Vaccine and Gene Therapy Institute Florida

Port Saint Lucie, FL, United States

Vaccine and Gene Therapy Institute Florida

Port Saint Lucie, FL, United States
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Klatt N.R.,University of Washington | Chomont N.,Vaccine and Gene Therapy Institute Florida | Douek D.C.,U.S. National Institutes of Health | Deeks S.G.,University of California at San Francisco
Immunological Reviews | Year: 2013

Despite complete or near-complete suppression of human immunodeficiency virus (HIV) replication with combination antiretroviral therapy, both HIV and chronic inflammation/immune dysfunction persist indefinitely. Untangling the association between the virus and the host immune environment during therapy might lead to novel interventions aimed at either curing the infection or preventing the development of inflammation-associated end-organ disease. Chronic inflammation and immune dysfunction might lead to HIV persistence by causing virus production, generating new target cells, enabling infecting of activated and resting target cells, altering the migration patterns of susceptible target cells, increasing the proliferation of infected cells, and preventing normal HIV-specific clearance mechanisms from function. Chronic HIV production or replication might contribute to persistent inflammation and immune dysfunction. The rapidly evolving data on these issues strongly suggest that a vicious cycle might exist in which HIV persistence causes inflammation that in turn contributes to HIV persistence. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Fukazawa Y.,Oregon Health And Science University | Park H.,Oregon Health And Science University | Cameron M.J.,Vaccine and Gene Therapy Institute Florida | Lefebvre F.,Vaccine and Gene Therapy Institute Florida | And 24 more authors.
Nature Medicine | Year: 2012

Live attenuated simian immunodeficiency virus (SIV) vaccines (LAVs) remain the most efficacious of all vaccines in nonhuman primate models of HIV and AIDS, yet the basis of their robust protection remains poorly understood. Here we show that the degree of LAV-mediated protection against intravenous wild-type SIVmac239 challenge strongly correlates with the magnitude and function of SIV-specific, effector-differentiated T cells in the lymph node but not with the responses of such T cells in the blood or with other cellular, humoral and innate immune parameters. We found that maintenance of protective T cell responses is associated with persistent LAV replication in the lymph node, which occurs almost exclusively in follicular helper T cells. Thus, effective LAVs maintain lymphoid tissue-based, effector-differentiated, SIV-specific T cells that intercept and suppress early wild-type SIV amplification and, if present in sufficient frequencies, can completely control and perhaps clear infection, an observation that provides a rationale for the development of safe, persistent vectors that can elicit and maintain such responses. © 2012 Nature America, Inc. All rights reserved.

Trono D.,Ecole Polytechnique Federale de Lausanne | Van Lint C.,Free University of Colombia | Rouzioux C.,University of Paris Descartes | Verdin E.,Gladstone | And 3 more authors.
Science | Year: 2010

HIV infection can persist in spite of efficacious antiretroviral therapies. Although incomplete inhibition of viral replication may contribute to this phenomenon, this is largely due to the early establishment of a stable reservoir of latently infected cells. Thus, life-long antiviral therapy may be needed to control HIV. Such therapy is prone to drug resistance and cumulative side effects and is an unbearable financial burden for regions of the world hit hardest by the epidemic. This review discusses our current understanding of HIV persistence and the limitations of potential approaches to eradicate the virus and accordingly pleads for a joint multidisciplinary effort toward two highly related goals: the development of an HIV prophylactic vaccine and the achievement of long-term drug-free remissions in HIV-infected individuals.

Joshi M.,Sahlgrenska University Hospital | B. Patil P.,Sahlgrenska University Hospital | He Z.,Vaccine and Gene Therapy Institute Florida | Jan H.,Sahlgrenska University Hospital | And 2 more authors.
Cytotherapy | Year: 2012

