scholarly journals Decay Kinetics of Human Immunodeficiency Virus-Specific CD8+ T Cells in Peripheral Blood after Initiation of Highly Active Antiretroviral Therapy

2001 ◽  
Vol 75 (14) ◽  
pp. 6508-6516 ◽  
Author(s):  
Joseph P. Casazza ◽  
Michael R. Betts ◽  
Louis J. Picker ◽  
Richard A. Koup
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Cells ◽  
Viral Load ◽  
T Cell ◽  
Cell Response ◽  
Highly Active Antiretroviral Therapy ◽  
Undetectable Viral Load ◽  
T Cell Response ◽  
Highly Active ◽  
Immunodeficiency Virus

ABSTRACT We measured the longitudinal responses to 95 HLA class I-restricted human immunodeficiency virus (HIV) epitopes and an immunodominant HLA A2-restricted cytomegalovirus (CMV) epitope in eight treatment-naive HIV-infected individuals, using intracellular cytokine staining. Patients were treated with highly active antiretroviral therapy (HAART) for a median of 78 weeks (range, 34 to 121 weeks). Seven of eight patients maintained an undetectable viral load for the duration of therapy. A rapid decline in HIV-specific CD8+ T-cell response was observed at initiation of therapy. After an undetectable viral load was achieved, a slower decrease in HIV-specific CD8+ T-cell response was observed that was well described by first-order kinetics. The median half-life for the rate of decay was 38.8 (20.3 to 68.0) weeks when data were expressed as percentage of peripheral CD8+ T cells. In most cases, data were similar when expressed as the number of responding CD8+ T cells per microliter of blood. In subjects who responded to more than one HIV epitope, rates of decline in response to the different epitopes were similar and varied by a factor of 2.2 or less. Discontinuation of treatment resulted in a rapid increase in HIV-specific CD8+ T cells. Responses to CMV increased 1.6- and 2.8-fold within 16 weeks of initiation of HAART in two of three patients with a measurable CMV response. These data suggest that HAART quickly starts to restore CD8+ T-cell responses to other chronic viral infections and leads to a slow decrease in HIV-specific CD8+ T-cell response in HIV-infected patients. The slow decrease in the rate of CD8+ T-cell response and rapid increase in response to recurrent viral replication suggest that the decrease in CD8+ T-cell response observed represents a normal memory response to withdrawal of antigen.

scholarly journals Analysis of Total Human Immunodeficiency Virus (HIV)-Specific CD4+ and CD8+ T-Cell Responses: Relationship to Viral Load in Untreated HIV Infection

2001 ◽  
Vol 75 (24) ◽  
pp. 11983-11991 ◽  
Author(s):  
Michael R. Betts ◽  
David R. Ambrozak ◽  
Daniel C. Douek ◽  
Sebastian Bonhoeffer ◽  
Jason M. Brenchley ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Cells ◽  
Viral Load ◽  
T Cell ◽  
Hiv Infection ◽  
Highly Active Antiretroviral Therapy ◽  
T Cell Responses ◽  
T Cell Response ◽  
Cell Responses ◽  
Immunodeficiency Virus

ABSTRACT Human immunodeficiency virus (HIV)-specific T-cell responses are thought to play a key role in viral load decline during primary infection and in determining the subsequent viral load set point. The requirements for this effect are unknown, partly because comprehensive analysis of total HIV-specific CD4+ and CD8+T-cell responses to all HIV-encoded epitopes has not been accomplished. To assess these responses, we used cytokine flow cytometry and overlapping peptide pools encompassing all products of the HIV-1 genome to study total HIV-specific T-cell responses in 23 highly active antiretroviral therapy naı̈ve HIV-infected patients. HIV-specific CD8+ T-cell responses were detectable in all patients, ranging between 1.6 and 18.4% of total CD8+ T cells. HIV-specific CD4+ T-cell responses were present in 21 of 23 patients, although the responses were lower (0.2 to 2.94%). Contrary to previous reports, a positive correlation was identified between the plasma viral load and the total HIV-, Env-, and Nef-specific CD8+ T-cell frequency. No correlation was found either between viral load and total or Gag-specific CD4+ T-cell response or between the frequency of HIV-specific CD4+ and CD8+ T cells. These results suggest that overall frequencies of HIV-specific T cells are not the sole determinant of immune-mediated protection in HIV-infection.

