ESTABLISHMENT AND CHARACTERIZATION OF AN ANTIIDIOTYPIC CD4(-) T-CELL LINE TO MURINE ANTI-ALPHA(1-]3) DEXTRAN ANTIBODY() CD8()

It is known that anti-alpha(1 --> 3) dextran antibodies of BALB/c mice are ordinarily of distinctive idiotypes (Id), one of which is the ind ividual idiotype (IdI) that is represented by J558 or M104E to myeloma protein. In the present study, we established T cell line of Th1 type which recognized the Id of anti-alpha(1 --> 3) dextran antibody, and investigated its specificity and functions. The T cell line, named J-2 R, had a phenotype of CD3(+) CD4(+) CD8(-) and expressed alpha beta-T cell receptors (TcR). J-2R proliferated in response to J558 in an I-E( d)-restricted manner but did not respond to M104E which had substituti on at amino acids 100 and 101. We confirmed that J-2R recognized J558 IdI, using synthetic peptides corresponding to two serial amino acid r esidues, Arg(100) and Tyr(101), spanning the J558 IdI in the third hyp ervariable region (hv3) of the heavy chain. alpha(1 --> 3) dextran-bin ding B cells which were isolated from dextran-immunized mice activated J-2R, but B cells from nonimmune mice did not. J-2R produced IL-2, IF N-gamma and IL-6, but did not produce IL-4, IL-5, or IL-10. Furthermor e, J-2R inhibited the growth of J558 myeloma cells inoculated to the s yngeneic mice in vivo. These findings suggest that Id-specific CD4(+) T cells, J-2R, are involved in Id network and may play a role in vivo. J-2R is useful for analysis of the role of the Id-specific helper T c ells in immune network because J558 IdI is frequently present on anti- alpha(1 --> 3) dextran antibodies. (C) 1996 Academic Press, Inc.