scholarly journals HLA-B*44 Is Associated with a Lower Viral Set Point and Slow CD4 Decline in a Cohort of Chinese Homosexual Men Acutely Infected with HIV-1

2013 ◽  
Vol 20 (7) ◽  
pp. 1048-1054 ◽  
Author(s):  
Xin Zhang ◽  
XiaoJie Huang ◽  
Wei Xia ◽  
WeiHua Li ◽  
Tong Zhang ◽  
...  
Keyword(s):  
Viral Load ◽  
T Cell ◽  
T Cell Responses ◽  
Hla Class I ◽  
T Cell Response ◽  
Class I ◽  
Set Point ◽  
Cell Responses ◽  
Lower Magnitude ◽  
Hiv 1

ABSTRACTHLA class I alleles have been shown to have differential impacts on the viral load and the outcome of HIV-1 disease progression. In this study, HLA class I types from residents of China with acute HIV-1 infection, diagnosed between 2006 and 2011, were identified and the association between expression of individual HLA alleles and the level of the set point viral load was analyzed. A lower level of set point viral load was found to be associated with the Bw4 homozygote on HLA-B alleles. B*44 and B*57 alleles have also been found to be associated with lower set point viral load. The set point viral load of B*44-positive individuals homozygous for Bw4 was significantly lower than that of B*44-negative individuals homozygous for Bw4 (P= 0.030). The CD4 count declined to <350 in fewer B*44-positive individuals than B*44-negative individuals (X2= 7.295,P= 0.026). B*44-positive individuals had a lower magnitude of p24 pool-specific T cell responses than B*44-negative individuals homozygous for Bw4, though this was not statistically significant. The p24 pool-specific T cell responses were also inversely correlated with lower viral load (rs= −0.88,P= 0.033). Six peptides within p24 were recognized to induce the specific-T cell response in B*44-positive individuals, and the peptide breadth of response was same as that in B*44-negative individuals homozygous for Bw4, but the median magnitude of specific-T cell responses to the recognized peptides in B*44-positive individuals was lower than that in B*44-negative individuals homozygous for Bw4 (P= 0.049). These findings imply that weak p24-specific CD8+T cell responses might play an important role in the control of HIV viremia in B*44 allele-positive individuals. Such studies might contribute to the development of future therapeutic strategies that take into account the genetic background of the patients.

scholarly journals Public T-cell epitopes shared among SARS-CoV-2 variants are presented on prevalent HLA class I alleles

2021 ◽  
Author(s):  
Saskia Meyer ◽  
Isaac Blaas ◽  
Ravi Chand Bollineni ◽  
Marina Delic-Sarac ◽  
Trung T Tran ◽  
...  
Keyword(s):  
T Cell ◽  
Cell Response ◽  
T Cell Responses ◽  
Hla Class I ◽  
Cd8 T Cell ◽  
T Cell Response ◽  
Class I ◽  
T Cell Epitopes ◽  
Low Frequencies ◽  
Cell Responses

T-cell epitopes with broad population coverage may form the basis for a new generation of SARS-CoV-2 vaccines. However, published studies on immunoprevalence are limited by small test cohorts, low frequencies of antigen-specific cells and lack of data correlating eluted HLA ligands with T-cell responsiveness. Here, we investigate CD8 T-cell responses to 48 peptides eluted from prevalent HLA alleles, and an additional 84 predicted binders, in a large cohort of convalescents (n=83) and pre-pandemic control samples (n=19). We identify nine conserved SARS-CoV-2 specific epitopes restricted by four of the most prevalent HLA class I alleles in Caucasians, to which responding CD8 T cells are detected in 70-100% of convalescents expressing the relevant HLA allele, including two novel epitopes. We find a strong correlation between immunoprevalence and immunodominance. Using a new algorithm, we predict that a vaccine including these epitopes would induce a T cell response in 83% of Caucasians. Significance Statement: Vaccines that induce broad T-cell responses may boost immunity as protection from current vaccines against SARS-CoV-2 is waning. From a manufacturing standpoint, and to deliver the highest possible dose of the most immunogenic antigens, it is rational to limit the number of epitopes to those inducing the strongest immune responses in the highest proportion of individuals in a population. Our data show that the CD8 T cell response to SARS-CoV-2 is more focused than previously believed. We identify nine conserved SARS-CoV-2 specific CD8 T cell epitopes restricted by four of the most prevalent HLA class I alleles in Caucasians and demonstrate that seven of these are endogenously presented.

