scholarly journals Memory CD4+ T-Lymphocyte Loss and Dysfunction during Primary Simian Immunodeficiency Virus Infection

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 (21) ◽  
pp. 13759-13768 ◽  
Author(s):  
Candice C. Clay ◽  
Denise S. Rodrigues ◽  
Danielle J. Harvey ◽  
Christian M. Leutenegger ◽  
Ursula Esser

ABSTRACT To define the possible impact of T-lymphocyte trafficking parameters on simian immunodeficiency virus (SIV) pathogenesis, we examined migratory profiles of carboxyfluorescein diacetate succinimidyl ester (CFSE)-labeled T lymphocytes in acutely SIVmac251-infected and uninfected macaques within 48 h after autologous transfer. Despite significant upregulation of homeostatic chemokine CCL19/macrophage inflammatory protein 3β and proinflammatory chemokine CXCL9/monokine induced by gamma interferon in secondary lymphoid tissue in SIV infection, no differences in CFSE+ T-lymphocyte frequencies or cell compartmentalization in lymph nodes were identified between animal groups. By contrast, a higher frequency of CFSE+ T lymphocytes in the small intestine was detected in acute SIV infection. This result correlated with increased numbers of gut CD4 T lymphocytes expressing chemokine receptors CCR9, CCR7, and CXCR3 and high levels of their respective chemokine ligands in the small intestine. The changes in trafficking parameters in SIV-infected macaques occurred concomitantly with acute gut CD4 T-lymphocyte depletion. Here, we present the first in vivo T-lymphocyte trafficking study in SIV infection and a novel approach to delineate T-lymphocyte recruitment into tissues in the nonhuman primate animal model for AIDS. Such studies are likely to provide unique insights into T-lymphocyte sequestration in distinct tissue compartments and possible mechanisms of CD4 T-lymphocyte depletion and immune dysfunction in simian AIDS.


2001 ◽  
Vol 75 (21) ◽  
pp. 10179-10186 ◽  
Author(s):  
Suzanne Robinson ◽  
William A. Charini ◽  
Michael H. Newberg ◽  
Marcelo J. Kuroda ◽  
Carol I. Lord ◽  
...  

ABSTRACT The ability to monitor vaccine-elicited CD8+ cytotoxic T-lymphocyte (CTL) responses in simian immunodeficiency virus (SIV)- and simian-human immunodeficiency virus (SHIV)-infected rhesus monkeys has been limited by our knowledge of viral epitopes predictably presented to those lymphocytes by common rhesus monkey MHC class I alleles. We now define an SIV and SHIV Nef CTL epitope (YTSGPGIRY) that is presented to CD8+ T lymphocytes by the common rhesus monkey MHC class I molecule Mamu-A*02. All seven infectedMamu-A*02 + monkeys evaluated demonstrated this response, and peptide-stimulated interferon gamma Elispot assays indicated that the response represents a large proportion of the entire CD8+ T-lymphocyte SIV- or SHIV-specific immune response of these animals. Knowledge of this epitope and MHC class I allele substantially increases the number of available rhesus monkeys that can be used for testing prototype HIV vaccines in this important animal model.


2007 ◽  
Vol 82 (3) ◽  
pp. 1084-1093 ◽  
Author(s):  
Amitinder Kaur ◽  
Michele Di Mascio ◽  
Amy Barabasz ◽  
Michael Rosenzweig ◽  
Harold M. McClure ◽  
...  

