scholarly journals Cellular targets of infection and route of viral dissemination after an intravaginal inoculation of simian immunodeficiency virus into rhesus macaques.

1996 ◽  
Vol 183 (1) ◽  
pp. 215-225 ◽  
Author(s):  
A I Spira ◽  
P A Marx ◽  
B K Patterson ◽  
J Mahoney ◽  
R A Koup ◽  
...  

We used the simian immunodeficiency virus (SIV)/rhesus macaque model to study events that underlie sexual transmission of human immunodeficiency virus type 1 (HIV-1). Four female rhesus macaques were inoculated intravaginally with SIVmac251, and then killed 2, 5, 7, and 9 d later. A technique that detected polymerase chain reaction-amplified SIV in situ showed that the first cellular targets for SIV were in the lamina propria of the cervicovaginal mucosa, immediately subjacent to the epithelium. Phenotypic and localization studies demonstrated that many of the infected cells were likely to be dendritic cells. Within 2 d of inoculation, infected cells were identified in the paracortex and subcapsular sinus of the draining internal iliac lymph nodes. Subsequently, systemic dissemination of SIV was rapid, since culturable virus was detectable in the blood by day 5. From these results, we present a model for mucosal transmission of SIV and HIV-1.

2017 ◽  
Vol 91 (18) ◽  
Author(s):  
Christoph H. Fellinger ◽  
Matthew R. Gardner ◽  
Charles C. Bailey ◽  
Michael Farzan

ABSTRACT Rhesus macaques are used to model human immunodeficiency virus type 1 (HIV-1) infections, but they are not natural hosts of HIV-1 or any simian immunodeficiency virus (SIV). Rather, they became infected with SIV through cross-species transfer from sooty mangabeys in captivity. It has been shown that HIV-1 utilizes rhesus CD4 less efficiently than human CD4. However, the relative ability of SIV envelope glycoproteins to bind or utilize these CD4 orthologs has not been reported. Here we show that several SIV isolates, including SIVmac239, are more efficiently neutralized by human CD4-Ig (huCD4-Ig) than by the same molecule bearing rhesus CD4 domains 1 and 2 (rhCD4-Ig). An I39N mutation in CD4 domain 1, present in human and sooty mangabey CD4 orthologs, largely restored rhCD4-Ig neutralization of SIVmac239 and other SIV isolates. We further observed that SIVmac316, a derivative of SIVmac239, bound to and was neutralized by huCD4-Ig and rhCD4-Ig with nearly identical efficiencies. Introduction of two SIVmac316 CD4-binding site residues (G382R and H442Y) into the SIVmac239 envelope glycoprotein (Env) markedly increased its neutralization sensitivity to rhesus CD4-Ig without altering neutralization by human CD4-Ig, SIV neutralizing antibodies, or sera from SIV-infected macaques. These changes also allowed SIVmac239 Env to bind rhCD4-Ig more efficiently than huCD4-Ig. The variant with G382R and H442Y (G382R/H442Y variant) also infected cells expressing rhesus CD4 with markedly greater efficiency than did unaltered SIVmac239 Env. We propose that infections of rhesus macaques with SIVmac239 G382R/H442Y might better model some aspects of human infections. IMPORTANCE Rhesus macaque infection with simian immunodeficiency virus (SIV) has served as an important model of human HIV-1 infection. However, differences between this model and the human case have complicated the development of vaccines and therapies. Here we report the surprising observation that SIVmac239, a commonly used model virus, more efficiently utilizes human CD4 than the CD4 of rhesus macaques, whereas the closely related virus SIVmac316 uses both CD4 orthologs equally well. We used this insight to generate a form of SIVmac239 envelope glycoprotein (Env) that utilized rhesus CD4 more efficiently, while retaining its resistance to antibodies and sera from infected macaques. This Env can be used to make the rhesus model more similar in some ways to human infection, for example by facilitating infection of cells with low levels of CD4. This property may be especially important to efforts to eradicate latently infected cells.


2003 ◽  
Vol 198 (10) ◽  
pp. 1551-1562 ◽  
Author(s):  
Ronald S. Veazey ◽  
Per Johan Klasse ◽  
Thomas J. Ketas ◽  
Jacqueline D. Reeves ◽  
Michael Piatak ◽  
...  

