scholarly journals Novel Strategy To Adapt Simian-Human Immunodeficiency Virus E1 Carryingenvfrom an RV144 Volunteer to Rhesus Macaques: Coreceptor Switch and Final Recovery of a Pathogenic Virus with Exclusive R5 Tropism

2018 ◽  
Vol 92 (14) ◽  
Author(s):  
Hanna B. Scinto ◽  
Sandeep Gupta ◽  
Swati Thorat ◽  
Muhammad M. Mukhtar ◽  
Anthony Griffiths ◽  
...  

ABSTRACTThe phase III RV144 human immunodeficiency virus (HIV) vaccine trial conducted in Thailand remains the only study to show efficacy in decreasing the HIV acquisition risk. In Thailand, circulating recombinant forms of HIV clade A/E (CRF01_AE) predominate; in such viruses,envoriginates from clade E (HIV-E). We constructed a simian-human immunodeficiency virus (SHIV) chimera carryingenvisolated from an RV144 placebo recipient in the SHIV-1157ipd3N4 backbone. The latter contains long terminal repeats (LTRs) with duplicated NF-κB sites, thus resembling HIV LTRs. We devised a novel strategy to adapt the parental infectious molecular clone (IMC), R5 SHIV-E1, to rhesus macaques: the simultaneous depletion of B and CD8+cells followed by the intramuscular inoculation of proviral DNA and repeated administrations of cell-free virus. High-level viremia and CD4+T-cell depletion ensued. Passage 3 virus unexpectedly caused acute, irreversible CD4+T-cell loss; the partially adapted SHIV had become dual tropic. Virus and IMCs with exclusive R5 tropism were reisolated from earlier passages, combined, and used to complete adaptation through additional macaques. The final isolate, SHIV-E1p5, remained solely R5 tropic. It had a tier 2 neutralization phenotype, was mucosally transmissible, and was pathogenic. Deep sequencing revealed 99% Env amino acid sequence conservation; X4-only and dual-tropic strains had evolved independently from an early branch of parental SHIV-E1. To conclude, our primate model data reveal that SHIV-E1p5 recapitulates important aspects of HIV transmission and pathobiology in humans.IMPORTANCEUnderstanding the protective principles that lead to a safe, effective vaccine against HIV in nonhuman primate (NHP) models requires test viruses that allow the evaluation of anti-HIV envelope responses. Reduced HIV acquisition risk in RV144 has been linked to nonneutralizing IgG antibodies with a range of effector activities. Definitive experiments to decipher the mechanisms of the partial protection observed in RV144 require passive-immunization studies in NHPs with a relevant test virus. We have generated such a virus by insertingenvfrom an RV144 placebo recipient into a SHIV backbone with HIV-like LTRs. The final SHIV-E1p5 isolate, grown in rhesus monkey peripheral blood mononuclear cells, was mucosally transmissible and pathogenic. Earlier SHIV-E passages showed a coreceptor switch, again mimicking HIV biology in humans. Thus, our series of SHIV-E strains mirrors HIV transmission and disease progression in humans. SHIV-E1p5 represents a biologically relevant tool to assess prevention strategies.

2009 ◽  
Vol 84 (1) ◽  
pp. 340-351 ◽  
Author(s):  
Wuze Ren ◽  
Silvana Tasca ◽  
Ke Zhuang ◽  
Agegnehu Gettie ◽  
James Blanchard ◽  
...  

