Transient Immune Activation in BCG-Vaccinated Infant Rhesus Macaques Is Not Sufficient to Influence Oral Simian Immunodeficiency Virus Infection.
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ABSTRACT:
SUBMITTER: Wood MP
PROVIDER: S-EPMC7457186 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:NK cell responses to HIV/SIV infection have been well studied in acute and chronic infected patients/monkeys, but little is known about NK cells during viral transmission, particularly in mucosal tissues. In this article, we report a systematic study of NK cell responses to high-dose vaginal exposure to SIVmac251 in the rhesus macaque female reproductive tract (FRT). Small numbers of NK cells were recruited into the FRT mucosa following vaginal inoculation. The influx of mucosal NK cells preceded local virus replication and peaked at 1 wk and, thus, was in an appropriate time frame to control an expanding population of infected cells at the portal of entry. However, NK cells were greatly outnumbered by recruited target cells that fuel local virus expansion and were spatially dissociated from SIV RNA+ cells at the major site of expansion of infected founder populations in the transition zone and adjoining endocervix. The number of NK cells in the FRT mucosa decreased rapidly in the second week, while the number of SIV RNA+ cells in the FRT reached its peak. Mucosal NK cells produced IFN-? and MIP-1?/CCL3 but lacked several markers of activation and cytotoxicity, and this was correlated with inoculum-induced upregulation of the inhibitory ligand HLA-E and downregulation of the activating receptor CD122/IL-2R?. Examination of SIV?nef-vaccinated monkeys suggested that recruitment of NK cells to the genital mucosa was not involved in vaccine-induced protection from vaginal challenge. In summary, our results suggest that NK cells play, at most, a limited role in defenses in the FRT against vaginal challenge.
| S-EPMC4083479 | biostudies-literature
Project description:Enteropathogenic Escherichia coli (EPEC) was recognized as a common opportunistic pathogen of simian immunodeficiency virus-infected rhesus macaques (Macaca mulatta) with AIDS. Retrospective analysis revealed that 27 of 96 (28.1%) animals with AIDS had features of EPEC infection, and EPEC was the most frequent pathogen of the gastrointestinal tract identified morphologically. In 7.3% of animals dying with AIDS, EPEC represented the sole opportunistic agent of the gastrointestinal tract at death. In 20.8% of cases, it was seen in combination with one or more gastrointestinal pathogens, including Cryptosporidium parvum, Enterocytozoon bieneusi, Mycobacterium avium, Entamoeba histolytica, Balantidium coli, Strongyloides stercoralis, cytomegalovirus, and adenovirus. Clinically, infection was associated with persistent diarrhea and wasting and was more frequent in animals that died at under 1 year of age (P < 0.001, Fisher exact test). The organism was associated with the characteristic attaching and effacing lesion in colonic tissue sections and produced a focal adherence pattern on a HEp-2 assay but was negative for Shiga toxin production as assessed by PCR and a HeLa cell cytotoxicity assay. A 2.6-kb fragment encompassing the intimin gene was amplified and sequenced and revealed 99.2% identity to sequences obtained from human isolates (GenBank AF116899) corresponding to the epsilon intimin subtype. Further investigations with rhesus macaques may offer opportunities to study the impact of EPEC on AIDS pathogenesis and gastrointestinal dysfunction.