ABSTRACT Increased lymphocyte turnover is a hallmark of pathogenic lentiviral infection. To investigate perturbations in lymphocyte dynamics in natural hosts with nonpathogenic simian immunodeficiency virus (SIV) infection, the nucleoside analog bromodeoxyuridine (BrdU) was administered to six naturally SIV-infected and five SIV-negative sooty mangabeys. As a measure of lymphocyte turnover, we estimated the mean death rate by fitting a mathematical model to the fraction of BrdU-labeled cells during a 2-week labeling and a median 10-week delabeling period. Despite significantly lower total T- and B-lymphocyte counts in SIV-infected sooty mangabeys than in SIV-negative mangabeys, the turnover rate of B lymphocytes and CD4+ and CD8+ T lymphocytes was not increased in the SIV-infected animals. A small, rapidly proliferating CD45RA+ memory subset and a large, slower-proliferating CD45RA− central memory subset of CD4+ T lymphocytes identified in the peripheral blood of sooty mangabeys also did not show evidence of increased turnover in the context of SIV infection. Independently of SIV infection, the turnover of CD4+ T lymphocytes in sooty mangabeys was significantly higher (P < 0.01) than that of CD8+ T lymphocytes, a finding hitherto not reported in rhesus macaques or humans. The absence of aberrant T-lymphocyte turnover along with an inherently high rate of CD4+ T-lymphocyte turnover may help to preserve the pool of central memory CD4+ T lymphocytes in viremic SIV-infected sooty mangabeys and protect against progression to AIDS.


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

2008 ◽  
Vol 83 (2) ◽  
pp. 572-583 ◽  
Author(s):  
Mareike Meythaler ◽  
Amanda Martinot ◽  
Zichun Wang ◽  
Sarah Pryputniewicz ◽  
Melissa Kasheta ◽  
...  

ABSTRACT In contrast to pathogenic lentiviral infections, chronic simian immunodeficiency virus (SIV) infection in its natural host is characterized by a lack of increased immune activation and apoptosis. To determine whether these differences are species specific and predicted by the early host response to SIV in primary infection, we longitudinally examined T-lymphocyte apoptosis, immune activation, and the SIV-specific cellular immune response in experimentally infected rhesus macaques (RM) and sooty mangabeys (SM) with controlled or uncontrolled SIV infection. SIVsmE041, a primary SIVsm isolate, reproduced set-point viremia levels of natural SIV infection in SM but was controlled in RM, while SIVmac239 replicated to high levels in RM. Following SIV infection, increased CD8+ T-lymphocyte apoptosis, temporally coinciding with onset of SIV-specific cellular immunity, and elevated plasma Th1 cytokine and gamma interferon-induced chemokine levels were common to both SM and RM. Different from SM, SIV-infected RM showed a significantly higher frequency of peripheral blood activated CD8+ T lymphocytes despite comparable magnitude of the SIV-specific gamma interferon enzyme-linked immunospot response. Furthermore, an increase in CD4+ and CD4−CD8− T-lymphocyte apoptosis and plasma tumor necrosis factor-related apoptosis-inducing ligand were observed only in RM and occurred in both controlled SIVsmE041 and uncontrolled SIVmac239 infection. These data suggest that the “excess” activated T lymphocytes in RM soon after SIV infection are predominantly of non-virus-specific bystander origin. Thus, species-specific differences in the early innate immune response appear to be an important factor contributing to differential immune activation in natural and nonnatural hosts of SIV infection.


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.


2010 ◽  
Vol 84 (19) ◽  
pp. 10406-10412 ◽  
Author(s):  
Jinyan Liu ◽  
Brandon F. Keele ◽  
Hui Li ◽  
Sheila Keating ◽  
Philip J. Norris ◽  
...  

ABSTRACT Defining the earliest virologic events following human immunodeficiency virus type 1 (HIV-1) transmission may be critical for the design of vaccine strategies aimed at blocking acquisition of HIV-1 infection. In particular, the length of the eclipse phase and the number of transmitted virus variants may define the window in which a prophylactic vaccine must act. Here we show that the dose of the virus inoculum affects these key virologic parameters following intrarectal simian immunodeficiency virus (SIV) infection of rhesus monkeys. Low-dose SIV infection resulted in a lengthened eclipse phase, fewer transmitted virus variants, and decreased innate immune activation compared with these parameters in high-dose SIV infection. These data suggest a mechanism by which it may be considerably easier for a vaccine to protect against low-risk HIV-1 transmission than against high-risk HIV-1 transmission. These findings have implications for the design and interpretation of HIV-1 vaccine efficacy studies.


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