Factor XIII deficiency in BALB/c mice with plasmacytoma.

These studies examined the fate of Factor XIII (fibrin-stabilizing factor) in mice with plasmacytoma (MOPC-300, MOPC-384, MOPC-467, and J-558). Plasma Factor XIII levels in these mice decreased progressively with tumor expansion. No plasma inhibitors of Factor XIII activity could be detected.

Surface immunoglobulins of lymphocytes in plasmacytoma. V. The effect of RNA-rich extract from mouse plasmacytoma MOPC 104E on the immune response.

BALB/c mice with the plasmacytoma MOPC 104E producing monoclonal IgM-lambda with antibody activity to alpha-1,3 dextran were found to have B lymphocytes with surface immunoglobulins with the immunochemical characteristics of 104E IgM capable of binding alpha-1,3 dextran. RNA extracted from this plasmacytoma induced the synthesis of such surface immunoglobulins on normal B lymphocytes in vitro and in vivo. Injection of 200 mug of MOPC 104E RNA into normal mice 72 hr prior to the administration of the antigen kept the immune response to dextran-S intact, but suppressed that to other antigens, such as DNP-Ficoll and LPS, T cell-independent antigens, and SRBC and BSA which are T cell-dependent.

Passive immunity to murine plasmacytoma by rabbit antiidiotypic antibody to myeloma protein.

Antiidiotypic antisera to LPC-1 and MOPC-300 plasmacytoma globulins were produced in rabbits by immunization with the corresponding antigen and exhaustive immunoabsorption with normal BALB/c plasma and other myeloma globulins. IgG fractions of these antisera when given intraperitoneally on three consecutive days after tumor implantation, protected the animal specifically from the grafting of the corresponding plasmacytoma or induced regression of the tumors after their initial grafting and growth. In vitro cytotoxicity of the antisera to plasmacytoma cells was not demonstrated.

Surface immunoglobulins of lymphocytes in mouse plasmacytoma. IV. Evidence for the persistence of the effect of plasmacytoma-RNA on the surface immunoglobulins of normal lymphocytes in vivo and in vitro.

The previous findings were confirmed that RNA extracted from murine plasmacytoma alters the character of the lymphocyte surface immunoglobulins (SIg) to express the idiotypic specificity of the Ig of the plasmacytoma from which the RNA was derived (cell conversion). RNA extracted from spleens of plasmacytoma-RNA-injected BALB/c mice also had convering activity, and if injected into other mice, caused the appearance of RNA active in cell conversion in spleens of the second set of mice. This activity was lost only after two additional transfers.