scholarly journals Potent, Persistent Induction and Modulation of Cellular Immune Responses in Rhesus Macaques Primed with Ad5hr-Simian Immunodeficiency Virus (SIV) env/rev, gag, and/or nef Vaccines and Boosted with SIV gp120

2003 ◽  
Vol 77 (16) ◽  
pp. 8607-8620 ◽  
Author(s):  
L. Jean Patterson ◽  
Nina Malkevitch ◽  
Joel Pinczewski ◽  
David Venzon ◽  
Yuanmei Lou ◽  
...  
Keyword(s):  
Immune Responses ◽  
Simian Immunodeficiency Virus ◽  
Rhesus Macaques ◽  
Immune Recognition ◽  
Gene Products ◽  
Cellular Immune Responses ◽  
Immunodeficiency Virus ◽  
Ifn Γ ◽  
Cellular Immune ◽  
Persistently Infect

ABSTRACT Immunity elicited by multicomponent vaccines delivered by replication-competent Ad5hr-simian immunodeficiency virus (SIV) recombinants was systematically investigated. Rhesus macaques were immunized mucosally at weeks 0 and 12 with Ad5hr-SIVsmH4 env/rev, with or without Ad5hr-SIVmac239 gag or Ad5hr-SIVmac239 nef, or with all three recombinants. The total Ad5hr dosage was comparably adjusted among all animals with empty Ad5hr-ΔE3 vector. The macaques were boosted with SIV gp120 in monophosphoryl A-stable emulsion adjuvant at 24 and 36 weeks. Controls received Ad5hr-ΔE3 vector or adjuvant only. By ELISPOT analysis, all four SIV gene products elicited potent cellular immune responses that persisted 42 weeks post-initial immunization. Unexpectedly, modulation of this cellular immune response was observed among macaques receiving one, two, or three Ad5hr-SIV recombinants. Env responses were significantly enhanced throughout the immunization period in macaques immunized with Ad5hr-SIV env/rev plus Ad5hr-SIV gag and tended to be higher in macaques that also received Ad5hr-SIV nef. Macaques primed with all three recombinants displayed significant down-modulation in numbers of gamma interferon (IFN-γ)-secreting cells specific for SIV Nef, and the Env- and Gag-specific responses were also diminished. Modulation of antibody responses was not observed. Down-modulation was seen only during the period of Ad5hr-recombinant priming, not during subunit boosting, although SIV-specific IFN-γ-secreting cells persisted. The effect was not attributable to Ad5hr replication differences among immunization groups. Vaccine delivery via replication-competent live vectors, which can persistently infect new cells and continuously present low-level antigen, may be advantageous in overcoming competition among complex immunogens for immune recognition. Effects of current multicomponent vaccines on individual immune responses should be evaluated with regard to future vaccine design.

scholarly journals Th-1-Type Cytotoxic CD8+ T-Lymphocyte Responses to Simian Immunodeficiency Virus (SIV) Are a Consistent Feature of Natural SIV Infection in Sooty Mangabeys

2006 ◽  
Vol 80 (6) ◽  
pp. 2771-2783 ◽  
Author(s):  
Zichun Wang ◽  
Benjamin Metcalf ◽  
Ruy M. Ribeiro ◽  
Harold McClure ◽  
Amitinder Kaur
Keyword(s):  
T Lymphocytes ◽  
Immune Responses ◽  
Rhesus Macaques ◽  
Elispot Response ◽  
Cellular Immune Responses ◽  
Immunodeficiency Virus ◽  
Sooty Mangabeys ◽  
Siv Infection ◽  
Ifn Γ ◽  
Cellular Immune

ABSTRACT Sooty mangabeys are a natural host of simian immunodeficiency virus (SIV) that remain asymptomatic and do not exhibit increased immune activation or increased T-lymphocyte turnover despite sustained high levels of SIV viremia. In this study we asked whether an altered immune response to SIV contributes to the lack of immunopathology in sooty mangabeys as opposed to species with pathogenic lentivirus infection. SIV-specific cellular immune responses were investigated in a cohort of 25 sooty mangabeys with natural SIV infection. Gamma interferon (IFN-γ) enzyme-linked immunospot (ELISPOT) assay responses targeting a median of four SIV proteins were detected in all 25 mangabeys and were comparable in magnitude to those of 13 rhesus macaques infected with SIVmac251 for more than 6 months. As with rhesus macaques, Th2 ELISPOT responses to SIV were absent or >10-fold lower than the IFN-γ ELISPOT response to the same SIV protein. The SIV-specific ELISPOT response was predominantly mediated by CD8+ T lymphocytes; the frequency of circulating SIV-specific CD8+ T lymphocytes ranged between 0.11% and 3.26% in 13 mangabeys. Functionally, the SIV-specific CD8+ T lymphocytes were cytotoxic; secreted IFN-γ, tumor necrosis factor alpha, and macrophage inflammatory protein 1β; and had an activated effector phenotype. Although there was a trend toward higher frequencies of SIV-specific CD8+ T lymphocytes in mangabeys with lower viral loads, a significant inverse correlation between SIV viremia and SIV-specific cellular immunity was not detected. The consistent detection of Th1-type SIV-specific cellular immune responses in naturally infected sooty mangabeys suggests that immune attenuation is neither a feature of nor a requirement for maintenance of nonpathogenic SIV infection in its natural host.

