Cytokine and free radical production by porcine microglia.

Swine have been used increasingly as an animal model for a variety of immunologic purposes. Because the functional activities of porcine microglia, the resident macrophages of the brain, have not been elucidated, highly enriched porcine microglial cell cultures were developed in the present study to assess cytokine and free radical production by these cells compared to microglia of human and murine origin. Porcine microglial cells were found to behave similarly to both human and murine cells in releasing tumor necrosis factor-alpha and interleukin-1 and in generating superoxide anion. In contrast to murine cells, porcine microglial cells, like human cells, failed to generate NO in response to cytokine stimulation. These findings suggest that swine will serve as an excellent model for investigations of central nervous system diseases in which microglia are involved in host defense or neuronal injury.