Stimulation of rat B-lymphocyte proliferation by corticotropin-releasing factor.
The mitogenic effect of corticotropin-releasing factor (CRF) on rat lymphocytes was investigated. When rat splenocytes were cultured for 48 hr with CFR, a dose-dependent increase in incorporation of 3H-thymidine (3H-Tdr) was observed, with a maximal response at 10 nM CRF. Comparison of the proliferative effect of CRF on enriched populations of B lymphocytes, T lymphocytes, or macrophages revealed that only B lymphocytes responded following treatment with CRF. When lymphocytes derived from different lymphoid tissues were compared, CRF had a greater proliferative effect on lymphocytes derived from gut-associated lymphoid tissue (mesenteric lymph nodes and Peyer's patches) than on lymphocytes from spleen or inguinal lymph nodes; CRF had no effect on thymocytes. Synthetic fragments of CRF were used to determine which portions of the peptide are recognized by lymphocytes. The C-terminal fragments alpha-helical CRF9-41 and CRF21-41 were as potent as native CRF in stimulating B-lymphocyte proliferation, whereas CRF1-20 did not stimulate proliferation. The activity of these peptides suggests that CRF stimulates lymphocyte proliferation by cellular recognition of structural determinants in the C-terminal one-half of the peptide.
McGillis
J P
JP
Department of Medicine, University of California, San Francisco.
Park
A
A
Rubin-Fletter
P
P
Turck
C
C
Dallman
M F
MF
Payan
D G
DG
D000818:Animals; D001402:B-Lymphocytes / Q000166:cytology* / Q000187:drug effects; D002478:Cells, Cultured; D003346:Corticotropin-Releasing Hormone / Q000494:pharmacology*; D005434:Flow Cytometry; D008213:Lymphocyte Activation / Q000187:drug effects*; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D013154:Spleen / Q000166:cytology / Q000187:drug effects / Q000276:immunology; D013936:Thymidine
D003346:Corticotropin-Releasing Hormone; D013936:Thymidine