| S-EPMC87859 | biostudies-literature
Project description:Mother-to-child transmission of human immunodeficiency virus type 1 (HIV-1) via breastfeeding is responsible for nearly half of new infections of children with HIV. Although innate lymphoid cells (ILC) and natural killer (NK) cells are found throughout the oral mucosae, the effects of HIV/simian-human immunodeficiency virus (SHIV) in these tissues are largely unknown. To better understand the mechanics of postnatal transmission, we performed a comprehensive study of simian immunodeficiency virus (SIV)/SHIV-infected infant rhesus macaques (RM) and tracked changes in frequency, trafficking, and function of group 3 ILC (ILC3) and NK cells using polychromatic flow cytometry and cell stimulation assays in colon, tonsil, and oral lymph node samples. Infection led to a 3-fold depletion of ILC3 in the colon and an increase in the levels of NK cells in tonsils and oral lymph nodes. ILC3 and NK cells exhibited alterations in their trafficking repertoires as a result of infection, with increased expression of CD103 in colon NK cells and curtailment of CXCR3, and a significant decrease in ?4?7 expression in colon ILC3. SPICE analyses revealed that ILC3 and NK cells displayed distinct functional profiles by tissue in naive samples. Infection perturbed these profiles, with a nearly total loss of interleukin-22 (IL-22) production in the tonsil and colon; an increase in the levels of CD107a, gamma interferon (IFN-?), and tumor necrosis factor alpha (TNF-?) from ILC3; and an increase in the levels of CD107a, macrophage inflammatory protein 1 beta (MIP-1?), and TNF-? from NK cells. Collectively, these data reveal that lentivirus infection alters the frequencies, receptor repertoires, and functions of innate cells in the oral and gut mucosa of infants. Further study will be required to delineate the full extent of the effect that these changes have on oral and gut homeostasis, SHIV/SIV pathogenesis, and oral opportunistic disease.IMPORTANCE Vertical transmission of HIV from mother to child accounts for many of the new cases seen worldwide. There is currently no vaccine to mitigate this transmission, and there has been limited research on the effects that lentiviral infection has on the innate immune system in oral tissues of infected children. To fill this knowledge gap, our laboratory studied infant rhesus macaques to evaluate how acute SIV/SHIV infections impacted ILC3 and NK cells, which are immune cells critical for mucosal homeostasis and antimicrobial defense. Our data revealed that SIV/SHIV infection led to a depletion of ILC3 and an increase of NK cells and to a functional shift from a homeostatic to a multifunctional proinflammatory state. Taking the results together, we describe how lentiviral infection perturbs the oral and gastrointestinal mucosae of infant macaques through alterations of resident innate immune cells giving rise to chronic inflammation and potentially exacerbating morbidity and mortality in children living with HIV.
| S-EPMC7022363 | biostudies-literature
Project description:Our goal is to develop a pediatric combination vaccine to protect the vulnerable infant population against human immunodeficiency virus type 1 (HIV-1) and tuberculosis (TB) infections. The vaccine consists of an auxotroph Mycobacterium tuberculosis strain that coexpresses HIV antigens. Utilizing an infant rhesus macaque model, we have previously shown that this attenuated M. tuberculosis (AMtb)-simian immunodeficiency virus (SIV) vaccine is immunogenic, and although the vaccine did not prevent oral SIV infection, a subset of vaccinated animals was able to partially control virus replication. However, unexpectedly, vaccinated infants required fewer SIV exposures to become infected compared to naive controls. Considering that the current TB vaccine, Mycobacterium bovis bacillus Calmette-Guérin (BCG), can induce potent innate immune responses and confer pathogen-unspecific trained immunity, we hypothesized that an imbalance between enhanced myeloid cell function and immune activation might have influenced the outcome of oral SIV challenge in AMtb-SIV-vaccinated infants. To address this question, we used archived samples from unchallenged animals from our previous AMtb-SIV vaccine studies and vaccinated additional infant macaques with BCG or AMtb only. Our results show that vaccinated infants, regardless of vaccine strain or regimen, had enhanced myeloid cell responses. However, CD4+ T cells were concurrently activated, and the persistence of these activated target cells in oral and/or gastrointestinal tissues may have facilitated oral SIV infection. Immune activation was more pronounced in BCG-vaccinated infant macaques than in AMtb-vaccinated infant macaques, indicating a role for vaccine attenuation. These findings underline the importance of understanding the interplay of vaccine-induced immunity and immune activation and its effect on HIV acquisition risk and outcome in infants.
