Regulatory T-cell profile in early and late lesions of cutaneous leishmaniasis due to Leishmania major

Abstract

• Context: Cutaneous leishmaniasis (CL) is a public health problem in several endemic countries. Recent studies on mouse model and also a few clinical experiments showed that the type of immune response generated at the site of infection and especially balance between regulatory and effector T-cells determines the outcome of the disease toward self-limiting or long-lasting lesions.
• Aims: The aim of this study was to evaluate the role of natural regulatory T cells (nTregs) in early and late cutaneous lesions of human Leishmania major (L. major) infection.
• Settings and Design: Skin biopsies were collected from parasitologically proven lesions of 28 CL patients, divided into two groups of early and late lesions. The causative agents were identified to be L. major.
•  Materials and Methods: Quantitative real-time reverse transcription polymerase chain reaction (PCR)<auq>AU: Please define PCR and PBMC at first occurrence.</ auq> and immunofluorescent staining of biopsies were used to assess the Foxp3 mRNA expression and frequency of nTregs in two groups. Mann-Whitney U test was used to determine the significance of deference between the two groups.
• Results: Mean relative expressions of Foxp3 mRNA were 0.53 Â} 0.23 and 1.26 Â} 0.99 in early and late lesions, respectively, which was significantly upper in chronic lesions (P = 0.007). Parallel results were obtained in tissue staining method.
• Conclusions: Increased in gene expression and protein staining of nTreg markers in chronic biopsy samples indicates a role for these cells in chronic L. major induced leishmaniasis and supports the effectiveness of regulatory T cell-based immunotherapy for treatment of chronic CL.
• Key words: Cutaneous, fluorescent antibody technique, Leishmania major, leishmaniasis, real-time PCR, regulatory T cells