In Vitro Immunomodulatory Activity of a Transition-State Analog Inhibitor of Human Purine Nucleoside Phosphorylase in Cutaneous Leishmaniasis.

Natália Barbosa Carvalho,Paulo Roberto Lima Machado,Rafael De Castro Da Silva,Temis Weber Furlanetto Corte,Mayra Elizabeth Ferreira Dourado,Fernanda Grendene Pacheco,Pablo Machado,Fernanda Ventin De Oliveira Prates,Edgar Marcelino De Carvalho,Camila Farias Amorim,Diógenes Santiago Santos

doi:10.1155/2017/3062892

Abstract

Cutaneous leishmaniasis (CL) is the most common clinical form of American tegumentary leishmaniasis caused by Leishmania (Viannia) braziliensis. CL is associated with a strong Th1 immune response. This exacerbated inflammatory response is correlated with severity of disease and delays the healing time of the ulcer. The fourth-generation immucillin derivative (DI4G), a potent inhibitor of purine nucleoside phosphorylase, has been proposed as a promising agent in the treatment of diseases associated with T cell activation. Herein, we evaluated the in vitro immunomodulatory activity of DI4G in cells of patients presenting with CL. Peripheral blood mononuclear cells (PBMC) from CL patients were stimulated with soluble leishmania antigen (SLA), in the presence or absence of DI4G, and IFN-γ, TNF, CXCL9, and CXCL10 levels were determined by ELISA. Lymphocyte proliferation in the presence or absence of DI4G was also evaluated, using flow cytometry. DI4G was able to decrease (p < 0.05) IFN-γ production but did not change the TNF, CXCL9, and CXCL10 levels. DI4G decreased (p < 0.05) the lymphoproliferative response mediated by CD8+ T cells, but not that by CD4+ T cells. DI4G is able to attenuate the exaggerated immune response in CL, exhibiting immunomodulatory activity in IFN-γ production and in CD8+ T cell proliferation.

Highlights

Leishmaniasis is a global health problem and it is considered one of the most important neglected tropical diseases
To determine the concentration of DI4G that was capable of impairing cytokine production by activated T cells, Peripheral blood mononuclear cells (PBMC) from healthy individuals were cultivated with the mitogen PHA (30 μl/ml) in the absence or in the presence of different concentrations of DI4G (150 nM, 300 nM, and 600 nM)
To evaluate the modulatory action of compound in cellular immune response, PBMCs from Cutaneous leishmaniasis (CL) patients were stimulated with soluble leishmania antigen (SLA) (5 μg/ml), in the presence and absence of HsPNP inhibitor (300 nM), and the levels of IFN-γ, TNF, CXCL9, and CXCL10 were measured by enzyme-linked immunosorbent assay (ELISA)

Summary

Introduction

Leishmaniasis is a global health problem and it is considered one of the most important neglected tropical diseases. The strong inflammatory response with infiltration of lymphocytes, macrophages, granuloma formation, and small numbers or absence of parasites within skin lesions is a hallmark of CL caused by L. braziliensis [3]. The cell-mediated immune response is considered the main defense mechanism against protozoan parasites. In CL, both CD4+ and CD8+ T cells have been associated with pathology [4,5,6,7]. The inflammatory cytokines, such as IFN-γ and TNF, are important for control of parasite replication, but an exaggerated Th1 immune

Methods

Results

Conclusion