scholarly journals Elicitation of Simian Immunodeficiency Virus-Specific Cytotoxic T Lymphocytes in Mucosal Compartments of Rhesus Monkeys by Systemic Vaccination

2002 ◽  
Vol 76 (22) ◽  
pp. 11484-11490 ◽  
Author(s):  
Jamal Baig ◽  
Daniel B. Levy ◽  
Paul F. McKay ◽  
Joern E. Schmitz ◽  
Sampa Santra ◽  
...  

ABSTRACT Since most human immunodeficiency virus (HIV) infections are initiated following mucosal exposure to the virus, the anatomic containment or abortion of an HIV infection is likely to require vaccine-elicited cellular immune responses in those mucosal sites. Studying vaccine-elicited mucosal immune responses has been problematic because of the difficulties associated with sampling T lymphocytes from those anatomic compartments. In the present study, we demonstrate that mucosal cytotoxic T lymphocytes (CTL) specific for simian immunodeficiency virus (SIV) and simian HIV can be reproducibly sampled from intestinal mucosal tissue of rhesus monkeys obtained under endoscopic guidance. These lymphocytes recognize peptide-major histocompatibility complex class I complexes and express gamma interferon on exposure to peptide antigen. Interestingly, systemic immunization of monkeys with plasmid DNA immunogens followed by live recombinant attenuated poxviruses or adenoviruses with genes deleted elicits high-frequency SIV-specific CTL responses in these mucosal tissues. These studies therefore suggest that systemic delivery of potent HIV immunogens may suffice to elicit substantial mucosal CTL responses.

2002 ◽  
Vol 76 (20) ◽  
pp. 10507-10511 ◽  
Author(s):  
Todd M. Allen ◽  
Peicheng Jing ◽  
Briana Calore ◽  
Helen Horton ◽  
David H. O'Connor ◽  
...  

ABSTRACT Vaccine-induced cytotoxic T lymphocytes (CTL) have been implicated in the control of virus replication in simian immunodeficiency virus (SIV)-challenged and simian-human immunodeficiency virus-challenged macaques. Therefore, we wanted to test the impact that vaccine-induced CTL responses against an immunodominant Gag epitope might have in the absence of other immune responses. By themselves, these strong CTL responses failed to control SIVmac239 replication.


2003 ◽  
Vol 77 (13) ◽  
pp. 7367-7375 ◽  
Author(s):  
Dan H. Barouch ◽  
Jennifer Kunstman ◽  
Jennifer Glowczwskie ◽  
Kevin J. Kunstman ◽  
Michael A. Egan ◽  
...  

ABSTRACT Virus-specific cytotoxic T lymphocytes (CTL) are critical for control of human immunodeficiency virus type 1 replication. However, viral escape from CTL recognition can undermine this immune control. Here we demonstrate the high frequency and pattern of viral escape from dominant epitope-specific CTL in SIV gag DNA-vaccinated rhesus monkeys following a heterologous simian immunodeficiency virus (SIV) challenge. DNA-vaccinated monkeys exhibited initial effective control of the SIV challenge, but this early control was lost by serial breakthroughs of viral replication over a 3-year follow-up period. Increases in plasma viral RNA correlated temporally with declines of dominant SIV epitope-specific CD8+ T-lymphocyte responses and the emergence of viral mutations that escaped recognition by dominant epitope-specific CTL. Viral escape from CTL occurred in a total of seven of nine vaccinated and control monkeys, including three animals that initially controlled viral replication to undetectable levels of plasma viral RNA. These data suggest that CTL exert selective pressure on viral replication and that viral escape from CTL may be a limitation of CTL-based AIDS vaccine strategies.


2001 ◽  
Vol 75 (11) ◽  
pp. 5151-5158 ◽  
Author(s):  
Dan H. Barouch ◽  
Sampa Santra ◽  
Marcelo J. Kuroda ◽  
Jörn E. Schmitz ◽  
Ronald Plishka ◽  
...  

ABSTRACT Since cytotoxic T lymphocytes (CTLs) are critical for controlling human immunodeficiency virus type 1 (HIV-1) replication in infected individuals, candidate HIV-1 vaccines should elicit virus-specific CTL responses. In this report, we study the immune responses elicited in rhesus monkeys by a recombinant poxvirus vaccine and the degree of protection afforded against a pathogenic simian-human immunodeficiency virus SHIV-89.6P challenge. Immunization with recombinant modified vaccinia virus Ankara (MVA) vectors expressing SIVmac239gag-pol and HIV-1 89.6 env elicited potent Gag-specific CTL responses but no detectable SHIV-specific neutralizing antibody (NAb) responses. Following intravenous SHIV-89.6P challenge, sham-vaccinated monkeys developed low-frequency CTL responses, low-titer NAb responses, rapid loss of CD4+ T lymphocytes, high-setpoint viral RNA levels, and significant clinical disease progression and death in half of the animals by day 168 postchallenge. In contrast, the recombinant MVA-vaccinated monkeys demonstrated high-frequency secondary CTL responses, high-titer secondary SHIV-89.6-specific NAb responses, rapid emergence of SHIV-89.6P-specific NAb responses, partial preservation of CD4+ T lymphocytes, reduced setpoint viral RNA levels, and no evidence of clinical disease or mortality by day 168 postchallenge. There was a statistically significant correlation between levels of vaccine-elicited CTL responses prior to challenge and the control of viremia following challenge. These results demonstrate that immune responses elicited by live recombinant vectors, although unable to provide sterilizing immunity, can control viremia and prevent disease progression following a highly pathogenic AIDS virus challenge.


