Bombesin, gastrin-releasing peptide, and neuromedin C modulate murine lymphocyte proliferation through adherent accessory cells and activate protein kinase C.
Recent data have shown the ability of bombesin-related peptides to stimulate murine macrophage functions. In the present study, we have investigated the effect of bombesin, gastrin-releasing peptide (GRP), and neuromedin C on the proliferative response of lymphocytes from murine axillary nodes, spleen, and thymus. The results show that these neuropeptides at 10(-9), 10(-10), and 10(-11) M concentrations modulate the lymphoproliferative response, stimulating to a small but significant extent the spontaneous proliferation and inhibiting to a great extent the lymphoproliferative response to the mitogen concanavalin A (Con A). This regulation is probably mediated through adherent accessory cells, since their presence for the neuropeptides to produce their effect. The increased interleukin-1 beta production by Con A in cultures of peritoneal macrophages (a model of adherent accessory cells) decreased after the addition of bombesin, GRP, and neuromedin C; this diminution is a possible mechanism for their inhibitory action on the lymphoproliferative response to Con A. In addition, these neuropeptides caused a significant protein kinase C activation in total leukocyte population and T-enriched lymphocytes from axillary nodes, as well as in peritoneal macrophages.
Departamento de Fisiología Animal, Facultad de CC. Biológicas, Universidad Complutense, Madrid, Spain.
M
M
Del Rio
A
A
Hernanz
M
M
de la Fuente
D000818:Animals; D000938:Antigen-Presenting Cells / Q000187:drug effects*; D001839:Bombesin / Q000494:pharmacology; D002448:Cell Adhesion / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D004789:Enzyme Activation; D019886:Gastrin-Releasing Peptide; D008214:Lymphocytes / Q000166:cytology / Q000187:drug effects* / Q000276:immunology; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D009479:Neuropeptides / Q000494:pharmacology*; D010446:Peptide Fragments / Q000494:pharmacology; D010455:Peptides / Q000494:pharmacology; D011493:Protein Kinase C / Q000187:drug effects*
D009479:Neuropeptides; D010446:Peptide Fragments; D010455:Peptides; D019886:Gastrin-Releasing Peptide; C040794:neuromedin C; D011493:Protein Kinase C; D001839:Bombesin