Expression of IgG Allotypes in Human Lymphoid Tumor Lines Serially Transplantable in the Neonatal Syrian Hamster

Abstract

The presence of Gm(a), Gm(z), Gm(f), Gm(b⁰) and Gm(g), genetic factors of IgG1 and IgG3 heavy (H) chains, were determined in sera from hamsters bearing 15 human lymphoid tumors by using the standard agglutination-inhibition test. Documentation of immunoglobulin synthesis had already been established, nine lines synthesizing γ H chain, three lines synthesizing µ H chain and three lines synthesizing no immunoglobulins. All γ H chain-synthesizing tumor lines expressed Gm allotypes, but only the IgG1 determinants were detected. Tumor lines were derived from two patients known to be heterozygous for Gm(a) and Gm(f). The line from one of these patients synthesized only Gm(a). In the other line, which initially synthesized both Gm factors, there was deletion of expression of of Gm(f) on serial passage in the hamster. One line intermittently expressed on serial passage an allotype not present in the donor phenotype.