Synthesis, assembly and secretion of γ globulin by mouse myeloma cells. V. Balanced and unbalanced synthesis of heavy and light chains by IgG producing tumors and cell lines

Normal lymphoid cells obtained from hyperimmunized BALB/c mice and cells from most but not all IgG producing mouse myeloma tumors and cell lines synthesized more light (L) than heavy (H) chains. While most myeloma tumors secreted their excess L chains, two tumors, MOPC 21 and MOPC 173, degraded the excess L chains and did not secrete them. A third group of tumors produced the same number of H and L chains. In the case of the MPC 11 tumor, excess L chains were synthesized by cloned tumors and cell lines.