scholarly journals The Differential Ability of HLA B*5701+ Long-Term Nonprogressors and Progressors To Restrict Human Immunodeficiency Virus Replication Is Not Caused by Loss of Recognition of Autologous Viral gag Sequences

2003 ◽  
Vol 77 (12) ◽  
pp. 6889-6898 ◽  
Author(s):  
Stephen A. Migueles ◽  
Alisha C. Laborico ◽  
Hiromi Imamichi ◽  
W. Lesley Shupert ◽  
Cassandra Royce ◽  
...  

ABSTRACT Although the HLA B*5701 class I allele is highly overrepresented among human immunodeficiency virus (HIV)-infected long-term nonprogressors (LTNPs), it is also present at the expected frequency (11%) in patients with progressive HIV infection. Whether B57+ progressors lack restriction of viral replication because of escape from recognition of highly immunodominant B57-restricted gag epitopes by CD8+ T cells remains unknown. In this report, we investigate the association between restriction of virus replication and recognition of autologous virus sequences in 27 B*57+ patients (10 LTNPs and 17 progressors). Amplification and direct sequencing of single molecules of viral cDNA or proviral DNA revealed low frequencies of genetic variations in these regions of gag. Furthermore, CD8+ T-cell recognition of autologous viral variants was preserved in most cases. In two patients, responses to autologous viral variants were not demonstrable at one epitope. By using a novel technique to isolate primary CD4+ T cells expressing autologous viral gene products, it was found that 1 to 13% of CD8+ T cells were able to respond to these cells by gamma interferon production. In conclusion, escape-conferring mutations occur infrequently within immunodominant B57-restricted gag epitopes and are not the primary mechanism of virus evasion from immune control in B*5701+ HIV-infected patients. Qualitative features of the virus-specific CD8+ T-cell response not measured by current assays remain the most likely determinants of the differential abilities of HLA B*5701+ LTNPs and progressors to restrict virus replication.

2008 ◽  
Vol 82 (22) ◽  
pp. 11181-11196 ◽  
Author(s):  
Meritxell Genescà ◽  
Pamela J. Skinner ◽  
Jung Joo Hong ◽  
Jun Li ◽  
Ding Lu ◽  
...  

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.


Virus Genes ◽  
1991 ◽  
Vol 5 (3) ◽  
pp. 189-202 ◽  
Author(s):  
Jun-Ichiro Gyotoku ◽  
Mohamed A. El-Farrash ◽  
Shinji Fujimoto ◽  
Wilfred T. V. Germeraad ◽  
Yoshihiko Watanabe ◽  
...  

2009 ◽  
Vol 90 (4) ◽  
pp. 915-926 ◽  
Author(s):  
Gerrit Koopman ◽  
Daniella Mortier ◽  
Sam Hofman ◽  
Marguerite Koutsoukos ◽  
Willy M. J. M. Bogers ◽  
...  

Human immunodeficiency virus (HIV) infection in humans and simian immunodeficiency virus (SIV) infection in macaques are accompanied by a combined early loss of CCR5 (CD195)-expressing CD4+ memory T cells, loss of T-helper function and T-cell hyperactivation, which have all been associated with development of high virus load and disease progression. Here, a cohort of vaccinated simian–human immunodeficiency virus strain 89.6p (SHIV89.6p)-infected rhesus macaques, where preferential depletion of these memory T-cell subsets does not take place and CD4+ T cells are relatively well maintained, was used to study the role of hyperactivation as an independent factor in the establishment of set-point virus load. In the acute phase of the infection, a transient loss of CD4+ T cells, as well as strong increases in expression of proliferation and activation markers on CD4+ and CD8+ T cells, together with CD152 expression on CD4+ T cells, were observed. Peak expression levels of these markers on CD4+ T cells, but not on CD8+ T cells, were correlated with high virus replication in the chronic phase of the infection. In addition, the peak expression level of these markers was correlated inversely with acute-phase, but not chronic-phase, HIV/SIV-specific gamma interferon responses. These data highlight a central role for an acute but transient CD4 decrease, as well as CD4+ T-cell activation, as independent factors for prediction of set-point levels of virus replication.


