scholarly journals The Majority of Currently Circulating Human Immunodeficiency Virus Type 1 Clade B Viruses Fail To Prime Cytotoxic T-Lymphocyte Responses against an Otherwise Immunodominant HLA-A2-Restricted Epitope: Implications for Vaccine Design

2005 ◽  
Vol 79 (8) ◽  
pp. 5000-5005 ◽  
Author(s):  
Marcus Altfeld ◽  
Todd M. Allen ◽  
Elizabeth T. Kalife ◽  
Nicole Frahm ◽  
Marylyn M. Addo ◽  
...  
Keyword(s):  
Acute Phase ◽  
T Lymphocyte ◽  
Cytotoxic T Lymphocyte ◽  
Consensus Sequence ◽  
Clade B ◽  
Immunodeficiency Virus ◽  
Hiv 1 ◽  
Restricted Epitope ◽  
Immunodominant Epitopes

ABSTRACT Human immunodeficiency virus type 1 (HIV-1) mutates to escape immune selection pressure, but there is little evidence of selection mediated through HLA-A2, the dominant class I allele in persons infected with clade B virus. Moreover, HLA-A2-restricted responses are largely absent in the acute phase of infection as the viral load is being reduced, suggesting that circulating viruses may lack immunodominant epitopes targeted through HLA-A2. Here we demonstrate an A2-restricted epitope within Vpr (Vpr59-67) that is targeted by acute-phase HIV-1-specific CD8+ T cells, but only in a subset of persons expressing HLA-A2. Individuals in the acute stage of infection with viruses containing the most common current sequence within this epitope (consensus sequence) were unable to mount epitope-specific T-cell responses, whereas subjects infected with the less frequent I60L variant all developed these responses. The I60L variant epitope was a stronger binder to HLA-A2 and was recognized by epitope-specific T cells at lower peptide concentrations than the consensus sequence epitope. These data demonstrate that HLA-A2 is capable of contributing to the acute-phase cytotoxic T-lymphocyte response in infected subjects, but that most currently circulating viruses lack a dominant immunogenic epitope presented by this allele, and suggest that immunodominant epitopes restricted by common HLA alleles may be lost as the epidemic matures.

scholarly journals Rabies Virus-Based Vectors Expressing Human Immunodeficiency Virus Type 1 (HIV-1) Envelope Protein Induce a Strong, Cross-Reactive Cytotoxic T-Lymphocyte Response against Envelope Proteins from Different HIV-1 Isolates

2001 ◽  
Vol 75 (9) ◽  
pp. 4430-4434 ◽  
Author(s):  
James P. McGettigan ◽  
Heather D. Foley ◽  
Igor M. Belyakov ◽  
Jay A. Berzofsky ◽  
Roger J. Pomerantz ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Rabies Virus ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
T Lymphocyte ◽  
Envelope Protein ◽  
Cytotoxic T Lymphocyte ◽  
Immunodeficiency Virus ◽  
Hiv 1

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.

scholarly journals Unique Acquisition of Cytotoxic T-Lymphocyte Escape Mutants in Infant Human Immunodeficiency Virus Type 1 Infection

2005 ◽  
Vol 79 (18) ◽  
pp. 12100-12105 ◽  
Author(s):  
Thillagavathie Pillay ◽  
Hua-Tang Zhang ◽  
Jan W. Drijfhout ◽  
Nicola Robinson ◽  
Helen Brown ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
T Lymphocyte ◽  
Cytotoxic T Lymphocyte ◽  
Viral Escape ◽  
Immunodeficiency Virus ◽  
Ctl Escape ◽  
Hiv 1

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.

scholarly journals Persistent Antibody Responses but Declining Cytotoxic T-Lymphocyte Responses to Multiple Human Immunodeficiency Virus Type 1 Antigens in a Long-Term Nonprogressing Individual with a Defective p17 Proviral Sequence and No Detectable Viral RNA Expression

