Serine proteases profiles of Leishmania (Viannia) braziliensis clinical isolates with distinct susceptibilities to antimony

• Published in: Scientific reports Vol. 11; no. 1; p. 14234
• Main Authors: Zabala-Peñafiel, Anabel, Dias-Lopes, Geovane, Cysne-Finkelstein, Léa, Conceição-Silva, Fátima, Miranda, Luciana de Freitas Campos, Fagundes, Aline, Schubach, Armando de Oliveira, Fernandes Pimentel, Maria Inês, Souza-Silva, Franklin, Machado, Lucas de Almeida, Alves, Carlos Roberto
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group 09.07.2021; Nature Publishing Group UK; Nature Portfolio
• Subjects: Amastigotes; Antimony; Clinical isolates; Germfree; Heterogeneity; Leishmania; Parasites; Parasitic diseases; Phenotypes; Promastigotes; Serine; Tegumentary leishmaniasis; Vector-borne diseases
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-021-93665-z

Abstract Glucantime (Sb V ) is the first-line treatment against American Tegumentary Leishmaniasis. Resistance cases to this drug have been reported and related to host characteristics and parasite phenotypes. In this study, 12 Leishmania ( Viannia ) braziliensis isolates from patients that presented clinical cure (Responders—R) and relapse or therapeutic failure (Non-responders—NR) after treatment with antimony, were analyzed. These parasites were assessed by in vitro susceptibility to Sb III and Sb V , serine proteases activity measured with substrate (z-FR-AMC) and specific inhibitors (TLCK, AEBSF and PMSF). In vitro susceptibility of axenic amastigotes to Sb III showed a significant difference between R and NR groups. The protease assays showed that TLCK inhibited almost 100% of activity in both axenic amastigotes and promastigotes while AEBSF inhibited around 70%, and PMSF showed lower inhibition of some isolates. Principal component and clustering analysis performed with these data yielded one homogeneous cluster with only NR isolates and three heterogeneous clusters with R and NR isolates. Additionally, differential expression of subtilisins (LbrM.13.0860 and LbrM.28.2570) and TXNPx (LbrM.15.1080) was evaluated in promastigotes and axenic amastigotes from both groups. The results showed a higher expression of LbrM.13.0860 and LbrM.15.1080 genes in axenic amastigotes, while LbrM.28.2570 gene had the lowest expression in all isolates, regardless of the parasite form. The data presented here show a phenotypic heterogeneity among the parasites, suggesting that exploration of in vitro phenotypes based on Sb III and serine proteases profiles can aid in the characterization of L. ( V. ) braziliensis clinical isolates.