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1.
Vaccine ; 42(5): 1122-1135, 2024 Feb 15.
Article in English | MEDLINE | ID: mdl-38262808

ABSTRACT

BACKGROUND: With SARS-CoV-2 continuing to evolve, there is a need to adapt COVID-19 vaccines to enhance mucosal immunity and better address immune-evasive variants. This pilot study was performed in mice and rhesus macaques to compare Advax-adjuvanted monovalent and bivalent recombinant spike protein vaccines, including when delivered via a combination of intramuscular (IM) and intrapulmonary (IPM) or oral routes. METHODS: Mice were first used to compare the immunogenicity of monovalent and bivalent vaccines containing a variety of spike protein variants. Then, rhesus macaques (n = 23) were divided into 5 groups to receive COVID-19 vaccines via different routes. Clinical signs, local vaccination site reactions, body weight, food consumption, serum, alveolar lavage, nasal and oral antibody levels, and nasal and alveolar lavage virus loads were assessed in response to a heterologous Omicron BA.5 virus challenge. RESULTS: The Wuhan + Mu bivalent vaccine gave the most broadly cross-neutralizing antibody responses. Robust serum neutralizing antibodies against Wuhan, Delta and Lambda variants were obtained, but BA.5 neutralizing antibodies were not detectable pre-challenge. Overall, the IM x3 and the IM x2 plus oral x2 vaccines delivered the best protection, with reduced lung virus load versus unimmunized controls across Days 2, 4 and 7. CONCLUSIONS: Advax-adjuvanted monovalent or bivalent recombinant spike protein vaccines given via parenteral and/or mucosal routes protected against a heterologous BA.5 challenge, despite absent serum BA.5 neutralizing antibody, pre-challenge. The possibility of using an oral Advax-adjuvanted protein booster to provide broad protection against newer SARS-CoV-2 variants warrants further investigation.


Subject(s)
COVID-19 Vaccines , COVID-19 , Animals , Humans , Mice , Macaca mulatta , Pilot Projects , Spike Glycoprotein, Coronavirus/genetics , COVID-19/prevention & control , SARS-CoV-2 , Adjuvants, Immunologic , Antibodies, Neutralizing , Protein Subunit Vaccines , Recombinant Proteins , Antibodies, Viral , Immunogenicity, Vaccine
2.
Mol Genet Metab ; 137(1-2): 192-200, 2022.
Article in English | MEDLINE | ID: mdl-36115282

ABSTRACT

Global COVID-19 pandemic is caused by infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Continuous emergence of new variants and their rapid spread are jeopardizing vaccine countermeasures to a significant extent. While currently available vaccines are effective at preventing illness associated with SARS-CoV-2 infection, these have been shown to be less effective at preventing breakthrough infection and transmission from a vaccinated individual to others. Here we demonstrate broad antiviral activity of cysteamine HCl in vitro against major emergent infectious variants of SARS-CoV-2 in a highly permissible Vero cell line. Cysteamine HCl inhibited infection of wild type, alpha, beta, gamma, delta, lambda, and omicron variants effectively. Cysteamine is a very well-tolerated US FDA-approved drug used chronically as a topical ophthalmic solution to treat ocular cystinosis in patients who receive it hourly or QID lifelong at concentrations 6 times higher than that required to inhibit SARS CoV-2 in tissue culture. Application of cysteamine as a topical nasal treatment can potentially1) mitigate existing infection 2) prevent infection in exposed individuals, and 3) limit the contagion in vulnerable populations.


Subject(s)
COVID-19 Drug Treatment , SARS-CoV-2 , Humans , Pandemics , Cysteamine/pharmacology , Antiviral Agents/pharmacology , Ophthalmic Solutions
4.
PLoS Pathog ; 16(3): e1008377, 2020 03.
Article in English | MEDLINE | ID: mdl-32163525

ABSTRACT

The recombinant Canarypox ALVAC-HIV/gp120/alum vaccine regimen was the first to significantly decrease the risk of HIV acquisition in humans, with equal effectiveness in both males and females. Similarly, an equivalent SIV-based ALVAC vaccine regimen decreased the risk of virus acquisition in Indian rhesus macaques of both sexes following intrarectal exposure to low doses of SIVmac251. Here, we demonstrate that the ALVAC-SIV/gp120/alum vaccine is also efficacious in female Chinese rhesus macaques following intravaginal exposure to low doses of SIVmac251 and we confirm that CD14+ classical monocytes are a strong correlate of decreased risk of virus acquisition. Furthermore, we demonstrate that the frequency of CD14+ cells and/or their gene expression correlates with blood Type 1 CD4+ T helper cells, α4ß7+ plasmablasts, and vaginal cytocidal NKG2A+ cells. To better understand the correlate of protection, we contrasted the ALVAC-SIV vaccine with a NYVAC-based SIV/gp120 regimen that used the identical immunogen. We found that NYVAC-SIV induced higher immune activation via CD4+Ki67+CD38+ and CD4+Ki67+α4ß7+ T cells, higher SIV envelope-specific IFN-γ producing cells, equivalent ADCC, and did not decrease the risk of SIVmac251 acquisition. Using the systems biology approach, we demonstrate that specific expression profiles of plasmablasts, NKG2A+ cells, and monocytes elicited by the ALVAC-based regimen correlated with decreased risk of virus acquisition.


