BACKGROUND & AIMS: In contrast to the infection with other hepatotropic viruses, hepatitis A virus (HAV) always causes acute self-limited hepatitis, although the role for virus-specific CD8 T cells in viral containment is unclear. Herein, we analyzed the T cell response in patients with acute hepatitis by utilizing a set of overlapping peptides and predicted HLA-A2 binders from the polyprotein. METHODS: A set of 11 predicted peptides from the HAV polyprotein, identified as potential binders, were synthesized. Peripheral blood mononuclear cells (PBMCs) from patients were tested for IFNγ secretion after stimulation with these peptides and ex vivo with HLA-A2 tetramers. Phenotyping was carried out by staining with the activation marker CD38 and the memory marker CD127. RESULTS: Eight out of 11 predicted HLA-A2 binders showed a high binding affinity and five of them were recognized by CD8+ T cells from patients with hepatitis A. There were significant differences in the magnitude of the responses to these five peptides. One was reproducibly immunodominant and the only one detectable ex vivo by tetramer staining of CD8+ T cells. These cells have an activated phenotype (CD38hi CD127lo) during acute infection. Three additional epitopes were identified in HLA-A2 negative patients, most likely representing epitopes restricted by other HLA-class I-alleles (HLA-A11, B35, B40). CONCLUSIONS: Patients with acute hepatitis A have a strong multi-specific T cell response detected by ICS. With the tetramer carrying the dominant HLA-A2 epitope, HAV-specific and activated CD8+ T cells could be detected ex vivo. This first description of the HAV specific CTL-epitopes will allow future studies on strength, breadth, and kinetics of the T-cell response in hepatitis A.
BACKGROUND & AIMS: In contrast to the infection with other hepatotropic viruses, hepatitis A virus (HAV) always causes acute self-limited hepatitis, although the role for virus-specific CD8 T cells in viral containment is unclear. Herein, we analyzed the T cell response in patients with acute hepatitis by utilizing a set of overlapping peptides and predicted HLA-A2 binders from the polyprotein. METHODS: A set of 11 predicted peptides from the HAV polyprotein, identified as potential binders, were synthesized. Peripheral blood mononuclear cells (PBMCs) from patients were tested for IFNγ secretion after stimulation with these peptides and ex vivo with HLA-A2 tetramers. Phenotyping was carried out by staining with the activation marker CD38 and the memory marker CD127. RESULTS: Eight out of 11 predicted HLA-A2 binders showed a high binding affinity and five of them were recognized by CD8+ T cells from patients with hepatitis A. There were significant differences in the magnitude of the responses to these five peptides. One was reproducibly immunodominant and the only one detectable ex vivo by tetramer staining of CD8+ T cells. These cells have an activated phenotype (CD38hi CD127lo) during acute infection. Three additional epitopes were identified in HLA-A2 negative patients, most likely representing epitopes restricted by other HLA-class I-alleles (HLA-A11, B35, B40). CONCLUSIONS:Patients with acute hepatitis A have a strong multi-specific T cell response detected by ICS. With the tetramer carrying the dominant HLA-A2 epitope, HAV-specific and activated CD8+ T cells could be detected ex vivo. This first description of the HAV specific CTL-epitopes will allow future studies on strength, breadth, and kinetics of the T-cell response in hepatitis A.
Authors: Hadi Karimzadeh; Muthamia M Kiraithe; Anna D Kosinska; Manuel Glaser; Melanie Fiedler; Valerie Oberhardt; Elahe Salimi Alizei; Maike Hofmann; Juk Yee Mok; Melanie Nguyen; Wim J E van Esch; Bettina Budeus; Jan Grabowski; Maria Homs; Antonella Olivero; Hossein Keyvani; Francisco Rodríguez-Frías; David Tabernero; Maria Buti; Andreas Heinold; Seyed Moayed Alavian; Tanja Bauer; Julian Schulze Zur Wiesch; Bijan Raziorrouh; Daniel Hoffmann; Antonina Smedile; Mario Rizzetto; Heiner Wedemeyer; Jörg Timm; Iris Antes; Christoph Neumann-Haefelin; Ulrike Protzer; Michael Roggendorf Journal: J Virol Date: 2018-06-13 Impact factor: 5.103
Authors: Yan Zhou; Benoît Callendret; Dan Xu; Kathleen M Brasky; Zongdi Feng; Lucinda L Hensley; Jeremie Guedj; Alan S Perelson; Stanley M Lemon; Robert E Lanford; Christopher M Walker Journal: J Exp Med Date: 2012-07-02 Impact factor: 14.307
Authors: Lin Qu; Zongdi Feng; Daisuke Yamane; Yuqiong Liang; Robert E Lanford; Kui Li; Stanley M Lemon Journal: PLoS Pathog Date: 2011-09-08 Impact factor: 6.823