MOLLUSK HEMOCYANIN AS A SOURCE OF ANTIMICROBIAL PEPTIDES AND IMMUNOSTIMULANT ELICITOR

CHIUMENTO, I; CORTEZ, M. F; A. C. PAULA-LIMA; M. A. TRICERRI; J. BRITO-MOREIRA; T. R BOMFIM; F. F. OLIVEIRA; M. H. MAGDESIAN; L. T GRINBERG; R. PANIZZUTTI; S. T. FERREIRA.; TRICERRI, M. A.; DREON, M

Mar del Plata

Congreso; Reunión Anual Sociedad Argentina de Investigaciones Clínicas; 2022

SAIC

MOLLUSK HEMOCYANIN AS A SOURCE OF ANTIMICROBIAL PEPTIDES AND IMMUNOSTIMULANT ELICITORChiumiento Ignacio, Cortez Fernanda, Brola Tabata, Tricerri Alejandra, Dreon MarcosInstituto de Investigaciones Bioquímicas de La Plata (INIBIOLP), CCT- La Plata, CONICET. Facultad de Ciencias Médicas. Universidad Nacional de La Plata. 60 y 120, La Plata (1900) Argentina Hemocyanins (Hcs) are large respiratory proteins widely distributed among invertebrates in nature. Particularly, mollusk Hcs have attracted biomedical interest as non-specific immunostimulants, some of them being already employed in antitumoral therapies. In addition, Hcs also stood out as precursors of antimicrobial peptides (AMPs), considered to be generated upon the action of bacterial proteases over Hc during infection. To contribute to the understanding of molluscan Hcs as bioactive compounds, specially focusing on the searching for derived AMPs, we studied the Hc of invasive South American freshwater snail Pomacea canaliculata (PcH). First, in silico analysis were conducted for searching potential AMPs in the previously deduced PcH protein sequence. A list of predicted candidates was obtained from Anti-BP and CAMPr3 tools, and further analyse in APD-3 server. The four best-scored candidates were synthesized de novo and employed in diffusion agar assays against Staphylococcus pseudintermedius and Escherichia coli. Subsequently, Minimum Inhibitory Concentration tests were carried out, retrieving mic values between 6mM and 3Mm. AMPs structures were predicted using PEP-FOLD 2.0, and peptide sequences mapped into the PcH Cryo-EM model previously resolved. To further explore the immunostimulant capability of PcH, THP-1 monocytes were exposed to PcH and showed a Th1-like cytokine secretion pattern. Moreover, a marked cellular adhesion, indicative of monocyte´s activation, was observed by Fluorescence Microscopy when THP-1 cells were directly incubated with PcH. In conclusion, we characterized four PcH-derived AMPs, reinforcing the idea of molluscan Hcs as AMP sources. Additionally, we demonstrated PcH may trigger a proinflammatory response and induces monocitic differentiation. Although more work is needed to elucidate the mechanisms implied in AMPs generation and immunostimulation, we propose PcH as a promising biomedical compound, easy to purify from a readily available source.