The homogeneous-γ-G-immunoglobulin produced by mouse plasmacytoma 5563 and its subsequent heterogeneity in serum

Abstract
The mouse plasma cell tumor 5563 has been shown to synthesize and secrete a single molecular species of gamma G-immunoglobulin, which was identified by labelling with 14c-labelled amino acids. The heterogeneity of G-myeloma globulin as it is found in serum of tumor-bearing mice is due to subsequent changes in the charge properties of the newly secreted molecules. These changes have been reproduced in vitro. On incubation with sterile serum, the newly formed radioactive myeloma protein changed its chromato-graphic and electrophoretic properties to coincide with those of myeloma protein isolated from serum. Incubation of purified myeloma protein band [alpha], under a variety of conditions, led to the characteristic pattern of serum myeloma protein showing multiple electrophoretic bands. The chemical nature of the molecular changes is not yet known. It is suggested that serum-induced changes could contribute to the electrophoretic heterogeneity of specific antibodies within the gammaG-class of immunoglobulins. This demonstration of the production of a single molecular species of immunoglobulin by a plasma cell tumor provides support for the concept of ''one-cell-one antibody''.