scholarly journals Naïve T-Cell Depletion Related to Infection by X4 Human Immunodeficiency Virus Type 1 in Poor Immunological Responders to Highly Active Antiretroviral Therapy

2006 ◽  
Vol 80 (20) ◽  
pp. 10229-10236 ◽  
Author(s):  
Pierre Delobel ◽  
Marie-Thérèse Nugeyre ◽  
Michelle Cazabat ◽  
Karine Sandres-Sauné ◽  
Christophe Pasquier ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Cells ◽  
T Cell ◽  
Antiretroviral Therapy ◽  
Highly Active Antiretroviral Therapy ◽  
T Cell Subsets ◽  
Highly Active ◽  
The Poor ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACT The reasons for poor CD4+ T-cell recovery in some human immunodeficiency virus (HIV)-infected subjects despite effective highly active antiretroviral therapy (HAART) remain unclear. We recently reported that CXCR4-using (X4) HIV-1 could be gradually selected in cellular reservoirs during sustained HAART. Because of the differential expression of HIV-1 coreceptors CCR5 and CXCR4 on distinct T-cell subsets, the residual replication of R5 and X4 viruses could have different impacts on T-cell homeostasis during immune reconstitution on HAART. We examined this hypothesis and the mechanisms of CD4+ T-cell restoration by comparing the virological and immunological features of 15 poor and 15 good immunological responders to HAART. We found a high frequency of X4 viruses in the poor immunological responders. But the levels of intrathymic proliferation of the two groups were similar regardless of whether they were infected by R5 or X4 virus. The frequency of recent thymic emigrants in the poor immunological responders was also similar to that found in the good immunological responders, despite their reduced numbers of naïve CD4+ T cells. Our data, rather, suggest that the naïve T-cell compartment is drained by a high rate of mature naïve cell loss in the periphery due to bystander apoptosis or activation-induced differentiation. X4 viruses could play a role in the depletion of naïve T cells in poor immunological responders to HAART by triggering persistent T-cell activation and bystander apoptosis via gp120-CXCR4 interactions.

scholarly journals Naïve T-Cell Dynamics in Human Immunodeficiency Virus Type 1 Infection: Effects of Highly Active Antiretroviral Therapy Provide Insights into the Mechanisms of Naïve T-Cell Depletion

2006 ◽  
Vol 80 (6) ◽  
pp. 2665-2674 ◽  
Author(s):  
Michele Di Mascio ◽  
Irini Sereti ◽  
Lynn T. Matthews ◽  
Ven Natarajan ◽  
Joseph Adelsberger ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Cells ◽  
T Cell ◽  
Highly Active Antiretroviral Therapy ◽  
Cell Numbers ◽  
Highly Active ◽  
Immunodeficiency Virus ◽  
Relative Change ◽  
Hiv 1

ABSTRACT Both naïve CD4+ and naïve CD8+ T cells are depleted in individuals with human immunodeficiency virus type 1 (HIV-1) infection by unknown mechanisms. Analysis of their dynamics prior to and after highly active antiretroviral therapy (HAART) could reveal possible mechanisms of depletion. Twenty patients were evaluated with immunophenotyping, intracellular Ki67 staining, T-cell receptor excision circle (TREC) quantitation in sorted CD4 and CD8 cells, and thymic computed tomography scans prior to and ∼6 and ∼18 months after initiation of HAART. Naïve T-cell proliferation decreased significantly during the first 6 months of therapy (P < 0.01) followed by a slower decline. Thymic indices did not change significantly over time. At baseline, naïve CD4+ T-cell numbers were lower than naive CD8+ T-cell numbers; after HAART, a greater increase in naïve CD4+ T cells than naïve CD8+ T cells was observed. A greater relative change (n-fold) in the number of TREC+ T cells/μl than in naïve T-cell counts was observed at 6 months for both CD4+ (median relative change [n-fold] of 2.2 and 1.7, respectively; P < 0.01) and CD8+ T cell pools (1.4 and 1.2; P < 0.01). A more pronounced decrease in the proliferation than the disappearance rate of naïve T cells after HAART was observed in a second group of six HIV-1-infected patients studied by in vivo pulse labeling with bromodeoxyuridine. These observations are consistent with a mathematical model where the HIV-1-induced increase in proliferation of naïve T cells is mostly explained by a faster recruitment into memory cells.