Subject(s)
Killer Cells, Natural/immunology , Monocytes/immunology , SAIDS Vaccines/immunology , Simian Immunodeficiency Virus/immunology , Th1 Cells/immunology , Vaccination , Vagina/immunology , Viral Vaccines/immunology , Animals , Female , Killer Cells, Natural/pathology , Macaca mulatta , Monocytes/pathology , Th1 Cells/pathology
5.
PLoS Pathog ; 15(12): e1008121, 2019 12.
Article in English | MEDLINE | ID: mdl-31794588

ABSTRACT

The ALVAC-HIV clade B/AE and equivalent SIV-based/gp120 + Alum vaccines successfully decreased the risk of virus acquisition in humans and macaques. Here, we tested the efficacy of HIV clade B/C ALVAC/gp120 vaccine candidates + MF59 or different doses of Aluminum hydroxide (Alum) against SHIV-Cs of varying neutralization sensitivity in macaques. Low doses of Alum induced higher mucosal V2-specific IgA that increased the risk of Tier 2 SHIV-C acquisition. High Alum dosage, in contrast, elicited serum IgG to V2 that correlated with a decreased risk of Tier 1 SHIV-C acquisition. MF59 induced negligible mucosal antibodies to V2 and an inflammatory profile with blood C-reactive Protein (CRP) levels correlating with neutralizing antibody titers. MF59 decreased the risk of Tier 1 SHIV-C acquisition. The relationship between vaccine efficacy and the neutralization profile of the challenge virus appear to be linked to the different immunological spaces created by MF59 and Alum via CXCL10 and IL-1ß, respectively.


Subject(s)
Adjuvants, Immunologic/pharmacology , Alum Compounds/pharmacology , Antibodies, Neutralizing/immunology , SAIDS Vaccines/chemistry , SAIDS Vaccines/immunology , AIDS Vaccines/chemistry , AIDS Vaccines/immunology , Animals , Antibodies, Viral/immunology , Female , HIV Infections , Macaca mulatta , Simian Acquired Immunodeficiency Syndrome , Simian Immunodeficiency Virus , Viral Vaccines/chemistry , Viral Vaccines/immunology
6.
Mol Syst Biol ; 15(5): e8747, 2019 05 02.
Article in English | MEDLINE | ID: mdl-31048360

ABSTRACT

Characterizing the antigen-binding and innate immune-recruiting properties of the humoral response offers the chance to obtain deeper insights into mechanisms of protection than revealed by measuring only overall antibody titer. Here, a high-throughput, multiplexed Fab-Fc Array was employed to profile rhesus macaques vaccinated with a gp120-CD4 fusion protein in combination with different genetically encoded adjuvants, and subsequently subjected to multiple heterologous simian immunodeficiency virus (SIV) challenges. Systems analyses modeling protection and adjuvant differences using Fab-Fc Array measurements revealed a set of correlates yielding strong and robust predictive performance, while models based on measurements of response magnitude alone exhibited significantly inferior performance. At the same time, rendering Fab-Fc measurements mathematically independent of titer had relatively little impact on predictive performance. Similar analyses for a distinct SIV vaccine study also showed that Fab-Fc measurements performed significantly better than titer. These results suggest that predictive modeling with measurements of antibody properties can provide detailed correlates with robust predictive power, suggest directions for vaccine improvement, and potentially enable discovery of mechanistic associations.


Subject(s)
Antibodies, Viral/immunology , Immunoglobulin Fragments/immunology , SAIDS Vaccines/immunology , Simian Acquired Immunodeficiency Syndrome/prevention & control , Simian Immunodeficiency Virus/immunology , Animals , CD4-Positive T-Lymphocytes/cytology , Humans , Immunity, Humoral , Immunoglobulin G/immunology , Macaca mulatta , Membrane Glycoproteins/immunology , Multivariate Analysis , Viral Envelope Proteins/immunology
7.
J Virol ; 92(14)2018 07 15.
Article in English | MEDLINE | ID: mdl-29743361

ABSTRACT

The 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, env originates from clade E (HIV-E). We constructed a simian-human immunodeficiency virus (SHIV) chimera carrying env isolated 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.IMPORTANCE Understanding 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 inserting env from 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.


