Mucosal type mast cells, in contrast to the serosal type ones, do not respond to cationic agents, or to the complement-derived peptides C3a and C5a . Earlier we have found that while C3a does not activate the rat mucosal type mast cells (line RBL-2H3), it strongly inhibits the IgE-mediated triggering of these cells, by interfering with the FcεRI-initiated signaling pathway . In the present study we further investigated the mechanism of this process. It is shown, that C3a interacts with the β-chain of the FcεRI complex. Binding of the complement peptide to the cells apparently causes a decrease in the proximity of the IgE-binding FcεRI. Investigating certain sequences of C3a we found that the inhibition is caused by the C-terminal sequences of the complement-peptide, ranging from positions 56 to 77 and also by a shorter sequence, ranging from positions 56 to 64. The inhibitory effect of these peptides was observed both in the case of RBL-2H3 cells and mouse bone marrow derived mast cells.
- Bone marrow derived mast cells
- Inhibition of IgE- mediated triggering
- RBL-2H3 cells
- β-chain of FcεRI
ASJC Scopus subject areas
- Immunology and Allergy