Protective Profile Involving CD23/IgE-mediated NO Release is a Hallmark of Cutaneous Leishmaniasis Patients from the Xakriabá Indigenous Community in Minas Gerais, Brazil.

In this study, we described, for the first time, specific aspects of an anti- Leishmania immune response in a Brazilian Xakriabá indigenous community. Induction of an intracellular NO pathway, triggered by the binding of IgE to CD23 receptor in IFN- γ/ IL-4 cytokines environment, was evaluated in localized cutaneous leishmaniasis ( LCL) carriers and positive Montenegro skin test ( MST) individuals without skin lesion ( MT⁺ SL⁻). Our data demonstrated that the higher frequency of CD23⁺ CD14⁺ monocytes and the increased serum levels of IgE observed in the LCL group were even higher in LCL carriers with late lesions ( LCL≥60). Furthermore, patients with LCL presented increased NO production after Leishmania (Viannia) braziliensis stimulation and this NO profile was independent of the time of the lesion (recent LCL<60 or late LCL≥60). We also showed that the increased frequency of IFN-γ⁺ and IL-4⁺ CD4⁺ T cells is related to the MT⁺ SL⁻ group. The results of biomarker signature curves demonstrated that in the MT⁺ SL⁻ group, the index signature was characterized by DAF-2T⁺ CD14⁺/ IL-4⁺ CD8⁺/ IFN-γ⁺ CD4⁺/ IL-4⁺ CD4⁺. On the other hand, the LCL group presented a higher index of DAF-2T⁺ CD14⁺/ CD23⁺ CD14⁺/ IL-4⁺ CD8⁺, associated with a lower index of IFN-γ⁺ CD8⁺. Considering the time of lesion, data analysis demonstrated that the main differences observed were highlighted in LCL<60 patients, with a higher index of CD23⁺ CD14⁺, which was also present in LCL≥60 patients. In conclusion, our data suggest that the protective immune response involving CD23-IgE-mediated NO release is a hallmark of patients with LCL. However, in MT⁺ SL⁻ individuals, another different leishmanicidal mechanism seems to be involved. [ABSTRACT FROM AUTHOR]