ABSTRACT We previously reported coreceptor switch in rhesus macaques inoculated intravenously with R5 simian-human immunodeficiency virus SF162P3N (SHIVSF162P3N). Whether R5-to-X4 virus evolution occurs in mucosally infected animals and in which anatomic site the switch occurs, however, were not addressed. We herein report a change in coreceptor preference in macaques infected intrarectally with SHIVSF162P3N. The switch occurred in infected animals with high levels of virus replication and undetectable antiviral antibody response and required sequence changes in the V3 loop of the gp120 envelope protein. X4 virus emergence was associated with an accelerated drop in peripheral CD4+ T-cell count but followed rather than preceded the onset of CD4+ T-cell loss. The conditions, genotypic requirements, and patterns of coreceptor switch in intrarectally infected animals were thus remarkably consistent with those found in macaques infected intravenously. They also overlapped with those reported for humans, suggestive of a common mechanism for coreceptor switch in the two hosts. Furthermore, two independent R5-to-X4 evolutionary pathways were identified in one infected animal, giving rise to dual-tropic and X4 viruses which differed in switch kinetics and tissue localization. The dual-tropic switch event predominated early, and the virus established infection in multiple tissues sites. In contrast, the switch to X4 virus occurred later, initiating and expanding mainly in peripheral lymph nodes. These findings help define R5 SHIVSF162P3N infection of rhesus macaques as a model to study the mechanistic basis, dynamics, and sites of HIV-1 coreceptor switch.


2008 ◽  
Vol 82 (22) ◽  
pp. 11181-11196 ◽  
Author(s):  
Meritxell Genescà ◽  
Pamela J. Skinner ◽  
Jung Joo Hong ◽  
Jun Li ◽  
Ding Lu ◽  
...  

ABSTRACT The presence, at the time of challenge, of antiviral effector T cells in the vaginal mucosa of female rhesus macaques immunized with live-attenuated simian-human immunodeficiency virus 89.6 (SHIV89.6) is associated with consistent and reproducible protection from pathogenic simian immunodeficiency virus (SIV) vaginal challenge (18). Here, we definitively demonstrate the protective role of the SIV-specific CD8+ T-cell response in SHIV-immunized monkeys by CD8+ lymphocyte depletion, an intervention that abrogated SHIV-mediated control of challenge virus replication and largely eliminated the SIV-specific T-cell responses in blood, lymph nodes, and genital mucosa. While in the T-cell-intact SHIV-immunized animals, polyfunctional and degranulating SIV-specific CD8+ T cells were present in the genital tract and lymphoid tissues from the day of challenge until day 14 postchallenge, strikingly, expansion of SIV-specific CD8+ T cells in the immunized monkeys was minimal and limited to the vagina. Thus, protection from uncontrolled SIV replication in animals immunized with attenuated SHIV89.6 is primarily mediated by CD8+ T cells that do not undergo dramatic systemic expansion after SIV challenge. These findings demonstrate that despite, and perhaps because of, minimal systemic expansion of T cells at the time of challenge, a stable population of effector-cytotoxic CD8+ T cells can provide significant protection from vaginal SIV challenge.


2004 ◽  
Vol 78 (2) ◽  
pp. 841-854 ◽  
Author(s):  
Kristina Abel ◽  
Lisa La Franco-Scheuch ◽  
Tracy Rourke ◽  
Zhong-Min Ma ◽  
Veronique de Silva ◽  
...  

ABSTRACT Although gamma interferon (IFN-γ) is a key mediator of antiviral defenses, it is also a mediator of inflammation. As inflammation can drive lentiviral replication, we sought to determine the relationship between IFN-γ-related host immune responses and challenge virus replication in lymphoid tissues of simian-human immunodeficiency virus 89.6 (SHIV89.6)-vaccinated and unvaccinated rhesus macaques 6 months after challenge with simian immunodeficiency virus SIVmac239. Vaccinated-protected monkeys had low tissue viral RNA (vRNA) levels, vaccinated-unprotected animals had moderate tissue vRNA levels, and unvaccinated animals had high tissue vRNA levels. The long-term challenge outcome in vaccinated monkeys was correlated with the relative balance between SIV-specific IFN-γ T-cell responses and nonspecific IFN-γ-driven inflammation. Vaccinated-protected monkeys had slightly increased tissue IFN-γ mRNA levels and a high frequency of IFN-γ-secreting T cells responding to in vitro SIVgag peptide stimulation; thus, it is likely that they could develop effective anti-SIV cytotoxic T lymphocytes in vivo. In contrast, both high tissue IFN-γ mRNA levels and strong in vitro SIV-specific IFN-γ T-cell responses were detected in lymphoid tissues of vaccinated-unprotected monkeys. Unvaccinated monkeys had increased tissue IFN-γ mRNA levels but weak in vitro anti-SIV IFN-γ T-cell responses. In addition, in lymphoid tissues of vaccinated-unprotected and unvaccinated monkeys, the increased IFN-γ mRNA levels were associated with increased Mig/CXCL9, IP-10/CXCL10, and CXCR3 mRNA levels, suggesting that increased Mig/CXCL9 and IP-10/CXCL10 expression resulted in recruitment of CXCR3+ activated T cells. Thus, IFN-γ-driven inflammation promotes SIV replication in vaccinated-unprotected and unvaccinated monkeys. Unlike all unvaccinated monkeys, most monkeys vaccinated with SHIV89.6 did not develop IFN-γ-driven inflammation, but they did develop effective antiviral CD8+-T-cell responses.


