Evaluation of Regulatory Immune Response in Skin Lesions of Patients Affected by Nonulcerated or Atypical Cutaneous Leishmaniasis in Honduras, Central America

Author(s)

Araujo Flores, Gabriela Venicia ; Sandoval Pacheco, Carmen Maria ; Tomokane, Thaise Yumie ; Ochoa, Wilfredo Sosa ; Valeriano, Concepcion Zuniga ; Castro Gomes, Claudia Maria ; Pereira Corbett, Carlos Eduardo ; Laurenti, Marcia Dalastra

• Document type: Journal article
• Source: Mediators of Inflammation; v. 2018, p. 7-pg., 2018-01-01.

Abstract

In Honduras, Leishmania (L.) infantum chagasi causes both visceral leishmaniasis (LV) and nonulcerated or atypical cutaneous leishmaniasis (NUCL). NUCL is characterized by mononuclear inflammatory infiltration of the dermis, composed mainly of lymphocytes followed by macrophages with discrete parasitism. Considering that little is known about the pathogenesis of NUCL, the aim of this study was to evaluate the regulatory response in situ in skin lesions of patients affected by NUCL. Biopsies (n = 20) from human cutaneous nonulcerative lesions were collected and processed by usual histological techniques. The in situ regulatory immune response was evaluated by immunohistochemistry using antihuman CD4, FoxP3, IL-10, and TGF-beta antibodies. CD4(+), FoxP3(+), TGF-beta(+), and IL-10(+) cells were observed in the dermis with inflammatory infiltration in all studied cases and at higher densities compared to the normal skin controls. A positive and strong correlation was observed between CD4(+) and FoxP3(+) cells, and a positive and moderate correlation was observed between FoxP3(+) and TGF-beta(+) but not with IL-10(+) cells. The data suggest that T regulatory FoxP3(+) cells and the regulatory cytokines, especially TGF-beta, play an important role in the immunopathogenesis of NUCL, modulating a cellular immune response in the skin, avoiding tissue damage, and leading to low tissue parasitic persistence. (AU)

• FAPESP's process: 14/50315-0 - Leishmaniasis in Latin America: an advanced perspective on immunopathogenetic factors of cutaneous and visceral infection, immunomodulators of the sandflies vector saliva and immunogenic exo-antigens of Leishmania (L.) infantum chagasi as vaccine candidates
• Grantee: Marcia Dalastra Laurenti
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 15/01154-7 - Non-ulcerated or atypical cutaneous leishmaniasis caused by Leishmania infantum chagasi in Amapala municipality, Valle, Honduras: immune-histological characterization of the skin lesions
• Grantee: Carmen Maria Sandoval Pacheco
• Support Opportunities: Scholarships in Brazil - Master