Expression of mu and gamma immunoglobulin heavy chains in different cells of a cloned mouse lymphoid line.

Abstract

A cloned cell line [18-81] derived from mouse bone marrow and transformed by Abelson [leukemia] virus synthesized 2 different H chains, .mu. and .gamma.2B, in vitro. This characteristic is stable because it persists upon subcloning. Although most of the Ig-synthesizing cells produce .mu. or .gamma.2B H chains, a few cells contain both H chains, suggesting Ig class switching. Karyotypes show a complement of 41 chromosomes. Two copies of chromosome 12, to which Ig H chain structural genes have been assigned, were found. No L chain was found in the .mu.- or the .gamma.2B-producing cells. Fusion of the cell line with a myeloma that synthesizes neither H nor L chains caused expression of .kappa. light chain in the hybridomas synthesizing .mu. chain. No L chain was detected in the hybridomas synthesizing .gamma.2B heavy chain.