Subject(s)
Gene Products, env , HIV Infections/virology , HIV-1/pathogenicity , Leukocytes, Mononuclear/virology , Simian Acquired Immunodeficiency Syndrome/virology , Simian Immunodeficiency Virus/pathogenicity , Tropism , Animals , Humans , Macaca mulatta , Proviruses/genetics , Receptors, CCR5/metabolism , Thailand , Viral Load , Viremia , Virus Replication , Volunteers
8.
J Gen Virol ; 98(8): 2143-2155, 2017 Aug.
Article in English | MEDLINE | ID: mdl-28758637

ABSTRACT

The partial success of the RV144 trial underscores the importance of envelope-specific antibody responses for an effective HIV-1 vaccine. Oligomeric HIV-1 envelope proteins delivered with a potent adjuvant are expected to elicit strong antibody responses with broad neutralization specificity. To test this hypothesis, two SIV envelope proteins were formulated with delta inulin-based adjuvant (Advax) and used to immunize nonhuman primates. Oligomeric gp140-gp145 from SIVmac251 and SIVsmE660 was purified to homogeneity. Oligomers showed high-affinity interaction with CD4 and were highly immunogenic in rabbits, inducing Tier 2 SIV-neutralizing antibodies. The immunogenicity of an oligomeric Env DNA prime and protein boost together with Advax was evaluated in Chinese rhesus macaques. DNA administration elicited antibodies to both envelopes, and titres were markedly enhanced following homologous protein boosts via intranasal and intramuscular routes. Strong antibody responses were detected against the V1 and V2 domains of gp120. During peak immune responses, a low to moderate level of neutralizing activity was detected against Tier 1A/1B SIV isolates, with a moderate level noted against a Tier 2 isolate. Increased serum antibody affinity to SIVmac251 gp140 and generation of Env-specific memory B cells were observed in the immunized macaques. Animals were subjected to low-dose intravaginal challenge with SIVmac251 one week after the last protein boost. One out of three immunized animals was protected from infection. Although performed with a small number of macaques, this study demonstrates the utility of oligomeric envelopes formulated with Advax in eliciting broad antibody responses with the potential to provide protection against SIV transmission.


Subject(s)
Antibodies, Viral/immunology , DNA, Viral/immunology , HIV Envelope Protein gp120/immunology , HIV Infections/immunology , SAIDS Vaccines/immunology , Simian Immunodeficiency Virus/immunology , AIDS Vaccines , Adjuvants, Immunologic/administration & dosage , Animals , Antibodies, Neutralizing/immunology , DNA, Viral/administration & dosage , DNA, Viral/genetics , HIV Antibodies/immunology , HIV Envelope Protein gp120/administration & dosage , HIV Envelope Protein gp120/genetics , HIV Infections/prevention & control , HIV Infections/virology , HIV-1/genetics , HIV-1/immunology , Humans , Immunity, Humoral , Immunization, Secondary , Inulin/administration & dosage , Macaca mulatta , Rabbits , SAIDS Vaccines/administration & dosage , SAIDS Vaccines/genetics , Simian Immunodeficiency Virus/genetics , Vaccination
9.
J Med Primatol ; 45(5): 215-21, 2016 10.
Article in English | MEDLINE | ID: mdl-27646719

ABSTRACT

BACKGROUND: Non-human primates infected with simian immunodeficiency virus (SIV) represent a robust model to evaluate pre-clinical efficacy of HIV-1 preventive strategies and to determine the size of reservoir. METHODS: We developed a real-time qPCR assay to specifically quantify episomal 2-LTR circular DNA in peripheral blood mononuclear cells and brain tissues from SIV-infected macaques. RESULTS: This assay has sensitivity, accuracy and reproducibility over seven orders of magnitude. High copy numbers of SIV 2-LTR circles were correlated to high proviral DNA levels in brains of two SIV encephalitic animals. In contrast, no 2-LTR circles were detectable in two SIV-infected animals with no sign of encephalitis or two animals that had mild encephalitis with low levels of proviral DNA. CONCLUSIONS: These results suggest that simultaneous application of total proviral DNA and 2-LTR circle assays provides quantitative evaluation of pathogenesis and outcome of SIV infection in macaques.


Subject(s)
DNA, Circular/genetics , DNA, Viral/genetics , Proviruses/genetics , Real-Time Polymerase Chain Reaction , Simian Acquired Immunodeficiency Syndrome/virology , Simian Immunodeficiency Virus/genetics , Animals , Base Sequence , Brain/virology , Female , Leukocytes, Mononuclear/virology , Male , Reproducibility of Results , Sequence Alignment
10.
J Virol ; 90(19): 8435-53, 2016 10 01.
Article in English | MEDLINE | ID: mdl-27412591