Human immunodeficiency virus type 1 (HIV-1) fuses with cells after sequential interactions between its envelope glycoproteins, CD4 and a coreceptor, usually CC chemokine receptor 5 (CCR5) or CXC receptor 4 (CXCR4). CMPD 167 is a CCR5-specific small molecule with potent antiviral activity in vitro. We show that CMPD 167 caused a rapid and substantial (4–200-fold) decrease in plasma viremia in six rhesus macaques chronically infected with simian immunodeficiency virus (SIV) strains SIVmac251 or SIVB670, but not in an animal infected with the X4 simian–human immunodeficiency virus (SHIV), SHIV-89.6P. In three of the SIV-infected animals, viremia reduction was sustained. In one, there was a rapid, but partial, rebound and in another, there was a rapid and complete rebound. There was a substantial delay (>21 d) between the end of therapy and the onset of full viremia rebound in two animals. We also evaluated whether vaginal administration of gel-formulated CMPD 167 could prevent vaginal transmission of the R5 virus, SHIV-162P4. Complete protection occurred in only 2 of 11 animals, but early viral replication was significantly less in the 11 CMPD 167-recipients than in 9 controls receiving carrier gel. These findings support the development of small molecule CCR5 inhibitors as antiviral therapies, and possibly as components of a topical microbicide to prevent HIV-1 sexual transmission.


2015 ◽  
Vol 90 (4) ◽  
pp. 1880-1887 ◽  
Author(s):  
S. Abigail Smith ◽  
Katie M. Kilgore ◽  
Sudhir Pai Kasturi ◽  
Bali Pulendran ◽  
Eric Hunter ◽  
...  

ABSTRACTMucosal surfaces are vulnerable to human immunodeficiency virus (HIV)/simian immunodeficiency virus (SIV) infection and thus are key sites for eliciting vaccine-mediated protection. Vaccine protocols carried out at the Yerkes Primate Research Center utilized SIVmac239-based immunization strategies with intrarectal and intravaginal SIVsmE660 challenge of rhesus macaques. We investigated whether there were genetic signatures associated with SIVsmE660 intrarectal and intravaginal transmissions in vaccinated and unvaccinated monkeys. When transmitted/founder (T/F) envelope (Env) sequences from 49 vaccinated and 15 unvaccinated macaques were compared to each other, we were unable to identify any vaccine breakthrough signatures. In contrast, when the vaccinated and control T/F Envs were combined and compared to the challenge stock, residues at gp120 positions 23, 45, 47, and 70 (Ile-Ala-Lys-Asn [I-A-K-N]) emerged as signatures of mucosal transmission. However, T/F Envs derived from intrarectal and intravaginal infections were not different. Our data suggest that the vaginal and rectal mucosal environments both imposed a strong selection bias for SIVsmE660 variants carrying I-A-K-N that was not further enhanced by immunization. These findings, combined with the strong conservation of A-K-N in most HIV-2/SIVsmm isolates and the analogous residues in HIV-1/SIVcpz isolates, suggest that these residues confer increased transmission fitness to SIVsmE660.IMPORTANCEMost HIV-1 infections occur across a mucosal barrier, and it is therefore important to understand why these sites are vulnerable and how to protect them with a vaccine. To gain insight into these questions, we studied rhesus macaques that were vaccinated with SIVmac239 and unvaccinated controls to determine whether the SIVsmE660 viral variants that infected these two groups were different. We did not find differences between viral variants in the absence versus presence of vaccination-induced immunity, but we did find that the SIVsmE660 viral variants that infected the monkeys, regardless of vaccination, were different from the dominant population found in the viral challenge inoculum. Our data suggest that the mucosal environments of the vagina and rectum both impose a strong selection for the SIVsmE660 variants in the challenge inoculum that are most like SIV and HIVs that circulate in nature.


1999 ◽  
Vol 73 (1) ◽  
pp. 855-860 ◽  
Author(s):  
Linqi Zhang ◽  
Peter J. Dailey ◽  
Tian He ◽  
Agegnehu Gettie ◽  
Sebastian Bonhoeffer ◽  
...  

ABSTRACT Perturbation of the equilibrium between human immunodeficiency virus type 1 (HIV-1) and the infected host by administering antiretroviral agents has revealed the rapid turnover of both viral particles and productively infected cells. In this study, we used the infusion of simian immunodeficiency virus (SIV) particles into rhesus macaques to obtain a more accurate estimate of viral clearance in vivo. Consistently, exogenously infused virions were cleared from plasma with an extremely short half-life, on the order of minutes (a mean of 3.3 min). This new estimate is ∼100-fold lower than the upper bound of 6 h previously reported for HIV-1 in infected humans. In select animals, multiple tissues were collected at the completion of each experiment to track the potential sites of virion clearance. Detectable levels of SIV RNA were found in lymph nodes, spleen, lungs, and liver, but not in other tissues examined. However, only ∼1 to 10% or less of the infused virions were accounted for by the thorough tissue sampling, indicating that the vast majority of the infused particles must have been degraded over a short period of time. Should the rapid clearance of virions described here be applicable to infected patients, then HIV-1 production and thus the number of productively infected CD4+ T lymphocytes or the viral burst size must be proportionally higher than previous minimal estimates.