1998 ◽  
Vol 72 (4) ◽  
pp. 3472-3474 ◽  
Author(s):  
James M. Binley ◽  
Xia Jin ◽  
Yaoxing Huang ◽  
Linqi Zhang ◽  
Yunzhen Cao ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Lymphocyte ◽  
Cytotoxic T Lymphocyte ◽  
Antibody Responses ◽  
The Past ◽  
Immunodeficiency Virus ◽  
Lymphocyte Responses ◽  
Hiv 1

ABSTRACT Long-term nonprogressor AD-18 has been infected with human immunodeficiency virus type 1 (HIV-1) for at least 16 years. During the past 5 years, he has had undetectable levels of plasma viremia, and HIV-1 cannot be isolated from him. Sequencing of proviral DNA indicates that the only HIV-1 sequences that can be identified in AD-18 have gross defects in the p17-encoding regions of the gag gene (Y. Huang, L. Zhang, and D. D. Ho, Virology 240:36–49, 1998). However, AD-18 has strong, sustained antibody responses to several HIV-1 antigens, including p17. Cytotoxic T-lymphocyte responses to Env and Gag antigens have gradually diminished over the past 4 years, at a time when the titers of antibodies to the same proteins have remained stable. We discuss what these observations might mean for the generation and maintenance of immunological memory.

scholarly journals Distinct Recognition of Non-Clade B Human Immunodeficiency Virus Type 1 Epitopes by Cytotoxic T Lymphocytes Generated from Donors Infected in Africa

1999 ◽  
Vol 73 (2) ◽  
pp. 1708-1714 ◽  
Author(s):  
Lucy Dorrell ◽  
Tao Dong ◽  
Graham S. Ogg ◽  
Simon Lister ◽  
Steve McAdam ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Lymphocytes ◽  
Cytotoxic T Lymphocytes ◽  
Human Immunodeficiency Virus Type ◽  
T Lymphocyte ◽  
Cytotoxic T Lymphocyte ◽  
Clade B ◽  
Immunodeficiency Virus ◽  
Hiv Type 1

ABSTRACT We present detailed studies of human immunodeficiency virus (HIV)-specific cytotoxic T-lymphocyte (CTL) responses to clade A or C HIV type 1 in three donors infected in East Africa. We define several novel non-clade B CTL epitopes, including some restricted by HLA alleles common in Africans. Although cross-clade CTL recognition of these epitopes does occur, recognition can also be highly clade specific.

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 ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Immune Responses ◽  
T Lymphocyte ◽  
Highly Active Antiretroviral Therapy ◽  
Cytotoxic T Lymphocyte ◽  
Highly Active ◽  
Immunodeficiency Virus ◽  
Hiv 1

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.

scholarly journals Association between Virus-Specific Cytotoxic T-Lymphocyte and Helper Responses in Human Immunodeficiency Virus Type 1 Infection

1999 ◽  
Vol 73 (8) ◽  
pp. 6715-6720 ◽  
Author(s):  
Spyros A. Kalams ◽  
S. P. Buchbinder ◽  
E. S. Rosenberg ◽  
J. M. Billingsley ◽  
D. S. Colbert ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
T Lymphocyte ◽  
Cytotoxic T Lymphocyte ◽  
Cell Counts ◽  
Wide Range ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACT Cellular immune responses are thought to be an important antiviral host defense, but the relationship between virus-specific T-helper and cytotoxic-T-lymphocyte (CTL) responses has not been defined. To investigate a potential link between these responses, we examined functional human immunodeficiency virus type 1 (HIV-1)-specific memory CTL precursor frequencies and p24-specific proliferative responses in a cohort of infected untreated persons with a wide range of viral loads and CD4 cell counts. Levels of p24-specific proliferative responses positively correlated with levels of Gag-specific CTL precursors and negatively correlated with levels of plasma HIV-1 RNA. These data linking the levels of HIV-specific CTL with virus-specific helper cell function during chronic viral infection provide cellular immunologic parameters to guide therapeutic and prophylactic vaccine development.

scholarly journals Between-Host Evolution of Cytotoxic T-Lymphocyte Epitopes in Human Immunodeficiency Virus Type 1: an Approach Based on Phylogenetically Independent Comparisons

