T-cell memory responses elicited by yellow fever vaccine are targeted to overlapping epitopes containing multiple HLA-I and -II binding motifs.

The yellow fever vaccines (YF-17D-204 and 17DD) are considered to be among the safest vaccines and the presence of neutralizing antibodies is correlated with protection, although other immune effector mechanisms are known to be involved. T-cell responses are known to play an important role modulatin...

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Main Authors: Andréa Barbosa de Melo, Eduardo J M Nascimento, Ulisses Braga-Neto, Rafael Dhalia, Ana Maria Silva, Mathias Oelke, Jonathan P Schneck, John Sidney, Alessandro Sette, Silvia M L Montenegro, Ernesto T A Marques
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2013-01-01
Series:PLoS Neglected Tropical Diseases
Online Access:https://doi.org/10.1371/journal.pntd.0001938
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author Andréa Barbosa de Melo
Eduardo J M Nascimento
Ulisses Braga-Neto
Rafael Dhalia
Ana Maria Silva
Mathias Oelke
Jonathan P Schneck
John Sidney
Alessandro Sette
Silvia M L Montenegro
Ernesto T A Marques
author_facet Andréa Barbosa de Melo
Eduardo J M Nascimento
Ulisses Braga-Neto
Rafael Dhalia
Ana Maria Silva
Mathias Oelke
Jonathan P Schneck
John Sidney
Alessandro Sette
Silvia M L Montenegro
Ernesto T A Marques
author_sort Andréa Barbosa de Melo
collection DOAJ
description The yellow fever vaccines (YF-17D-204 and 17DD) are considered to be among the safest vaccines and the presence of neutralizing antibodies is correlated with protection, although other immune effector mechanisms are known to be involved. T-cell responses are known to play an important role modulating antibody production and the killing of infected cells. However, little is known about the repertoire of T-cell responses elicited by the YF-17DD vaccine in humans. In this report, a library of 653 partially overlapping 15-mer peptides covering the envelope (Env) and nonstructural (NS) proteins 1 to 5 of the vaccine was utilized to perform a comprehensive analysis of the virus-specific CD4(+) and CD8(+) T-cell responses. The T-cell responses were screened ex-vivo by IFN-γ ELISPOT assays using blood samples from 220 YF-17DD vaccinees collected two months to four years after immunization. Each peptide was tested in 75 to 208 separate individuals of the cohort. The screening identified sixteen immunodominant antigens that elicited activation of circulating memory T-cells in 10% to 33% of the individuals. Biochemical in-vitro binding assays and immunogenetic and immunogenicity studies indicated that each of the sixteen immunogenic 15-mer peptides contained two or more partially overlapping epitopes that could bind with high affinity to molecules of different HLAs. The prevalence of the immunogenicity of a peptide in the cohort was correlated with the diversity of HLA-II alleles that they could bind. These findings suggest that overlapping of HLA binding motifs within a peptide enhances its T-cell immunogenicity and the prevalence of the response in the population. In summary, the results suggests that in addition to factors of the innate immunity, "promiscuous" T-cell antigens might contribute to the high efficacy of the yellow fever vaccines.
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spelling doaj-art-66f399d704bb4238a4f74dcfe99f188a2025-08-20T02:22:40ZengPublic Library of Science (PLoS)PLoS Neglected Tropical Diseases1935-27271935-27352013-01-0171e193810.1371/journal.pntd.0001938T-cell memory responses elicited by yellow fever vaccine are targeted to overlapping epitopes containing multiple HLA-I and -II binding motifs.Andréa Barbosa de MeloEduardo J M NascimentoUlisses Braga-NetoRafael DhaliaAna Maria SilvaMathias OelkeJonathan P SchneckJohn SidneyAlessandro SetteSilvia M L MontenegroErnesto T A MarquesThe yellow fever vaccines (YF-17D-204 and 17DD) are considered to be among the safest vaccines and the presence of neutralizing antibodies is correlated with protection, although other immune effector mechanisms are known to be involved. T-cell responses are known to play an important role modulating antibody production and the killing of infected cells. However, little is known about the repertoire of T-cell responses elicited by the YF-17DD vaccine in humans. In this report, a library of 653 partially overlapping 15-mer peptides covering the envelope (Env) and nonstructural (NS) proteins 1 to 5 of the vaccine was utilized to perform a comprehensive analysis of the virus-specific CD4(+) and CD8(+) T-cell responses. The T-cell responses were screened ex-vivo by IFN-γ ELISPOT assays using blood samples from 220 YF-17DD vaccinees collected two months to four years after immunization. Each peptide was tested in 75 to 208 separate individuals of the cohort. The screening identified sixteen immunodominant antigens that elicited activation of circulating memory T-cells in 10% to 33% of the individuals. Biochemical in-vitro binding assays and immunogenetic and immunogenicity studies indicated that each of the sixteen immunogenic 15-mer peptides contained two or more partially overlapping epitopes that could bind with high affinity to molecules of different HLAs. The prevalence of the immunogenicity of a peptide in the cohort was correlated with the diversity of HLA-II alleles that they could bind. These findings suggest that overlapping of HLA binding motifs within a peptide enhances its T-cell immunogenicity and the prevalence of the response in the population. In summary, the results suggests that in addition to factors of the innate immunity, "promiscuous" T-cell antigens might contribute to the high efficacy of the yellow fever vaccines.https://doi.org/10.1371/journal.pntd.0001938
spellingShingle Andréa Barbosa de Melo
Eduardo J M Nascimento
Ulisses Braga-Neto
Rafael Dhalia
Ana Maria Silva
Mathias Oelke
Jonathan P Schneck
John Sidney
Alessandro Sette
Silvia M L Montenegro
Ernesto T A Marques
T-cell memory responses elicited by yellow fever vaccine are targeted to overlapping epitopes containing multiple HLA-I and -II binding motifs.
PLoS Neglected Tropical Diseases
title T-cell memory responses elicited by yellow fever vaccine are targeted to overlapping epitopes containing multiple HLA-I and -II binding motifs.
title_full T-cell memory responses elicited by yellow fever vaccine are targeted to overlapping epitopes containing multiple HLA-I and -II binding motifs.
title_fullStr T-cell memory responses elicited by yellow fever vaccine are targeted to overlapping epitopes containing multiple HLA-I and -II binding motifs.
title_full_unstemmed T-cell memory responses elicited by yellow fever vaccine are targeted to overlapping epitopes containing multiple HLA-I and -II binding motifs.
title_short T-cell memory responses elicited by yellow fever vaccine are targeted to overlapping epitopes containing multiple HLA-I and -II binding motifs.
title_sort t cell memory responses elicited by yellow fever vaccine are targeted to overlapping epitopes containing multiple hla i and ii binding motifs
url https://doi.org/10.1371/journal.pntd.0001938
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