2001 ◽  
Vol 75 (24) ◽  
pp. 11983-11991 ◽  
Author(s):  
Michael R. Betts ◽  
David R. Ambrozak ◽  
Daniel C. Douek ◽  
Sebastian Bonhoeffer ◽  
Jason M. Brenchley ◽  
...  

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.


2004 ◽  
Vol 78 (22) ◽  
pp. 12537-12547 ◽  
Author(s):  
Jörg G. Baumann ◽  
Derya Unutmaz ◽  
Michael D. Miller ◽  
Sabine K. J. Breun ◽  
Stacy M. Grill ◽  
...  

ABSTRACT Development of a mouse model for human immunodeficiency virus type 1 (HIV-1) infection has advanced through the progressive identification of host cell factors required for HIV-1 replication. Murine cells lack HIV-1 receptor molecules, do not support efficient viral gene expression, and lack factors necessary for the assembly and release of virions. Many of these blocks have been described using mouse fibroblast cell lines. Here we identify a postentry block to HIV-1 infection in mouse T-cell lines that has not been detected in mouse fibroblasts. While murine fibroblastic lines are comparable to human T-cell lines in permissivity to HIV-1 transduction, infection of murine T cells is 100-fold less efficient. Virus entry occurs efficiently in murine T cells. However, reduced efficiency of the completion of reverse transcription and nuclear transfer of the viral preintegration complex are observed. Although this block has similarities to the restriction of murine retroviruses by Fv1, there is no correlation of HIV-1 susceptibility with cellular Fv1 genotypes. In addition, the block to HIV-1 infection in murine T-cell lines cannot be saturated by a high virus dose. Further studies of this newly identified block may lend insight into the early events of retroviral replication and reveal new targets for antiretroviral interventions.


2019 ◽  
Vol 11 (1) ◽  
Author(s):  
César N. Cortés-Rubio ◽  
Gonzalo Salgado-Montes de Oca ◽  
Francisco J. Prado-Galbarro ◽  
Margarita Matías-Florentino ◽  
Akio Murakami-Ogasawara ◽  
...  

Abstract Background Persistence of latent, replication-competent provirus in CD4+ T cells of human immunodeficiency virus (HIV)-infected individuals on antiretroviral treatment (ART) is the main obstacle for virus eradication. Methylation of the proviral 5′ long terminal repeat (LTR) promoter region has been proposed as a possible mechanism contributing to HIV latency; however, conflicting observations exist regarding its relevance. We assessed 5′-LTR methylation profiles in total CD4+ T cells from blood of 12 participants on short-term ART (30 months) followed up for 2 years, and a cross-sectional group of participants with long-term ART (6–15 years), using next generation sequencing. We then looked for associations between specific 5′-LTR methylation patterns and baseline and follow-up clinical characteristics. Results 5′-LTR methylation was observed in all participants and behaved dynamically. The number of 5′-LTR variants found per sample ranged from 1 to 13, with median sequencing depth of 16270× (IQR 4107×-46760×). An overall significant 5′-LTR methylation increase was observed at month 42 compared to month 30 (median CpG Methylation Index: 74.7% vs. 0%, p = 0.025). This methylation increase was evident in a subset of participants (methylation increase group), while the rest maintained fairly high and constant methylation (constant methylation group). Persons in the methylation increase group were younger, had higher CD4+ T cell gain, larger CD8% decrease, and larger CD4/CD8 ratio change after 48 months on ART (all p < 0.001). Using principal component analysis, the constant methylation and methylation increase groups showed low evidence of separation along time (factor 2: p = 0.04). Variance was largely explained (21%) by age, CD4+/CD8+ T cell change, and CD4+ T cell subpopulation proportions. Persons with long-term ART showed overall high methylation (median CpG Methylation Index: 78%; IQR 71–87%). No differences were observed in residual plasma viral load or proviral load comparing individuals on short-term (both at 30 or 42 months) and long-term ART. Conclusions Our study shows evidence that HIV 5′-LTR methylation in total CD4+ T cells is dynamic along time and that it can follow different temporal patterns that are associated with a combination of baseline and follow-up clinical characteristics. These observations may account for differences observed between previous contrasting studies.


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