1993 ◽  
Vol 5 (3) ◽  
pp. 215-223 ◽  
Author(s):  
Norman L. Letvin ◽  
Michael D. Miller ◽  
Ling Shen ◽  
Zheng W. Chen ◽  
Yasuhiro Yasutomi

2001 ◽  
Vol 17 (10) ◽  
pp. 873-886 ◽  
Author(s):  
Abie Craiu ◽  
Dan H. Barouch ◽  
Xin Xiao Zheng ◽  
Marcelo J. Kuroda ◽  
Joern E. Schmitz ◽  
...  

2007 ◽  
Vol 81 (15) ◽  
pp. 8009-8015 ◽  
Author(s):  
Yue Sun ◽  
Sallie R. Permar ◽  
Adam P. Buzby ◽  
Norman L. Letvin

ABSTRACT It has long been appreciated that CD4+ T lymphocytes are dysfunctional in human immunodeficiency virus (HIV)/simian immunodeficiency virus (SIV)-infected individuals, and it has recently been shown that HIV/SIV infections are associated with a dramatic early destruction of memory CD4+ T lymphocytes. However, the relative contributions of CD4+ T-lymphocyte dysfunction and loss to immune dysregulation during primary HIV/SIV infection have not been fully elucidated. In the current study, we evaluated CD4+ T lymphocytes and their functional repertoire during primary SIVmac251 infection in rhesus monkeys. We show that the extent of loss of memory CD4+ T lymphocytes and staphylococcal enterotoxin B-stimulated cytokine production by total CD4+ T lymphocytes during primary SIVmac251 infection is tightly linked in a cohort of six rhesus monkeys to set point plasma viral RNA levels, with greater loss and dysfunction being associated with higher steady-state viral replication. Moreover, in exploring the mechanism underlying this phenomenon, we demonstrate that the loss of functional CD4+ T lymphocytes during primary SIVmac251 infection is associated with both a selective depletion of memory CD4+ T cells and a loss of the functional capacity of the memory CD4+ T lymphocytes that escape viral destruction.


2005 ◽  
Vol 79 (19) ◽  
pp. 12264-12272 ◽  
Author(s):  
Richard Stebbings ◽  
Neil Berry ◽  
Herman Waldmann ◽  
Pru Bird ◽  
Geoff Hale ◽  
...  

ABSTRACT In order to test the hypothesis that CD8+ cytotoxic T lymphocytes mediate protection against acute superinfection, we depleted >99% of CD8+ lymphocytes in live attenuated simian immunodeficiency virus macC8 (SIVmacC8) vaccinees from the onset of vaccination, maintained that depletion for 20 days, and then challenged with pathogenic, wild-type SIVmacJ5. Vaccinees received 5 mg per kg of humanized anti-CD8 monoclonal antibody (MAb) 1 h before inoculation, followed by the same dose again on days 3, 7, 10, 13, and 17. On day 13, peripheral CD8+ T lymphocytes were >99% depleted in three out of four anti-CD8 MAb-treated vaccinees. At this time attenuated SIVmacC8 viral RNA loads in anti-CD8 MAb-treated vaccinees were significantly higher than control vaccinees treated contemporaneously with nonspecific human immunoglobulin. Lymphoid tissue CD8+ T lymphocyte depletion was >99% in three out of four anti-CD8 MAb-treated vaccinees on the day of wild-type SIVmacJ5 challenge. All four control vaccinees and three out of four anti-CD8 MAb-treated vaccinees were protected against detectable superinfection with wild-type SIVmacJ5. Although superinfection with wild-type SIVmacJ5 was detected at postmortem in a single anti-CD8 MAb-treated vaccinee, this did not correlate with the degree of preceding CD8+ T lymphocyte depletion. Clearance of attenuated SIVmacC8 viremia coincided with recovery of normal CD8+ T lymphocyte counts between days 48 and 76. These results support the view that cytotoxic T lymphocytes are important for host-mediated control of SIV primary viremia but do not indicate a central role in protection against acute superinfection conferred by inoculation with live attenuated SIV.


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