Submitted to: Journal of Interferon Research
Publication Type: Abstract Only
Publication Acceptance Date: 8/1/1996
Publication Date: N/A
Technical Abstract: Previous research indicated that a protein secreted by porcine alveolar macrophages, stimulated by IgG or beta-glucan, cross reacted with antihuman interleukin-1 receptor antagonist (IL-1Ra). In this study, we examined some of the effects of recombinant human IL-1Ra on porcine blood neutrophils and peripheral blood mononuclear cells (PBMC). Porcine neutrophils were incubated for 30 minutes with 500 pg/ml rhIL-1,50 ng/ml rhIL-1Ra, both cytokines, or only media, and each of those treatments plus LPS (1 micro-g/ml). Adhesion molecule (CD18) and LPS receptor (CD14) expression and TNF-alpha and nitric oxide production were measured. PBMC were stimulated with the same treatments for 24 hours and lymphocyte blastogenesis was measured colormetrically. Lymphocyte proliferation was suppressed by IL-1Ra (P<0.01). At the concentrations of IL-1 and IL-1Ra used here, only slight trends of suppression by IL-1Ra were seen for nitric coxide production (419 nM for IL-1 + LPS and 138 when the receptor antagonist was also included) and only LPS effects on TNF production were detected (268 pg/ml without and 520 pg/ml with LPS). The cytokines had no effect on the CD18 or CD14 molecule expression on neutrophils as these experiments were conducted. Recombinant human IL-1Ra was effective in suppressing the effects of IL-1 on porcine lymphocytes but not neutrophils at concentrations that are approximated 5 times physiological concentrations of those cytokines in humans. Therefore, the IL-1Ra produced by pigs in response to IgG or beta-glucan may have profound effects on the outcome of an immune response by regulation of the lymphocyte population.