title: Identification of conserved and HLA promiscuous DENV3 T-cell epitopes.
abstract: Anti-dengue T-cell responses have been implicated in both protection and immunopathology. However, most of the T-cell studies for dengue include few epitopes, with limited knowledge of their inter-serotype variation and the breadth of their human leukocyte antigen (HLA) affinity. In order to expand our knowledge of HLA-restricted dengue epitopes, we screened T-cell responses against 477 overlapping peptides derived from structural and non-structural proteins of the dengue virus serotype 3 (DENV3) by use of HLA class I and II transgenic mice (TgM): A2, A24, B7, DR2, DR3 and DR4. TgM were inoculated with peptides pools and the T-cell immunogenic peptides were identified by ELISPOT. Nine HLA class I and 97 HLA class II novel DENV3 epitopes were identified based on immunogenicity in TgM and their HLA affinity was further confirmed by binding assays analysis. A subset of these epitopes activated memory T-cells from DENV3 immune volunteers and was also capable of priming naïve T-cells, ex vivo, from dengue IgG negative individuals. Analysis of inter- and intra-serotype variation of such an epitope (A02-restricted) allowed us to identify altered peptide ligands not only in DENV3 but also in other DENV serotypes. These studies also characterized the HLA promiscuity of 23 HLA class II epitopes bearing highly conserved sequences, six of which could bind to more than 10 different HLA molecules representing a large percentage of the global population. These epitope data are invaluable to investigate the role of T-cells in dengue immunity/pathogenesis and vaccine design.
authors.affiliation: Department of Infectious Disease and Microbiology, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America ; Center for Vaccine Research, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America.
authors.forename: Eduardo J M
authors.initials: EJ
authors.lastname: Nascimento
authors.forename: Robbie B
authors.initials: RB
authors.lastname: Mailliard
authors.forename: Asif M
authors.initials: AM
authors.lastname: Khan
authors.forename: John
authors.initials: J
authors.lastname: Sidney
authors.forename: Alessandro
authors.initials: A
authors.lastname: Sette
authors.forename: Nicole
authors.initials: N
authors.lastname: Guzman
authors.forename: Michael
authors.initials: M
authors.lastname: Paulaitis
authors.forename: Andréa Barbosa
authors.initials: AB
authors.lastname: de Melo
authors.forename: Marli T
authors.initials: MT
authors.lastname: Cordeiro
authors.forename: Laura V G
authors.initials: LV
authors.lastname: Gil
authors.forename: Françoir
authors.initials: F
authors.lastname: Lemonnier
authors.forename: Charles
authors.initials: C
authors.lastname: Rinaldo
authors.forename: J Thomas
authors.initials: JT
authors.lastname: August
authors.forename: Ernesto T A
authors.initials: ET
authors.lastname: Marques
mesh_terms: D000293:Adolescent; D000328:Adult; D000818:Animals; D000956:Antigens, Viral / Q000276:immunology*; D002648:Child; D003716:Dengue Virus / Q000276:immunology*; D058501:Enzyme-Linked Immunospot Assay; D018604:Epitope Mapping; D018984:Epitopes, T-Lymphocyte / Q000276:immunology*; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D008297:Male; D051379:Mice; D008822:Mice, Transgenic; D010750:Phosphoproteins / Q000276:immunology* / Q000378:metabolism*; D011485:Protein Binding
chemical_list: D000956:Antigens, Viral; D018984:Epitopes, T-Lymphocyte; C574674:La protein, human; D010750:Phosphoproteins