Interleukin-10 has different effects on proliferation of Listeria monocytogenes in livers and spleens of mice

The aim of this study was to investigate the effect of interleukin-10 (IL-1 0) on the course of Listeria monocytogenes infection in naive and immune mi ce. Treatment with IL-10 during the course of a primary infection significa ntly decreased the number of bacteria in the spleen and did not affect the number in the liver. During a secondary infection in immune mice treated wi th IL-10, the number of bacteria was significantly lower in the spleen but significantly higher in the liver in comparison to mock-treated immune mice . IL-10 treatment during a primary Listeria infection decreased the concent ration of gamma interferon (IFN-gamma) in plasma and the toxoplasmastatic a ctivity of macrophages, whereas it increased the percentage of mildly CD3-p ositive T cells in the spleen. During a secondary infection, the concentrat ion of IFN-gamma in plasma was decreased on day 1 but remained unaffected d uring later days of infection. From these results, we conclude that IL-10 h as different effects on the proliferation oft. monocytogenes in the spleen and liver during primary and secondary Listeria infections.