Genetic Polymorphism at CCL5 Is Associated With Protection in Chagas' Heart Disease: Antagonistic Participation of CCR1+ and CCR5+ Cells in Chronic Chagasic Cardiomyopathy

Chronic cardiomyopathy is the main clinical manifestation of Chagas disease (CD), a disease caused by Trypanosorna cruzi infection. A hallmark of chronic chagasic cardiomyopathy (CCC) is a fibrogenic inflammation mainly composed of CD8 and CD4(+) T cells and macrophages. CC-chemokine ligands and receptors have been proposed to drive cell migration toward the heart tissue of CD patients. Single nucleotide polymorphisms (SNPs) in CC-chemokine ligand and receptor genes may determine protein expression. Herein, we evaluated the association of SNPs in the CC-chemokines CCL2 (rs1024611) and CCL5 (rs2107538, rs2280788) and the CCL5/RANTES receptors CCR1 (rs3181077, rs1491961, rs3136672) and CCR5 (rs1799987) with risk and progression toward CCC. We performed a cross-sectional association study of 406 seropositive patients from endemic areas for CD in the State of Pernambuco, Northeast Brazil. The patients were classified as non-cardiopathic (A, n = 110) or cardiopathic (mild, B1, n = 163; severe, C, n = 133). Serum levels of CCL5 and CCL2/MCP-1 were elevated in CD patients but were neither associated with risk/severity of CCC nor with SNP genotypes. After logistic regression analysis with adjustment for the covariates gender and ethnicity, CCL5-403 (rs2107538) CT heterozygotes (OR = 0.5, P-value = 0.04) and T carriers (OR = 0.5, P-value = 0.01) were associated with protection against CCC. To gain insight into the participation of the CCL5-CCR5/CCR1 axis in CCC, mice were infected with the Colombian T cruzi strain. Increased CCL5 concentrations were detected in cardiac tissue. In spleen, frequencies of CCR1(+) CD8(+) T cells and CD14(+) macrophages were decreased, while frequencies of CCwR5(+) cells were increased. Importantly, CCR1(+)CD14(+) macrophages were mainly IL-10(+), while CCR5(+) cells were mostly INF+. CCR5-deficient infected mice presented reduced TNF concentrations and injury in heart tissue. Selective blockade of CCR1 (Met-RANTES therapy) in infected Ccr5(-/-) mice supported a protective role for CCR1 in CCC. Furthermore, parasite antigen stimulation of CD patient blood cells increased the frequency of CCR1(+)CD8(+) T cells and CCL5 production. Collectively, our data support that a genetic variant of CCL5 and CCR1(+) cells confer protection against Chagas heart disease, identifying the CCL5-CCR1 axis as a target for immunostimulation.