| S-EPMC5216431 | biostudies-literature
Project description:Human cytomegalovirus (HCMV) possesses low pathogenic potential in an immunocompetent host. In the immunosuppressed host, however, a wide spectrum of infection outcomes, ranging from asymptomatic to life threatening, can follow either primary or nonprimary infection. The variability in the manifestations of HCMV infection in immunosuppressed individuals implies that there is a threshold of host antiviral immunity that can effectively limit disease potential. We used a nonhuman primate model of CMV infection to assess the relationship between CMV disease and the levels of developing anti-CMV immunity. Naive rhesus macaques were inoculated with rhesus cytomegalovirus (RhCMV) followed 2 or 11 weeks later by inoculation with pathogenic simian immunodeficiency virus SIVmac239. Two of four monkeys inoculated with SIV at 2 weeks after inoculation with RhCMV died within 11 weeks with simian AIDS (SAIDS), including activated RhCMV infection. Neither animal had detectable anti-SIV antibodies. The other two animals died 17 and 27 weeks after SIV inoculation with either SAIDS or early lymphoid depletion, although no histological evidence of activated RhCMV was observed. Both had weak anti-SIV antibody titers. RhCMV antibody responses for this group of monkeys were significantly below those of control animals inoculated with only RhCMV. In addition, all animals of this group had persistent RhCMV DNA in plasma and high copy numbers of RhCMV in tissues. In contrast, animals that were inoculated with SIV at 11 weeks after RhCMV infection rarely exhibited RhCMV DNA in plasma, had low copy numbers of RhCMV DNA in most tissues, and did not develop early onset of SAIDS or activated RhCMV. SIV antibody titers were mostly robust and sustained in these monkeys. SIV inoculation blunted further development of RhCMV humoral responses, unlike the normal pattern of development in control monkeys following RhCMV inoculation. Anti-RhCMV immunoglobulin G levels and avidity were slightly below control values, but levels maintained were higher than those observed following SIV infection at 2 weeks after RhCMV inoculation. These findings demonstrate that SIV produces long-lasting insults to the humoral immune system beginning very early after SIV infection. The results also indicate that anti-RhCMV immune development at 11 weeks after infection was sufficient to protect the host from acute RhCMV sequelae following SIV infection, in contrast to the lack of protection afforded by only 2 weeks of immune response to RhCMV. As previously observed, monkeys that were not able to mount a significant immune response to SIV were the most susceptible to SAIDS, including activated RhCMV infection. Rapid development of SAIDS in animals inoculated with SIV 2 weeks after RhCMV inoculation suggests that RhCMV can augment SIV pathogenesis, particularly during primary infection by both viruses.
| S-EPMC136401 | biostudies-literature
Project description:UnlabelledDespite significant progress in reducing peripartum mother-to-child transmission (MTCT) of human immunodeficiency virus (HIV) with antiretroviral therapy (ART), continued access to ART throughout the breastfeeding period is still a limiting factor, and breast milk exposure to HIV accounts for up to 44% of MTCT. As abstinence from breastfeeding is not recommended, alternative means are needed to prevent MTCT of HIV. We have previously shown that oral vaccination at birth with live attenuated Mycobacterium tuberculosis strains expressing simian immunodeficiency virus (SIV) genes safely induces persistent SIV-specific cellular and humoral immune responses both systemically and at the oral and intestinal mucosa. Here, we tested the ability of oral M. tuberculosis vaccine strains expressing SIV Env and Gag proteins, followed by systemic heterologous (MVA-SIV Env/Gag/Pol) boosting, to protect neonatal macaques against oral SIV challenge. While vaccination did not protect infant macaques against oral SIV acquisition, a subset of immunized animals had significantly lower peak viremia which inversely correlated with prechallenge SIV Env-specific salivary and intestinal IgA responses and higher-avidity SIV Env-specific IgG in plasma. These controller animals also maintained CD4(+) T cell populations better and showed reduced tissue pathology compared to noncontroller animals. We show that infants vaccinated at birth can develop vaccine-induced SIV-specific IgA and IgG antibodies and cellular immune responses within weeks of life. Our data further suggest that affinity maturation of vaccine-induced plasma antibodies and induction of mucosal IgA responses at potential SIV entry sites are associated with better control of viral replication, thereby likely reducing SIV morbidity.ImportanceDespite significant progress in reducing peripartum MTCT of HIV with ART, continued access to ART throughout the breastfeeding period is still a limiting factor. Breast milk exposure to HIV accounts for up to 44% of MTCT. Alternative measures, in addition to ART, are needed to achieve the goal of an AIDS-free generation. Pediatric HIV vaccines constitute a core component of such efforts. The results of our pediatric vaccine study highlight the potential importance of vaccine-elicited mucosal Env-specific IgA responses in combination with high-avidity systemic Env-specific IgG in protection against oral SIV transmission and control of viral replication in infant macaques. The induction of potent mucosal IgA antibodies by our vaccine is remarkable considering the age-dependent development of mucosal IgA responses postbirth. A deeper understanding of postnatal immune development may inform the design of improved vaccine strategies to enhance systemic and mucosal SIV/HIV antibody responses.
| S-EPMC4984660 | biostudies-literature
Project description:Lentiviral replication in its target cells affects a delicate balance between cellular cofactors required for virus propagation and immunoregulation for host defense. To better elucidate cellular proteins linked to viral infection, we tested plasma from rhesus macaques infected with the simian immunodeficiency viral strain SIVsmm9, prior to, 10 days (acute), and 49 weeks (chronic) after viral infection. Changes in plasma protein content were measured by quantitative mass spectrometry by isobaric tags for absolute and relative quantitation (iTRAQ) methods. An 81 and 232% increase in SERPINA1 was seen during acute and chronic infection, respectively. Interestingly, gelsolin, vitamin D binding protein and histidine rich glycoprotein were decreased by 45% in acute conditions but returned to baseline during chronic infection. When compared to uninfected controls, a 48-103% increase in leucine rich alpha 2-glycoprotein, vitronectin, and ceruloplasmin was observed during chronic viral infection. Observed changes in plasma proteins expression likely represent a compensatory host response to persistent viral infection.
