Hepatitis C Virus Induces Regulatory T Cells by Naturally Occurring Viral Variants to Suppress T Cell Responses

Figure 10

MHC class II tetramers are able to stain NS3_358–375 antigen-specific CD4⁺ T cells. PBMC from PB3019, PH1127, and PH1079 were prestained with CFSE and stimulated with NS3_358–375 synthetic peptide for 7 days. The CFSE^low cells were sorted and then stained with each tetramer. The cells are >99% CD4⁺ as determined by flow cytometry (data not shown). Trop no. 20 are CFSE^low tropomysoin-specific CD4⁺ T cells expanded by the same procedure as NS3_358–375. Trop #20 was used to control for tetramer specificity (first column). Nonspecific tetramer (CLIP) was used for each experiment (bottom 2 panels). NS3₃₅₈ and variant MHC class II tetramers stain PB3019, PH1127, and PH1079 CD4⁺ CFSE^low T cells. Not Tested (NT). Tetramer used is labeled on the right.