Synthesis, Assembly, and Secretion of Gamma Globulin by Mouse Myeloma Cells

Abstract

The fully assembled gamma G globulin molecule consists of two heavy and two light polypeptide chains linked by disulfide bonds. The synthesis and assembly of this multichained molecule can be effectively studied in transplantable mouse plasma cell tumors which synthesize large amounts of homogeneous gamma globulin (1). In some of these tumors blocks at different stages in the assembly process (2, 3) make it possible to identify precursors of the assembled gamma globulin molecule.In previous studies Merwin plasma cell t u m o r -l l (MPC-11) 1 myeloma cells freshly dissociated from tumors were found to secrete fully assembled molecules (HzL2), half molecules (HI.), light chain dimers (L2), and free light chains (L) (4). The production of relatively large amounts of partially assembled molecules could have been due to significant numbers of nonviable cells and to the suboptimal metabolic conditions in the incubation mixture. Since some of the subunits appeared to be end products while others were precursors of the fully assembled molecule (4), it was important to determine whether all the precursors could be produced by an individual cell.These possibilities have now been explored in MPC-11 myeloma cells adapted to growth in continuous culture. Such cultures provided a uniform population of viable cells which could be studied during logarithmic growth to ensure

Synthesis and Assembly of Immunoglobulins by Malignant Human Plasmacytes

“…However, degradation has been reported in some mouse tumors (6,7). No evidence is available on the degree of homogeneity of malignant human plasma cells but studies with certain mouse tumors have demonstrated a heterogeneity with respect to assembly and synthesis of immunoglobulin subunits (26,27).…”

Requirements for control of B‐cell lymphoma by NK cells

“…Cells were kept at 371C in a humidified 5% CO 2 atmosphere. A20 and MPC11 are BALB/cderived B-cell lymphoma cell lines [45,46]. The variant A20 low expressing reduced levels of MHC class I was generated by transfection of A20 with an mCMV-derived gene [6].…”

Synthesis, Assembly, and Secretion of Gamma Globulin by Mouse Myeloma Cells

“…The MPC-11 cell line was adapted to continuous culture in this laboratory and has been described in detail elsewhere (4,5). The P3 cell line was originally adapted to culture from the MOPC 21 tumor by Dr. Horibata at the Salk Institute, and has been described in detail by Schubert (6).…”

“…:--Single cell suspensions were prepared from tumor fragments and from popliteal lymph nodes as described previously (4,5), and were suspended in Eagle's spinner medium (8) containing 1/20th the normal amounts of valine, threonine, and leucine. In the continuous labeling experiments, 15 )< 106 cells in 3 ml were incubated at 37°C with 3 #Ci each of L-valine-liC, threonine-14C, and leucine-14C (uniformly labeled, specific activity > 0.15 Ci/mmole, New England Nuclear Corp., Boston, Mass.).…”