[Preliminary study on HBsAg-specific T cell clones]

Abstract

Clones of HBsAg-reactive CD8+ and CD4+ T cells were obtained from PBM of a hepatitis B immunized individual whose PBM proliferated when cultured with HBsAg. Lymphocytes were activated by culturing for 2 weeks with HBsAg and high concentrations of IL-2, then cloned in the presence of irradiated HBsAg-activated PBM and autologous EBV-transformed B cells, together with antigen and IL-2. All clones examined exhibited proliferation in an antigen-specific manner. Of 7 clones examined by flow cytometry, 4 were CD4+, CD8-; and 3 were CD4-, CD8+. Several clones produced IL-2 activity after stimulation with HBsAg. Since development of CD8+ T-cell clones specific for soluble antigens has been difficult, the high frequency with which CD8+ cells were cloned in these experiments suggests that the cloning strategy employed may have general use for development of CD8+ clones, Availability of HBV-specific T cell clones of different phenotype may help elucidate the mechanisms of immunotolerance in HB infection.