2000 ◽  
Vol 74 (15) ◽  
pp. 6935-6945 ◽  
Author(s):  
Yasuyuki Endo ◽  
Tatsuhiko Igarashi ◽  
Yoshiaki Nishimura ◽  
Charles Buckler ◽  
Alicia Buckler-White ◽  
...  

ABSTRACT A highly pathogenic simian/human immunodeficiency virus (SHIV), SHIVDH12R, isolated from a rhesus macaque that had been treated with anti-human CD8 monoclonal antibody at the time of primary infection with the nonpathogenic, molecularly cloned SHIVDH12, induced marked and rapid CD4+ T cell loss in all rhesus macaques intravenously inoculated with 1.0 50% tissue culture infective dose (TCID50) to 4.1 × 105 TCID50s of virus. Animals inoculated with 650 TCID50s of SHIVDH12R or more experienced irreversible CD4+ T lymphocyte depletion and developed clinical disease requiring euthanasia between weeks 12 and 23 postinfection. In contrast, the CD4+ T-cell numbers in four of five monkeys receiving 25 TCID50s of SHIVDH12R or less stabilized at low levels, and these surviving animals produced antibodies capable of neutralizing SHIVDH12R. In the fifth monkey, no recovery from the CD4+ T cell decline occurred, and the animal had to be euthanized. Viral RNA levels, subsequent to the initial peak of infection but not at peak viremia, correlated with the virus inoculum size and the eventual clinical course. Both initial infection rate constants, k, and decay constants, d, were determined, but only the latter were statistically correlated to clinical outcome. The attenuating effects of reduced inoculum size were also observed when virus was inoculated by the mucosal route. Because the uncloned SHIVDH12R stock possessed the genetic properties of a lentivirus quasispecies, we were able to assess the evolution of the input virus swarm in animals surviving the acute infection by monitoring the emergence of neutralization escape viral variants.


1998 ◽  
Vol 72 (2) ◽  
pp. 1600-1605 ◽  
Author(s):  
Krista K. Steger ◽  
Marta Dykhuizen ◽  
Jacque L. Mitchen ◽  
Paul W. Hinds ◽  
Brenda L. Preuninger ◽  
...  

ABSTRACT Simian-human immunodeficiency virus 89.6PD (SHIV89.6PD) was pathogenic after intrarectal inoculation of rhesus macaques. Infection was achieved with a minimum of 2,500 tissue culture infectious doses of cell-free virus stock, and there was no evidence for transient viremia in animals receiving subinfectious doses by the intrarectal route. Some animals experienced rapid progression of disease characterized by loss of greater than 90% of circulating CD4+ T cells, sustained decreases in CD20+ B cells, failure to elicit virus-binding antibodies in plasma, and high levels of antigenemia. Slower-progressing animals had moderate but varying losses of CD4+ T cells; showed increases in circulating CD20+ B cells; mounted vigorous responses to antibodies in plasma, including neutralizing antibodies; and had low or undetectable levels of antigenemia. Rapid progression led to death within 30 weeks after intrarectal inoculation. Plasma antigenemia at 2 weeks after inoculation (P ≤ 0.002), B- and T-cell losses (P ≤ 0.013), and failure to seroconvert (P ≤ 0.005) were correlated statistically with rapid progression. Correlations were evident by 2 to 4 weeks after intrarectal SHIV inoculation, indicating that early events in the host-pathogen interaction determined the clinical outcome.


