scholarly journals Levels of Human Immunodeficiency Virus Type 1-Specific Cytotoxic T-Lymphocyte Effector and Memory Responses Decline after Suppression of Viremia with Highly Active Antiretroviral Therapy

1999 ◽  
Vol 73 (8) ◽  
pp. 6721-6728 ◽  
Author(s):  
Spyros A. Kalams ◽  
Philip J. Goulder ◽  
Amy K. Shea ◽  
Norman G. Jones ◽  
Alicja K. Trocha ◽  
...  

ABSTRACT Therapeutic suppression of human immunodeficiency virus type 1 (HIV-1) replication may help elucidate interactions between the host cellular immune responses and HIV-1 infection. We performed a detailed longitudinal evaluation of two subjects before and after the start of highly active antiretroviral therapy (HAART). Both subjects had evidence of in vivo-activated and memory cytotoxic T-lymphocyte precursor (CTLp) activity against multiple HIV-1 gene products. After the start of therapy, both subjects had declines in the levels of in vivo-activated HIV-1-specific CTLs and had immediate increases in circulating HIV-1-specific CTL memory cells. With continued therapy, and continued suppression of viral load, levels of memory CTLps declined. HLA A*0201 peptide tetramer staining demonstrated that declining levels of in vivo-activated CTL activity were associated with a decrease in the expression of the CD38+ activation marker. Transient increases in viral load during continued therapy were associated with increases in the levels of virus-specific CTLps in both individuals. The results were confirmed by measuring CTL responses to discrete optimal epitopes. These studies illustrate the dynamic equilibrium between the host immune response and levels of viral antigen burden and suggest that efforts to augment HIV-1-specific immune responses in subjects on HAART may decrease the incidence of virologic relapse.

2002 ◽  
Vol 76 (6) ◽  
pp. 2634-2640 ◽  
Author(s):  
John Wilkinson ◽  
Alethea Cope ◽  
Jas Gill ◽  
Dimitra Bourboulia ◽  
Peter Hayes ◽  
...  

ABSTRACT Following the introduction of highly active antiretroviral therapy (HAART), the incidence of Kaposi's sarcoma (KS) has significantly declined in human immunodeficiency virus type 1 (HIV-1)-positive (HIV-1+) individuals and clinical remission is often observed. We hypothesize that these effects are partly due to anti-KS-associated herpesvirus (KSHV) immune restoration. Here, 15-mer overlapping peptides from proteins K12 and K8.1 were used to identify novel KSHV-specific cytotoxic T-lymphocyte epitopes. Three immunogenic peptides, two lytic and one latent, were subsequently used to monitor the anti-KSHV CD8+ T-cell responses in a cohort of 19 HIV-1+ KSHV+/− KS+/− individuals during 52 weeks of HAART. KSHV and HIV-1 loads, KSHV antibody titers, and both CD4+ and CD8+ T-lymphocyte counts were enumerated. Prior to HAART, the total number of spot-forming cells (SFC) for all three peptides correlated with both CD4+ and CD8+ T-lymphocyte counts (P ≤ 0.05) in the KSHV-positive KS-positive cohort (n = 11). Following 52 weeks of HAART, significant decreases in HIV-1 and KSHV loads were associated with significant increases in CD4+ T-lymphocyte counts and number of SFC for the three KSHV-specific peptides. Although these increases were modest in comparison to the number of SFC observed with the HIV-1 gag peptide SLYNTVATL, they represented a fourfold increase from the baseline, continuing an upward trend to week 52.


2002 ◽  
Vol 76 (2) ◽  
pp. 707-716 ◽  
Author(s):  
Tuofu Zhu ◽  
David Muthui ◽  
Sarah Holte ◽  
David Nickle ◽  
Feng Feng ◽  
...  

