Effects of granulocyte-macrophage colony stimulating factor (GM-CSF) in vivo on cytokine production and proliferation by spleen cells.
GM-CSF is a potent stimulator of haematopoietic cells as well as some functions of granulocytes and macrophages. GM-CSF has many clinical uses; however, little is known about the effects of GM-CSF treatment in vivo on the responses of tissue lymphocytes in terms of secretion of Th-1 and Th-2 cytokines. We investigated this issue by measuring the responses of spleen cells from mice 24 h after treatment i.p. with saline or rmGM-CSF. GM-CSF at 16.7-50.0 microg/kg significantly increased (P < 0.01) spleen cellularity 2-2.5-fold and enhanced proliferative responses of non-stimulated (no mitogen) as well as concanavalin A (Con A)-stimulated spleen cells. Secretion of IFN-gamma by Con A (2.5 microg/ml)-stimulated spleen cells was significantly (P < 0.01) increased from 1.8 microg/ml by control spleen cells to 5.2 microg/ml by GM-CSF spleen cells. IL-10 production was greater (0.25 microg/ml, P < 0.05) by Con A-stimulated spleen cells from GM-CSF-treated mice compared to control spleen cells (0.06 microg/ml). By contrast, there were no significant differences in IL-4 production by Con A-stimulated spleen cells from the different groups. These results show that GM-CSF treatment increases spleen cellularity and primes lymphocytes for enhanced responses. The enhanced production of Th-1 cytokines by primed lymphocytes may partially explain the beneficial role of in vivo administration of GM-CSF in several clinical situations.
Khatami
S
S
California Institute for Medical Research, Santa Clara Valley Medical Center, San Jose, CA, USA.
Brummer
E
E
Stevens
D A
DA
D000818:Animals; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D003208:Concanavalin A / Q000494:pharmacology; D016207:Cytokines / Q000096:biosynthesis*; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000494:pharmacology*; D007371:Interferon-gamma / Q000096:biosynthesis; D016753:Interleukin-10 / Q000096:biosynthesis; D015847:Interleukin-4 / Q000096:biosynthesis; D008213:Lymphocyte Activation / Q000187:drug effects; D008297:Male; D051379:Mice; D013154:Spleen / Q000166:cytology / Q000187:drug effects / Q000276:immunology*; D018417:Th1 Cells / Q000276:immunology; D018418:Th2 Cells / Q000276:immunology
D016207:Cytokines; D003208:Concanavalin A; D016753:Interleukin-10; D015847:Interleukin-4; D007371:Interferon-gamma; D016178:Granulocyte-Macrophage Colony-Stimulating Factor