T cell regulation of light chain expression: preferential enhancement of Ig kappa production by T cells in the response to DNP.

We have reported that the relative amounts of Ig kappa and Ig lambda anti-DNP antibodies produced depend on the molecular form in which the hapten was presented. Here we confirm this finding by demonstrating that 1) the effects of adjuvant are not sufficient to result in differential light chain production and 2) the presence of some DNP-containing epitopes unique to DNP-KLH are not sufficient to give rise to enhancement of Ig kappa production. We further demonstrate that preferential augmentation of Ig kappa in the response to DNP is a T cell-mediated effect. Although we cannot rule out the possibility that some Ig kappa antibodies specific for protein-conjugated DNP require T cells for their expression, one of several other possible mechanisms whereby T cells influence light chain production is considered likely.