title: Detection of different macrophage-activating factor and interferon activities in supernatants of chicken lymphocyte cultures.
abstract: Chicken spleen lymphocytes were cultivated under various conditions in order to produce and characterise functionally avian lymphokines. Biological properties of lymphokine-containing culture supernatants were evaluated with regard to their antiviral activity and their effects on cultured bone marrow-derived chicken macrophages, including induction of cytostatic activity, enhancement of phagocytic activity towards vital Candida albicans, and giant cell formation. Optimal doses of concanavalin A (ConA) for stimulation of lymphocytes varied between 2.5 and 40 microg/ml, depending on the cell concentration and presence or absence of serum. Lymphokine production occurred even without exogenous mitogen stimulation when cells were cultured at sufficiently high concentrations (1 to 2 x 10(7) cells/ml). Cytostasis-inducing capacity of lymphokine preparations against lymphoblastoid MDCC-RP1 cells was always combined with the presence of antiviral activity. Experimental results suggested that these two activities had to be attributed to at least two distinct lymphokines, i.e. macrophage-activating factor and interferon (IFN). ConA stimulation of lymphocytes from a single donor appeared to be the appropriate signal for production of IFN-gamma. Endogenous stimulation in mixed lymphocyte cultures more appropriately triggered production of IFN-alpha or IFN-ss, although production of IFN-gamma was not completely suppressed. Phagocytic activity of macrophages could also be increased by a cytokine present in conditioned media from confluent cultures of chicken embryo fibroblasts, chicken kidney cells, or bone marrow-derived chicken macrophages. In lymphokine preparations, this mediator may-even be a cofactor necessary for induction of multinucleated giant cell formation of cultured macrophages.
authors.affiliation: Institute of Veterinary Pathology, Free University Berlin, Berlin 37, W. Germany.
authors.forename: H
authors.initials: H
authors.lastname: Weiler
authors.forename: V
authors.initials: V
authors.lastname: Von Bülow