ORCID Profile
0000-0003-1024-9128
Current Organisation
Ospedale San Raffaele
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Publisher: American Society of Hematology
Date: 19-12-2006
DOI: 10.1182/BLOOD-2006-10-049312
Abstract: Liver gene transfer is a highly sought goal for the treatment of inherited and infectious diseases. Lentiviral vectors (LVs) have many desirable properties for hepatocyte-directed gene delivery, including the ability to integrate into non iding cells. Unfortunately, upon systemic administration, LV transduces hepatocytes relatively inefficiently compared with nonparenchymal cells, and the duration of transgene expression is often limited by immune responses. Here, we investigated the role of innate antiviral responses in these events. We show that administration of LVs to mice triggers a rapid and transient IFNαβ response. This effect was dependent on functional vector particles, and in vitro challenge of antigen-presenting cells suggested that plasmacytoid dendritic cells initiated the response. Remarkably, when LVs were administered to animals that lack the capacity to respond to IFNαβ, there was a dramatic increase in hepatocyte transduction, and stable transgene expression was achieved. These findings indicate that, even in the setting of acute delivery of replication-defective vectors, IFNs effectively interfere with transduction in a cell-type–specific manner. Moreover, because disabling a single component of the innate/immune network was sufficient to establish persistent xenoantigen expression, our results raise the hope that the immunologic barriers to gene therapy are less insurmountable than expected.
Publisher: SAGE Publications
Date: 08-2010
Abstract: High levels of donor-derived CCL2 have been associated with poor islet allograft outcome in patients with type 1 diabetes. The aim of our work was to determine whether CCL2 secreted by the islet has independent proinflammatory effects that influence engraftment and graft acceptance. Both in mice and humans CCL2 is significantly positively associated with other cytokines/chemokines, in particular with the highly released “proinflammatory” IL-6 and CXCL8 or CXCL1. Transplantation of CCL2-/- islets into syngenic recipients did not improve the transplant function. Transplantation of islets into CCL2-/- syngenic recipients led to a significant improvement of transplant function and partial abrogation of local hepatic inflammation. When evaluated in human islets CCL2 release was strongly related to the immediate local inflammatory response in the liver and impacted short-term human islet function dependently by the induced inflammatory response and independently by the immunosuppressive therapy. The data showed that islet CCL2 release is a sign of “inflamed” islets without having a direct role in graft failure. On the other hand, a causal effect for developing detrimental proinflammatory conditions after transplant was proved for recipient CCL2. Strategies to selectively decrease recipient, but not donor, CCL2 release may increase the success of islet transplantation.
Publisher: Elsevier BV
Date: 09-2006
DOI: 10.1016/J.HEPRES.2006.05.006
Abstract: Based on previous studies in experimental models, pro-inflammatory Th1 cytokines (i.e. TNF-alpha and IFN-gamma) are thought to play a pathogenic role in hepatic ischemia/reperfusion injury, while anti-inflammatory Th2 cytokines (i.e. IL-4 and IL-10) have been associated with reduced liver disease severity. To test the relevance of these concepts in humans, cytokine expression profiles were characterized in liver biopsies from patients undergoing hepatic resection following intermittent portal cl ing. Twelve patients were analyzed for the intrahepatic expression of TNF-alpha, IFN-gamma, IL-4 and IL-10 before and about 90min after the last reperfusion. In addition, parameters of liver damage including sALT and serum levels of TNF-alpha were analyzed at 2, 24 and 48h after surgery. When compared with pre-reperfusion liver specimens, all post-reperfusion biopsies showed significantly increased levels of TNF-alpha and IFN-gamma mRNAs. Conversely IL-4 and IL-10 mRNA levels were significantly increased in only seven patients. A negative correlation was observed between Th2 cytokines (IL-4, IL-10) and ALT and serum levels of TNF-alpha. Furthermore, the presence of hepatic steatosis was significantly associated with lower intrahepatic contents of IL-4 and IL-10. The results suggest that the local early expression of Th2 cytokines may contribute to attenuate liver injury following ischemia reperfusion in humans. The early imbalance between pro- and anti-inflammatory cytokines seen in steatotic liver subjected to I/R could explain, at least partially, the decreased tolerance of steatotic livers to I/R injury.
Publisher: Elsevier BV
Date: 04-2013
Publisher: Elsevier BV
Date: 10-2008
DOI: 10.1016/J.CCR.2008.09.004
Abstract: The use of type I interferons (IFNs) in cancer therapy has been limited by ineffective dosing and significant toxicity. Here, we exploited the tumor-homing ability of proangiogenic Tie2-expressing monocytes (TEMs) to deliver IFN-alpha to tumors. By transplanting hematopoietic progenitors transduced with a Tie2 promoter/enhancer-driven Ifna1 gene, we turned TEMs into IFN-alpha cell vehicles that efficiently targeted the IFN response to orthotopic human gliomas and spontaneous mouse mammary carcinomas and obtained significant antitumor responses and near complete abrogation of metastasis. TEM-mediated IFN-alpha delivery inhibited tumor angiogenesis and activated innate and adaptive immune cells but did not impair myelopoiesis and wound healing detectably. These results illustrate the therapeutic potential of gene- and cell-based IFN-alpha delivery and should allow the development of IFN treatments that more effectively treat cancer.
Publisher: American Society for Clinical Investigation
Date: 15-04-2004
DOI: 10.1172/JCI200421087
No related grants have been discovered for Giovanni Sitia.