scholarly journals Improved Protection of Rhesus Macaques against Intrarectal Simian Immunodeficiency Virus SIVmac251 Challenge by a Replication-Competent Ad5hr-SIVenv/rev and Ad5hr-SIVgag Recombinant Priming/gp120 Boosting Regimen

2003 ◽  
Vol 77 (15) ◽  
pp. 8354-8365 ◽  
Author(s):  
Jun Zhao ◽  
Joel Pinczewski ◽  
Victor R. Gómez-Román ◽  
David Venzon ◽  
V. S. Kalyanaraman ◽  
...  
Keyword(s):  
Immune Responses ◽  
Simian Immunodeficiency Virus ◽  
Rhesus Macaques ◽  
Acute Infection ◽  
Neutralizing Antibody ◽  
Antibody Activity ◽  
Viral Loads ◽  
Cellular Immune Responses ◽  
Immunodeficiency Virus ◽  
Cellular Immune

ABSTRACT In this study we investigated the ability of a replication-competent Ad5hr-SIVenv/rev and Ad5hr-SIVgag recombinant priming/gp120 boosting regimen to induce protective immunity in rhesus macaques against pathogenic simian immunodeficiency virusmac251. Immunization of macaques by two sequential administrations of the same recombinants by the same route resulted in boosting and persistence of SIV-specific cellular immune responses for 42 weeks past the initial immunization. Anti-SIV gp120 immunoglobulin G (IgG) and IgA antibodies were induced in secretory fluids, and all macaques exhibited serum neutralizing antibody activity. After intrarectal SIVmac251 challenge, all of the macaques became infected. However, relative protection, as assessed by statistically significant lower SIV viral loads in plasma at both acute infection and set point, was observed in 8 out of 12 immunized non-Mamu-A∗01 animals. Elevated mean cellular immune responses to Gag and Env, neutralizing antibody activity, and IgG and IgA binding antibody levels were observed in the eight protected macaques. Statistically significant correlations with protective outcome were observed for cellular immune responses to SIV Env and Gag and for SIV gp120-specific IgG antibodies in nasal and vaginal fluids. Two macaques that exhibited the greatest and most persistent viremia control also exhibited strong CD8+ T-cell antiviral activity. The results suggest that a spectrum of immune responses may be necessary for adequate control of viral replication and disease progression and highlight a potential role for nonneutralizing antibodies at mucosal sites.

scholarly journals Effect of CD8+ Lymphocyte Depletion on Virus Containment after Simian Immunodeficiency Virus SIVmac251 Challenge of Live Attenuated SIVmac239Δ3-Vaccinated Rhesus Macaques

2005 ◽  
Vol 79 (13) ◽  
pp. 8131-8141 ◽  
Author(s):  
Jörn E. Schmitz ◽  
R. Paul Johnson ◽  
Harold M. McClure ◽  
Kelledy H. Manson ◽  
Michael S. Wyand ◽  
...  
Keyword(s):  
Immune Responses ◽  
Simian Immunodeficiency Virus ◽  
Rhesus Macaques ◽  
Intravenous Route ◽  
Partial Control ◽  
Challenge Virus ◽  
Lymphocyte Depletion ◽  
Cellular Immune Responses ◽  
Immunodeficiency Virus ◽  
Cellular Immune

