Microsporidia are eukaryotic, obligate, intracellular protists that are emerging pathogens in immunocompromised hosts, including AIDS patients and organ transplant recipients. The efficacy of IFN-gamma for treatment of microsporidiosis caused by Encephalitozoon cuniculi was studied by means of adoptive transfer and IFN-gamma administration in SCID mice. While the adoptive transfer of CD4+ T cells from immunocompetent mice prolonged survival of SCID mice infected perorally with E. cuniculi, survival was not improved by adoptive transfer of CD4+ T lymphocytes from IFN-gamma-deficient mice. The protective effect of IFN-gamma was confirmed in cytokine therapy experiments in which SCID mice receiving IFN-gamma survived significantly longer than mice receiving mock injections. The administration of serum containing specific antibodies against E. cuniculi was found to prolong survival of concurrently IFN-gamma treated SCID mice. The data presented in this study suggest that IFN-gamma is potentially useful as a cytokine therapy for microsporidiosis, especially in CD4+ T cell-deficient patients.

Salát J, JelÃnek J, Chmelar J, Kopecky J.