抄録
We previously reported that mast cell surface antigen-1 (MASA-1) is specifically expressed on mast cells from day 3 following antigenic stimulation in a rat type I allergy model. In addition, expression of MASA-1 on a human mast cell line, HMC-1, was up-regulated by TGF-β1 and TNF-α. However, expression of MASA-1 during the course of the differentiation of mast cells is unclear. To investigate the mechanism of MASA-1 expression, bone marrow cells from NC/Nga mice were cultured for 8 weeks in the presence of SCF and IL-3 in order to differentiate bone marrow derived mast cells (BMMC), and followed by FACS analysis. The frequency of metachromatic cells was 89% at 4 weeks and 78% at 8 weeks of culture. Furthermore, many cultured bone marrow cells expressed both FcεRI and c-kit (82.6 ± 1.8 and 75.4 ± 2.3%, at 4 and 8 weeks of culture). However, the percentage of MASA-1+c-kit+ cells was less than 2.5% at 4 weeks of culture, while MASA-1 was weakly expressed on BMMC at 8 weeks of culture (11.3 ± 1.8%). The 4-week culture of BMMC was then treated with TGF-β1, and cultured for another 4 weeks. TGF-β1 did not induced MASA-1 expression on BMMC. The percentage of MASA-1+c-kit+ cells on BMMC co-cultured with fibroblasts derived from NC/Nga skin was nearly identical to that of BMMC at 8 weeks culture. These results show that MASA-1 is not markedly expressed during the course of maturation. Analysis of regulatory mechanisms of MASA-1 expression on mast cells is currently in progress. [J Physiol Sci. 2007;57 Suppl:S114]
