taken together, these results provide basic insights into ZIKV infection of endothelial and neuroglial cells and will form the basis for further study of ZIKV disease mechanisms.
Publisher: American Society for Microbiology
Date: 26-04-2022
Abstract: CHIKV has been prevalent in Africa, Asia, and the Indian Ocean Islands for decades. There are currently no clinically approved vaccines or specific antiviral drugs targeting CHIKV.
Publisher: Springer Science and Business Media LLC
Date: 28-08-2017
DOI: 10.1038/S41564-017-0015-4
Abstract: Mosquito-borne viruses can cause severe inflammatory diseases and there are limited therapeutic solutions targeted specifically at virus-induced inflammation. Chikungunya virus (CHIKV), a re-emerging alphavirus responsible for several outbreaks worldwide in the past decade, causes debilitating joint inflammation and severe pain. Here, we show that CHIKV infection activates the NLRP3 inflammasome in humans and mice. Peripheral blood mononuclear cells isolated from CHIKV-infected patients showed elevated NLRP3, caspase-1 and interleukin-18 messenger RNA expression and, using a mouse model of CHIKV infection, we found that high NLRP3 expression was associated with peak inflammatory symptoms. Inhibition of NLRP3 activation using the small-molecule inhibitor MCC950 resulted in reduced CHIKV-induced inflammation and abrogated osteoclastogenic bone loss and myositis, but did not affect in vivo viral replication. Mice treated with MCC950 displayed lower expression levels of the cytokines interleukin-6, chemokine ligand 2 and tumour necrosis factor in joint tissue. Interestingly, MCC950 treatment abrogated disease signs in mice infected with a related arthritogenic alphavirus, Ross River virus, but not in mice infected with West Nile virus-a flavivirus. Here, using mouse models of alphavirus-induced musculoskeletal disease, we demonstrate that NLRP3 inhibition in vivo can reduce inflammatory pathology and that further development of therapeutic solutions targeting inflammasome function could help treat arboviral diseases.
Publisher: Public Library of Science (PLoS)
Date: 29-01-2018
Publisher: Wiley
Date: 24-09-2013
DOI: 10.1002/ART.38090
Publisher: Wiley
Date: 30-11-2022
DOI: 10.1111/BPH.15987
Abstract: A cytokine storm is one of the leading causes of acute respiratory distress syndrome (ARDS) and sepsis‐associated multiple organ failure in many respiratory viral infections, including severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2). The coronavirus disease 2019 (COVID‐19) pandemic has caused millions of deaths worldwide, resulting in an urgent need for effective therapeutic interventions. Repurposing immunosuppressive drugs that target cytokines with immunomodulatory properties is a promising approach to counteract SARS‐CoV‐2‐induced ARDS at the infective and post‐infective stages. In this minireview, we examine drugs targeting IL‐1β, IL‐4/IL‐13, IL‐6 and TNF‐α tested in COVID‐19 patients.
Publisher: American Society for Microbiology
Date: 28-04-2020
Abstract: Arthritogenic alphaviruses cause debilitating inflammatory disease, and current therapies are restricted to palliative approaches. Here, we show that following monocyte-driven muscle inflammation, tissue recovery is associated with the accumulation of CX 3 CR1 + macrophages in the muscle. Modulating inflammatory monocyte infiltration using immune-modifying microparticles (IMP) reduced tissue damage and inflammation and enhanced the formation of tissue repair-associated CX 3 CR1 + macrophages in the muscle. This shows that modulating key effectors of viral inflammation using microparticles can alter the outcome of disease by facilitating the accumulation of macrophage subsets associated with tissue repair.
Publisher: American Society for Microbiology
Date: 06-2011
DOI: 10.1128/JVI.01189-10
Abstract: Alphaviruses, such as chikungunya virus, o'nyong-nyong virus, and Ross River virus (RRV), cause outbreaks of human rheumatic disease worldwide. RRV is a positive-sense single-stranded RNA virus endemic to Australia and Papua New Guinea. In this study, we sought to establish an in vitro model of RRV evolution in response to cellular antiviral defense mechanisms. RRV was able to establish persistent infection in activated macrophages, and a small-plaque variant (RRV PERS ) was isolated after several weeks of culture. Nucleotide sequence analysis of RRV PERS found several nucleotide differences in the nonstructural protein (nsP) region of the RRV PERS genome. A point mutation was also detected in the E2 gene. Compared to the parent virus (RRV-T48), RRV PERS showed significantly enhanced resistance to beta interferon (IFN-β)-stimulated antiviral activity. RRV PERS infection of RAW 264.7 macrophages induced lower levels of IFN-β expression and production than infection with RRV-T48. RRV PERS was also able to inhibit type I IFN signaling. Mice infected with RRV PERS exhibited significantly enhanced disease severity and mortality compared to mice infected with RRV-T48. These results provide strong evidence that the cellular antiviral response can direct selective pressure for viral sequence evolution that impacts on virus fitness and sensitivity to alpha/beta IFN (IFN-α/β).