| S-EPMC3285256 | biostudies-literature
Project description:Chimeric simian/human immunodeficiency viruses (SHIVs) that express the env genes derived from distinct HIV type 1 (HIV-1) isolates were tested for the ability to infect rhesus macaques following intravaginal inoculation. SHIVs containing either the HIV-1 HXBc2 or the HIV-1 89.6 envelope glycoproteins were capable of replicating in intravenously inoculated rhesus macaques. However, intravaginal inoculation of animals with these two SHIVs resulted in infection only with the SHIV containing the HIV-1 89.6 glycoprotein. Thus, properties conferred by the envelope glycoproteins in the chimeric virus affect the ability of particular SHIVs to initiate a systemic infection following vaginal inoculation. These results provide indirect support for the hypothesis that the selection of specific viral variants occurs in the genital tracts of individuals exposed to HIV by sexual contact.
| S-EPMC190165 | biostudies-other
Project description:In this study, we compared the immunogenicity and protection from repeated low-dose intrarectal SIVmac251 challenge in two groups of vaccinated RMs. Animals were immunized with live SIVmac239, which had been attenuated by a deletion of the nef sequence, or they were vaccinated twice with an E1-deleted AdHu5, expressing SIVmac239gag. The vaccinated animals and a cohort of unvaccinated control animals were then challenged 10 times in weekly intervals with low doses of SIVmac251 given rectally. Our results confirm previous studies showing that whereas SIV?nef provides some degree of protection against viral acquisition after repeated low-dose rectal SIVmac251 challenges, vaccination with an AdHu5gag vaccine designed to induce only antiviral T cell responses is ineffective. As immunological analyses of prechallenge, vaccine-induced T and B cell responses failed to reveal correlates of protection that distinguished the more susceptible from the more resistant vaccinated animals, we carried out RNA-Seq studies of paired pre- and postvaccination samples to identify transcriptional patterns that correlated with the differences in response. We show that gene expression signatures associated with the delayed SIV infection seen in some AdHu5gag recipients were largely present in prevaccination samples of those animals. In contrast, the responding SIV?nef-immunized animals showed a predominance of vaccine-induced changes, thus enabling us to define inherited and vaccine-induced gene expression signatures and their associated pathways that may play a role in preventing SIV acquisition.
| S-EPMC3579023 | biostudies-literature
Project description:TRIM5? is a natural resistance factor that binds retroviral capsid proteins and restricts virus replication. The B30.2/SPRY domain of TRIM5? is polymorphic in rhesus macaques, and some alleles are associated with reduced simian immunodeficiency virus (SIV) SIV(mac251) and SIV(smE543) replication in vivo. We determined the distribution of TRIM5? alleles by PCR and sequence analysis of the B30.2/SPRY domain in a cohort of 82 macaques. Thirty-nine of these macaques were mock vaccinated, 43 were vaccinated with either DNA-SIV/ALVAC-SIV/gp120, ALVAC-SIV/gp120, or gp120 alone, and all were exposed intrarectally to SIV(mac251) at one of three doses. We assessed whether the TRIM5? genotype of the macaques affected the replication of challenge virus by studying the number of SIV variants transmitted, the number of exposures required, the SIV(mac251) viral level in plasma and tissue, and the CD4(+) T-cell counts. Our results demonstrated that TRIM5? alleles, previously identified as restrictive for SIV(mac251) replication in vivo following intravenous exposure, did not affect SIV(mac251) replication following mucosal exposure, regardless of prior vaccination, challenge dose, or the presence of the protective major histocompatibility complex alleles (MamuA01(+), MamuB08(+), or MamuB017(+)). The TRIM5? genotype had no apparent effect on the number of transmitted variants or the number of challenge exposures necessary to infect the animals. DNA sequencing of the SIV(mac251) Gag gene of the two stocks used in our study revealed SIV(mac239)-like sequences that are predicted to be resistant to TRIM5? restriction. Thus, the TRIM5? genotype does not confound results of mucosal infection of rhesus macaques with SIV(mac251).
| S-EPMC3209340 | biostudies-literature