Background aims. One important problem commonly encountered after hepatocyte transplantation is the low numbers of transplanted cells found in the graft. If hepatocyte transplantation is to be a viable therapeutic approach, significant liver parenchyma repopulation is required. Mesenchymal stromal cells (MSC) produce high levels of various growth factors, cytokines and metalloproteinases, and have immunomodulatory effects. We therefore hypothesized that co-transplantation of MSC with human fetal hepatocytes (hFH) could augment in vivo expansion after transplantation. We investigated the ability of human fetal liver MSC (hFLMSC) to augment expansion of phenotypically and functionally well-characterized hFH. Methods. Two million hFH (passage 6) were either transplanted alone or together (1:1 ratio) with green fluorescence protein-expressing hFLMSC into the spleen of C57BL/6 nude mice with retrorsine-induced liver injury. Results. After 4 weeks, engraftment of cells was detected by fluorescence in situ hybridization using a human-specific DNA probe. Significantly higher numbers of cells expressing human cytokeratin (CK)8, CK18, CK19, Cysteine-rich MNNG HOS Transforming gene (c-Met), alpha-fetoprotein (AFP), human nuclear antigen, mitochondrial antigen, hepatocyte-specific antigen and albumin (ALB) were present in the livers of recipient animals co-transplanted with hFLMSC compared with those without. Furthermore, expression of human hepatocyte nuclear factor (HNF)-4α and HNF-1β, and cytochrome P450 (CYP) 3A7 mRNA was demonstrated by reverse transcriptasepolymerase chain reaction (RT-PCR) in these animals. In addition, significantly increased amounts of human ALB were detected. Importantly, hFLMSC did not transdifferentiate into hepatocytes. Conclusions. Our study reports the use of a novel strategy for enhanced liver repopulation and thereby advances this experimental procedure closer to clinical liver cell therapy. © 2012 Informa Healthcare.

Ananworanich J.,U.S. Army | Ananworanich J.,Foundation Medicine | Dube K.,University of North Carolina at Chapel Hill | Chomont N.,Vaccine and Gene Therapy Institute Florida
Current Opinion in HIV and AIDS | Year: 2015

Purpose of review: The long-lived viral reservoir is a major obstacle to achieving a cure for HIV. Therapeutic strategies, such as early antiretroviral therapy (ART), may be a prerequisite to achieving long-term control of viral replication upon ART withdrawal.Recent findings: HIV persistence is established early in acute HIV infection (AHI) with infection in long-lived memory CD4+ T cells. Studies conducted in nonhuman primates have suggested that this could occur as early as 3 days postinfection; however, the timing in humans is uncertain. ART during AHI significantly restricts the HIV reservoirs as compared with later treatment. Early ART, particularly prior to the detection of HIV immunoglobulin M, may also reduce the contribution of the long-lived central memory CD4+ T cells to the total HIV reservoir, a profile observed in individuals who naturally control HIV without ART.It is clear that early ART has a greater impact in limiting the HIV reservoirs than later treatment. However, latently infected long-lived memory CD4+ T cells persist in most early treated individuals. Therefore, additional interventions will likely be required to eliminate all cells capable of producing replication-competent virus but treatment in AHI may be the critical first step in containing the HIV reservoirs. © 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins.

Mooney M.,Oregon Health And Science University | Mooney M.,Oregon Clinical and Translational Research Institute | Mooney M.,OHSU Knight Cancer Institute | McWeeney S.,Oregon Health And Science University | And 4 more authors.
Seminars in Immunology | Year: 2013

Vaccines are the most cost effective public health measure for preventing viral infection and limiting epidemic spread within susceptible populations. However, the efficacy of current protective vaccines is highly variable, particularly in aging populations. In addition, there have been a number of challenges in the development of new vaccines due to a lack of detailed understanding of the immune correlates of protection. To identify the mechanisms underlying the variability of the immune response to vaccines, system-level tools need to be developed that will further our understanding of virus-host interactions and correlates of vaccine efficacy. This will provide critical information for rational vaccine design and allow the development of an analog to the "precision medicine" framework (already acknowledged as a powerful approach in medicine and therapeutics) to be applied to vaccinology. © 2013 Elsevier Ltd.

Vandergeeten C.,Vaccine and Gene Therapy Institute Florida
Blood | Year: 2013

HIV persists in latently infected memory CD4(+) T cells during antiretroviral therapy (ART). When administered to HIV-infected subjects receiving suppressive ART, interleukin-7 (IL-7) increases the number of CD4(+) T cells by promoting their survival and proliferation. However, little is known about the impact of IL-7 on HIV persistence during ART. By isolating large numbers of CD4(+) T cells from HIV-infected subjects, we demonstrate that IL-7 enhances viral production in productively infected cells but does not disrupt viral latency in latently infected cells. When administered to virally suppressed subjects, IL-7 led to the rapid proliferation of memory CD4(+) T cells, which resulted in a 70% increase in the absolute number of circulating CD4(+) T cells harboring integrated HIV DNA 4 weeks after therapy. The genetic diversity of the viral reservoir increased transiently in the majority of the subjects studied before returning to baseline values. Altogether, our results indicate that IL-7 promotes the mechanisms of HIV persistence during ART by enhancing residual levels of viral production and inducing proliferation of latently infected cells, and suggest that IL-7 does not represent a suitable candidate therapeutic strategy for HIV eradication. This trial was registered at as #NCT00099671 (AIDS Clinical Trials Group protocol 5214).