scholarly journals Broad Cross-Clade T-Cell Responses to Gag in Individuals Infected with Human Immunodeficiency Virus Type 1 Non-B Clades (A to G): Importance of HLA Anchor Residue Conservation

2005 ◽  
Vol 79 (17) ◽  
pp. 11247-11258 ◽  
Author(s):  
Mark J. Geels ◽  
Sheri A. Dubey ◽  
Kiersten Anderson ◽  
Elly Baan ◽  
Margreet Bakker ◽  
...  
Keyword(s):  
T Cell ◽  
T Cell Responses ◽  
Hla Class I ◽  
Class I ◽  
Cell Reactivity ◽  
Cell Responses ◽  
Clade B ◽  
Immunodeficiency Virus ◽  
T Cell Reactivity ◽  
Hiv 1

ABSTRACT We aimed to identify cross-clade human immunodeficiency virus type 1 (HIV-1) specific T-cell responses among 10 HLA-typed individuals who were infected with non-B HIV-1 strains (A, AG, C, D, G, or F) and to correlate these responses with genetic variation in documented T-cell epitopes. T-cell reactivity was tested against peptide pools spanning clade B Gag, Pol, Nef, Rev, and Tat consensus, with Gag and Nef providing the highest responses. Nine individuals who responded to clade B Gag demonstrated cross-reactive T-cell responses against clade A and C Gag pools, while six of seven responders to Nef-B reacted to clade A and C Nef pools. An inverse correlation between the height of the T-cell responses and the sequence divergence of the HLA class I-restricted epitopes was identified when we compared autologous Gag and Nef sequences with the reactive consensus pools. This could be explained for the Gag sequences through observed variations in the HLA anchor residues. Through mapping of 30 amino acid cross-clade-reactive regions using Gag-B pools, we were able to link 58% (14/24) of the T-cell responses to regions containing previously described HLA class I-restricted epitopes. Forty-two percent (10/24) of the responses were directed to regions containing new epitopes, for which predicted HLA class I motifs could be recognized in 70% (7/10) of individuals. We demonstrate here that cross-clade T-cell responses are frequently induced in individuals infected with distinct HIV-1 clades, suggesting that interclade variation outside of HLA anchor residues may have less impact on vaccine-induced T-cell reactivity than previously thought.

scholarly journals CD8+T Cell Breadth andEx VivoVirus Inhibition Capacity Distinguish between Viremic Controllers with and without Protective HLA Class I Alleles

2016 ◽  
Vol 90 (15) ◽  
pp. 6818-6831 ◽  
Author(s):  
Catherine K. Koofhethile ◽  
Zaza M. Ndhlovu ◽  
Christina Thobakgale-Tshabalala ◽  
Julia G. Prado ◽  
Nasreen Ismail ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Ex Vivo ◽  
T Cell Responses ◽  
Hla Class I ◽  
Class I ◽  
Viral Control ◽  
Gag Protein ◽  
Cell Responses ◽  
Hiv 1

