Involvement of the SgIGSF/Necl-2 adhesion molecule in degranulation of mesenteric mast cells.

Spermatogenic immunoglobulin superfamily (SgIGSF) expressed on nerve and mast cells, binds homophilically between both in culture. In the steady-state mesentery of mice, the proportion of morphologically degranulating mast cells was approximately 20%, and it increased nearly two-fold when the mesenteric nerve root was stimulated electrically. In contrast, there was no significant increase detectable in the mesentery of MITF-mutants, from which bone marrow-derived cultured mast cells (BMMCs) lack SgIGSF. BMMCs from SgIGSF-knockout mice transplanted to the mesentery of mast cell-deficient W/W(v) mice did not degranulate in response to the mesenteric nerve stimulation, whereas transfection with SgIGSF cDNA restored those responses. SgIGSF appeared to promote communication between nerves and mast cells in the murine mesentery.