Open Access1 alpha,25-dihydroxyvitamin D3 promotes fusion of mouse alveolar macrophages both by a direct mechanism and by a spleen cell-mediated indirect mechanism.
Author(s) -
Etsuko Abe,
Chisato Miyaura,
Hirofumi Tanaka,
Yoshiko Shiina,
Takeo Kuribayashi,
Satoshi Suda,
Yasuho Nishii,
Hector F. DeLuca,
Toshio Suda
Publication year - 1983
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.80.18.5583
Subject(s) - concanavalin a , spleen , cell fusion , microbiology and biotechnology , alpha (finance) , sephadex , cell culture , medicine , endocrinology , chemistry , cell , biology , immunology , biochemistry , in vitro , construct validity , genetics , nursing , patient satisfaction , enzyme
Extensive fusion was induced in mouse alveolar macrophages by treatment with conditioned media obtained from spleen cell cultures treated with 15 micrograms of phytohemagglutinin or concanavalin A per ml or with 12 nM 1 alpha,25-dihydroxyvitamin D3 [1 alpha,25(OH)2D3]. The fusion rate was 80-90% on day 3. In addition, 1 alpha,25(OH)2D3 added directly to alveolar macrophages induced fusion of about 35% of the cells on day 3, whereas direct addition of phytohemagglutinin and concanavalin A did not enhance fusion at all. When conditioned media from spleen cell or T cell cultures treated with 12 nM 1 alpha,25(OH)2D3 were applied to a Sephadex G-100 column, a fusion factor (Mr 37,000-70,000) could be separated from 1 alpha,25(OH)2D3. 1 alpha,25(OH)2D3 induced fusion at 0.012-120 nM in a dose-dependent manner both by direct action and by spleen cell-mediated indirect action, but the fusion rate was always much greater in the latter than in the former at each concentration of the vitamin. Of the vitamin D3 derivatives tested, 1 alpha,25(OH)2D3 was the most potent, followed successively by 1 alpha,24R,25-trihydroxyvitamin D3, 1 alpha-hydroxyvitamin D3, 25-hydroxyvitamin D3, and 24R,25-dihydroxyvitamin D3. These results clearly indicate that 1 alpha,25(OH)2D3 induces fusion of mouse alveolar macrophages by both a direct and an indirect mechanism, the latter mediated by spleen cells, probably by T cells.