[Cultivation and activation of Th1 and Th2 clones].

Murine T helper clones are classified into two subpopulations, Th1 and Th2, according to the cytokines they produce. Immune function is considered to depend which subpopulation is activated by an antigen stimulation. These subpopulations are different from each other in humoral second signal molecules required for their proliferation produced by antigen-presenting cells. Th1 requires IL-12, and Th2 IL-1, indicating that antigen-presenting cells regulate subpopulation responding to some stimulation. These subpopulations are also different in their activation signal transduction pathway mediated by TCR stimulation, suggesting a possibility of a selective activation of these subpopulations.