ABSTRACTThe mechanisms of viral control and loss of viral control in chronically infected individuals with or without protective HLA class I alleles are not fully understood. We therefore characterized longitudinally the immunological and virological features that may explain divergence in disease outcome in 70 HIV-1 C-clade-infected antiretroviral therapy (ART)-naive South African adults, 35 of whom possessed protective HLA class I alleles. We demonstrate that, over 5 years of longitudinal study, 35% of individuals with protective HLA class I alleles lost viral control compared to none of the individuals without protective HLA class I alleles (P= 0.06). Sustained HIV-1 control in patients with protective HLA class I alleles was characteristically related to the breadth of HIV-1 CD8+T cell responses against Gag and enhanced ability of CD8+T cells to suppress viral replicationex vivo. In some cases, loss of virological control was associated with reduction in the total breadth of CD8+T cell responses in the absence of differences in HIV-1-specific CD8+T cell polyfunctionality or proliferation. In contrast, viremic controllers without protective HLA class I alleles possessed reduced breadth of HIV-1-specific CD8+T cell responses characterized by reduced ability to suppress viral replicationex vivo. These data suggest that the control of HIV-1 in individuals with protective HLA class I alleles may be driven by broad CD8+T cell responses with potent viral inhibitory capacity while control among individuals without protective HLA class I alleles may be more durable and mediated by CD8+T cell-independent mechanisms.IMPORTANCEHost mechanisms of natural HIV-1 control are not fully understood. In a longitudinal study of antiretroviral therapy (ART)-naive individuals, we show that those with protective HLA class I alleles subsequently experienced virologic failure compared to those without protective alleles. Among individuals with protective HLA class I alleles, viremic control was associated with broad CD8+T cells that targeted the Gag protein, and CD8+T cells from these individuals exhibited superior virus inhibition capacity. In individuals without protective HLA class I alleles, HIV-1-specific CD8+T cell responses were narrow and poorly inhibited virus replication. These results suggest that broad, highly functional cytotoxic T cells (cytotoxic T lymphocytes [CTLs]) against the HIV-1 Gag protein are associated with control among those with protective HLA class I alleles and that loss of these responses eventually leads to viremia. A subset of individuals appears to have alternative, non-CTL mechanisms of viral control. These controllers may hold the key to an effective HIV vaccine.

Generation of Cytotoxic T Cell Responses Directed to HLA Class I Restricted Epitopes from the Aspergillus f16 Allergen.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 1644-1644
Author(s):  
Gamal Ramadan ◽  
Barbara Davies ◽  
Viswanath P. Kurup ◽  
Carolyn A. Keever-Taylor
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Cell Response ◽  
T Cell Responses ◽  
Peptide Pool ◽  
Hla Class I ◽  
T Cell Response ◽  
Class I ◽  
Cell Responses

Abstract Invasive pulmonary aspergillosis is a primary cause of morbidity and mortality in immunocompromised patients such as hematopoietic progenitor cell transplant patients. Studies both in patients with allergic bronchopulmonary aspergillosis and murine models demonstrated the importance of a CD4+ Th1 T cell response in conferring protection from infection or preventing disease progression. The role of CD8+ T cell response to A. fumigatus is less clear. Our efforts to develop effective immunotherapeutic approaches against A. fumigatus included preparation of 104 overlapping pentadecapeptides spanning the 427 aa coding region of the aspergillus allergen, Asp f16 previously shown to induce T cell responses. Each 15 aa peptide overlaps the preceding peptide by 11 aa. Monocytes from healthy donors were treated with GM-CSF and IL-4 for 2-3 days to generate immature dendritic cells (fast DC), pulsed with a pool containing 1 μg of each pentadecapeptide, then matured with inflammatory cytokines (IL-1β, IL-6, PGE2 and TNF-alpha) for 2 days. Mature, pulsed fast DC were used to prime proliferative and CTL responses (weekly primings). T cells from 5/5 donors proliferated to the peptide pool. CTL lines were obtained from each of the first two donors that were primed. After 4 weeks the line from donor #2 was strongly cytotoxic to autologous peptide pool-pulsed and aspergillus culture extract-pulsed DC and peptide pool pulsed HLA Class I matched BLCL. Supernatant from this line killed fresh aspergillus conidia. Six of 21 smaller pools of 4-11 peptides showed reactivity. Specificity could be narrowed by screening peptides shared by the pools to 3 candidate peptides. Pool-pulsed BLCL matched for only 1 or 2 HLA alleles were used to demonstrate CTL restriction by HLA-B-3501. A database search of peptides likely to be restricted to B3501 identified the likely sequences as YFKYTAAAL, LPLCSAQTW, and GTRFPQTPM. Each induced similar reactivity when pulsed onto B-3501+ targets. CD8+ T cells steadily increased from 5.2% at week 3 to 19.0% after the 7th priming. CTL activity and IFNγ production were exclusively mediated by CD8+ T cells and CD107a was expressed by 42% of the CD8+ T cells in response to pool-pulsed BLCL indicating degranulation. CTL cross-reacted with pool pulsed B3503+ BLCL but not B3502+, or B3508+ BLCL. B3503+ BLCL presented YFKYTAAAL and to a lesser extent GTRFPQTPM but not peptide LPLCSAQTW. Our data show that DC pulsed with a pentadecapeptide pool from Asp f16 are capable of inducing a CD8+, HLA-Class I restricted Aspergillus-specific T cell response directed to multiple peptides contained within the pool. Further characterization of this system is in progress to identify additional immunogenic peptides from Asp f16 that might be useful in clinical immunotherapy protocols to prime protective immune responses to prevent or treat aspergillus infection.

