Doxycycline and Benznidazole Reduce the Profile of Th1, Th2, and Th17 Chemokines and Chemokine Receptors in Cardiac Tissue from Chronic Trypanosoma cruzi-Infected Dogs.

Guilherme De Paula Costa,Andre Talvani,Laís Roquete Lopes,João Santana Da Silva,Maria Cláudia Da Silva,Cristiane M Milanezi,Richard Schulz,Paulo Marcos Da Mata Guedes,Washington Martins Pontes,Wanderson Geraldo De Lima,Aline Luciano Horta

doi:10.1155/2016/3694714

Abstract

Chemokines (CKs) and chemokine receptors (CKR) promote leukocyte recruitment into cardiac tissue infected by the Trypanosoma cruzi. This study investigated the long-term treatment with subantimicrobial doses of doxycycline (Dox) in association, or not, with benznidazole (Bz) on the expression of CK and CKR in cardiac tissue. Thirty mongrel dogs were infected, or not, with the Berenice-78 strain of T. cruzi and grouped according their treatments: (i) two months after infection, Dox (50 mg/kg) 2x/day for 12 months; (ii) nine months after infection, Bz (3,5 mg/kg) 2x/day for 60 days; (iii) Dox + Bz; and (iv) vehicle. After 14 months of infection, hearts were excised and processed for qPCR analysis of Th1 (CCL2, CCL3, CCL4, CCL5, CXCL9, and CXCL11), Th2 (CCL1, CCL17, CCL24, and CCL26), Th17 (CCL20) CKs, Th1 (CCR5, CCR6, and CXCR3), and Th2/Th17 (CCR3, CCR4, and CCR8) CKR, as well as IL-17. T. cruzi infection increases CCL1, CCL2, CCL4, CCL5, CCL17, CXCL10, and CCR5 expression in the heart. Dox, Bz, or Dox + Bz treatments cause a reversal of CK and CKR and reduce the expression of CCL20, IL-17, CCR6, and CXCR3. Our data reveal an immune modulatory effect of Dox with Bz, during the chronic phase of infection suggesting a promising therapy for cardiac protection.

Highlights

Chemokines are low molecular weight proteins that promote leukocyte trafficking in homeostasis and inflammatory processes
Chronic inflammation is usually characterized by the persistence of leukocyte infiltration into the inflammatory site driven by chemokine production [1,2,3]
Male and female animals were grouped (n = 5) according to their treatment: (i) doxycycline (Dox) (50 mg/kg) twice a day for 12 months starting at 2 months after T. cruzi infection, (ii) benznidazole (Bz) (3,5 mg/kg) twice a day for 60 days starting at the 9th month of infection, (iii) Dox + Bz, and (iv) vehicle (0.5% carboxymethylcellulose, in water)

Summary

Introduction

Chemokines are low molecular weight proteins that promote leukocyte trafficking in homeostasis and inflammatory processes. Chronic inflammation is usually characterized by the persistence of leukocyte infiltration into the inflammatory site driven by chemokine production [1,2,3]. Trypanosoma cruzi infection is a well-known parasite disease where the presence of this protozoan triggers activation and continued leukocyte infiltration into the muscle tissues in order to eliminate it [4,5,6]. Since the stimulus persists over months, years, or decades, cell infiltration conducted by Th1 and Th2-like chemokines and their receptors may lead to loss of tissue’s architecture and function, in some cases causing severe disability, especially in the heart [7, 8]. Mediators of Inflammation cells, TCD4+, TCD8+, and gamma-delta T cells releases vasoactive substances and inflammatory mediators triggered by the invasion of blood trypomastigote forms of this parasite [9, 10]. IL-12 induces a Th1-type differentiation, mediated by IFN-γ, TNF, and IL-17, culminating in NO biosynthesis by macrophages and in the generation of a panel of inflammatory chemokines that orchestrates and accelerates acute immunopathogenesis [11,12,13]

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