Téllez GA, Zapata JA, Toro LJ, Henao DC, Bedoya JP, Rivera JD, Trujillo JV, Rivas-Santiago B, Hoyos RO, Castano JC. Identification, Characterization, Immunolocalization, and Biological Activity of Lucilin Peptide.
Acta Trop 2018;
185:318-326. [PMID:
29890152 DOI:
10.1016/j.actatropica.2018.06.003]
[Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Revised: 06/06/2018] [Accepted: 06/07/2018] [Indexed: 10/14/2022]
Abstract
Maggots from the Lucilia sp. genus are used for debridement of infected and necrotic wounds. Broad-spectrum antimicrobial activity has been described in the excretion/secretions (ES1) of these larvae. This study identifies the genetic sequence of a cecropin-like antimicrobial peptide from Lucilia eximia. Total RNA was extracted and used for PCR-RACE amplification of a cecropin, the native peptide was immunolocalized in the tissues and secretions of the larvae, and a synthetic analog was used to explore its antimicrobial, cytotoxic, LPS neutralizing and wound-healing activities in vitro. The genetic cDNA sequence of a cecropin-like antimicrobial peptide in L. eximia called "Lucilin" was amplified, corresponding to 63 aa completed protein and 40 aa mature peptide; the structure of the mature peptide was predicted as an α-helix. The peptide was immunolocalized in the salivary glands, fat body, the ES, and hemolymph of the maggots. Lucilin synthetic peptide analog was active against E. coli DH10B with a MIC2 of 7.8 μg/mL, E. coli extended spectrum b-lactamase (ESBL) (MIC: 15.6 μg/mL), and Enterobacter cloacae (MIC: 125 μg/mL), but it was not active against Pseudomonas aeruginosa and Staphylococcus epidermidis; and had no cytotoxic or hemolytic activity. It showed immunomodulatory activity against human peripheral blood mononuclear cells (PBMCs) stimulated with LPS, reducing the TNF-α production when treated at 17 μg/mL and induces cell migration of Hacat at 5 and 50 μg/mL. Lucilin is a cecropin-like peptide from L. eximia with antimicrobial activity against Gram negative bacteria and immunomodulatory activities, decreasing the TNF-α production in PBMCs and inducing cellular migration in human keratinocytes.
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