title: Demonstration of a murine cell surface component with affinity for exogenous beta 2-microglobulin.
abstract: Murine and human beta 2-microglobulin (beta 2m) bind to various types of mouse cells. The binding is saturable and displays a single association constant of about 1 x 10(9) liter/mol. The binding of beta 2m to splenocytes was not affected by a variety of metabolic inhibitors but was temperature-dependent. It is suggested that the beta 2m "receptor" exhibits a temperature-dependent conformational change since the "receptor", whether integrated into the membrane or solubilized by the detergent Triton X-100, binds beta 2m poorly at low temperatures. Spleen T and B lymphocytes display more binding sites than thymocytes, kidney, liver and brain cells. The relative amounts of the beta 2m-binding "receptor" on these cell types are strongly correlated to the relative amounts of H-2 antigens. This correlation is also obvious for the teratocarcinoma cell line F9, which lacks both beta 2m "receptor" and H-2 antigens, but spermatozoa, which express very small amounts of H-2 antigens, have an appreciable amount of the beta 2m "receptor". The latter observation, together with the fact that alloantisera directed against H-2 K and D antigens do not measurably affect the binding of beta 2m to the "receptor", may argue against the notion that the beta 2m "receptor" represents H-2 antigens which have lost their endogenous beta 2m. Normal mouse serum contains a component which inhibits the binding of beta 2m to splenocytes. It is likely that this serum protein is identical to a newly discovered H-2 antigen-like glycoprotein. The beta 2m "receptor" appears to be under the control of the major histocompatibility complex as splenocytes of the H-2f haplotype bind considerably more beta 2m than splenocytes of other haplotypes.
mesh_terms: D000818:Animals; D001609:Beta-Globulins / Q000378:metabolism*; D002462:Cell Membrane / Q000276:immunology; D002478:Cells, Cultured; D006183:H-2 Antigens; D006801:Humans; D051379:Mice; D011485:Protein Binding; D011971:Receptors, Immunologic / Q000032:analysis*; D013154:Spleen; D013696:Temperature; D013950:Thymus Gland; D013997:Time Factors; D001613:beta 2-Microglobulin / Q000378:metabolism*
chemical_list: D001609:Beta-Globulins; D006183:H-2 Antigens; D011971:Receptors, Immunologic; D001613:beta 2-Microglobulin