ABSTRACT In vitro studies show that human immunodeficiency virus type 1 (HIV-1) does not replicate in freshly isolated monocytes unless monocytes differentiate to monocyte-derived macrophages. Similarly, HIV-1 may replicate in macrophages in vivo, whereas it is unclear whether blood monocytes are permissive to productive infection with HIV-1. We investigated HIV-1 replication in CD14+ monocytes and resting and activated CD4+ T cells by measuring the levels of cell-associated viral DNA and mRNA and the genetic evolution of HIV-1 in seven acutely infected patients whose plasma viremia had been <100 copies/ml for 803 to 1,544 days during highly active antiretroviral therapy (HAART). HIV-1 DNA was detected in CD14+ monocytes as well as in activated and resting CD4+ T cells throughout the course of study. While significant variation in the decay slopes of HIV-1 DNA was seen among individual patients, viral decay in CD14+ monocytes was on average slower than that in activated and resting CD4+ T cells. Measurements of HIV-1 sequence evolution and the concentrations of unspliced and multiply spliced mRNA provided evidence of ongoing HIV-1 replication, more pronounced in CD14+ monocytes than in resting CD4+ T cells. Phylogenetic analyses of HIV-1 sequences indicated that after prolonged HAART, viral populations related or identical to those found only in CD14+ monocytes were seen in plasma from three of the seven patients. In the other four patients, HIV-1 sequences in plasma and the three cell populations were identical. CD14+ monocytes appear to be one of the potential in vivo sources of HIV-1 in patients receiving HAART.


2001 ◽  
Vol 75 (9) ◽  
pp. 4430-4434 ◽  
Author(s):  
James P. McGettigan ◽  
Heather D. Foley ◽  
Igor M. Belyakov ◽  
Jay A. Berzofsky ◽  
Roger J. Pomerantz ◽  
...  

ABSTRACT Novel viral vectors that are able to induce both strong and long-lasting immune responses may be required as effective vaccines for human immunodeficiency virus type 1 (HIV-1) infection. Our previous experiments with a replication-competent vaccine strain-based rabies virus (RV) expressing HIV-1 envelope protein from a laboratory-adapted HIV-1 strain (NL4–3) and a primary HIV-1 isolate (89.6) showed that RV-based vectors are excellent for B-cell priming. Here we report that cytotoxic T-lymphocyte (CTL) responses against HIV-1 gp160 are induced by recombinant RVs. Our results indicated that a single inoculation of mice with an RV expressing HIV-1 gp160 induced a solid and long-lasting memory CTL response specific for HIV-1 envelope protein. Moreover, CTLs from immunized mice were not restricted to the homologous HIV-1 envelope protein and were able to cross-kill target cells expressing HIV-1 gp160 from heterologous HIV-1 strains. These studies further suggest promise for RV-based vectors to elicit a persistent immune response against HIV-1 and their potential utility as efficacious anti-HIV-1 vaccines.


2002 ◽  
Vol 76 (6) ◽  
pp. 2817-2826 ◽  
Author(s):  
Georg M. Lauer ◽  
Tam N. Nguyen ◽  
Cheryl L. Day ◽  
Gregory K. Robbins ◽  
Theresa Flynn ◽  
...  

ABSTRACT Both human immunodeficiency virus type 1 (HIV-1) and hepatitis C virus (HCV) lead to chronic infection in a high percentage of persons, and an expanding epidemic of HIV-1-HCV coinfection has recently been identified. These individuals provide an opportunity for simultaneous assessment of immune responses to two viral infections associated with chronic plasma viremia. In this study we analyzed the breadth and magnitude of the CD8+- and CD4+-T-lymphocyte responses in 22 individuals infected with both HIV-1 and HCV. A CD8+-T-lymphocyte response against HIV-1 was readily detected in all subjects over a broad range of viral loads. In marked contrast, HCV-specific CD8+-T-lymphocyte responses were rarely detected, despite viral loads in plasma that were on average 1,000-fold higher. The few HCV-specific responses that were observed were relatively weak and limited in breadth. CD4-proliferative responses against HIV-1 were detected in about half of the coinfected subjects tested, but no proliferative response against any HCV protein was found in these coinfected persons. These data demonstrate a major discordance in immune responses to two persistent RNA viruses. In addition, they show a consistent and profound impairment in cellular immune responses to HCV compared to HIV-1 in HIV-1-HCV-coinfected persons.


