scholarly journals Recombinant Mycobacterium bovis Bacillus Calmette-Guérin Vectors Prime for Strong Cellular Responses to Simian Immunodeficiency Virus Gag in Rhesus Macaques

2014 ◽  
Vol 21 (10) ◽  
pp. 1385-1395 ◽  
Author(s):  
Jaimie D. Sixsmith ◽  
Michael W. Panas ◽  
Sunhee Lee ◽  
Geoffrey O. Gillard ◽  
KeriAnn White ◽  
...  
Keyword(s):  
Immune Responses ◽  
Simian Immunodeficiency Virus ◽  
Mycobacterium Bovis ◽  
Rhesus Macaques ◽  
Vaccine Vector ◽  
Effective Vaccine ◽  
Bacillus Calmette Guerin ◽  
Immunodeficiency Virus ◽  
Specific Priming

ABSTRACTLive attenuated nonpathogenicMycobacterium bovisbacillus Calmette-Guérin (BCG) mediates long-lasting immune responses, has been safely administered as a tuberculosis vaccine to billions of humans, and is affordable to produce as a vaccine vector. These characteristics make it very attractive as a human immunodeficiency virus (HIV) vaccine vector candidate. Here, we assessed the immunogenicity of recombinant BCG (rBCG) constructs with different simian immunodeficiency virus (SIV)gagexpression cassettes as priming agents followed by a recombinant replication-incompetent New York vaccinia virus (NYVAC) boost in rhesus macaques. Unmutated rBCG constructs were used in comparison to mutants with gene deletions identified in anin vitroscreen for augmented immunogenicity. We demonstrated that BCG-SIVgagis able to elicit robust transgene-specific priming responses, resulting in strong SIV epitope-specific cellular immune responses. While enhanced immunogenicity was sustained at moderate levels for >1 year following the heterologous boost vaccination, we were unable to demonstrate a protective effect after repeated rectal mucosal challenges with pathogenic SIVmac251. Our findings highlight the potential for rBCG vaccines to stimulate effective cross-priming and enhanced major histocompatibility complex class I presentation, suggesting that combining this approach with other immunogens may contribute to the development of effective vaccine regimens against HIV.

scholarly journals Induction of CD8+ Cells Able To Suppress CCR5-Tropic Simian Immunodeficiency Virus SIVmac239 Replication by Controlled Infection of CXCR4-Tropic Simian-Human Immunodeficiency Virus in Vaccinated Rhesus Macaques

2007 ◽  
Vol 81 (21) ◽  
pp. 11640-11649 ◽  
Author(s):  
Tetsuo Tsukamoto ◽  
Mitsuhiro Yuasa ◽  
Hiroyuki Yamamoto ◽  
Miki Kawada ◽  
Akiko Takeda ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Virus Infection ◽  
Immune Responses ◽  
Simian Immunodeficiency Virus ◽  
Viral Vector ◽  
Rhesus Macaques ◽  
Chronic Phase ◽  
Live Virus ◽  
Immunodeficiency Virus

ABSTRACT Recent recombinant viral vector-based AIDS vaccine trials inducing cellular immune responses have shown control of CXCR4-tropic simian-human immunodeficiency virus (SHIV) replication but difficulty in containment of pathogenic CCR5-tropic simian immunodeficiency virus (SIV) in rhesus macaques. In contrast, controlled infection of live attenuated SIV/SHIV can confer the ability to contain SIV superchallenge in macaques. The specific immune responses responsible for this control may be induced by live virus infection but not consistently by viral vector vaccination, although those responses have not been determined. Here, we have examined in vitro anti-SIV efficacy of CD8+ cells in rhesus macaques that showed prophylactic viral vector vaccine-based control of CXCR4-tropic SHIV89.6PD replication. Analysis of the effect of CD8+ cells obtained at several time points from these macaques on CCR5-tropic SIVmac239 replication in vitro revealed that CD8+ cells in the chronic phase after SHIV challenge suppressed SIV replication more efficiently than those before challenge. SIVmac239 superchallenge of two of these macaques at 3 or 4 years post-SHIV challenge was contained, and the following anti-CD8 antibody administration resulted in transient CD8+ T-cell depletion and appearance of plasma SIVmac239 viremia in both of them. Our results indicate that CD8+ cells acquired the ability to efficiently suppress SIV replication by controlled SHIV infection, suggesting the contribution of CD8+ cell responses induced by controlled live virus infection to containment of HIV/SIV superinfection.

scholarly journals Analysis and Prospects of Using Recombinant Vaccinia Virus MVA Strain as a Vector in the Development of the Vaccines against Human and Simian Immunodeficiency Virus Diseases