Publisher: Wiley
Date: 28-05-2012
DOI: 10.1002/RMV.1718
Abstract: Sphingosine kinase 1 (SphK1) is an enzyme that phosphorylates the lipid sphingosine to generate sphingosine-1-phosphate (S1P). S1P can act intracellularly as a signaling molecule and extracellularly as a receptor ligand. The SphK1/S1P axis has well-described roles in cell signaling, the cell death/survival decision, the production of a pro-inflammatory response, immunomodulation, and control of vascular integrity. Agents targeting the SphK1/S1P axis are being actively developed as therapeutics for cancer and immunological and inflammatory disorders. Control of cell death/survival and pro-inflammatory immune responses is central to the pathology of infectious disease, and we can capitalize on the knowledge provided by investigations of SphK1/S1P in cancer and immunology to assess its application to selected human infections. We have herein reviewed the growing literature relating viral infections to changes in SphK1 and S1P. SphK1 activity is reportedly increased following human cytomegalovirus and respiratory syncytial virus infections, and elevated SphK1 enhances influenza virus infection. In contrast, SphK1 activity is reduced in bovine viral diarrhea virus and dengue virus infections. Sphingosine analogs that modulate S1P receptors have proven useful in animal models in alleviating influenza virus infection but have shown no benefit in simian human immunodeficiency virus and lymphocytic choriomeningitis virus infections. We have rationalized a role for SphK1/S1P in dengue virus, chikungunya virus, and Ross River virus infections, on the basis of the biology and the pathology of these diseases. The increasing number of effective SphK1 and S1P modulating agents currently in development makes it timely to investigate these roles with the potential for developing modulators of SphK1 and S1P for novel anti-viral therapies.
Publisher: MDPI AG
Date: 22-12-2019
Abstract: Our previous investigation of the nucleolar localisation sequence (NoLS) of chikungunya virus (CHIKV) capsid protein demonstrated the role of capsid in CHIKV virulence. Mutating the NoLS of capsid in CHIKV led to the development of a unique live-attenuated CHIKV vaccine candidate, termed CHIKV-NoLS. CHIKV-NoLS-immunised mice developed long-term immunity from CHIKV infection after a single dose. To further evaluate CHIKV-NoLS attenuation and suitability as a vaccine, we examined the footpad of inoculated mice for underlying CHIKV-NoLS-induced immunopathology by histological and flow cytometric analysis. In comparison to CHIKV-WT-infected mice, CHIKV-NoLS-inoculated mice exhibited minimal inflammation and tissue damage. To examine the stability of attenuation, the plaque phenotype and replication kinetics of CHIKV-NoLS were determined following extended in vitro passage. The average plaque size of CHIKV-NoLS remained notably smaller than CHIKV-WT after extended passage and attenuated replication was maintained. To examine thermostability, CHIKV-NoLS was stored at 21 °C, 4 °C, −20 °C and −80 °C and infectious CHIKV-NoLS quantified up to 84 days. The infectious titre of CHIKV-NoLS remains stable after 56 days when stored at either −20 °C or −80 °C. Interestingly, unlike CHIKV-WT, the infectious titre of CHIKV-NoLS is not sensitive to freeze thaw cycles. These data further demonstrate preclinical safety and stability of CHIKV-NoLS.
Publisher: American Society for Microbiology
Date: 22-02-2022
Abstract: RRV has been prevalent in the South Pacific region for decades and causes substantial economic and social costs. Though RRV is geographically restricted, a number of other alphaviruses have spread globally due to expansion of the mosquito vectors and increased international travel.
