Characterization of a (BALB/c x C57BL/6)F1 T cell hybridoma with double specificity: recognition of antigen in context of I-Ad and autoreactivity to I-Ab.

An antigen-specific, IL-2-producing, Lyt-1+2-, T cell hybridoma has been derived by the fusion of keyhole limpet hemocyanin (KLH)-primed (BALB/c x C57BL/6)F1 lymph node with BW5147 thymoma cells. The hybridoma FN13-21 recognizes KLH in association with I-Ad of BALB/c parental antigen-presenting cells, and also responds to I-Ab of the other parent C57BL/6 spleen cells in the absence of antigen. The KLH-specific response of FN13-21 is blocked by monoclonal anti-I-Ad antibody, while the response to C57BL/6 spleen cells is blocked by anti-I-Ab antibody. The specificity of the autoreactivity is to an antigen encoded for in the I-Ab region, as shown by the pattern of stimulation obtained with spleen cells from H-2-recombinant mice.