2019 ◽  
pp. 37-44
Author(s):  
L. F. Stovba ◽  
V. T. Krotkov ◽  
D. I. Paveli’ev ◽  
S. A. Mel’nikov ◽  
V. N. Lebedev ◽  
...  
Keyword(s):  
Immune Response ◽  
Simian Immunodeficiency Virus ◽  
Structural Changes ◽  
Rhesus Macaques ◽  
Laboratory Animals ◽  
Cell Immune Response ◽  
Effective Vaccine ◽  
Protective Efficiency ◽  
Immunodeficiency Virus ◽  
Immunodominant Antigens

The review presents the results of preclinical use of vector vaccines against human immunodeficiency virus (HIV) disease and simian immunodeficiency virus (SIV) disease. Application of antiretroviral therapy exclusively is insufficient for elimination of HIV from patient’s body. This dictates the need for an effective vaccine which will reduce the number of new cases of the disease and reduce the risk of virus transmission. Current practice of medicinal product development showed the effectiveness of heterologous prime-boost regimens for the induction of expressed immune response in laboratory animals. Various vector constructs were used as priming vaccines: DNA vaccines, Bacille Calmette-Guerin vaccine, chimpanzee adenovirus, vesicular stomatitis virus, alphavirus repli-clone. Booster vaccine was represented by recombinant MVA strain. In all vector vaccines, different genes of immunodominant antigens of HIV and SIV agents were inserted. On rhesus macaques, murine, rabbit models, it was demonstrated that deployed vaccination schemes were safe and induced immune response. Because membrane HIV protein is highly variable, strongly glycoziled and subjected to structural changes during receptor binding, it cannot be viewed as a target for induction of virus neutralized antibodies. Therefore, we mainly studied the cell immune response that was presented by poly-functional CD8+ T-cells. However, some recent researches are aimed at such modification of envelope HIV immunogene that would provide for virus neutralizing antibody induction. The study of protective efficiency of the induced immunity in rhesus macaques, immunized with recombinant vectors expressing SIV’ s immunodominant antigens, in case of subsequent inoculation with virulent SIV strain has revealed that all monkeys developed illness. Assuming that the constructions with SIV’ s immunodominant antigens under protective efficiency testing on rhesus macaques imitate AIDS in humans, it seems that vaccines, developed up-to-date, will not be effective for collective immunity formation against AIDS. Therefore, the search for novel combinations of expressed immunodominant antigens for the inclusion into the composition of priming and booster vaccines remains a priority area at present time.

scholarly journals Immunization with a Live, Attenuated Simian Immunodeficiency Virus Vaccine Leads to Restriction of Viral Diversity in Rhesus Macaques Not Protected from Pathogenic Challenge

1999 ◽  
Vol 73 (5) ◽  
pp. 4443-4446 ◽  
Author(s):  
Donald L. Sodora ◽  
Kristine E. Sheridan ◽  
Preston A. Marx ◽  
Ruth I. Connor
Keyword(s):  
Genetic Diversity ◽  
Simian Immunodeficiency Virus ◽  
Virus Vaccine ◽  
Rhesus Macaques ◽  
Biological Characteristics ◽  
Viral Diversity ◽  
Immunodeficiency Virus ◽  
Sivmac251 Challenge ◽  
Selection Of

ABSTRACT Rhesus macaques immunized with simian immunodeficiency virus SIVmac239Δnef but not protected from SIVmac251 challenge were studied to determine the genetic and biological characteristics of the breakthrough viruses. Assessment of SIV genetic diversity (env V1-V2) revealed a reduction in the number of viral species in the immunized, unprotected macaques, compared to the number in nonimmunized controls. However, no evidence for selection of a specific V1-V2 genotype was observed, and biologically cloned isolates from the animals with breakthrough virus were similar with respect to replication kinetics and coreceptor use in vitro.

scholarly journals Vaccine-induced immune responses against both Gag and Env improve control of simian immunodeficiency virus replication in rectally challenged rhesus macaques

2017 ◽  
Vol 13 (7) ◽  
pp. e1006529 ◽  
Author(s):  
Mauricio A. Martins ◽  
Young C. Shin ◽  
Lucas Gonzalez-Nieto ◽  
Aline Domingues ◽  
Martin J. Gutman ◽  
...  
Keyword(s):  
Immune Responses ◽  
Simian Immunodeficiency Virus ◽  
Virus Replication ◽  
Rhesus Macaques ◽  
Immunodeficiency Virus

scholarly journals Expanded Tissue Targets for Foamy Virus Replication with Simian Immunodeficiency Virus-Induced Immunosuppression

2006 ◽  
Vol 80 (2) ◽  
pp. 663-670 ◽  
Author(s):  
S. M. Murray ◽  
L. J. Picker ◽  
M. K. Axthelm ◽  
M. L. Linial
Keyword(s):  
Small Intestine ◽  
T Cell ◽  
Simian Immunodeficiency Virus ◽  
Rhesus Macaques ◽  
Foamy Virus ◽  
Viral Rna ◽  
Cell Depletion ◽  
T Cell Depletion ◽  
Immunodeficiency Virus