2002 ◽  
Vol 76 (8) ◽  
pp. 3800-3809 ◽  
Author(s):  
Peter Silvera ◽  
Max W. Richardson ◽  
Jack Greenhouse ◽  
Jake Yalley-Ogunro ◽  
Nigel Shaw ◽  
...  

ABSTRACT The regulatory proteins Nef, Rev, and Tat of human immunodeficiency virus type 1 (HIV-1) are attractive targets for vaccine development, since induction of effective immune responses targeting these early proteins may best control virus replication. Here we investigated whether vaccination with biologically active Tat or inactive Tat toxoid derived from HIV-1IIIB and simian-human immunodeficiency virus (SHIV) strain 89.6p would induce protective immunity in rhesus macaques. Vaccination induced high titers of anti-Tat immunoglobulin G in all immunized animals by week 7, but titers were somewhat lower in the 89.6p Tat group. Dominant B-cell epitopes mapped to the amino terminus, the basic domain, and the carboxy-terminal region. Tat-specific T-helper responses were detected in 50% of immunized animals. T-cell epitopes appeared to map within amino acids (aa) 1 to 24 and aa 37 to 66. In addition, Tat-specific gamma interferon responses were detected in CD4+ and/or CD8+ T lymphocytes in 11 of 16 immunized animals on the day of challenge. However, all animals became infected upon intravenous challenge with 30 50% minimal infective doses of SHIV 89.6p, and there were no significant differences in viral loads or CD4+ T-cell counts between immunized and control animals. Thus, vaccination with HIV-1IIIB or SHIV 89.6p Tat or with Tat toxoid preparations failed to confer protection against SHIV 89.6p infection despite robust Tat-specific humoral and cellular immune responses in some animals. Given its apparent immunogenicity, Tat may be more effective as a component of a cocktail vaccine in combination with other regulatory and/or structural proteins of HIV-1.


2004 ◽  
Vol 85 (10) ◽  
pp. 2915-2924 ◽  
Author(s):  
Gerrit Koopman ◽  
Daniella Mortier ◽  
Sam Hofman ◽  
Henk Niphuis ◽  
Zahra Fagrouch ◽  
...  

Candidate human immunodeficiency virus (HIV) vaccine strategies that induce strong cellular immune responses protect rhesus macaques that are infected with recombinant simian/human immunodeficiency virus SHIV89.6p from acute CD4+ T-cell loss and delay progression to AIDS. However, similar strategies have not proven as efficacious in the simian immunodeficiency virus (SIV)mac model of AIDS, an infection that causes a slow, steady loss of CD4+ T-cell function and numbers in rhesus macaques similar to that caused by HIV-1, the principal cause of AIDS in humans. Efforts to increase vaccine efficacy by repeated boosting with the same vector are quickly limited by rising anti-vector immune responses. Here, the sequential use of three different vectors (DNA, Semliki Forest virus and modified vaccinia virus Ankara) encoding the same SIVmac structural and regulatory antigens was investigated and demonstrated to prevent or slow the loss of CD4+ T-cells after mucosal challenge with the highly pathogenic SIVmac251 strain. Of particular interest was an inverse association between the extent of T-helper 2 cytokine responses and steady-state virus load. Although limited in the number of animals, this study provides important proof of the efficacy of the triple-vector vaccine strategy against chronic, progressive CD4+ T-cell loss in the rigorous SIVmac/rhesus macaque model of AIDS.


2018 ◽  
Vol 92 (11) ◽  
pp. e00222-18 ◽  
Author(s):  
Denise C. Hsu ◽  
Piyanate Sunyakumthorn ◽  
Matthew Wegner ◽  
Alexandra Schuetz ◽  
Decha Silsorn ◽  
...  

