title: A new antimicrobial protein from the anterior midgut of Triatoma infestans mediates Trypanosoma cruzi establishment by controlling the microbiota.
abstract: The Reduviid Triatoma infestans is a vector for the protozoan Trypanosoma cruzi, the etiological agent of Chagas disease. The parasite must address the defense molecules and microbiota that colonize the anterior midgut of T. infestans. To obtain insight into T. cruzi - microbiota interactions in triatomine insects, we characterized a new antimicrobial product from the anterior midgut of T. infestans (TiAP) that may be involved in these relationships. The TiAP DNA fragment was cloned and expressed in a bacterial system, and the effect of the protein on bacteria and T. cruzi was evaluated by RNAi, qPCR and antimicrobial experiments. The number of T. cruzi in T. infestans anterior midguts was significantly lower in TiAP knockdown insects than in unsilenced groups. We also verified that the amount of bacteria in silenced T. infestans is approximately 600-fold higher than in unsilenced insects by qPCR. The 327-bp cDNA fragment that encodes mature TiAP was cloned into the pET-14b vector and expressed fused to a His-tag in Escherichia coli C43. The recombinant protein (rTiAP) was purified using an Ni-NTA column, followed by a HiTrap SP column. According to a trypanocidal assay, rTiAP did not interfere with the viability of T. cruzi trypomastigotes. Moreover, in antimicrobial experiments using E. coli and Micrococcus luteus, the protein was only bacteriostatic for Gram-negative bacteria. The data indicate that infection by T. cruzi increases the expression of TiAP to modulate the microbiota. The inhibition of microbiota growth by TiAP is important for parasite establishment in the T. infestans anterior midgut.
authors.affiliation: Department of Biochemistry, Universidade Federal de São Paulo, Escola Paulista de Medicina, 04044-020 São Paulo, SP, Brazil. Electronic address: diego_bq@yahoo.com.br.
authors.forename: Diego S
authors.initials: DS
authors.lastname: Buarque
authors.affiliation: Department of Biochemistry, Universidade Federal de São Paulo, Escola Paulista de Medicina, 04044-020 São Paulo, SP, Brazil. Electronic address: cicera_gomes@uol.com.br.
authors.forename: Cícera M
authors.initials: CM
authors.lastname: Gomes
authors.affiliation: Department of Parasitology, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, 31270-901 Belo Horizonte, MG, Brazil. Electronic address: ricnaraujo@yahoo.com.
authors.forename: Ricardo N
authors.initials: RN
authors.lastname: Araújo
authors.affiliation: Department of Parasitology, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, 31270-901 Belo Horizonte, MG, Brazil. Electronic address: marcoshp@icb.ufmg.br.
authors.forename: Marcos H
authors.initials: MH
authors.lastname: Pereira
authors.affiliation: Centro de Pesquisas René Rachou, FIOCRUZ, 30190-002 Belo Horizonte, MG, Brazil. Electronic address: robertac@cpqrr.fiocruz.br.
authors.forename: Roberta C
authors.initials: RC
authors.lastname: Ferreira
authors.affiliation: Centro de Pesquisas René Rachou, FIOCRUZ, 30190-002 Belo Horizonte, MG, Brazil. Electronic address: guarneri@cpqrr.fiocruz.br.
authors.forename: Alessandra A
authors.initials: AA
authors.lastname: Guarneri
authors.affiliation: Department of Biochemistry, Universidade Federal de São Paulo, Escola Paulista de Medicina, 04044-020 São Paulo, SP, Brazil. Electronic address: tanaka.bioq@epm.br.
authors.forename: Aparecida S
authors.initials: AS
authors.lastname: Tanaka
mesh_terms: D000818:Animals; D000890:Anti-Infective Agents / Q000494:pharmacology*; D064307:Microbiota; D010455:Peptides / Q000494:pharmacology*; D014224:Triatoma / Q000737:chemistry*; D014349:Trypanosoma cruzi / Q000187:drug effects*
chemical_list: D000890:Anti-Infective Agents; D010455:Peptides
keywords: Antimicrobial properties; Bacteria; Midgut; Parasite; Triatoma infestans; Trypanosoma cruzi