Cytokine response to infection with the microsporidian, Encephalitozoon cuniculi

The production of three cytokines, interferon gamma (IFN-gamma), interleukin 10 (IL-10) and interleukin 12 (IL-12), was measured after intraperitoneal infection of immunocompetent Balb/c mice and immunodeficient SCID mice with the microsporidian, Encephalitozoon cuniculi Levaditi, Nicolau et Schoen, 1923. High levels of IFN-gamma were detected in ex vivo cultures of peritoneal exudate cells (PEC) of Balb/c mice, a lower, but earlier IFN-gamma response was observed in PEC from SCID mice. The early IL-10 response was detected in ex vivo cultures of splenocytes from Balb/c but not from SCID mice, explaining a delay in the IFN-gamma response in Balb/c mice. IL-12 was detected in PEC cultures from SCID mice, indicating an alternative pathway of IFN-gamma production by NK cells stimulated by IL-12 derived from macrophages.