Human recombinant granulocyte-macrophage colony-stimulating factor increases cell-to-cell adhesion and surface expression of adhesion-promoting surface glycoproteins on mature granulocytes.
Human granulocyte-macrophage colony-stimulating factor (GM-CSF) has been shown to inhibit migration of mature granulocytes and to enhance their antibody-dependent cellular cytotoxicity. We found that human recombinant GM-CSF also enhanced granulocyte-granulocyte adhesion and increased by two- to threefold the surface expression of Mo1 and LeuM5 (P150, 95), two members of a family of leukocyte adhesion molecules (Leu-CAM). Increased Mo1 surface expression occurred within 15 min at 37 degrees C and was maximal at the migration inhibitory concentration of 500 pM. One-half maximal rise in the expression of Mo1 on the cell surface occurred at 5 pM. The chemotactic peptide f-Met-Leu-Phe produced a comparable rise in surface Mo1 with one-half maximal expression occurring at 7 nM. Both GM-CSF and f-Met-Leu-Phe produced optimal granulocyte-granulocyte adhesion at 500 pM and 100 nM, respectively. This adhesion-promoting effect induced by either stimulus was inhibited by a mouse monoclonal antibody directed against Mo1 antigen. These data indicate that GM-CSF promotes cell-to-cell adhesion, presumably through enhanced expression of leukocyte adhesion molecules. This mechanism may explain, in part, the known effects of GM-CSF on the function of mature granulocytes.
D000818:Animals; D000945:Antigens, Differentiation, T-Lymphocyte; D000954:Antigens, Surface / Q000096:biosynthesis*; D002448:Cell Adhesion / Q000187:drug effects; D015815:Cell Adhesion Molecules; D002449:Cell Aggregation / Q000187:drug effects; D002454:Cell Differentiation; D003115:Colony-Stimulating Factors / Q000494:pharmacology*; D006224:Cricetinae; D003412:Cricetulus; D006023:Glycoproteins / Q000096:biosynthesis*; D006098:Granulocytes / Q000378:metabolism* / Q000502:physiology; D006801:Humans; D016169:Lymphocyte Function-Associated Antigen-1; D011994:Recombinant Proteins / Q000494:pharmacology*
D000945:Antigens, Differentiation, T-Lymphocyte; D000954:Antigens, Surface; D015815:Cell Adhesion Molecules; D003115:Colony-Stimulating Factors; D006023:Glycoproteins; D016169:Lymphocyte Function-Associated Antigen-1; D011994:Recombinant Proteins