Mast cells are responsible for anaphylaxis and allergy and regulate various innate and adaptive immune responses.1,2 Although several“small”Rab GTPases were reported to regulate exocytosis of mast cells,3-5 little i...Mast cells are responsible for anaphylaxis and allergy and regulate various innate and adaptive immune responses.1,2 Although several“small”Rab GTPases were reported to regulate exocytosis of mast cells,3-5 little is known about the contribution of“large”Rab GTPases.Rab44 is a large Rab-GTPase that contains a Rab-GTPase domain and some additional N-terminal domains.6,7 Here,we investigated the role of Rab44 in the physiology of mast cells and in anaphylaxis.Rab44 was expressed as two isoforms in murine bone-marrow mast cells(BMMCs),both of which were deleted in Rab44-knockout mice.The Rab44-knockout mice exhibited diminished anaphylaxis,and the Rab44-knockout BMMCs showed a decrease in FcεRImediated histamine andβ-hexosaminidase secretion.Thus,Rab44 regulates granule exocytosis in mast cells and IgEmediated anaphylaxis in mice.展开更多
基金supported by the Japan Society for the Promotion of Science KAKENHI grant numbers 15K11079,17H04379,and 18K09536.
文摘Mast cells are responsible for anaphylaxis and allergy and regulate various innate and adaptive immune responses.1,2 Although several“small”Rab GTPases were reported to regulate exocytosis of mast cells,3-5 little is known about the contribution of“large”Rab GTPases.Rab44 is a large Rab-GTPase that contains a Rab-GTPase domain and some additional N-terminal domains.6,7 Here,we investigated the role of Rab44 in the physiology of mast cells and in anaphylaxis.Rab44 was expressed as two isoforms in murine bone-marrow mast cells(BMMCs),both of which were deleted in Rab44-knockout mice.The Rab44-knockout mice exhibited diminished anaphylaxis,and the Rab44-knockout BMMCs showed a decrease in FcεRImediated histamine andβ-hexosaminidase secretion.Thus,Rab44 regulates granule exocytosis in mast cells and IgEmediated anaphylaxis in mice.
