Antigen-binding mutants of mouse myeloma cells.

Abstract

A cultured mouse myeloma cell line, S107, that secretes an Ig[immunoglobulin]A phosphocholine-binding Ig was cloned in soft agar and overlaid with phosphocholine-[keyhole limpet]hemocyanin. Spontaneous mutants that secrete Ig with a decreased ability to precipitate antigen were detected with this plate assay and occur at a very high frequency. From 1 such mutant, phenotypic revertants arise sponteneously with a frequency of 0.28-2.8%. This mutant and 1 of its revertants were studied; they differed from the parent and from each other serologically and in antigen binding. While it is not yet clear whether these findings bear any relationship to the normal generation of antibody diversity, they indicate that it is possible to generate antigen binding diversity in somatic cells.