2005 ◽  
Vol 79 (18) ◽  
pp. 12100-12105 ◽  
Author(s):  
Thillagavathie Pillay ◽  
Hua-Tang Zhang ◽  
Jan W. Drijfhout ◽  
Nicola Robinson ◽  
Helen Brown ◽  
...  

ABSTRACT The role of cytotoxic T-lymphocyte (CTL) escape in rapidly progressive infant human immunodeficiency virus type 1 (HIV-1) infection is undefined. The data presented here demonstrate that infant HIV-1-specific CTL can select for viral escape variants very early in life. These variants, furthermore, may be selected specifically in the infant, despite the same CTL specificity being present in the mother. Additionally, pediatric CTL activity may be compromised both by the transmission of maternal escape variants and by mother-to-child transmission of escape variants that originally arose in the father. The unique acquisition of these CTL escape forms may help to explain the severe nature of some pediatric HIV infections.


2004 ◽  
Vol 78 (17) ◽  
pp. 9105-9114 ◽  
Author(s):  
Kara G. Lassen ◽  
Justin R. Bailey ◽  
Robert F. Siliciano

ABSTRACT A stable latent reservoir for human immunodeficiency virus type 1 (HIV-1) in resting memory CD4+ T cells presents a barrier to eradication of the infection even in patients on highly active antiretroviral therapy. Potential mechanisms for latency include inaccessibility of the integrated viral genome, absence of key host transcription factors, premature termination of HIV-1 RNAs, and abnormal splicing patterns. To differentiate among these mechanisms, we isolated extremely pure populations of resting CD4+ T cells from patients on highly active antiretroviral therapy. These cells did not produce virus but retained the capacity to do so if appropriately stimulated. Products of HIV-1 transcription were examined in purified resting CD4+ T cells. Although short, prematurely terminated HIV-1 transcripts have been suggested as a marker for latently infected cells, the production of short transcripts had not been previously demonstrated in purified populations of resting CD4+ T cells. By separating RNA into polyadenylated and nonpolyadenylated fractions, we showed that resting CD4+ T cells from patients on highly active antiretroviral therapy produce abortive transcripts that lack a poly(A) tail and that terminate prior to nucleotide 181. Short transcripts dominated the pool of total HIV-1 transcripts in resting CD4+ T cells. Processive, polyadenylated HIV-1 mRNAs were also present at a low level. Both unspliced and multiply spliced forms were found. Taken together, these results show that the nonproductive nature of the infection in resting CD4+ T cells from patients on highly active antiretroviral therapy is not due to absolute blocks at the level of either transcriptional initiation or elongation but rather relative inefficiencies at multiple steps.


2009 ◽  
Vol 54 (2) ◽  
pp. 937-939 ◽  
Author(s):  
Caroline Barau ◽  
Constance Delaugerre ◽  
Joséphine Braun ◽  
Nathalie de Castro ◽  
Valérie Furlan ◽  
...  

ABSTRACT Raltegravir concentrations and human immunodeficiency virus type 1 (HIV-1) RNA levels in semen samples from 10 treatment-experienced HIV-1-infected patients were measured after 24 weeks of raltegravir-based highly active antiretroviral therapy (HAART). Semen and plasma HIV-1 RNA levels were below 100 copies/ml and 50 copies/ml, respectively, in all samples. The median raltegravir concentrations in semen samples (n = 10) and in plasma samples (n = 9) drawn simultaneously were 345 (range, 83 to 707) ng/ml and 206 (range, 106 to 986) ng/ml, respectively. The median semen-to-plasma ratio of raltegravir concentration was 1.42 (range, 0.52 to 6.66), indicating good although variable levels of drug penetration of raltegravir in the seminal compartment.


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