Hybridoma proteins expressing the predominant idiotype of the antiazophenylarsonate response of A/J mice.

Abstract

Hybridoma cell lines that secrete monoclonal antiazophenylarsonate antibodies were isolated from the fusion of A/J splenic lymphocytes with a myeloma cell line. A small percentage of these hybridoma proteins were recognized by rabbit antisera that detect the crossreactive idiotype characteristic of the antiazophenylarsonate response of A/J mice. The isotype, pI value and amino-terminal sequences of 4 independently derived idiotype-positive hybridoma proteins were determined. These proteins were either of the Ig[immunoglobulin]G1 or IgG2a H chain class. For 2 mice tested, the majority of the idiotype in the immune serum was of the same isotype as the fusion-derived monoclonal antibodies. The pI values of the hybridoma proteins differed and ranged from 6.9-7.6. Amino acid sequences of the H chains showed a significant degree of homology with each other, but each chain was unique in the framework or the 1st complementarity determining region (or both). A comparable pattern of sequence variation was evident for the L chains. The azophenylarsonate idiotype appears to consist of a family of nonidentical but closely related molecules that are the product of > 1 germline gene or the result of somatic mutation of a single germline gene.