ABSTRACT

UNLABELLED: Currently available simian immunodeficiency virus (SIV) infectious molecular clones (IMCs) and isolates used in nonhuman primate (NHP) models of AIDS were originally derived from infected macaques during chronic infection or end stage disease and may not authentically recapitulate features of transmitted/founder (T/F) genomes that are of particular interest in transmission, pathogenesis, prevention, and treatment studies. We therefore generated and characterized T/F IMCs from genetically and biologically heterogeneous challenge stocks of SIVmac251 and SIVsmE660. Single-genome amplification (SGA) was used to identify full-length T/F genomes present in plasma during acute infection resulting from atraumatic rectal inoculation of Indian rhesus macaques with low doses of SIVmac251 or SIVsmE660. All 8 T/F clones yielded viruses that were infectious and replication competent in vitro, with replication kinetics similar to those of the widely used chronic-infection-derived IMCs SIVmac239 and SIVsmE543. Phenotypically, the new T/F virus strains exhibited a range of neutralization sensitivity profiles. Four T/F virus strains were inoculated into rhesus macaques, and each exhibited typical SIV replication kinetics. The SIVsm T/F viruses were sensitive to TRIM5α restriction. All T/F viruses were pathogenic in rhesus macaques, resulting in progressive CD4(+) T cell loss in gastrointestinal tissues, peripheral blood, and lymphatic tissues. The animals developed pathological immune activation; lymphoid tissue damage, including fibrosis; and clinically significant immunodeficiency leading to AIDS-defining clinical endpoints. These T/F clones represent a new molecular platform for the analysis of virus transmission and immunopathogenesis and for the generation of novel "bar-coded" challenge viruses and next-generation simian-human immunodeficiency viruses that may advance the HIV/AIDS vaccine agenda. IMPORTANCE: Nonhuman primate research has relied on only a few infectious molecular clones for a myriad of diverse research projects, including pathogenesis, preclinical vaccine evaluations, transmission, and host-versus-pathogen interactions. With new data suggesting a selected phenotype of the virus that causes infection (i.e., the transmitted/founder virus), we sought to generate and characterize infectious molecular clones from two widely used simian immunodeficiency virus lineages (SIVmac251 and SIVsmE660). Although the exact requirements necessary to be a T/F virus are not yet fully understood, we generated cloned viruses with all the necessary characteristic of a successful T/F virus. The cloned viruses revealed typical acute and set point viral-load dynamics with pathological immune activation, lymphoid tissue damage progressing to significant immunodeficiency, and AIDS-defining clinical endpoints in some animals. These T/F clones represent a new molecular platform for studies requiring authentic T/F viruses.


Subject(s)
Genotype , Phenotype , Simian Acquired Immunodeficiency Syndrome/transmission , Simian Acquired Immunodeficiency Syndrome/virology , Simian Immunodeficiency Virus/genetics , Simian Immunodeficiency Virus/pathogenicity , Animals , Macaca mulatta , Simian Immunodeficiency Virus/classification , Simian Immunodeficiency Virus/isolation & purification , Virus Replication
11.
Clin Vaccine Immunol ; 23(7): 618-27, 2016 07.
Article in English | MEDLINE | ID: mdl-27193040

ABSTRACT

A promising concept for human immunodeficiency virus (HIV) vaccines focuses immunity on the highly conserved transition state structures and epitopes that appear when the HIV glycoprotein gp120 binds to its receptor, CD4. We are developing chimeric antigens (full-length single chain, or FLSC) in which gp120 and CD4 sequences are flexibly linked to allow stable intrachain complex formation between the two moieties (A. DeVico et al., Proc Natl Acad Sci U S A 104:17477-17482, 2007, doi:10.1073/pnas.0707399104; T. R. Fouts et al., J Virol 74:11427-11436, 2000, doi:10.1128/JVI.74.24.11427-11436.2000). Proof of concept studies with nonhuman primates show that FLSC elicited heterologous protection against simian-human immunodeficiency virus (SHIV)/simian immunodeficiency virus (SIV) (T. R. Fouts et al., Proc Natl Acad Sci U S A 112:E992-E999, 2016, doi:10.1073/pnas.1423669112), which correlated with antibodies against transition state gp120 epitopes. Nevertheless, advancement of any vaccine that comprises gp120-CD4 complexes must consider whether the CD4 component breaks tolerance and becomes immunogenic in the autologous host. To address this, we performed an immunotoxicology study with cynomolgus macaques vaccinated with either FLSC or a rhesus variant of FLSC containing macaque CD4 sequences (rhFLSC). Enzyme-linked immunosorbent assay (ELISA) binding titers, primary CD3(+) T cell staining, and temporal trends in T cell subset frequencies served to assess whether anti-CD4 autoantibody responses were elicited by vaccination. We find that immunization with multiple high doses of rhFLSC did not elicit detectable antibody titers despite robust responses to rhFLSC. In accordance with these findings, immunized animals had no changes in circulating CD4(+) T cell counts or evidence of autoantibody reactivity with cell surface CD4 on primary naive macaque T cells. Collectively, these studies show that antigens using CD4 sequences to stabilize transition state gp120 structures are unlikely to elicit autoimmune antibody responses, supporting the advancement of gp120-CD4 complex-based antigens, such as FLSC, into clinical testing.


