TY - JOUR KW - Neurological involvement KW - leprosy AU - Hagge D AU - Scollard D AU - Ray NA AU - Marks V AU - Deming AT AU - Spencer JS AU - Adams LW AB -
BACKGROUND: Although immunopathology dictates clinical outcome in leprosy, the dynamics of early and chronic infection are poorly defined. In the tuberculoid region of the spectrum, Mycobacterium leprae growth is restricted yet a severe granulomatous lesion can occur. The evolution and maintenance of chronic inflammatory processes like those observed in the leprosy granuloma involve an ongoing network of communications via cytokines. IL-10 has immunosuppressive properties and IL-10 genetic variants have been associated with leprosy development and reactions.
METHODOLOGY/PRINCIPAL FINDINGS: The role of IL-10 in resistance and inflammation in leprosy was investigated using Mycobacterium leprae infection of mice deficient in IL-10 (IL-10-/-), as well as mice deficient in both inducible nitric oxide synthase (NOS2-/-) and IL-10 (10NOS2-/-). Although a lack of IL-10 did not affect M. leprae multiplication in the footpads (FP), inflammation increased from C57Bl/6 (B6) CONCLUSIONS/SIGNIFICANCE: The 10NOS2-/- strain offers insight on the regulation of granuloma formation and maintenance by immune modulators in the resistant forms of leprosy and presents a new model for investigating the pathogenesis of neurological involvement. BACKGROUND: Although immunopathology dictates clinical outcome in leprosy, the dynamics of early and chronic infection are poorly defined. In the tuberculoid region of the spectrum, Mycobacterium leprae growth is restricted yet a severe granulomatous lesion can occur. The evolution and maintenance of chronic inflammatory processes like those observed in the leprosy granuloma involve an ongoing network of communications via cytokines. IL-10 has immunosuppressive properties and IL-10 genetic variants have been associated with leprosy development and reactions. METHODOLOGY/PRINCIPAL FINDINGS: The role of IL-10 in resistance and inflammation in leprosy was investigated using Mycobacterium leprae infection of mice deficient in IL-10 (IL-10-/-), as well as mice deficient in both inducible nitric oxide synthase (NOS2-/-) and IL-10 (10NOS2-/-). Although a lack of IL-10 did not affect M. leprae multiplication in the footpads (FP), inflammation increased from C57Bl/6 (B6) CONCLUSIONS/SIGNIFICANCE: The 10NOS2-/- strain offers insight on the regulation of granuloma formation and maintenance by immune modulators in the resistant forms of leprosy and presents a new model for investigating the pathogenesis of neurological involvement.