Mast cell membrane antigens and Fc receptors in anaphylaxis. I. Products of the major histocompatibility complex involved in alloantibody-induced mast cell activation.

Mast cell membrane antigens, coded by the K, I and D regions of the major histocompatibility complex of the mouse, were investigated for their presence at the cell surface and their participation in alloantibody-induced anaphylactic degranulation (DAAD). Anti-H-2 K, as well as anti-H-2 D antibodies were found to elicit DAAD. Recognition, on the mast cell membrane, of any product of the K or the D regions, either as the whole molecule, or as public or private antigens only, or even as a single private specificity, enabled alloimmune sera to trigger mast cell degranulation. By contrast, anti-Ia antibodies failed to elicit DAAD. By the autoradiographic technique, peritoneal mast cells were found to constitute a single homogeneous population, bearing H-2 D-coded antigens, although in smaller amounts than other peritoneal cells, but no Ia antigens or, if any, in much smaller amounts than other peritoneal cell type. These findings bring new evidence that mast cell alloantigens do participate in anaphylactic alloantibody-induced mast cell degranulation, by allowing bridging of (one?) Fc receptor with H-2 molecules.