scholarly journals Recognition of a Defined Region within p24 Gag by CD8+ T Cells during Primary Human Immunodeficiency Virus Type 1 Infection in Individuals Expressing Protective HLA Class I Alleles

2007 ◽  
Vol 81 (14) ◽  
pp. 7725-7731 ◽  
Author(s):  
Hendrik Streeck ◽  
Mathias Lichterfeld ◽  
Galit Alter ◽  
Angela Meier ◽  
Nickolas Teigen ◽  
...  
Keyword(s):  
T Cell ◽  
Disease Progression ◽  
T Cell Responses ◽  
Hla Class I ◽  
Class I ◽  
Hla B27 ◽  
Cell Responses ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACT Human immunodeficiency virus type 1 (HIV-1)-specific immune responses during primary HIV-1 infection appear to play a critical role in determining the ultimate speed of disease progression, but little is known about the specificity of the initial HIV-1-specific CD8+ T-cell responses in individuals expressing protective HLA class I alleles. Here we compared HIV-1-specific T-cell responses between subjects expressing the protective allele HLA-B27 or -B57 and subjects expressing nonprotective HLA alleles using a cohort of over 290 subjects identified during primary HIV-1 infection. CD8+ T cells of individuals expressing HLA-B27 or -B57 targeted a defined region within HIV-1 p24 Gag (amino acids 240 to 272) early in infection, and responses against this region contributed over 35% to the total HIV-1-specific T-cell responses in these individuals. In contrast, this region was rarely recognized in individuals expressing HLA-B35, an HLA allele associated with rapid disease progression, or in subjects expressing neither HLA-B57/B27 nor HLA-B35 (P < 0.0001). The identification of this highly conserved region in p24 Gag targeted in primary infection specifically in individuals expressing HLA class I alleles associated with slower HIV-1 disease progression provides a rationale for vaccine design aimed at inducing responses to this region restricted by other, more common HLA class I alleles.

scholarly journals Class I-restricted T-cell responses to a polymorphic peptide in a gene therapy clinical trial for α-1-antitrypsin deficiency

2017 ◽  
Vol 114 (7) ◽  
pp. 1655-1659 ◽  
Author(s):  
Roberto Calcedo ◽  
Suryanarayan Somanathan ◽  
Qiuyue Qin ◽  
Michael R. Betts ◽  
Andrew J. Rech ◽  
...  
Keyword(s):  
Gene Therapy ◽  
T Cell ◽  
T Cell Responses ◽  
Hla Class I ◽  
T Cell Response ◽  
Class I ◽  
Adeno Associated Virus ◽  
Endogenous Gene ◽  
Cell Responses ◽  
Antitrypsin Deficiency

Adeno-associated virus (AAV)-mediated gene therapy is currently being pursued as a treatment for the monogenic disorder α-1-antitrypsin (AAT) deficiency. Results from phase I and II studies have shown relatively stable and dose-dependent increases in transgene-derived wild-type AAT after local intramuscular vector administration. In this report we describe the appearance of transgene-specific T-cell responses in two subjects that were part of the phase II trial. The patient with the more robust T-cell response, which was associated with a reduction in transgene expression, was characterized more thoroughly in this study. We learned that the AAT-specific T cells in this patient were cytolytic in phenotype, mapped to a peptide in the endogenous mutant AAT protein that contained a common polymorphism not incorporated into the transgene, and were restricted by a rare HLA class I C alleles present only in this patient. These human studies illustrate the genetic influence of the endogenous gene and HLA haplotype on the outcome of gene therapy.