2010 ◽  
Vol 84 (14) ◽  
pp. 7083-7095 ◽  
Author(s):  
Mars Stone ◽  
Brandon F. Keele ◽  
Zhong-Min Ma ◽  
Elizabeth Bailes ◽  
Joseph Dutra ◽  
...  

ABSTRACT Single-genome amplification (SGA) and sequencing of HIV-1 RNA in plasma of acutely infected humans allows the identification and enumeration of transmitted/founder viruses responsible for productive systemic infection. Use of this strategy as a means for identifying transmitted viruses suggested that intrarectal simian immunodeficiency virus (SIV) inoculation of macaques recapitulates key features of human rectal infection. However, no studies have used the SGA strategy to identify vaginally transmitted virus(es) in macaques or to determine how early SIV diversification in vaginally infected animals compares with HIV-1 in humans. We used SGA to amplify 227 partial env sequences from a SIVmac251 challenge stock and from seven rhesus macaques at the earliest plasma viral RNA-positive time point after low- and high-dose intravaginal inoculation. Sequences were analyzed phylogenetically to determine the relationship of transmitted/founder viruses within and between each animal and the challenge stock. In each animal, discrete low-diversity env sequence lineages were evident, and these coalesced phylogenetically to identical or near-identical env sequences in the challenge stock, thus confirming the validity of the SGA sequencing and modeling strategy for identifying vaginally transmitted SIV. Between 1 and 10 viruses were responsible for systemic infection, similar to humans infected by sexual contact, and the set of viruses transmitted to the seven animals studied represented the full genetic constellation of the challenge stock. These findings recapitulate many of the features of sexual HIV-1 transmission in women. Furthermore, the SIV rhesus macaque model can be used to understand the factors that influence the transmission of single versus multiple SIV variants.


2019 ◽  
Vol 93 (21) ◽  
Author(s):  
Neil Almond ◽  
Neil Berry ◽  
Richard Stebbings ◽  
Mark Preston ◽  
Claire Ham ◽  
...  

ABSTRACT Vaccines aimed at inducing T cell responses to protect against human immunodeficiency virus (HIV) infection have been under development for more than 15 years. Replication-defective adenovirus (rAd) vaccine vectors are at the forefront of this work and have been tested extensively in the simian immunodeficiency virus (SIV) challenge macaque model. Vaccination with rAd vectors coding for SIV Gag or other nonenvelope proteins induces T cell responses that control virus load but disappointingly is unsuccessful so far in preventing infection, and attention has turned to inducing antibodies to the envelope. However, here we report that Mauritian cynomolgus macaques (MCM), Macaca fascicularis, vaccinated with unmodified SIV gag alone in a DNA prime followed by an rAd boost exhibit increased protection from infection by repeated intrarectal challenge with low-dose SIVmac251. There was no evidence of infection followed by eradication. A significant correlation was observed between cytokine expression by CD4 T cells and delayed infection. Vaccination with gag fused to the ubiquitin gene or fragmented, designed to increase CD8 magnitude and breadth, did not confer resistance to challenge or enhance immunity. On infection, a significant reduction in peak virus load was observed in all vaccinated animals, including those vaccinated with modified gag. These findings suggest that a nonpersistent viral vector vaccine coding for internal virus proteins may be able to protect against HIV type 1 (HIV-1) infection. The mechanisms are probably distinct from those of antibody-mediated virus neutralization or cytotoxic CD8 cell killing of virus-infected cells and may be mediated in part by CD4 T cells. IMPORTANCE The simian immunodeficiency virus (SIV) macaque model represents the best animal model for testing new human immunodeficiency virus type 1 (HIV-1) vaccines. Previous studies employing replication-defective adenovirus (rAd) vectors that transiently express SIV internal proteins induced T cell responses that controlled virus load but did not protect against virus challenge. However, we show for the first time that SIV gag delivered in a DNA prime followed by a boost with an rAd vector confers resistance to SIV intrarectal challenge. Other partially successful SIV/HIV-1 protective vaccines induce antibody to the envelope and neutralize the virus or mediate antibody-dependent cytotoxicity. Induction of CD8 T cells which do not prevent initial infection but eradicate infected cells before infection becomes established has also shown some success. In contrast, the vaccine described here mediates resistance by a different mechanism from that described above, which may reflect CD4 T cell activity. This could indicate an alternative approach for HIV-1 vaccine development.


