Chemokines and chemokine receptors in distinct clinical forms of human tegumentary leishmaniasis

PIMENTEL SOLÁ, MJ; GARCÍA BUSTOS, MF; MARCO, DJ; BARROSO, PA; RAGONE, P; MESIAS, AC; PEREZ BRANDAN, C; PARODI, C

Evento virtual

Congreso; 6th European Congress of Immunology; 2021

The aim of this work was to study the participation of CCL20 and CCL17, chemokines directed to skin and mucosal tissues in cutaneous (CL) and mucosal (ML) leishmaniasis. Weprocessed peripheral blood samples from patients with CL (n=20), ML (n=15) and healthy subjects (HS, n=10). Plasma levels were measured by ELISA. We evaluated the chemokine receptors CCR4 and CCR6 on CD45RO+ CD4+ and CD8+ T cells by flow cytometry. Also, PBMC cultures were performed (1x106 cells/ml,7 days) in presence of (L. braziliensis) or (L. amazonensis) soluble antigens (20ug/ml). Single nucleotide polymorphisms (SNP) for CCL17 and CCL20 were analyzed by RLP‐PCR and gene fragment digestion. Higher plasma levels of CCL20 (p=0.0017) and diminished values of CCL17 (p=0.0023) were found in ML (p=0.0017), indicating that this clinical form presents altered chemokine patterns. In (in vitro) assays, proteins of (L. amazonensis) inhibited the supernatant (SN) production of CCL17 (p=0.0085) in ML, while (L. braziliensis) slightly increased the SN production of CCL20 in CL (p=0.038) and ML (p=0.031).We suggest that (Leishmania) spp. could influence the degree of chemokine responses. The number of CR4+CCR6+ T cells was similar between groups with the majority of them expressing CD45RO+. Analyzing SNP, the most frequent genotype for CCL17 was CT (CL, 72%; ML, 44%; HS, 80%), while TT genotype predominated for CCL20 (CL,45%; ML,87%; HS,60%). This represents a preliminary approach for chemokine polymorphisms in leishmaniasis. We need further research to determine their correlation with plasma levels and pathology outcome.