2004 ◽  
Vol 78 (21) ◽  
pp. 11758-11765 ◽  
Author(s):  
Helen Piontkivska ◽  
Austin L. Hughes
Keyword(s):  
Natural Selection ◽  
T Lymphocyte ◽  
Cytotoxic T Lymphocyte ◽  
Ctl Epitopes ◽  
Term Evolution ◽  
Immunodeficiency Virus ◽  
Host Evolution ◽  
Hiv 1

ABSTRACT In human immunodeficiency virus type 1 (HIV-1), mutations that escape from cytotoxic T-lymphocyte (CTL) recognition have been documented, and sequence analyses have provided indirect support for the hypothesis that natural selection has favored CTL escape mutants within an infected host. In spite of such evidence for within-host selection by CTL, it has been more difficult to determine how natural selection by host CTL has influenced long-term evolution of HIV-1. We used statistical analysis of published HIV-1 genomic sequences to examine the role of natural selection in between-host evolution of CTL epitopes. Based on a phylogenetic analysis, we identified 21 pairs of closely related genomes isolated from different hosts and examined the pattern of nucleotide substitution in genomic regions encoding well-characterized CTL epitopes. The results revealed that certain CTL epitopes have been subject to repeated positive selection across the population, while others are generally conserved. Furthermore, evidence of positive selection was associated with divergence from the canonical epitope sequence and with an enhanced frequency of convergent amino acid sequence changes in CTL epitopes. The results support the hypothesis that CTL-driven selection has been a major factor in the long-term evolution of HIV-1.

scholarly journals Patient-Specific Cytotoxic T-Lymphocyte Cross-Recognition of Naturally Occurring Variants of a Human Immunodeficiency Virus Type 1 (HIV-1) p24gagEpitope by HIV-1-Infected Children

2001 ◽  
Vol 75 (10) ◽  
pp. 4941-4946 ◽  
Author(s):  
F. Buseyne ◽  
M.-L. Chaix ◽  
C. Rouzioux ◽  
S. Blanche ◽  
Y. Rivière
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Lymphocyte ◽  
Cytotoxic T Lymphocyte ◽  
Patient Specific ◽  
Interindividual Variations ◽  
Naturally Occurring ◽  
Immunodeficiency Virus ◽  
First Time ◽  
Hiv 1

ABSTRACT We tested seven human immunodeficiency virus-infected children for their cytotoxic T-lymphocyte (CTL) activities towards the p24 gag QASQEVKNW epitope and its nine variant sequences. Our data confirm that most, but not all, CTL responses are broadly cross-specific. For the first time, we show the high interpatient variability in cross-recognition of mutant CTL epitopes. These interindividual variations in the CTL response to the same epitope should be taken into account in the design and the evaluation of vaccines.

scholarly journals Intrapatient Escape in the A*0201-Restricted Epitope SLYNTVATL Drives Evolution of Human Immunodeficiency Virus Type 1 at the Population Level

2005 ◽  
Vol 79 (14) ◽  
pp. 9363-9366 ◽  
Author(s):  
Charles T. T. Edwards ◽  
Katja J. Pfafferott ◽  
Philip J. R. Goulder ◽  
Rodney E. Phillips ◽  
Edward C. Holmes
Keyword(s):  
Human Immunodeficiency Virus ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
T Lymphocyte ◽  
Cytotoxic T Lymphocyte ◽  
Population Level ◽  
Immunodeficiency Virus ◽  
Hla Type ◽  
Restricted Epitope

ABSTRACT The hypothesis that the intrapatient emergence of cytotoxic T-lymphocyte escape variants contributes to the evolution of human immunodeficiency virus type 1 at the population (interpatient) level was tested using the HLA-A*0201-restricted gag p17 epitope SLYNTVATL. Using a simple experimental design, we investigated the evolutionary processes operating within this epitope among patients while compensating for the confounding influence of intrapatient natural selection. Using this approach, we revealed a pattern of A*0201-driven escape within patients, followed by the sustained transmission of these escape variants among patients irrespective of their HLA type.

Sign in / Sign up

Export Citation Format

Share Document