ABSTRACT Although live attenuated vaccines can provide potent protection against simian immunodeficiency virus (SIV) and simian-human immunodeficiency virus challenges, the specific immune responses that confer this protection have not been determined. To test whether cellular immune responses mediated by CD8+ lymphocytes contribute to this vaccine-induced protection, we depleted rhesus macaques vaccinated with the live attenuated virus SIVmac239Δ3 of CD8+ lymphocytes and then challenged them with SIVmac251 by the intravenous route. While vaccination did not prevent infection with the pathogenic challenge virus, the postchallenge levels of virus in the plasmas of vaccinated control animals were significantly lower than those for unvaccinated animals. The depletion of CD8+ lymphocytes at the time of challenge resulted in virus levels in the plasma that were intermediate between those of the vaccinated and unvaccinated controls, suggesting that CD8+ cell-mediated immune responses contributed to protection. Interestingly, at the time of challenge, animals expressing the Mamu-A*01 major histocompatibility complex class I allele showed significantly higher frequencies of SIV-specific CD8+ T-cell responses and lower neutralizing antibody titers than those in Mamu-A*01 − animals. Consistent with these findings, the depletion of CD8+ lymphocytes abrogated vaccine-induced protection, as judged by the peak postchallenge viremia, to a greater extent in Mamu-A*01 + than in Mamu-A*01 − animals. The partial control of postchallenge viremia after CD8+ lymphocyte depletion suggests that both humoral and cellular immune responses induced by live attenuated SIV vaccines can contribute to protection against a pathogenic challenge and that the relative contribution of each of these responses to protection may be genetically determined.

scholarly journals Induction of Neutralizing Antibodies and Gag-Specific Cellular Immune Responses to an R5 Primary Isolate of Human Immunodeficiency Virus Type 1 in Rhesus Macaques

2001 ◽  
Vol 75 (13) ◽  
pp. 5879-5890 ◽  
Author(s):  
David C. Montefiori ◽  
Jeffrey T. Safrit ◽  
Shari L. Lydy ◽  
Ashley P. Barry ◽  
Miroslawa Bilska ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Immune Responses ◽  
Neutralizing Antibodies ◽  
Rhesus Macaques ◽  
Cellular Immune Responses ◽  
Immunodeficiency Virus ◽  
Ifn Γ ◽  
Cellular Immune ◽  
Hiv 1

ABSTRACT The ability to generate antibodies that cross-neutralize diverse primary isolates is an important goal for human immunodeficiency virus type 1 (HIV-1) vaccine development. Most of the candidate HIV-1 vaccines tested in humans and nonhuman primates have failed in this regard. Past efforts have focused almost entirely on the envelope glycoproteins of a small number of T-cell line-adapted strains of the virus as immunogens. Here we assessed the immunogenicity of noninfectious virus-like particles (VLP) consisting of Gag, Pro (protease), and Env from R5 primary isolate HIV-1Bx08. Immunogens were delivered to rhesus macaques in the form of either purified VLP, recombinant DNA and canarypox (ALVAC) vectors engineered to express VLP, or a combination of these products. Seroconversion to Gag and Pro was detected in all of the immunized animals. Antibodies that could neutralize HIV-1Bx08 were detected in animals that received (i) coinoculations with DNABx08 and VLPBx08, (ii) DNABx08 followed by ALVACBx08 boosting, and (iii) VLPBx08 alone. The neutralizing antibodies were highly strain specific despite the fact that they did not appear to be directed to linear epitopes in the V3 loop. Virus-specific cellular immune responses also were generated, as judged by the presence of Gag-specific gamma interferon (IFN-γ)-producing cells. These cellular immune responses required the inclusion of DNABx08 in the immunization modality, since few or no IFN-γ-producing cells were detected in animals that received either VLPBx08 or ALVACBx08 alone. The results demonstrate the feasibility of generating neutralizing antibodies and cellular immune responses that target an R5 primary HIV-1 isolate by vaccination in primates.

Cellular immune responses in rhesus macaques infected rectally with low dose simian immunodeficiency virus

1994 ◽  
Vol 23 (2-3) ◽  
pp. 125-130 ◽  
Author(s):  
Maria S. Salvato ◽  
Peter Emau ◽  
Miroslav Malkovsky ◽  
Kevin T. Schultz ◽  
Eric Johnson ◽  
...  
Keyword(s):  
Immune Responses ◽  
Simian Immunodeficiency Virus ◽  
Low Dose ◽  
Rhesus Macaques ◽  
Cellular Immune Responses ◽  
Immunodeficiency Virus ◽  
Cellular Immune

scholarly journals Long-Lasting Decrease in Viremia in Macaques Chronically Infected with Simian Immunodeficiency Virus SIVmac251 after Therapeutic DNA Immunization

2006 ◽  
Vol 81 (4) ◽  
pp. 1972-1979 ◽  
Author(s):  
Agneta S. von Gegerfelt ◽  
Margherita Rosati ◽  
Candido Alicea ◽  
Antonio Valentin ◽  
Patricia Roth ◽  
...  
Keyword(s):  
Immune Responses ◽  
Simian Immunodeficiency Virus ◽  
Rhesus Macaques ◽  
Antiretroviral Drugs ◽  
Therapeutic Vaccination ◽  
Highly Pathogenic ◽  
Cellular Immune Responses ◽  
Immunodeficiency Virus ◽  
Cellular Immune ◽  
Dna Vectors

