Immunological effects of IgT synthesized by thetapositive cell lines

The effects of immunologlobulin (Ig) purified by affinity chromatography from two cultured T cell lines on in vitro immune responses was studied. IgT purified from both EL‐4 and WEHI‐22 suppressed the thymus‐dependent IgM response, but had no effect on thethymus‐independent IgM response. In contrast, the IgG responses to both thymus‐dependent and independent antigens were augmented at optimal concentrations of IgT. Ig of B cell origin — serum Ig, myeloma Ig, B cell surface Ig — did not have any of these effects. Because of the similarity of the effects of IgT purified from the lymphomas with the effects of T cells and their IgT, it seems likely that the IgT obtained from EL‐4 and WEHI‐22 cell lines are analogues of normal IgT and thus should be useful in elucidating some of the chemicaland biological properties of IgT.