Efficacy of Gamma Interferon and Specific Antibody for Treatment of Microsporidiosis Caused by Encephalitozoon cuniculi in SCID Mice

摘要

Microsporidia are eukaryotic, obligate, intracellular protists that are emerging pathogens in immunocompromised hosts, including AIDS patients and organ transplant recipients. The efficacy of gamma interferon (IFN-γ) for the treatment of microsporidiosis caused by Encephalitozoon cuniculi was studied by means of adoptive transfer and IFN-γ 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-γ-deficient mice. The protective effect of IFN-γ was confirmed in cytokine therapy experiments in which SCID mice receiving IFN-γ survived significantly longer than mice receiving mock injections. The administration of serum containing specific antibodies against E. cuniculi was found to prolong the survival of concurrently IFN-γ-treated SCID mice. The data presented in this study suggest that IFN-γ is potentially useful as a cytokine therapy for microsporidiosis, especially in CD4⁺ T-cell-deficient patients.