NITRIC-OXIDE INDUCING FACTOR AS A MEASURE OF ANTIGEN AND MITOGEN-SPECIFIC T-CELL RESPONSES IN CHICKENS

We describe here an assay to measure responses of T cells to in vitro stimulation with antigens and a T cell mitogen (ConA). Spleen cells fr om chickens immunized with live viruses and an inactivated antigen pro duced macrophage activating factors (MAF) in response to in vitro stim ulation with homologous antigens. The production of MAF, quantitated b y the induction of NO in a retrovirus transformed macrophage cell line , HD11 (Beug et al., 1979, Cell 18, 375) was antigen-specific and corr elated well with T cell proliferation. Further studies showed that pro duction of MAF was abrogated by cyclosporin A, anti-CD4 and anti-CD8 m onoclonal antibodies. These data suggested that production of MAF requ ired T cell activation and can be used as measure of antigen and mitog en-specific T cell responses in chickens.