Publisher: Elsevier BV
Date: 02-2011
Publisher: Wiley
Date: 30-07-2009
DOI: 10.1002/ART.24682
Abstract: Alphaviruses such as chikungunya virus, Sindbis virus, o'nyong-nyong virus, Mayaro virus, and Ross River virus (RRV), are commonly associated with arthralgias and overt arthritides worldwide. Understanding the processes by which arthritogenic viruses cause disease is a prerequisite in the quest for better treatments. In this regard, we have recently established that monocyte/macrophages are mediators of alphavirus-induced arthritis in mice. We hypothesized that chemokines associated with monocyte/macrophage recruitment may play an important role in disease. The aim of the present investigations was to determine whether bindarit, an inhibitor of monocyte chemotactic protein (MCP) synthesis, could ameliorate alphavirus-induced rheumatic disease in mice. Using our recently developed mouse model of RRV-induced arthritis, which has many characteristics of RRV disease (RRVD) in humans, the effects of bindarit treatment on RRVD in mice were determined via histologic analyses, immunohistochemistry, flow cytometry, real-time polymerase chain reaction analysis, enzyme-linked immunosorbent assay, and electrophoretic mobility shift assay. Bindarit-treated RRV-infected mice developed mild disease and had substantially reduced tissue destruction and inflammatory cell recruitment as compared with untreated RRV-infected mice. The virus load in the tissues was not affected by bindarit treatment. Bindarit exhibited its activity by down-regulating MCPs, which in turn led to inhibition of cell infiltration and lower production of NF-kappaB and tumor necrosis factor alpha, which are involved in mediating tissue damage. Our data support the use of inhibitors of MCP production in the treatment of arthritogenic alphavirus syndromes and suggest that bindarit may be useful in treating RRVD and other alphavirus-induced arthritides in humans.
Publisher: Public Library of Science (PLoS)
Date: 19-02-2015
Publisher: American Society for Microbiology
Date: 14-09-2022
DOI: 10.1128/JVI.00999-22
Abstract: Arthritogenic alphaviruses are transmitted via mosquito bites through the skin, potentially causing debilitating diseases. Our understanding of how viral infection starts in the skin and how virus systemically disseminates to cause disease remains limited.
Publisher: F1000 Research Ltd
Date: 08-12-2017
DOI: 10.12688/F1000RESEARCH.12461.1
Abstract: Chikungunya virus (CHIKV) has come to prominence as a global, re-emerging pathogen over the last two decades, progressing from sporadic, remote outbreaks to worldwide explosive epidemics. From contained, though considerable, outbreaks in the southern Indian Ocean, parts of South America and the Caribbean, CHIKV continues to be a significant pathogen in Southeast Asia and India. CHIKV circulates during epidemics through an urban mosquito-to-human transmission cycle, and with no available treatments or licensed vaccines to specifically target CHIKV disease, limiting transmission relies on vector control, which poses significant challenges, especially in developing countries. This review summarizes the current findings and progress in the development of safe, effective and affordable therapeutics and vaccines for CHIKV disease.
Publisher: Apollo - University of Cambridge Repository
Date: 2018
DOI: 10.17863/CAM.23403
Publisher: Public Library of Science (PLoS)
Date: 22-03-2012
Publisher: American Society for Microbiology
Date: 08-03-2017
Abstract: Mosquito-transmitted chikungunya virus (CHIKV) is an arthritogenic alphavirus of the Togaviridae family responsible for frequent outbreaks of arthritic disease in humans. Capsid protein, a structural protein encoded by the CHIKV RNA genome, is able to translocate to the host cell nucleolus. In encephalitic alphaviruses, nuclear translocation induces host cell transcriptional shutoff however, the role of capsid protein nucleolar localization in arthritogenic alphaviruses remains unclear. Using recombinant enhanced green fluorescent protein (EGFP)-tagged expression constructs and CHIKV infectious clones, we describe a nucleolar localization sequence (NoLS) in the N-terminal region of capsid protein, previously uncharacterized in CHIKV. Mutation of the NoLS by site-directed mutagenesis reduced efficiency of nuclear import of CHIKV capsid protein. In the virus, mutation of the capsid protein NoLS (CHIKV-NoLS) attenuated replication in mammalian and mosquito cells, producing a small-plaque phenotype. Attenuation of CHIKV-NoLS is likely due to disruption of the viral replication cycle downstream of viral RNA synthesis. In mice, CHIKV-NoLS infection caused no disease signs compared to wild-type CHIKV (CHIKV-WT)-infected mice lack of disease signs correlated with significantly reduced viremia and decreased expression of proinflammatory factors. Mice immunized with CHIKV-NoLS, challenged with CHIKV-WT at 30 days postimmunization, develop no disease signs and no detectable viremia. Serum from CHIKV-NoLS-immunized mice is able to efficiently neutralize CHIKV infection in vitro . Additionally, CHIKV-NoLS-immunized mice challenged with the related alphavirus Ross River