Subject(s)
Autoantibodies/blood , CD4 Antigens/immunology , HIV Antibodies/blood , HIV Envelope Protein gp120/immunology , Recombinant Proteins/immunology , Animals , CD4 Antigens/genetics , CD4 Lymphocyte Count , Enzyme-Linked Immunosorbent Assay , Female , HIV Envelope Protein gp120/genetics , Macaca fascicularis , Male , Recombinant Proteins/genetics , T-Lymphocyte Subsets/immunology
12.
Vaccine ; 34(21): 2444-2452, 2016 05 05.
Article in English | MEDLINE | ID: mdl-27032514

ABSTRACT

The partial success of RV144 human clinical trial demonstrated that ALVAC prime/envelope protein boost vaccine regimen may represent a promising strategy for the development of an effective HIV-1 vaccine. Our earlier study demonstrated that a trimeric HIV-1 envelope gp145 from an Indian clade C isolate elicited cross clade neutralizing antibodies primarily towards Tier 1 isolates. In the present study, we examined the immunogenicity of DNA prime/envelope protein boost vaccine in rabbits using gp160 DNA of the Indian clade C isolate with various cytoplasmic tail truncations and trimeric gp145 protein. Cytoplasmic tail mutants of gp160 exposed epitopes that reacted strongly with a number of broadly neutralizing human monoclonal antibodies against HIV-1. Overall, envelope specific titers were found to be similar in all rabbit groups with higher pseudovirus neutralization in protein only immunized rabbits. The complete linear epitope mapping of rabbit immune sera revealed strong binding to C1, C2, V3, C3 and C4 domains of gp145. Importantly, reactivity of gp41 ecto-domain peptides was observed in DNA prime/protein boost sera but not in the sera of rabbits immunized with protein alone. Moreover, membrane anchored but not soluble envelope encoding DNA immunization elicited antibodies against linear epitopes on the conserved gp41 ecto-domain. Together, these results suggest that priming with DNA encoding cytoplasmic domains of Env alters the quality of antibodies elicited following protein boost and hence may be utilized to generate protective immunity by HIV-1 vaccine.


Subject(s)
AIDS Vaccines/immunology , Epitopes/immunology , HIV Antibodies/blood , HIV Envelope Protein gp160/immunology , HIV-1/immunology , Immunization, Secondary , Vaccines, DNA/immunology , Animals , Antibodies, Monoclonal , Antibodies, Neutralizing/blood , Antibodies, Neutralizing/immunology , Binding Sites, Antibody , Epitope Mapping , HIV Antibodies/immunology , HIV Envelope Protein gp120/genetics , HIV Envelope Protein gp120/immunology , HIV Envelope Protein gp160/chemistry , HIV Envelope Protein gp160/genetics , HIV-1/chemistry , Humans , Neutralization Tests , Rabbits , Vaccines, DNA/administration & dosage
13.
J Acquir Immune Defic Syndr ; 71(4): 353-8, 2016 Apr 01.
Article in English | MEDLINE | ID: mdl-26545123

ABSTRACT

OBJECTIVE: Few studies have examined the eclipse time of simian immunodeficiency virus/HIV infection through the anal route. We aimed to measure the eclipse time after SIVmac251 intrarectal inoculation, and to investigate the factor(s) associated with early dissemination. DESIGN: Forty macaques were intrarectally challenged with SIVmac251 3 times at 2-week intervals. METHODS: Plasma viral RNA was monitored at 4, 7, 11, 14, 21, and 28 days after infection. Rectal/vaginal tissues were obtained and tissue viral loads (VLs) were measured at day 14 postinfection. RESULTS: Of 40 macaques 26 (65%) had first detectable viral RNAs in the plasma at day 7 after the challenge that led to productive infection. Strikingly, 6 animals (15%) had detectable viral RNA in the plasma as early as at day 4. The Ki67 viral target CD4 T cells in the colorectal tissues were significantly higher in the early or middle-transmitter groups than those in the late-transmitter group. The rectal VL did not correlate with plasma VL at 14-day postinoculation, but did positively correlate with plasma VLs at days 21 and 28 postinfection. CONCLUSIONS: The median eclipse time after intrarectal challenge was 7 days, with a few early transmitters at 4 days. More rapid viral dissemination was associated with a high frequency of colorectal Ki67CCR5CD4T cells, which fuel the local viral replication. Furthermore, local viral replication in the colorectal tissue during the early stage might affect the plasma VL in a delayed manner. Therefore, to reduce/limit these target cells at the portal of viral entry is essential.


