ORCID Profile
0000-0002-6645-684X
Current Organisations
Fonds De La Recherche Scientifique - FNRS
,
Université catholique de Louvain
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Publisher: American Society for Microbiology
Date: 15-06-2013
DOI: 10.1128/JVI.02943-12
Abstract: Interleukin-22 (IL-22) has redundant, protective, or pathogenic functions during autoimmune, inflammatory, and infectious diseases. Here, we addressed the potential role of IL-22 in host defense and pathogenesis during lethal and sublethal respiratory H3N2 influenza A virus (IAV) infection. We show that IL-22, as well as factors associated with its production, are expressed in the lung tissue during the early phases of IAV infection. Our data indicate that retinoic acid receptor-related orphan receptor-γt (RORγt)-positive αβ and γδ T cells, as well as innate lymphoid cells, expressed enhanced Il22 transcripts as early as 2 days postinfection. During lethal or sublethal IAV infections, endogenous IL-22 played no role in the control of IAV replication and in the development of the IAV-specific CD8 + T cell response. During lethal infection, where wild-type (WT) mice succumbed to severe pneumonia, the lack of IL-22 did not accelerate or delay IAV-associated pathogenesis and animal death. In stark contrast, during sublethal IAV infection, IL-22-deficient animals had enhanced lung injuries and showed a lower airway epithelial integrity relative to WT littermates. Of importance, the protective effect of endogenous IL-22 in pulmonary damages was associated with a more controlled secondary bacterial infection. Indeed, after challenge with Streptococcus pneumoniae , IAV-experienced Il22 −/− animals were more susceptible than WT controls in terms of survival rate and bacterial burden in the lungs. Together, IL-22 plays no major role during lethal influenza but is beneficial during sublethal H3N2 IAV infection, where it limits lung inflammation and subsequent bacterial superinfections.
Publisher: Cold Spring Harbor Laboratory
Date: 18-02-2018
DOI: 10.1101/2021.02.18.431818
Abstract: The commensal microbiota regulates susceptibility to enteric pathogens by fine-tuning mucosal innate immune responses, but how susceptibility to enteric viruses is shaped by the microbiota remains incompletely understood. Past reports have indicated that commensal bacteria may either promote or repress rotavirus replication in the small intestine of mice. We now report that rotavirus replicated more efficiently in the intestines of germ-free and antibiotic-treated mice compared to animals with an unmodified microbiota. Antibiotic treatment also facilitated rotavirus replication in type I and type III interferon (IFN) receptor-deficient mice, revealing IFN-independent proviral effects. Expression of interleukin-22 (IL-22) was strongly diminished in the intestine of antibiotic-treated mice. Treatment with exogenous IL-22 blocked rotavirus replication in microbiota-depleted wild-type and Stat1 -/- mice, demonstrating that the antiviral effect of IL-22 in animals with altered microbiome is not dependent on IFN signaling. In antibiotic-treated animals, IL-22-induced a specific set of genes including Fut2 , encoding fucosyl-transferase 2 that participates in the biosynthesis of fucosylated glycans which can mediate rotavirus binding. Interestingly, IL-22 also blocked rotavirus replication in antibiotic-treated Fut2 -/- mice. Furthermore, IL-22 inhibited rotavirus replication in antibiotic-treated mice lacking key molecules of the necroptosis or pyroptosis pathways of programmed cell death. Taken together, our results demonstrate that IL-22 determines rotavirus susceptibility of antibiotic-treated mice, yet the IL-22-induced effector molecules conferring rotavirus resistance remain elusive.
Publisher: Microbiology Society
Date: 06-2004
Abstract: Poxviruses express numerous proteins involved in manipulating the host immune response. Analysis of the primary sequence and predicted structure of the 134R protein of Yaba-like disease virus (Y134R) indicated that it is similar to cellular proteins of the IL-10 family, specifically IL-19, IL-20 and IL-24. A flag-tagged Y134R was expressed from mammalian cells and identified as a secreted, monomeric glycoprotein that stimulated signal transduction from class II cytokine receptors IL-20R α /IL-20R β (IL-20R type1) and IL-22R/IL-20R β (IL-20R type 2). Y134R induced phosphorylation of signal transducers and activators of transcription, their translocation to the nucleus and the induction of reporter gene expression. In contrast, Y134R was unable to induce similar responses from either the IL-22 or IFN- λ (IL-28A, IL-28B, IL-29) class II cytokine receptors. To examine the role Y134R plays during a poxvirus infection, a vaccinia virus recombinant expressing Y134R was constructed and tested in a murine intranasal infection model. Compared with control viruses, the virus expressing Y134R had a reduced virulence, manifested by reduced weight loss, signs of illness and virus titres in infected organs. These results demonstrate that Y134R is a new viral member of the IL-10-related cytokine family and that its activity in vivo affects virus virulence.
Publisher: American Society for Microbiology
Date: 15-05-2006
DOI: 10.1128/JVI.80.10.5032-5040.2006
Abstract: The mechanism by which respiratory syncytial virus (RSV) suppresses T-cell proliferation to itself and other antigens is poorly understood. We used monocyte-derived dendritic cells (MDDC) and CD4 T cells and measured [ 3 H]thymidine incorporation to determine the factors responsible for RSV-induced T-cell suppression. These two cell types were sufficient for RSV-induced suppression of T-cell proliferation in response to cytomegalovirus or Staphylococcus enterotoxin B. Suppressive activity was transferable with supernatants from RSV-infected MDDC and was not due to transfer of live virus or RSV F (fusion) protein. Supernatants from RSV-infected MDDC, but not MDDC exposed to UV-killed RSV or mock conditions, contained alpha interferon (IFN-α median, 43 pg/ml) and IFN-λ (approximately 1 to 20 ng/ml). Neutralization of IFN-α with monoclonal antibody (MAb) against one of its receptor chains, IFNAR2, or of IFN-λ with MAb against either of its receptor chains, IFN-λR1 (interleukin 28R [IL-28R]) or IL-10R2, had a modest effect. In contrast, blocking the two receptors together markedly reduced or completely blocked the RSV-induced suppression of CD4 T-cell proliferation. Defining the mechanism of RSV-induced suppression may guide vaccine design and provide insight into previously uncharacterized human T-cell responses and activities of interferons.
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 2007
Publisher: Elsevier BV
Date: 03-2012
Location: No location found
No related grants have been discovered for Laure Dumoutier.