Polyfunctional CD8+ T-Cell Response to Autologous Peptides from Protease and Reverse Transcriptase of HIV-1 Clade B

2019 ◽  
Vol 17 (5) ◽  
pp. 350-359
Author(s):  
Liliana Acevedo-Saenz ◽  
Federico Perdomo-Celis ◽  
Carlos J. Montoya ◽  
Paula A. Velilla
Keyword(s):  
T Cell ◽  
Reverse Transcriptase ◽  
Cellular Response ◽  
T Cell Responses ◽  
Cd8 T Cell ◽  
T Cell Response ◽  
Effective Vaccine ◽  
Cell Responses ◽  
Clade B ◽  
Hiv 1

Background: : The diversity of the HIV proteome influences the cellular response and development of an effective vaccine, particularly due to the generation of viral variants with mutations located within CD8+ T-cell epitopes. These mutations can affect the recognition of the epitopes, that may result in the selection of HIV variants with mutated epitopes (autologous epitopes) and different CD8+ T-cell functional profiles. Objective:: To determine the phenotype and functionality of CD8+ T-cell from HIV-infected Colombian patients in response to autologous and consensus peptides derived from HIV-1 clade B protease and reverse transcriptase (RT). Methods:: By flow cytometry, we compared the ex vivo CD8+ T-cell responses from HIV-infected patients to autologous and consensus peptides derived from HIV-1 clade B protease and RT, restricted by HLA-B*35, HLA-B*44 and HLA-B*51 alleles. Results:: Although autologous peptides restricted by HLA-B*35 and HLA-B*44 did not show any differences compared with consensus peptides, we observed the induction of a higher polyfunctional profile of CD8+ T-cells by autologous peptides restricted by HLA-B*51, particularly by the production of interferon-γ and macrophage inflammatory protein-1β. The response by different memory CD8+ T-cell populations was comparable between autologous vs. consensus peptides. In addition, the magnitude of the polyfunctional response induced by the HLA-B*51-restricted QRPLVTIRI autologous epitope correlated with low viremia. Conclusion:: Autologous peptides should be considered for the evaluation of HIV-specific CD8+ Tcell responses and to reveal some relevant epitopes that could be useful for therapeutic strategies aiming to promote polyfunctional CD8+ T-cell responses in a specific population of HIV-infected patients.

scholarly journals Human Immunodeficiency Virus Type 1 (HIV-1)-Specific CD8+ TEMRA Cells in Early Infection Are Linked to Control of HIV-1 Viremia and Predict the Subsequent Viral Load Set Point

2007 ◽  
Vol 81 (11) ◽  
pp. 5759-5765 ◽  
Author(s):  
John W. Northfield ◽  
Christopher P. Loo ◽  
Jason D. Barbour ◽  
Gerald Spotts ◽  
Frederick M. Hecht ◽  
...  
Keyword(s):  
T Cells ◽  
Viral Load ◽  
T Cell ◽  
Absolute Number ◽  
T Cell Response ◽  
Effector Memory ◽  
Set Point ◽  
Effector Memory T Cells ◽  
Viral Load Set Point ◽  
Hiv 1

ABSTRACT CD8+ T cells are believed to play an important role in the control of human immunodeficiency virus type 1 (HIV-1) infection. However, despite intensive efforts, it has not been possible to consistently link the overall magnitude of the CD8+ T-cell response with control of HIV-1. Here, we have investigated the association of different CD8+ memory T-cell subsets responding to HIV-1 in early infection with future control of HIV-1 viremia. Our results demonstrate that both a larger proportion and an absolute number of HIV-1-specific CD8+ CCR7− CD45RA+ effector memory T cells (TEMRA cells) were associated with a lower future viral load set point. In contrast, a larger absolute number of HIV-1-specific CD8+ CCR7− CD45RA− effector memory T cells (TEM) was not related to the viral load set point. Overall, the findings suggest that CD8+ TEMRA cells have superior antiviral activity and indicate that both qualitative and quantitative aspects of the CD8+ T-cell response need to be considered when defining the characteristics of protective immunity to HIV-1.

scholarly journals Strong HLA Class I–Restricted T Cell Responses in Dengue Hemorrhagic Fever: A Double‐Edged Sword?

2001 ◽  
Vol 184 (11) ◽  
pp. 1369-1373 ◽  
Author(s):  
Hsin Loke ◽  
Delia B. Bethell ◽  
C. X. T. Phuong ◽  
Minh Dung ◽  
Joerg Schneider ◽  
...  
Keyword(s):  
T Cell ◽  
Dengue Hemorrhagic Fever ◽  
T Cell Responses ◽  
Hla Class I ◽  
Hemorrhagic Fever ◽  
Class I ◽  
Cell Responses
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