Subject(s)
Colon/cytology , Rectum/cytology , Simian Acquired Immunodeficiency Syndrome/virology , Simian Immunodeficiency Virus , T-Lymphocytes/classification , Virus Replication/physiology , Animals , Cell Proliferation , Colon/virology , Female , Macaca mulatta , Male , RNA, Viral/blood , Rectum/virology , T-Lymphocytes/physiology , Time Factors , Viral Load
14.
J Med Primatol ; 44(5): 263-74, 2015 Oct.
Article in English | MEDLINE | ID: mdl-26332118

ABSTRACT

BACKGROUND: Insights into the host factors that contribute to an effective antiviral immune response may be obtained by examining global gene expression in simian-human immunodeficiency virus (SHIV)-infected non-human primates that exhibit different virological outcomes. METHODS: Six chronically SHIV-infected macaques were rectally challenged with SIVmac251. Viral RNA and proviral DNA load in blood were measured. Gene expression profiles in CD4+ T cells were examined and compared between animals with different levels of infection following challenge. RESULTS AND CONCLUSIONS: Viral RNA was markedly controlled in four challenged animals, whereas two animals had persistent high viremia. Analysis of the gene expression profiles at early infection revealed gene expression signatures between protectors and non-protectors and identified potential protective biomarkers. Pathway analyses revealed that IFN pathway genes are down-regulated in protectors compared to unprotectors. This study suggests that high levels of expression of type 1 IFN-related genes may paradoxically promote virus replication.


Subject(s)
Antibodies, Viral/blood , Simian Acquired Immunodeficiency Syndrome/genetics , Simian Immunodeficiency Virus/immunology , Animals , CD4 Lymphocyte Count , Gene Expression Profiling , Leukocytes, Mononuclear/immunology , Leukocytes, Mononuclear/virology , Macaca mulatta , Male , Simian Acquired Immunodeficiency Syndrome/immunology , Simian Acquired Immunodeficiency Syndrome/virology , Simian Immunodeficiency Virus/isolation & purification , Simian Immunodeficiency Virus/physiology , Viremia
15.
PLoS Pathog ; 11(8): e1005101, 2015 Aug.
Article in English | MEDLINE | ID: mdl-26267144

ABSTRACT

Many viral infections, including HIV, exhibit sex-based pathogenic differences. However, few studies have examined vaccine-related sex differences. We compared immunogenicity and protective efficacy of monomeric SIV gp120 with oligomeric SIV gp140 in a pre-clinical rhesus macaque study and explored a subsequent sex bias in vaccine outcome. Each immunization group (16 females, 8 males) was primed twice mucosally with replication-competent Ad-recombinants encoding SIVsmH4env/rev, SIV239gag and SIV239nefΔ1-13 and boosted twice intramuscularly with SIVmac239 monomeric gp120 or oligomeric gp140 in MF59 adjuvant. Controls (7 females, 5 males) received empty Ad and MF59. Up to 9 weekly intrarectal challenges with low-dose SIVmac251 were administered until macaques became infected. We assessed vaccine-induced binding, neutralizing, and non-neutralizing antibodies, Env-specific memory B cells and plasmablasts/plasma cells (PB/PC) in bone marrow and rectal tissue, mucosal Env-specific antibodies, and Env-specific T-cells. Post-challenge, only one macaque (gp140-immunized) remained uninfected. However, SIV acquisition was significantly delayed in vaccinated females but not males, correlated with Env-specific IgA in rectal secretions, rectal Env-specific memory B cells, and PC in rectal tissue. These results extend previous correlations of mucosal antibodies and memory B cells with protective efficacy. The gp140 regimen was more immunogenic, stimulating elevated gp140 and cyclic V2 binding antibodies, ADCC and ADCP activities, bone marrow Env-specific PB/PC, and rectal gp140-specific IgG. However, immunization with gp120, the form of envelope immunogen used in RV144, the only vaccine trial to show some efficacy, provided more significant acquisition delay. Further over 40 weeks of follow-up, no gp120 immunized macaques met euthanasia criteria in contrast to 7 gp140-immunized and 2 control animals. Although males had higher binding antibodies than females, ADCC and ADCP activities were similar. The complex challenge outcomes may reflect differences in IgG subtypes, Fc glycosylation, Fc-R polymorphisms, and/or the microbiome, key areas for future studies. This first demonstration of a sex-difference in SIV vaccine-induced protection emphasizes the need for sex-balancing in vaccine trials. Our results highlight the importance of mucosal immunity and memory B cells at the SIV exposure site for protection.