scholarly journals Virological Outcome after Structured Interruption of Antiretroviral Therapy for Human Immunodeficiency Virus Infection Is Associated with the Functional Profile of Virus-Specific CD8+ T Cells

2008 ◽  
Vol 82 (8) ◽  
pp. 4102-4114 ◽  
Author(s):  
Marybeth Daucher ◽  
David A. Price ◽  
Jason M. Brenchley ◽  
Laurie Lamoreaux ◽  
Julia A. Metcalf ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Cells ◽  
T Cell ◽  
Antiretroviral Therapy ◽  
Cell Response ◽  
T Cell Response ◽  
Functional Profile ◽  
Plasma Virus ◽  
Cell Functions ◽  
Immunodeficiency Virus

ABSTRACT A clear understanding of the antiviral effects of CD8+ T cells in the context of chronic human immunodeficiency virus (HIV) infection is critical for the development of prophylactic vaccines and therapeutics designed to support T-cell-mediated immunity. However, defining the potential correlates of effective CD8+ T-cell immunity has proven difficult; notably, comprehensive analyses have demonstrated that the size and shape of the CD8+ T-cell response are not necessarily indicative of efficacy determined by measures of plasma viral load. Here, we conducted a detailed quantitative and qualitative analysis of CD8+ T-cell responses to autologous virus in a cohort of six HIV-infected individuals with a history of structured interruption of antiretroviral therapy (ART) (SIT). The magnitude and breadth of the HIV-specific response did not, by themselves, explain the changes observed in plasma virus levels after the cessation of ART. Furthermore, mutational escape from targeted epitopes could not account for the differential virological outcomes in this cohort. However, the functionality of HIV-specific CD8+ T-cell populations upon antigen encounter, determined by the simultaneous and independent measurement of five CD8+ T-cell functions (degranulation and gamma interferon, macrophage inflammatory protein 1β, tumor necrosis factor alpha, and interleukin-2 levels) reflected the emergent level of plasma virus, with multiple functions being elicited in those individuals with lower levels of viremia after SIT. These data show that the quality of the HIV-specific CD8+ T-cell response, rather than the quantity, is associated with the dynamics of viral replication in the absence of ART and suggest that the effects of SIT can be assessed by measuring the functional profile of HIV-specific CD8+ T cells.

scholarly journals Highly Active Antiretroviral Therapy in Human Immunodeficiency Virus Type 1-Infected Children: Analysis of Cellular Immune Responses

2001 ◽  
Vol 8 (5) ◽  
pp. 943-948 ◽  
Author(s):  
Vesna Blazevic ◽  
Shirley Jankelevich ◽  
Seth M. Steinberg ◽  
Freda Jacobsen ◽  
Robert Yarchoan ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Cell ◽  
Antiretroviral Therapy ◽  
Highly Active Antiretroviral Therapy ◽  
Delayed Type Hypersensitivity ◽  
Strong Increase ◽  
Highly Active ◽  
Cell Counts ◽  
Immunodeficiency Virus

ABSTRACT The present study analyzes the effect of highly active antiretroviral therapy (HAART) on restoration of cellular immunity in human immunodeficiency virus (HIV)-infected children over a 24-week period following initiation of HAART with ritonavir, nevirapine, and stavudine. The immunological parameters evaluated at four time points (at enrollment and at 4, 12, and 24 weeks of therapy) included cytokine production by monocytes as well as T-cell proliferation in response to mitogen, alloantigen, and recall antigens including HIV type 1 envelope peptides. Circulating levels of interleukin-16 (IL-16) were measured, in addition to CD4+ T-cell counts, plasma HIV RNA levels, and the delayed-type hypersensitivity (DTH) response. At enrollment the children exhibited defects in several immune parameters measured. Therapy increased CD4+ T-cell counts and decreased viral loads significantly. By contrast, the only immunological parameter that was significantly increased was IL-12 p70 production by monocytes; the DTH response to Candida albicans also showed a strong increase in patients becoming positive. In conclusion, these results demonstrate that HAART in HIV-infected children affects the dynamics of HIV replication and the CD4+ T-cell count over 24 weeks, similar to the pattern seen in HIV-infected adults. Furthermore, these data indicate improvement in antigen-presenting cell immunological function in HIV-infected children induced by HAART.