ABSTRACT Rhesus macaques chronically infected with highly pathogenic simian immunodeficiency virus (SIV) SIVmac251 were treated with antiretroviral drugs and vaccinated with combinations of DNA vectors expressing SIV antigens. Vaccination during therapy increased cellular immune responses. After the animals were released from therapy, the virus levels of 12 immunized animals were significantly lower (P = 0.001) compared to those of 11 animals treated with only antiretroviral drugs. Vaccinated animals showed a persistent increase in immune responses, thus indicating both a virological and an immunological benefit following DNA therapeutic vaccination. Several animals show a long-lasting decrease in viremia, suggesting that therapeutic vaccination may provide an additional benefit to antiretroviral therapy.

scholarly journals Induction of Cellular Immune Responses to Simian Immunodeficiency Virus Gag by Two Recombinant Negative-Strand RNA Virus Vectors

2004 ◽  
Vol 78 (17) ◽  
pp. 9366-9375 ◽  
Author(s):  
Yurie Nakaya ◽  
Takaaki Nakaya ◽  
Man-Seong Park ◽  
Jerome Cros ◽  
Jiro Imanishi ◽  
...  
Keyword(s):  
Immune Responses ◽  
Vaccinia Virus ◽  
Simian Immunodeficiency Virus ◽  
Rna Virus ◽  
Influenza Viruses ◽  
Gag Protein ◽  
Virus Vectors ◽  
Cellular Immune Responses ◽  
Immunodeficiency Virus ◽  
Cellular Immune

ABSTRACT A recombinant Newcastle disease virus (rNDV) expressing simian immunodeficiency virus (SIV) Gag protein (rNDV/SIVgag) was generated. The rNDV/SIVgag virus induced Gag-specific cellular immune responses in mice, leading to a specific anti-Gag antiviral immunity. This was evidenced by the inhibition of growth of recombinant vaccinia virus expressing an identical Gag antigen (rVac/SIVgag) but not of wild-type vaccinia virus in rNDV/SIVgag-immunized mice. Among intravenous, intraperitoneal, or intranasal immunization routes, intranasal administration induced the strongest protective response against challenge with rVac/SIVgag. We further demonstrated that these immune responses were greatly enhanced after booster immunization with recombinant influenza viruses expressing immunogenic portions of SIV Gag. The magnitude of the protective immune response correlated with the levels of cellular immune responses to Gag, which were still evident 9 weeks after immunization. These results suggest that rNDV and influenza virus vectors are suitable candidate vaccines against AIDS as well as against other infectious diseases.

scholarly journals Vaccine-Induced Cellular Immune Responses Reduce Plasma Viral Concentrations after Repeated Low-Dose Challenge with Pathogenic Simian Immunodeficiency Virus SIVmac239

2006 ◽  
Vol 80 (12) ◽  
pp. 5875-5885 ◽  
Author(s):  
Nancy A. Wilson ◽  
Jason Reed ◽  
Gnankang S. Napoe ◽  
Shari Piaskowski ◽  
Andy Szymanski ◽  
...  
Keyword(s):  
Immune Responses ◽  
Viral Replication ◽  
Simian Immunodeficiency Virus ◽  
Neutralizing Antibodies ◽  
Low Dose ◽  
Chronic Phase ◽  
Set Point ◽  
Cellular Immune Responses ◽  
Immunodeficiency Virus ◽  
Cellular Immune

ABSTRACT The goal of an AIDS vaccine regimen designed to induce cellular immune responses should be to reduce the viral set point and preserve memory CD4 lymphocytes. Here we investigated whether vaccine-induced cellular immunity in the absence of any Env-specific antibodies can control viral replication following multiple low-dose challenges with the highly pathogenic SIVmac239 isolate. Eight Mamu-A*01-positive Indian rhesus macaques were vaccinated with simian immunodeficiency virus (SIV) gag, tat, rev, and nef using a DNA prime-adenovirus boost strategy. Peak viremia (P = 0.007) and the chronic phase set point (P = 0.0192) were significantly decreased in the vaccinated cohort, out to 1 year postinfection. Loss of CD4+ memory populations was also ameliorated in vaccinated animals. Interestingly, only one of the eight vaccinees developed Env-specific neutralizing antibodies after infection. The control observed was significantly improved over that observed in animals vaccinated with SIV gag only. Vaccine-induced cellular immune responses can, therefore, exert a measure of control over replication of the AIDS virus in the complete absence of neutralizing antibody and give us hope that a vaccine designed to induce cellular immune responses might control viral replication.

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