de Paula Jéssica I, Lopes-Torres Eduardo J, Jacobs-Lorena Marcelo, Paes Marcia Cristina, Cha Sung-Jae
Laboratório de Interação Tripanossomatídeos e Vetores - Departamento de Bioquímica, IBRAG - UERJ, Rio de Janeiro, Brazil.
Laboratório de Helmintologia Romero Lascasas Porto, Faculdade de Ciências Médicas, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, Brazil.
Front Microbiol. 2022 Mar 10;13:864788. doi: 10.3389/fmicb.2022.864788. eCollection 2022.
Chagas is a neglected tropical disease caused by the protozoan parasite . On the order of seven million people are infected worldwide and current therapies are limited, highlighting the urgent need for new interventions. trypomastigotes can infect a variety of mammalian cells, recognition and adhesion to the host cell being critical for parasite entry. This study focuses on trypomastigote surface ligands involved in cell invasion.
Three selection rounds of a phage peptide display library for isolation of phages that bind to trypomastigotes, resulted in the identification of the N3 dodecapeptide. N3 peptide binding to developmental forms (trypomastigotes, amastigotes and epimastigotes) was evaluated by flow cytometry and immunofluorescence assays. Parasite invasion of Vero cells was assessed by flow cytometry and immunofluorescence assays.
Phage display screening identified the N3 peptide that binds preferentially to the surface of the trypomastigote and amastigote infective forms as opposed to non-infective epimastigotes. Importantly, the N3 peptide, but not a control scrambled peptide, inhibits trypomastigote invasion of Vero cells by 50%.
The N3 peptide specifically binds to , and by doing so, inhibits Vero cell infection. Follow-up studies will identify the molecule on the parasite surface to which the N3 peptide binds. This putative ligand may advance chemotherapy design and vaccine development.
恰加斯病是一种由原生动物寄生虫引起的被忽视的热带疾病。全球约有700万人感染，目前的治疗方法有限，这凸显了对新干预措施的迫切需求。锥鞭毛体可感染多种哺乳动物细胞，对宿主细胞的识别和黏附是寄生虫进入的关键。本研究聚焦于参与细胞入侵的锥鞭毛体表面配体。
对噬菌体肽展示文库进行三轮筛选，以分离与锥鞭毛体结合的噬菌体，从而鉴定出N3十二肽。通过流式细胞术和免疫荧光测定评估N3肽与不同发育形式（锥鞭毛体、无鞭毛体和上鞭毛体）的结合情况。通过流式细胞术和免疫荧光测定评估寄生虫对Vero细胞的侵袭。
噬菌体展示筛选鉴定出N3肽，该肽优先结合锥鞭毛体和无鞭毛体感染形式的表面，而非非感染性的上鞭毛体。重要的是，N3肽而非对照乱序肽可抑制锥鞭毛体对Vero细胞的侵袭达50%。
N3肽特异性结合并由此抑制Vero细胞感染。后续研究将确定N3肽在寄生虫表面结合的分子。这种假定的配体可能推动化疗设计和疫苗开发。