Subject(s)
B-Lymphocytes/immunology , Intestinal Mucosa/immunology , SAIDS Vaccines/immunology , Sex Factors , Simian Acquired Immunodeficiency Syndrome/immunology , Animals , Antibodies, Viral/blood , Antibodies, Viral/immunology , Female , Immunity, Cellular/immunology , Immunity, Mucosal/immunology , Macaca mulatta , Male , Rectum , Simian Acquired Immunodeficiency Syndrome/prevention & control , Simian Immunodeficiency Virus/immunology
16.
J Med Primatol ; 44(5): 275-85, 2015 Oct.
Article in English | MEDLINE | ID: mdl-26075700

ABSTRACT

BACKGROUND: Recent preclinical studies have demonstrated the use of properly folded trimeric HIV-1 envelope proteins as immunogen for eliciting protecting immune response in macaques. METHODS: Trimeric gp145 protein of Indian clade C HIV-1 (93IN101) was characterized for antigenicity by evaluating its binding to sCD4, and several monoclonal antibodies to HIV-1 by bio-layer interferometry. Ten macaques were immunized four times with purified gp145 in adjuplex adjuvant, and serum antibodies were characterized for binding to gp145 and neutralization. Immunized macaques were subjected to weekly low-dose vaginal challenge with SHIV1157-ipEL-p for 8 weeks. RESULTS: Env protein elicited strong antibody response in macaques. Following challenge, seven of ten immunized macaques resisted challenge, while six of eight control animals were infected. CONCLUSIONS: Env proteins from a clade C Indian isolate can elicit protective immune response and therefore may be a candidate for inclusion in a multiclade-based HIV-1 vaccine.


Subject(s)
HIV-1/physiology , Macaca mulatta , Monkey Diseases/immunology , Viral Envelope Proteins/genetics , Animals , Molecular Sequence Data , Monkey Diseases/virology , Sequence Analysis, DNA , Viral Envelope Proteins/metabolism
17.
J Virol ; 89(15): 7521-35, 2015 Aug.
Article in English | MEDLINE | ID: mdl-25972547

ABSTRACT

UNLABELLED: Off-therapy control of viremia by HIV-infected individuals has been associated with two likely players: a restricted viral reservoir and an efficient cell-mediated immune response. We previously showed that a combination of highly suppressive antiretroviral therapy and two experimental drugs, i.e., auranofin and buthionine sulfoximine, was able to reduce the viral reservoir, elicit efficient cell-mediated antiviral responses, and induce intermittent posttherapy viral load control in chronically SIVmac251-infected macaques. We here show that the macaques that had received this drug combination and then stopped antiretroviral therapy were also able to maintain low numbers of activated CD4+ T cells at viral rebound. Moreover, these macaques consistently displayed low-level simian immunodeficiency virus (SIV) diversity, which was in line with the strong and broadly reactive cell-mediated immune responses against conserved Gag antigens. Extended follow-up showed that the two macaques that had received the complete drug combination remained healthy and did not develop AIDS in 2 years of follow-up after therapy suspension. This disease-free survival is longer than twice the average time of progression to AIDS in SIVmac251-infected rhesus macaques. These results suggest that limited numbers of activated T cells at viral rebound and subsequent development of broadly reactive cell-mediated responses may be interrelated in reducing the viral reservoir. IMPORTANCE: The HIV reservoir in CD4+ T cells represents one main obstacle to HIV eradication. Recent studies, however, show that a drastic reduction of this reservoir is insufficient for inducing a functional cure of AIDS. In the present work, we thoroughly studied and subjected to long-term follow-up two macaques showing intermittent control of the virus following suspension of antiretroviral therapy plus an experimental antireservoir treatment, i.e., the gold salt auranofin and the investigational chemotherapeutic agent buthionione sulfoximine (BSO). We found that these drugs were able to decrease the number of activated CD4+ T cells, which are preferential targets for HIV infection. Then, efficient immune responses against the virus were developed in the macaques, which remained healthy during 2 years of follow-up. This result may furnish another building block for future attempts to cure HIV/AIDS.


Subject(s)
HIV Infections/immunology , Simian Acquired Immunodeficiency Syndrome/immunology , Simian Immunodeficiency Virus/physiology , Animals , Antiviral Agents/administration & dosage , CD4-Positive T-Lymphocytes/immunology , CD4-Positive T-Lymphocytes/virology , Disease Models, Animal , Follow-Up Studies , Gene Products, gag , HIV Infections/drug therapy , HIV Infections/virology , Humans , Macaca mulatta , Simian Acquired Immunodeficiency Syndrome/drug therapy , Simian Acquired Immunodeficiency Syndrome/virology , Simian Immunodeficiency Virus/drug effects , Simian Immunodeficiency Virus/genetics , Viral Load
18.
J Virol ; 89(16): 8643-50, 2015 Aug.
Article in English | MEDLINE | ID: mdl-26018159

ABSTRACT

To evaluate antibody specificities induced by simian immunodeficiency virus (SIV) versus human immunodeficiency virus type 1 (HIV-1) envelope antigens in nonhuman primate (NHP), we profiled binding antibody responses to linear epitopes in NHP studies with HIV-1 or SIV immunogens. We found that, overall, HIV-1 Env IgG responses were dominated by V3, with the notable exception of the responses to the vaccine strain A244 Env that were dominated by V2, whereas the anti-SIVmac239 Env responses were dominated by V2 regardless of the vaccine regimen.


