Neuropathy and anti-myelin-associated glycoprotein IgM M proteins: T cell regulation of M protein secretion in vitro.
In patients with plasma cell dyscrasia, individual clones of antibody-producing cells proliferate abnormally and secrete monoclonal antibodies or M proteins in excess. The cause of the monoclonal proliferation of lymphocytes and M protein secretion is unknown and it is not known whether the M protein-secreting B cells are autonomous or capable of responding to regulatory T cells. We carried out experiments using lymphocytes from a patient with neuropathy and plasma cell dyscrasia whose IgM M protein bound to the myelin-associated glycoprotein (MAG) to determine whether secretion of the M protein in vitro was responsive to T cell help or suppression. M protein secretion was measured by an enzyme-linked immunosorbent assay system for measuring anti-MAG IgM, and the number of M protein-secreting lymphocytes was enumerated by a reverse hemolytic plaque assay specific for the M protein idiotype. The patient's B cells were maximally stimulated by pokeweed mitogen-activated autologous OKT4+ T-helper cells and the helper effect was inhibited by OKT8+ suppressor/cytotoxic T cells. Low levels of M protein secretion in the absence of T cells were also observed and there was partial stimulation of M protein secretion by T cells in the absence of pokeweed mitogen.
Latov
N
N
Godfrey
M
M
Thomas
Y
Y
Nobile-Orazio
E
E
Spatz
L
L
Abraham
J
J
Perman
G
G
Freddo
L
L
Chess
L
L
D001323:Autoantibodies; D001402:B-Lymphocytes / Q000378:metabolism*; D001798:Blood Proteins / Q000378:metabolism*; D002469:Cell Separation; D006801:Humans; D007075:Immunoglobulin M / Q000378:metabolism*; D007136:Immunoglobulins; D066298:In Vitro Techniques; D008211:Lymphocyte Cooperation; D009185:Myelin Proteins / Q000276:immunology*; D018992:Myelin-Associated Glycoprotein; D010523:Peripheral Nervous System Diseases / Q000150:complications / Q000276:immunology*; D013601:T-Lymphocytes / Q000502:physiology*; D008258:Waldenstrom Macroglobulinemia / Q000150:complications / Q000276:immunology*
D001323:Autoantibodies; D001798:Blood Proteins; D007075:Immunoglobulin M; D007136:Immunoglobulins; C009823:M-proteins (Myeloma); D009185:Myelin Proteins; D018992:Myelin-Associated Glycoprotein