ABSTRACTStudies utilizing highly pathogenic simian immunodeficiency virus (SIV) and simian-human immunodeficiency virus (SHIV) have largely focused on the immunopathology of the central nervous system (CNS) during end-stage neurological AIDS and SIV encephalitis. However, this may not model pathophysiology in earlier stages of infection. In this nonaccelerated SHIV model, plasma SHIV RNA levels and peripheral blood and colonic CD4+T cell counts mirrored early human immunodeficiency virus (HIV) infection in humans. At 12 weeks postinfection, cerebrospinal fluid (CSF) detection of SHIV RNA and elevations in IP-10 and MCP-1 reflected a discrete neurovirologic process. Immunohistochemical staining revealed a diffuse, low-level CD3+CD4−cellular infiltrate in the brain parenchyma without a concomitant increase in CD68/CD163+monocytes, macrophages, and activated microglial cells. Rare SHIV-infected cells in the brain parenchyma and meninges were identified by RNAScopein situhybridization. In the meninges, there was also a trend toward increased CD4+infiltration in SHIV-infected animals but no differences in CD68/CD163+cells between SHIV-infected and uninfected control animals. These data suggest that in a model that closely recapitulates human disease, CNS inflammation and SHIV in CSF are predominantly mediated by T cell-mediated processes during early infection in both brain parenchyma and meninges. Because SHIV expresses an HIV rather than SIV envelope, this model could inform studies to understand potential HIV cure strategies targeting the HIV envelope.IMPORTANCEAnimal models of the neurologic effects of HIV are needed because brain pathology is difficult to assess in humans. Many current models focus on the effects of late-stage disease utilizing SIV. In the era of antiretroviral therapy, manifestations of late-stage HIV are less common. Furthermore, new interventions, such as monoclonal antibodies and therapeutic vaccinations, target HIV envelope. We therefore describe a new model of central nervous system involvement in rhesus macaques infected with SHIV expressing HIV envelope in earlier, less aggressive stages of disease. Here, we demonstrate that SHIV mimics the early clinical course in humans and that early neurologic inflammation is characterized by predominantly T cell-mediated inflammation accompanied by SHIV infection in the brain and meninges. This model can be utilized to assess the effect of novel therapies targeted to HIV envelope on reducing brain inflammation before end-stage disease.


2002 ◽  
Vol 76 (19) ◽  
pp. 10038-10043 ◽  
Author(s):  
Michael J. Caulfield ◽  
Su Wang ◽  
Jeffrey G. Smith ◽  
Timothy W. Tobery ◽  
Xu Liu ◽  
...  

ABSTRACT We examined the influence of dose and method of antigen delivery on the dynamics and durability of T-cell responses to candidate human immunodeficiency virus (HIV) vaccines. Codon-optimized sequences from the HIV gag gene were inserted into alternative DNA vaccine vectors to express the coding sequence with or without the tissue plasminogen activator leader sequence. We delivered the vaccines by intramuscular injection as plasmid DNA without adjuvant or as plasmid DNA formulated with a novel block copolymer adjuvant (CRL8623) and then monitored the ensuing T-cell responses by using a gamma interferon enzyme-linked immunospot assay. We demonstrated persistence of the cell-mediated immune (CMI) response in rhesus macaques for at least 18 months following a four-dose vaccination regimen. The plasmid vaccine, with or without CRL8623, was immunogenic in macaques; however, the form coadministered with adjuvant exhibited improved T-cell responses, with a bias toward more antigen-specific CD8+ T cells. Finally, we examined the fine specificity of the T-cell response to the gag vaccines by testing the response of 23 vaccinated macaques to individual Gag 20-mer peptides. Collectively, the monkeys responded to 25 epitopes, and, on average, each monkey recognized a minimum of 2.7 epitopes. The results indicate that a broad and durable CMI response to HIV DNA vaccines can be induced in a relevant nonhuman primate model.


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