Specific and nonspecific desensitization of mouse mast cells.

Peritoneal mast cells from BALB/c X C57BL/6I mice actively or passively sensitized with antiovalbumin and anti-hemocyanin IgE antibodies were desensitized in vitro by preincubation with antigen in suboptimal for histamine release conditions. Preincubation with an optimal antigen dose under calcium-free conditions induced rapid (15 min) complete desensitization of actively and passively sensitized cells to subsequent challenge with antigen under calcium-containing conditions. The responsiveness to anti-IgE under these conditions was unchanged in mast cells from passively and actively sensitized mice showing low level of IgE antibodies, whereas in the cells from mice showing very high IgE level partial desensitization to anti-IgE was observed (nonspecific desensitization). The results suggest the relationship between the level of mouse mast cell sensitization with IgE antibody and the mode of desensitization.