ABSTRACT Foamy viruses (FV) are the oldest known genus of retroviruses and have persisted in nonhuman primates for over 60 million years. FV are efficiently transmitted, leading to a lifelong nonpathogenic infection. Transmission is thought to occur through saliva, but the detailed mechanism is unknown. Interestingly, this persistent infection contrasts with the rapid cytopathicity caused by FV in vitro, suggesting a host defense against FV. To better understand the tissue specificity of FV replication and host immunologic defense against FV cytopathicity, we quantified FV in tissues of healthy rhesus macaques (RM) and those severely immunosuppressed by simian immunodeficiency virus (SIV). Contrary to earlier findings, we find that all immunocompetent animals consistently have high levels of viral RNA in oral tissues but not in other tissues examined, including the small intestine. Strikingly, abundant viral transcripts were detected in the small intestine of all of the SIV-infected RM, which has been shown to be a major site of SIV (and human immunodeficiency virus)-induced CD4+ T-cell depletion. In contrast, there was a trend to lower viral RNA levels in oropharyngeal tissues of SIV-infected animals. The expansion of FV replication to the small intestine but not to other CD4+ T-cell-depleted tissues suggests that factors other than T-cell depletion, such as dysregulation of the jejunal microenvironment after SIV infection, likely account for the expanded tissue tropism of FV replication.

scholarly journals Breakthrough of SIV strain smE660 challenge in SIV strain mac239-vaccinated rhesus macaques despite potent autologous neutralizing antibody responses

2015 ◽  
Vol 112 (34) ◽  
pp. 10780-10785 ◽  
Author(s):  
Samantha L. Burton ◽  
Katie M. Kilgore ◽  
S. Abigail Smith ◽  
Sharmila Reddy ◽  
Eric Hunter ◽  
...  
Keyword(s):  
Simian Immunodeficiency Virus ◽  
Neutralizing Antibodies ◽  
Rhesus Macaques ◽  
Neutralizing Antibody ◽  
Active Immunization ◽  
Antibody Responses ◽  
Challenge Virus ◽  
Gm Csf ◽  
Immunodeficiency Virus

Although the correlates of immunological protection from human immunodeficiency virus or simian immunodeficiency virus infection remain incompletely understood, it is generally believed that medium to high titers of serum neutralizing antibodies (nAbs) against the challenge virus will prevent infection. This paradigm is based on a series of studies in which passive transfer of HIV-specific nAbs protected rhesus macaques (RMs) from subsequent mucosal challenge with a chimeric human/simian immunodeficiency virus. However, it is unknown whether nAb titers define protection in the setting of active immunization. Here we determined serum nAb titers against breakthrough transmitted/founder (T/F) SIVsmE660-derived envelope glycoprotein (Env) variants from 14 RMs immunized with SIVmac239-based DNA-prime/modified vaccinia virus Ankara-boost vaccine regimens that included GM-CSF or CD40L adjuvants and conferred significant but incomplete protection against repeated low-dose intrarectal challenge. A single Env variant established infection in all RMs except one, with no identifiable genetic signature associated with vaccination breakthrough compared with T/F Envs from four unvaccinated monkeys. Breakthrough T/F Env pseudoviruses were potently neutralized in vitro by heterologous pooled serum from chronically SIVsmE660-infected monkeys at IC50 titers exceeding 1:1,000,000. Remarkably, the T/F Env pseudoviruses from 13 of 14 monkeys were also susceptible to neutralization by autologous prechallenge serum at in vitro IC50 titers ranging from 1:742–1:10,832. These titers were similar to those observed in vaccinated RMs that remained uninfected. These data suggest that the relationship between serum nAb titers and protection from mucosal SIV challenge in the setting of active immunization is more complex than previously recognized, warranting further studies into the balance between immune activation, target cell availability, and protective antibody responses.

scholarly journals A Period of Transient Viremia and Occult Infection Precedes Persistent Viremia and Antiviral Immune Responses during Multiple Low-Dose Intravaginal Simian Immunodeficiency Virus Inoculations

2004 ◽  
Vol 78 (24) ◽  
pp. 14048-14052 ◽  
Author(s):  
Zhong-Min Ma ◽  
Kristina Abel ◽  
Tracy Rourke ◽  
Yichuan Wang ◽  
Christopher J. Miller
Keyword(s):  
Immune Responses ◽  
Simian Immunodeficiency Virus ◽  
Low Dose ◽  
Rhesus Macaques ◽  
Systemic Infection ◽  
Variable Number ◽  
Transmission Model ◽  
High Dose ◽  
Persistent Viremia ◽  
Immunodeficiency Virus