scholarly journals Response to Superantigen Stimulation in Peripheral Blood Mononuclear Cells from Children Perinatally Infected with Human Immunodeficiency Virus and Receiving Highly Active Antiretroviral Therapy

2004 ◽  
Vol 11 (5) ◽  
pp. 957-962 ◽  
Author(s):  
Thomas W. McCloskey ◽  
Viraga Haridas ◽  
Lucy Pontrelli ◽  
Savita Pahwa
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Cells ◽  
Antiretroviral Therapy ◽  
Highly Active Antiretroviral Therapy ◽  
Mononuclear Cells ◽  
Peripheral Blood Mononuclear ◽  
Highly Active ◽  
Immunodeficiency Virus ◽  
Blood Mononuclear Cells ◽  
Ifn Γ

ABSTRACT Our understanding of the pathogenesis of perinatal human immunodeficiency virus (HIV) infection is still evolving. We sought to characterize the response to the bacterial superantigen Staphylococcus enterotoxin B (SEB) of lymphocytes from HIV-infected children receiving treatment with highly active antiretroviral therapy (HAART). Using the flow cytometric methodology, we quantified apoptosis, proliferation, cytokine production, and activation antigen upregulation in CD4 and CD8 T lymphocytes following in vitro stimulation of peripheral blood mononuclear cells (PBMCs) with SEB. The levels of proliferation, CD4 interleukin-2 (IL-2) production, CD8 gamma interferon (IFN-γ) production, and upregulation of CD69 expression by cells from HIV-infected children were indistinguishable from those by cells from controls. However, stimulation with SEB dramatically decreased the ratio of resting apoptotic cells to cycling apoptotic cells in the controls but not in the patients. In addition, unstimulated spontaneous apoptosis of CD4 T cells remained greater in the patients than in the controls. The percentages of IL-2-positive CD8 T cells and IFN-γ-positive CD4 T cells following SEB stimulation were significantly lower in the patients than in the controls. Our multiparameter approach was able to demonstrate differences in lymphocyte superantigen responsiveness in HIV-infected children receiving HAART in comparison to that in uninfected controls, notably, an apoptotic versus a proliferative response to stimulation.

scholarly journals With Minimal Systemic T-Cell Expansion, CD8+ T Cells Mediate Protection of Rhesus Macaques Immunized with Attenuated Simian-Human Immunodeficiency Virus SHIV89.6 from Vaginal Challenge with Simian Immunodeficiency Virus

2008 ◽  
Vol 82 (22) ◽  
pp. 11181-11196 ◽  
Author(s):  
Meritxell Genescà ◽  
Pamela J. Skinner ◽  
Jung Joo Hong ◽  
Jun Li ◽  
Ding Lu ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Cells ◽  
T Cell ◽  
Simian Immunodeficiency Virus ◽  
Rhesus Macaques ◽  
T Cell Response ◽  
Lymphoid Tissues ◽  
Vaginal Mucosa ◽  
Challenge Virus ◽  
Immunodeficiency Virus

ABSTRACT The presence, at the time of challenge, of antiviral effector T cells in the vaginal mucosa of female rhesus macaques immunized with live-attenuated simian-human immunodeficiency virus 89.6 (SHIV89.6) is associated with consistent and reproducible protection from pathogenic simian immunodeficiency virus (SIV) vaginal challenge (18). Here, we definitively demonstrate the protective role of the SIV-specific CD8+ T-cell response in SHIV-immunized monkeys by CD8+ lymphocyte depletion, an intervention that abrogated SHIV-mediated control of challenge virus replication and largely eliminated the SIV-specific T-cell responses in blood, lymph nodes, and genital mucosa. While in the T-cell-intact SHIV-immunized animals, polyfunctional and degranulating SIV-specific CD8+ T cells were present in the genital tract and lymphoid tissues from the day of challenge until day 14 postchallenge, strikingly, expansion of SIV-specific CD8+ T cells in the immunized monkeys was minimal and limited to the vagina. Thus, protection from uncontrolled SIV replication in animals immunized with attenuated SHIV89.6 is primarily mediated by CD8+ T cells that do not undergo dramatic systemic expansion after SIV challenge. These findings demonstrate that despite, and perhaps because of, minimal systemic expansion of T cells at the time of challenge, a stable population of effector-cytotoxic CD8+ T cells can provide significant protection from vaginal SIV challenge.

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