Fine specificity and idiotypic expression of monoclonal antibodies directed against poly(Tyr,Glu)-poly(DLAla)--poly(Lys) and its ordered analogue (Tyr-Tyr-Glu-Glu)-poly(DLAla)--poly(Lys).

In order to study the repertoire of poly(Tyr,Glu)-poly(DLAla)--poly(Lys) [(T,G)-A--L] specific antibodies, monoclonal antibodies were prepared by fusing myeloma cells with spleen cells from C3H.SW mice immunized with (T,G)-A--L and boosted with (Tyr-Tyr-Glu-Glu)-poly(DLAla)--poly(Lys)](T-T-G-G)-A--L]. Eleven clones which secreted homogeneous antibodies were obtained. In general, two families of monoclonal antibodies were detected: those which bind exclusively (T-T-G-G)-A--L and those which bind both (T-T-G-G)-A--L and (T,G)-A--L. Analysis for idiotypic expression revealed that only two antibodies (clones no. 103 and 160), which were found to be similar in their fine specificity, cross-reacted with antibodies against the major idiotypes of (T,G)A--L specific antibodies. Guinea-pig antibodies against clone no. 160 reacted with the polyclonal (T,G)-A--L specific antibodies, whereas antibodies against 103 monoclonal antibodies did not react with C3H.SW anti-(T,G)-A--L antibodies, but did cross-react with four other monoclonal antibodies. It appears that the idiotypic determinants expressed on polyclonal (T,G)-A--L specific antibodies are heterogeneous, and consist of at least two serologically different idiotypes detected by clones no. 103 and 160.