Role of L3T4 Antigen in the Activation of Various Functions of Lyt-1⁺2^- T Cells against Vaccinia Virus

抄録

The present study defines assay systems for vaccinia virus-reactive Lyt-1⁺2^- T cells mediating various functions and investigates the positivity of L3T4 antigen on these Lyt-1⁺2^- T cells as well as the role of L3T4 antigen in the activation of these T cells with respect to their functions. C3H/He mice were immunized against vaccinia virus by inoculating viable virus intraperitoneally (i.p.). Anti-vaccinia virus reactivity in lymphoid cells from these immunized mice was assessed by a) proliferative response, b) helper T cell activities involved in cytotoxic T lymphocyte (CTL) and B cell (antibody) responses, c) delayed type-hypersensitivity (DTH) response, and d) production of lymphokines such as interleukin 2 (IL2) and macrophage-activating factor (MAF). The results demonstrate that all of the above anti-vaccinia virus responses were mediated by Lyt-1⁺2^- T cells and that these Lyt-1⁺2^- T cells expressed L3T4 antigens on their cell surfaces. Moreover, such anti-vaccinia Lyt-1⁺2^- T cell responses were inhibited in the presence of anti-L3T4 antigen antibody. These results indicate that there is a reciprocal relationship between Lyt-2 and L3T4 markers, and that L3T4 antigen is closely related to the activation of various functions of anti-vaccinia virus Lyt-1⁺2^- T cells.