Beta-endorphin stimulates Ia expression on mouse B cells by inducing interleukin-4 secretion by CD4+ T cells.
In the present study we show that the opioid peptide beta-endorphin (beta-End) enhances Ia expression on murine B cells in cultures of unseparated spleen cells, mediated by low concentrations of IL-4 in the absence of antigenic or mitogenic stimulation. Since this effect was not found with purified B cells and no enhancement of IL-4 receptor expression on B cells could be observed, we studied the effect of beta-End on IL-4 production. To this end, purified CD4+ T cells were stimulated with suboptimal concentrations of Con A in the presence of irradiated spleen cells. It was indeed shown that beta-End enhances IL-4 production. To establish the role of macrophages in this process, we measured IL-1 and IL-6 production under the influence of beta-End. Splenic adherent cells as well as peritoneal macrophages produced higher levels of IL-1 and IL-6 in response to beta-End, whereas IL-1 was shown to enhance Ia expression similar to beta-End. Using anti-IL-6 it was demonstrated that IL-6 was required for the stimulation of Ia expression by beta-End. It is concluded that a local increase in beta-End may result in upregulation of Ia expression on B cells, thereby most likely improving their antigen-presenting capacity.
van den Bergh
P
P
Section of Immunology, TNO-Institute of Ageing and Vascular Research, Leiden, The Netherlands.
Rozing
J
J
Nagelkerken
L
L
D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology*; D015496:CD4-Positive T-Lymphocytes / Q000378:metabolism*; D000949:Histocompatibility Antigens Class II / Q000378:metabolism*; D066298:In Vitro Techniques; D053590:Interleukin 1 Receptor Antagonist Protein; D007375:Interleukin-1 / Q000378:metabolism; D015847:Interleukin-4 / Q000378:metabolism*; D015850:Interleukin-6 / Q000378:metabolism; D008213:Lymphocyte Activation; D008264:Macrophages / Q000378:metabolism; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D009270:Naloxone / Q000494:pharmacology; D010529:Peritoneal Cavity / Q000166:cytology; D012795:Sialoglycoproteins / Q000494:pharmacology; D013154:Spleen / Q000166:cytology; D001615:beta-Endorphin / Q000494:pharmacology*
D000949:Histocompatibility Antigens Class II; C507764:Il1rn protein, mouse; D053590:Interleukin 1 Receptor Antagonist Protein; D007375:Interleukin-1; D015850:Interleukin-6; D012795:Sialoglycoproteins; D015847:Interleukin-4; D009270:Naloxone; D001615:beta-Endorphin