title: Autoregulation of B cell growth by an immunoglobulin M autoantibody.
abstract: This study documents the autoregulation of B cell growth by an IgM autoantibody. This autoantibody is secreted by B lymphocytes upon stimulation by polyclonal activators and is identified by its potent inhibition of B cell growth induced by these agents (endotoxin, Fc fragment of human gamma-globulin, Mycoplasma bovirhinis, and anti-mouse Ig). The autoantibody specifically affects B cells: there was no effect on mitogen- or antigen-induced T cell proliferation and of responses to interleukin 1, interleukin 2, or interferon. Nonspecific effects were excluded by the ineffectiveness of serum and myeloma IgM. Also, IgG-IgM immune complexes were excluded. The binding specificity of the IgM autoantibody is not yet defined but appears to be a B cell surface structure distinct from membrane Ig. The autoantibody constitutes a ubiquitous, autoregulatory influence on B cell growth, which may be an important component in physiologic and pathologic states of B cell homeostasis.
mesh_terms: D000818:Animals; D000918:Antibody Specificity; D001323:Autoantibodies / Q000096:biosynthesis / Q000502:physiology*; D001402:B-Lymphocytes / Q000166:cytology* / Q000276:immunology / Q000378:metabolism; D002455:Cell Division; D003470:Culture Media; D005260:Female; D006131:Growth Inhibitors / Q000502:physiology*; D006706:Homeostasis; D007075:Immunoglobulin M / Q000096:biosynthesis / Q000502:physiology*; D008213:Lymphocyte Activation; D008297:Male; D051379:Mice; D008806:Mice, Inbred AKR; D008809:Mice, Inbred C3H; D008808:Mice, Inbred CBA; D008819:Mice, Nude
chemical_list: D001323:Autoantibodies; D003470:Culture Media; D006131:Growth Inhibitors; D007075:Immunoglobulin M