Analysis of localized immune responses reveals presence of Th17 and Treg cells in cutaneous leishmaniasis due to Leishmania tropica
1 National Institute of Pathology (ICMR), Safdarjung Hospital Campus, New Delhi 110029, India
2 Department of Dermatology, STD and Leprosy, SP Medical College, Bikaner, Rajasthan, India
3 Present address: Department of Microbiology & Immunology, Rosalind Franklin University of Medicine and Science, North Chicago, IL 60064, USA
4 Present address: Laboratory of Erythropoietin, National Dope Testing laboratory (NDTL), JN Stadium Complex, New Delhi 110003, India
5 Present address: Department of Tropical Medicine, Tulane University, School of Public Health, New Orleans, LA 70112, USA
6 Present address: Medical Research Centre, Jazan University, Jazan, Saudi Arabia
BMC Immunology 2013, 14:52 doi:10.1186/1471-2172-14-52Published: 22 November 2013
The interaction between the Leishmania parasite and the host cell involves complex, multifaceted processes. The disease severity in cutaneous leishmaniasis (CL) is largely dependent on the causative species. Most of the information on immune responses in human CL is available with respect to L. major infection and is lacking for L. tropica species. In this study, we employed cytokine/chemokine/receptor membrane cDNA array to capture comprehensive picture of immuno-determinants in localized human tissue during L. tropica infection. Expression of selected molecules was evaluated by real time PCR in dermal lesion tissues at pre- and post treatment stages. Plasma IL-17 level was estimated by sandwich ELISA.
The cDNA array analysis identified several immuno-determinants in tissue lesions of Indian CL including cytokines (IFN-γ, TNF-α, IL-1β, IL-10, IL-13), chemokines (IL-8, CCL2, CCL3, CCL4) and apoptotic molecules (Fas, TRAIL, IRF-1). Elevated mRNA levels of Th17 (IL-17, IL-23 and RORγt) and Treg (CD25, CTLA-4 and Foxp3) markers were observed in lesion tissues of CL patients compared to the control group, which subsided post treatment. Plasma IL-17 levels were found to be significantly higher in CL samples compared to controls.
In addition to defining comprehensive immunological responses inside lesion tissues of CL patients, our study demonstrated the presence of Th17 and Treg cells in CL caused by L. tropica.