virus showed reduced early and peak viremia postchallenge, indicating a cross-protective effect. The high degree of CHIKV-NoLS attenuation may improve CHIKV antiviral and rational vaccine design. IMPORTANCE CHIKV is a mosquito-borne pathogen capable of causing explosive epidemics of incapacitating joint pain affecting millions of people. After a series of major outbreaks over the last 10 years, CHIKV and its mosquito vectors have been able to expand their range extensively, now making CHIKV a human pathogen of global importance. With no licensed vaccine or antiviral therapy for the treatment of CHIKV disease, there is a growing need to understand the molecular determinants of viral pathogenesis. These studies identify a previously uncharacterized nucleolar localization sequence (NoLS) in CHIKV capsid protein, begin a functional analysis of site-directed mutants of the capsid protein NoLS, and examine the effect of the NoLS mutation on CHIKV pathogenesis in vivo and its potential to influence CHIKV vaccine design. A better understanding of the pathobiology of CHIKV disease will aid the development of effective therapeutic strategies.
Publisher: American Society for Microbiology
Date: 31-03-2020
DOI: 10.1128/JVI.01788-19
Abstract: By identifying natural Ross River virus (RRV) amino acid determinants for type I interferon (IFN) modulation, this study gives further insight into the mechanism of type I IFN modulation by alphaviruses. Here, the crucial role of type I IFN in the early stages of RRV disease pathogenesis is further demonstrated. This study also provides a comparison of the roles of different parts of the RRV nonstructural region in type I IFN modulation, highlighting the importance of nonstructural protein 1 (nsP1) and nsP2 in this process. Three substitutions in nsP1 and nsP2 were found to be independently associated with enhanced type I IFN sensitivity, and four independent substitutions in nsP2 were important in elevated type I IFN induction. Such evidence has clear implications for RRV immunobiology, persistence, and pathology. The identification of viral proteins that modulate type I IFN may also have importance for the pathogenesis of other alphaviruses.
Publisher: Public Library of Science (PLoS)
Date: 27-12-2017
Publisher: Microbiology Society
Date: 03-2021
DOI: 10.1099/JGV.0.001547
Abstract: The complement alternative pathway (AP) is tightly regulated and changes in two important AP components, factor B (FB) and factor H (FH) are linked to severe dengue in humans. Here, a mouse model of dengue was investigated to define the changes in FB and FH and assess the utility of this model to study the role of the AP in severe dengue. Throughout the period of viremia in the AG129 IFN signalling-deficient mouse, an increase in FB and a decrease in FH was observed following dengue virus (DENV) infection, with the former only seen in a model of more severe disease associated with antibody-dependent enhancement (ADE). Terminal disease was associated with a decrease in FB and FH, with greater changes during ADE, and accompanied by increased C3 degradation consistent with complement activation. In silico analysis of NFκΒ, signal transducer and activator of transcription (STAT) and IFN-driven FB and FH promoter elements to reflect the likely impact of the lack of IFN-responses in AG129 mice, demonstrated that these elements differed markedly between human and mouse, notably with mouse FH lacking NFκΒ and key IFN-stimulated response elements (ISRE), and FB with many more NFκΒ and STAT-responsive elements than human FB. Thus, the AG129 mouse offers utility in demonstrating changes in FB and FH that, similar to humans, are associated with severe disease, but lack predicted important human-specific and IFN-dependent responses of FB and FH to DENV-infection that are likely to regulate the subtleties of the overall AP response during dengue disease in humans.
Start Date: 2015
End Date: 2018
Funder: National Health and Medical Research Council
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Funder: Australian Research Council
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Funder: National Health and Medical Research Council
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Funder: National Health and Medical Research Council
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Funder: Australian Research Council
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Funder: National Health and Medical Research Council
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Funder: Australian Research Council
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Funder: Australian Research Council
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Funder: Australian Research Council
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Funder: Australian Research Council
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Funder: National Health and Medical Research Council
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Funder: Australian Research Council
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Funder: Australian Research Council
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