2008 ◽  
Vol 82 (13) ◽  
pp. 6591-6599 ◽  
Author(s):  
Zandrea Ambrose ◽  
Lara Compton ◽  
Michael Piatak ◽  
Ding Lu ◽  
W. Gregory Alvord ◽  
...  

ABSTRACT The rising prevalence of human immunodeficiency virus type 1 (HIV-1) infection in women, especially in resource-limited settings, accentuates the need for accessible, inexpensive, and female-controlled preexposure prophylaxis strategies to prevent mucosal transmission of the virus. While many compounds can inactivate HIV-1 in vitro, evaluation in animal models for mucosal transmission of virus may help identify which approaches will be effective in vivo. Macaques challenged intravaginally with pathogenic simian immunodeficiency virus (SIVmac251) provide a model to preclinically evaluate candidate microbicides. 2-Hydroxypropyl-β-cyclodextrin (BCD) prevents HIV-1 and SIV infection of target cells at subtoxic doses in vitro. Consistent with these findings, intravaginal challenge of macaques with SIVmac251 preincubated with BCD prevented mucosal transmission, as measured by plasma viremia and antiviral antibodies, through 10 weeks postchallenge. In an initial challenge, BCD applied topically prior to SIVmac251 prevented intravaginal transmission of virus compared to controls (P < 0.0001). However, upon a second virus challenge following BCD pretreatment, the majority of the previously protected animals became infected. The mechanism through which animals become infected at a frequency similar to that of controls after prior exposure to BCD and SIVmac251 in subsequent intravaginal virus challenges (P = 0.63), despite the potent antiviral properties of BCD, remains to be determined. These results highlight the unpredictability of antiviral compounds as topical microbicides and suggest that repeated exposures to candidate treatments should be considered for in vivo evaluation.


2015 ◽  
Vol 89 (16) ◽  
pp. 8130-8151 ◽  
Author(s):  
Katie M. Kilgore ◽  
Megan K. Murphy ◽  
Samantha L. Burton ◽  
Katherine S. Wetzel ◽  
S. Abigail Smith ◽  
...  

ABSTRACTAntibodies that can neutralize diverse viral strains are likely to be an important component of a protective human immunodeficiency virus type 1 (HIV-1) vaccine. To this end, preclinical simian immunodeficiency virus (SIV)-based nonhuman primate immunization regimens have been designed to evaluate and enhance antibody-mediated protection. However, these trials often rely on a limited selection of SIV strains with extreme neutralization phenotypes to assess vaccine-elicited antibody activity. To mirror the viral panels used to assess HIV-1 antibody breadth, we created and characterized a novel panel of 14 genetically and phenotypically diverse SIVsm envelope (Env) glycoproteins. To assess the utility of this panel, we characterized the neutralizing activity elicited by four SIVmac239 envelope-expressing DNA/modified vaccinia virus Ankara vector- and protein-based vaccination regimens that included the immunomodulatory adjuvants granulocyte-macrophage colony-stimulating factor, Toll-like receptor (TLR) ligands, and CD40 ligand. The SIVsm Env panel exhibited a spectrum of neutralization sensitivity to SIV-infected plasma pools and monoclonal antibodies, allowing categorization into three tiers. Pooled sera from 91 rhesus macaques immunized in the four trials consistently neutralized only the highly sensitive tier 1a SIVsm Envs, regardless of the immunization regimen. The inability of vaccine-mediated antibodies to neutralize the moderately resistant tier 1b and tier 2 SIVsm Envs defined here suggests that those antibodies were directed toward epitopes that are not accessible on most SIVsm Envs. To achieve a broader and more effective neutralization profile in preclinical vaccine studies that is relevant to known features of HIV-1 neutralization, more emphasis should be placed on optimizing the Env immunogen, as the neutralization profile achieved by the addition of adjuvants does not appear to supersede the neutralizing antibody profile determined by the immunogen.IMPORTANCEMany in the HIV/AIDS vaccine field believe that the ability to elicit broadly neutralizing antibodies capable of blocking genetically diverse HIV-1 variants is a critical component of a protective vaccine. Various SIV-based nonhuman primate vaccine studies have investigated ways to improve antibody-mediated protection against a heterologous SIV challenge, including administering adjuvants that might stimulate a greater neutralization breadth. Using a novel SIV neutralization panel and samples from four rhesus macaque vaccine trials designed for cross comparison, we show that different regimens expressing the same SIV envelope immunogen consistently elicit antibodies that neutralize only the very sensitive tier 1a SIV variants. The results argue that the neutralizing antibody profile elicited by a vaccine is primarily determined by the envelope immunogen and is not substantially broadened by including adjuvants, resulting in the conclusion that the envelope immunogen itself should be the primary consideration in efforts to elicit antibodies with greater neutralization breadth.


