An in vitro CD8 T-cell priming assay enables epitope selection for hepatitis C virus vaccines.
Vaccine
; 42(22): 126032, 2024 Sep 17.
Article
em En
| MEDLINE
| ID: mdl-38964950
ABSTRACT
For the rational design of epitope-specific vaccines, identifying epitopes that can be processed and presented is essential. As algorithm-based epitope prediction is frequently discordant with actually recognized CD8+ T-cell epitopes, we developed an in vitro CD8 T-cell priming protocol to enable the identification of truly and functionally expressed HLA class I epitopes. The assay was established and validated to identify epitopes presented by hepatitis C virus (HCV)-infected cells. In vitro priming of naïve CD8 T cells was achieved by culturing unfractionated PBMCs in the presence of a specific cocktail of growth factors and cytokines, and next exposing the cells to hepatic cells expressing the NS3 protein of HCV. After a 10-day co-culture, HCV-specific T-cell responses were identified based on IFN-γ ELISpot analysis. For this, the T cells were restimulated with long synthetic peptides (SLPs) spanning the whole NS3 protein sequence allowing the identification of HCV-specificity. We demonstrated that this protocol resulted in the in vitro priming of naïve precursors to antigen-experienced T-cells specific for 11 out of 98 SLPs tested. These 11 SLPs contain 12 different HLA-A*0201-restricted epitopes, as predicted by a combination of three epitope prediction algorithms. Furthermore, we identified responses against 3 peptides that were not predicted to contain any immunogenic HLA class I epitopes, yet showed HCV-specific responses in vitro. Separation of CD8+ and CD8- T cells from PBMCs primed in vitro showed responses only upon restimulation with short peptides. We established an in vitro method that enables the identification of HLA class I epitopes resulting from cross-presented antigens and that can cross-prime T cells and allows the effective selection of functional immunogenic epitopes, but also less immunogenic ones, for the design of tailored therapeutic vaccines against persistent viral infections and tumor antigens.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Vacinas contra Hepatite Viral
/
Proteínas não Estruturais Virais
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Hepacivirus
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Linfócitos T CD8-Positivos
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Epitopos de Linfócito T
Limite:
Humans
Idioma:
En
Revista:
Vaccine
Ano de publicação:
2024
Tipo de documento:
Article
País de afiliação:
Holanda