Subject(s)
Antibodies, Viral/immunology , Epitopes/genetics , HIV-1/immunology , Primates/immunology , Simian Immunodeficiency Virus/immunology , Viral Envelope Proteins/immunology , Animals , Antibodies, Viral/genetics , Antibody Specificity , Immunoglobulin G/blood , Microarray Analysis , Species Specificity
19.
J Biol Chem ; 290(14): 9195-208, 2015 Apr 03.
Article in English | MEDLINE | ID: mdl-25691567

ABSTRACT

Human immunodeficiency virus type 1 (HIV-1) isolates from India mainly belong to clade C and are quite distinct from clade C isolates from Africa in terms of their phylogenetic makeup, serotype, and sensitivity to known human broadly neutralizing monoclonal antibodies. Because many of these properties are associated with the envelope proteins of HIV-1, it is of interest to study the envelope proteins of Indian clade C isolates as part of the ongoing efforts to develop a vaccine against HIV-1. To this end, we purified trimeric uncleaved gp145 of a CCR5 tropic Indian clade C HIV-1 (93IN101) from the conditioned medium of 293 cells. The purified protein was shown to be properly folded with stable structure by circular dichroism. Conformational integrity was further demonstrated by its high affinity binding to soluble CD4, CD4 binding site antibodies such as b12 and VRC01, quaternary epitope-specific antibody PG9, and CD4-induced epitope-specific antibody 17b. Sera from rabbits immunized with gp145 elicited high titer antibodies to various domains of gp120 and neutralized a broad spectrum of clade B and clade C HIV-1 isolates. Similar to other clade B and clade C envelope immunogens, most of the Tier 1 neutralizing activity could be absorbed with the V3-specific peptide. Subsequent boosting of these rabbits with a clade B HIV-1 Bal gp145 resulted in an expanded breadth of neutralization of HIV-1 isolates. The present study strongly supports the inclusion of envelopes from Indian isolates in a future mixture of HIV-1 vaccines.


Subject(s)
HIV Antigens/immunology , HIV-1/immunology , Viral Envelope Proteins/immunology , Animals , Binding Sites , CHO Cells , Circular Dichroism , Cricetinae , Cricetulus , Enzyme-Linked Immunosorbent Assay , HEK293 Cells , Humans , Viral Envelope Proteins/metabolism
20.
Proc Natl Acad Sci U S A ; 112(9): E992-9, 2015 Mar 03.
Article in English | MEDLINE | ID: mdl-25681373

ABSTRACT

A guiding principle for HIV vaccine design has been that cellular and humoral immunity work together to provide the strongest degree of efficacy. However, three efficacy trials of Ad5-vectored HIV vaccines showed no protection. Transmission was increased in two of the trials, suggesting that this vaccine strategy elicited CD4+ T-cell responses that provide more targets for infection, attenuating protection or increasing transmission. The degree to which this problem extends to other HIV vaccine candidates is not known. Here, we show that a gp120-CD4 chimeric subunit protein vaccine (full-length single chain) elicits heterologous protection against simian-human immunodeficiency virus (SHIV) or simian immunodeficiency virus (SIV) acquisition in three independent rhesus macaque repeated low-dose rectal challenge studies with SHIV162P3 or SIVmac251. Protection against acquisition was observed with multiple formulations and challenges. In each study, protection correlated with antibody-dependent cellular cytotoxicity specific for CD4-induced epitopes, provided that the concurrent antivaccine T-cell responses were minimal. Protection was lost in instances when T-cell responses were high or when the requisite antibody titers had declined. Our studies suggest that balance between a protective antibody response and antigen-specific T-cell activation is the critical element to vaccine-mediated protection against HIV. Achieving and sustaining such a balance, while enhancing antibody durability, is the major challenge for HIV vaccine development, regardless of the immunogen or vaccine formulation.


Subject(s)
AIDS Vaccines/pharmacology , CD4-Positive T-Lymphocytes/immunology , HIV Antibodies/immunology , HIV Infections/prevention & control , Immunity, Cellular/drug effects , AIDS Vaccines/immunology , Animals , CD4 Antigens/genetics , CD4 Antigens/immunology , CD4 Antigens/pharmacology , CD4-Positive T-Lymphocytes/pathology , Disease Models, Animal , Female , HIV Envelope Protein gp120/genetics , HIV Envelope Protein gp120/immunology , HIV Envelope Protein gp120/pharmacology , HIV Infections/immunology , HIV Infections/pathology , Humans , Immunity, Humoral , Macaca mulatta , Male , Recombinant Fusion Proteins/genetics , Recombinant Fusion Proteins/immunology , Recombinant Fusion Proteins/pharmacology
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