Trautmann L.,Vaccine and Gene Therapy Institute Florida | Trautmann L.,University of Miami | Mbitikon-Kobo F.-M.,Vaccine and Gene Therapy Institute Florida | Goulet J.-P.,University of Montréal | And 12 more authors.
Blood | Year: 2012

Immediate-early host-virus interactions that occur during the first weeks after HIV infection have a major impact on disease progression. The mechanisms underlying the failure of HIV-specific CD8 T-cell response to persist and control viral replication early in infection are yet to be characterized. In this study, we performed a thorough phenotypic, gene expression and functional analysis to compare HIV-specific CD8 T cells in acutely and chronically infected subjects. We showed that HIV-specific CD8 T cells in primary infection can be distinguished by their metabolic state, rate of proliferation, and susceptibility to apoptosis. HIV-specific CD8 T cells in acute/early HIV infection secreted less IFN-γ but were more cytotoxic than their counterparts in chronic infection. Importantly, we showed that the levels of IL-7R expression and the capacity of HIV-specific CD8 T cells to secrete IL-2 on antigenic restimulation during primary infection were inversely correlated with the viral set-point. Altogether, these data suggest an altered metabolic state of HIV-specific CD8 T cells in primary infection resulting from hyperproliferation and stress induced signals, demonstrate the discordant function of HIV-specific CD8 T cells during early/acute infection, and highlight the importance of T-cell maintenance for viral control. © 2012 by The American Society of Hematology.

Vandergeeten C.,Vaccine and Gene Therapy Institute Florida | Fromentin R.,Vaccine and Gene Therapy Institute Florida | Merlini E.,University of Milan | Lawani M.B.,Vaccine and Gene Therapy Institute Florida | And 9 more authors.
Journal of Virology | Year: 2014

A small pool of infected cells persists in HIV-infected individuals receiving antiretroviral therapy (ART). Here, we developed ultrasensitive assays to precisely measure the frequency of cells harboring total HIV DNA, integrated HIV DNA, and two long terminal repeat (2-LTR) circles. These assays are performed on cell lysates, which circumvents the labor-intensive step of DNA extraction, and rely on the coquantification of each HIV molecular form together with CD3 gene sequences to precisely measure cell input. Using primary isolates from HIV subtypes A, B, C, D, and CRF01_A/E, we demonstrate that these assays can efficiently quantify low target copy numbers from diverse HIV subtypes. We further used these assays to measure total HIV DNA, integrated HIV DNA, and 2-LTR circles in CD4+ T cells from HIV-infected subjects infected with subtype B. All samples obtained from ART-naive subjects were positive for the three HIV molecular forms (n=15). Total HIV DNA, integrated HIV DNA, and 2-LTR circles were detected in, respectively, 100%, 94%, and 77% of the samples from individuals in which HIV was suppressed by ART. Higher levels of total HIV DNA and 2-LTR circles were detected in untreated subjects than individuals on ART (P = 0.0003 and P = 0.0004, respectively), while the frequency of CD4+ T cells harboring integrated HIV DNA did not differ between the two groups. These results demonstrate that these novel assays have the ability to quantify very low levels of HIV DNA of multiple HIV subtypes without the need for nucleic acid extraction, making them well suited for the monitoring of viral persistence in large populations of HIV-infected individuals. © 2014, American Society for Microbiology.

Anderson J.L.,University of Melbourne | Fromentin R.,Vaccine and Gene Therapy Institute Florida | Corbelli G.M.,European AIDS Treatment Group | Ostergaard L.,Aarhus University Hospital | Ross A.L.,ANRS
AIDS Research and Human Retroviruses | Year: 2015

Biomedical research has led to profound advances in the treatment of HIV infection. Combination antiretroviral therapy (ART) now provides the means to readily control viral infection, and people living with HIV who receive timely and effective ART can expect to benefit from a life expectancy comparable to uninfected individuals. Nevertheless, despite effective treatment, ART does not fully restore the immune system and importantly HIV persists indefinitely in latent reservoirs, resulting in the need for life-long treatment. The challenges and limits of life-long treatment have spurred significant scientific interest and global investment into research towards an HIV cure. The International AIDS Society (IAS) 2014 Towards an HIV cure symposium brought together researchers and community to discuss the most recent advances in our understanding of latency and HIV reservoirs, and the clinical approaches towards an HIV cure under current investigation. This report summarizes and reviews some of the major findings discussed during the symposium. © Mary Ann Liebert, Inc. 2015.

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