Quantification of the number of cytotoxic T cells specific for an immunodominant HCV-specific CTL epitope primed by DNA immunization

Priming of strong cellular immune responses to hepatitis C (HCV) is thought to be important for eradication of infection. Although productive infectio n of HCV occurs only reproducibly in humans and chimpanzees, definition of HCV-specific T cell epitopes in mice is necessary to screen efficiently HCV vaccine strategies for their ability to prime cellular immune responses. O ut of seven strains of mice screened for immunodominant CTL epitopes agains t HCV-la Core, E2, NS5a and NS5b, only one epitope (p214K9) in only one mou se strain was identified. Enumeration of p214K9-specific CD8+ cells by flow cytometry revealed that the number of epitope specific CTL primed by 'nake d' DNA immunization was lower than that reported during viral infection. Th e p214K9 epitope described here, combined with analysis of CTL responses by flow cytometry, should be instrumental in ranking various HCV vaccine stra tegies for their ability to prime CTL responses, (C) 2000 Elsevier Science Ltd, All rights reserved.