Fig. 4.

Downregulation of HLA class I molecules at the surface of pancreatic beta cells persistently infected with CV-B4. a Pancreatic beta cells persistently infected with CV-B4 and mock-infected cells were analysed for cell surface HLA class I expression by flow cytometry at various weeks post-infection (p.i.), using anti-human HLA-ABC-FITC. Results from one representative experiment out of three are shown. b Percentage of cell surface HLA class I positive pancreatic beta cells (1.1B4) infected with CV-B4 harvested 48 h p.i., 52, 58 and 70 weeks p.i. and Panc-1 cells persistently infected with CV-B4 harvested 56 weeks p.i. The cells were analysed by flow cytometry using anti-human HLA-ABC-FITC. c Mean fluorescence intensity of cell surface HLA class I expression on mock and CV-B4-persistently infected 1.1B4 cells harvested 38 and 46 weeks p.i. was analysed by flow cytometry using anti-human HLA-ABC-FITC. Results presented in b and c are mean ± SD of three independent acute and persistent infections.*p < 0.05. d Mock and persistently infected 1.1B4 cells were stained with anti-human HLA-ABC-FITC and were evaluated for apoptosis by flow cytometry, using Annexin V APC and propidium iodide (PI) stainings. Results from one representative experiment out of three are shown. e Mock-infected and persistently infected 1.1B4 cells harvested 58 weeks p.i. were double-stained for HLA class I and for VP1 analysis by indirect immunofluorescence. Pictures from one representative experiment out of three are shown