ABSTRACT In rhesus macaques, classic systemic infection, characterized by persistent viremia and seroconversion, occurred after multiple low-dose (103 50% tissue culture infective doses) intravaginal (IVAG) inoculations with simian immunodeficiency virus (SIV) strain SIVmac251. Monkeys developed classic SIV infections after a variable number of low-dose IVAG exposures to SIVmac251. Once established, the systemic infection was identical to SIV infection following high-dose IVAG SIV inoculation. However, occult systemic infection characterized by transient cell-associated or cell-free viremia consistently occurred early in the series of multiple vaginal SIV exposures. Further, antiviral cellular immune responses were present prior to the establishment of a classic systemic infection in the low-dose vaginal SIV transmission model.

scholarly journals Intrinsic Susceptibility of Rhesus Macaque Peripheral CD4+ T Cells to Simian Immunodeficiency Virus In Vitro Is Predictive of In Vivo Viral Replication

2000 ◽  
Vol 74 (20) ◽  
pp. 9388-9395 ◽  
Author(s):  
Simoy Goldstein ◽  
Charles R. Brown ◽  
Houman Dehghani ◽  
Jeffrey D. Lifson ◽  
Vanessa M. Hirsch
Keyword(s):  
T Cell ◽  
Simian Immunodeficiency Virus ◽  
Rank Order ◽  
Rhesus Macaques ◽  
Target Cells ◽  
Plasma Viremia ◽  
Immunodeficiency Virus ◽  
Siv Infection

ABSTRACT Previous studies with simian immunodeficiency virus (SIV) infection of rhesus macaques suggested that the intrinsic susceptibility of peripheral blood mononuclear cells (PBMC) to infection with SIV in vitro was predictive of relative viremia after SIV challenge. The present study was conducted to evaluate this parameter in a well-characterized cohort of six rhesus macaques selected for marked differences in susceptibility to SIV infection in vitro. Rank order relative susceptibility of PBMC to SIVsmE543-3-infection in vitro was maintained over a 1-year period of evaluation. Differential susceptibility of different donors was maintained in CD8+T-cell-depleted PBMC, macrophages, and CD4+ T-cell lines derived by transformation of PBMC with herpesvirus saimiri, suggesting that this phenomenon is an intrinsic property of CD4+target cells. Following intravenous infection of these macaques with SIVsmE543-3, we observed a wide range in plasma viremia which followed the same rank order as the relative susceptibility established by in vitro studies. A significant correlation was observed between plasma viremia at 2 and 8 weeks postinoculation and in vitro susceptibility (P < 0.05). The observation that the two most susceptible macaques were seropositive for simian T-lymphotropic virus type 1 may suggests a role for this viral infection in enhancing susceptibility to SIV infection in vitro and in vivo. In summary, intrinsic susceptibility of CD4+ target cells appears to be an important factor influencing early virus replication patterns in vivo that should be considered in the design and interpretation of vaccine studies using the SIV/macaque model.

scholarly journals Comprehensive Analysis of Nef Functions Selected in Simian Immunodeficiency Virus-Infected Macaques

2004 ◽  
Vol 78 (19) ◽  
pp. 10588-10597 ◽  
Author(s):  
Michael Schindler ◽  
Jan Münch ◽  
Matthias Brenner ◽  
Christiane Stahl-Hennig ◽  
Jacek Skowronski ◽  
...  
Keyword(s):  
Simian Immunodeficiency Virus ◽  
Rhesus Macaques ◽  
Surface Expression ◽  
Viral Fitness ◽  
Cell Surface Expression ◽  
Mhc I ◽  
Mhc Ii ◽  
Immunodeficiency Virus

ABSTRACT A variety of simian immunodeficiency virus (SIVmac) nef mutants have been investigated to clarify which in vitro Nef functions contribute to efficient viral replication and pathogenicity in rhesus macaques. Most of these nef alleles, however, were only functionally characterized for their ability to down-modulate CD4 and class I major histocompatibility complex (MHC-I) cell surface expression and to enhance SIV replication and infectivity. To obtain information on the in vivo relevance of more recently established Nef functions, we examined the ability of a large panel of constructed SIVmac Nef mutants and of variants that emerged in infected macaques to down-regulate CD3, CD28, and MHC-II and to up-regulate the MHC-II-associated invariant chain (Ii). We found that all these four Nef functions were restored in SIV-infected macaques. In most cases, however, the initial mutations and the changes selected in vivo affected several in vitro Nef functions. For example, truncated Nef proteins that emerged in animals infected with SIVmac239 containing a 152-bp deletion in nef efficiently modulated both CD3 and Ii surface expression. Overall, our results suggest that the effect of Nef on each of the six cellular receptors investigated contributes to viral fitness in the infected host but also indicate that modulation of CD3, MHC-I, MHC-II, or Ii surface expression alone is insufficient for SIV virulence.

Sign in / Sign up

Export Citation Format

Share Document