02658nas a2200229   4500000000100000008004100001653002900042653001200071100001200083700001500095700001100110700001200121700001400133700001500147700001300162245011500175856007700290300001000367490000600377520203100383022001402414       2014                            d10aNeurological involvement10aleprosy1 aHagge D1 aScollard D1 aRay NA1 aMarks V1 aDeming AT1 aSpencer JS1 aAdams LW00aIL-10 and NOS2 Modulate Antigen-Specific Reactivity and Nerve Infiltration by T Cells in Experimental Leprosy.  uhttp://www.ncbi.nlm.nih.gov/pmc/articles/PMC4161319/pdf/pntd.0003149.pdf  ae31490 v83 a<p><b>BACKGROUND: </b>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.</p><p><b>METHODOLOGY/PRINCIPAL FINDINGS: </b>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)<IL-10-/-<NOS2-/-<10NOS2-/-. While IL-10-/- mice exhibited modest FP induration compared to B6, NOS2-/- and 10NOS2-/- mice developed markedly enlarged FP marking distinct phases: early (1 month), peak (3-4 months), and chronic (8 months). IFN-γ-producing CD4+CD44+ cells responding to M. leprae cell wall, membrane, and cytosol antigens and ML2028 (Ag85B) were significantly increased in the evolved granuloma in NOS2-/- FP compared to B6 and IL-10-/- during early and peak phases. In 10NOS2-/- FP, CD4+CD44+ and especially CD8+CD44+ responses were augmented even further to these antigens as well as to ML0380 (GroES), ML2038 (bacterioferritin), and ML1877 (EF-Tu). Moreover, fragmented nerves containing CD4+ cells were present in 10NOS2-/- FP.</p><p><b>CONCLUSIONS/SIGNIFICANCE: </b>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.</p>  a1935-2735