Characterization of murine Th1 clones specific to egg antigen of Schistosoma japonicum and their interaction with cytokines

T cell clones (BI, B21, B7, A25) specific to the soluble egg antigen (SEA) of Schistosoma japonicum were established from C3H/He mice immunized with S EA. These clones belonged to CD3(+), CD4(+) and CD8(-)Th1 cells showing TCR -gamma delta(-), TCR-alpha beta(+) and V beta 10b(+). The molecular weights of target antigens recognized by the clones ranged from 51 to 80 kDa. Inte rleukin-2 (IL-2) and IL-12 could vigorously increase the proliferation resp onse of the T clones to SEA; while IL-10 and transforming growth factor-bet a 1 (TGF-beta 1) strongly inhibited the response. IL-12 activity was detect ed in the culture supernatant of T clones stimulated with SEA in the presen ce of APC (antigen presenting cells). This stimulation also upregulated the expression of the IL-12 receptor on the T clones. IL-12 from APC sewed as a costimulatory factor for the SEA induced proliferation of the T clone cel ls. Clone BI was able to induce granuloma formation both in vivo and in vit ro. These data provide further insight into the complicated interaction amo ng SEA, T cell and cytokine at a clonal level in S. japonicum infection.