2016 ◽  
Vol 90 (13) ◽  
pp. 6127-6139 ◽  
Author(s):  
Benjamin von Bredow ◽  
Juan F. Arias ◽  
Lisa N. Heyer ◽  
Brian Moldt ◽  
Khoa Le ◽  
...  

ABSTRACTAlthough antibodies to the human immunodeficiency virus type 1 (HIV-1) envelope glycoprotein have been studied extensively for their ability to block viral infectivity, little data are currently available on nonneutralizing functions of these antibodies, such as their ability to eliminate virus-infected cells by antibody-dependent cell-mediated cytotoxicity (ADCC). HIV-1 Env-specific antibodies of diverse specificities, including potent broadly neutralizing and nonneutralizing antibodies, were therefore tested for ADCC against cells infected with a lab-adapted HIV-1 isolate (HIV-1NL4-3), a primary HIV-1 isolate (HIV-1JR-FL), and a simian-human immunodeficiency virus (SHIV) adapted for pathogenic infection of rhesus macaques (SHIVAD8-EO). In accordance with the sensitivity of these viruses to neutralization, HIV-1NL4-3-infected cells were considerably more sensitive to ADCC, both in terms of the number of antibodies and magnitude of responses, than cells infected with HIV-1JR-FLor SHIVAD8-EO. ADCC activity generally correlated with antibody binding to Env on the surfaces of virus-infected cells and with viral neutralization; however, neutralization was not always predictive of ADCC, as instances of ADCC in the absence of detectable neutralization, and vice versa, were observed. These results reveal incomplete overlap in the specificities of antibodies that mediate these antiviral activities and provide insights into the relationship between ADCC and neutralization important for the development of antibody-based vaccines and therapies for combating HIV-1 infection.IMPORTANCEThis study provides fundamental insights into the relationship between antibody-dependent cell-mediated cytotoxicity (ADCC) and virus neutralization that may help to guide the development of antibody-based vaccines and immunotherapies for the prevention and treatment of HIV-1 infection.


2005 ◽  
Vol 79 (13) ◽  
pp. 8560-8571 ◽  
Author(s):  
Marie-Christine Dazza ◽  
Michel Ekwalanga ◽  
Monique Nende ◽  
Karhemere Bin Shamamba ◽  
Pitchou Bitshi ◽  
...  

ABSTRACT We report the identification of a new simian immunodeficiency virus (SIV), designated SIVden, in a naturally infected Dent's Mona monkey (Cercopithecus mona denti), which was kept as pet in Kinshasa, capital of the Democratic Republic of Congo. SIVden is genetically distinct from the previously characterized primate lentiviruses. Analysis of the full-length genomic sequence revealed the presence of a vpu open reading frame. This gene is also found in the virus lineage of human immunodeficiency virus type 1 (HIV-1) and chimpanzee immunodeficiency virus (SIVcpz) and was recently described in viruses isolated from Cercopithecus nictitans, Cercopithecus mona, and Cercopithecus cephus. The SIVden vpu coding region is shorter than the HIV-1/SIVcpz and the SIVgsn, SIVmon, and SIVmus counterparts. Unlike Pan troglodytes schweinfurthii viruses (SIVcpzPts) and Cercopithecus monkey viruses (SIVgsn, SIVmon, and SIVmus), the SIVden Vpu contains the characteristic DSGXES motif which was shown to be involved in Vpu-mediated CD4 and IκBα proteolysis in HIV-1 infected cells. Although it harbors a vpu gene, SIVden is phylogenetically closer to SIVdeb isolated from De Brazza's monkeys (Cercopithecus neglectus), which lacks a vpu gene, than to Cercopithecus monkey viruses, which harbor a vpu sequence.


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