Opossum Cathelicidins Exhibit Antimicrobial Activity Against a Broad Spectrum of Pathogens Including West Nile Virus

Abstract

This study aimed to characterize cathelicidins from the gray short-tailed opossum in silico and experimentally validate their antimicrobial effects against various pathogenic bacteria and West Nile virus (WNV). Genome-wide in silico analysis against the current genome assembly of the gray short-tailed opossum yielded 56 classical antimicrobial peptides (AMPs) from eight different families, among which 19 cathelicidins, namely ModoCath1-19, were analyzed in silico to predict their antimicrobial domains and three of which, ModoCath1,-5, and-6, were further experimentally evaluated for their antimicrobial activity, and were found to exhibit a wide spectrum of antimicroial effects against a panel of gram-positive and gram-negative bacterial strains. In addition, these peptides displayed low-to-moderate cytotoxicity in mammalian cells as well as stability in serum and various salt and pH conditions. Circular dichroism analysis of the spectra resulting from interactions between ModoCaths and lipopolysaccharides (LPS) showed formation of a helical structure, while a dual-dye membrane disruption assay and scanning electron microscopy analysis revealed that ModoCaths exerted bactericidal effects by causing membrane damage. Furthermore, ModoCath5 displayed potent antiviral activity against WNV by inhibiting viral replication, suggesting that opossum cathelicidins may serve as potentially novel antimicrobial endogenous substances of mammalian origin, considering their large number. Moreover, analysis of publicly available RNA-seq data revealed the expression of eight ModoCaths from five different tissues, suggesting that gray short-tailed opossums may be an interesting source of cathelicidins with diverse characteristics.

High-Quality Nucleic Acid Isolation from Hard-to-Lyse Bacterial Strains Using PMAP-36, a Broad-Spectrum Antimicrobial Peptide

“…Vesicle formation on the bacterial cell surface has been detected after PMAP-36 treatment using electron microscopy [ 22 , 41 ]. This phenomenon has also been found in other AMPs with membrane-perturbing activity, such as magainin 2, temporin L, ModoCaths, and SMAP-29 [ 42 , 43 , 44 , 45 ]. In addition, the appearance of blebs has been reported as indicative of the ability of temporin L to destabilize the outer membrane of Gram-negative bacteria owing to the displacement of divalent cations that bridge and neutralize LPS [ 42 , 46 ].…”

“…MIC was determined using a colorimetric method specified by the Microbial Viability Assay Kit-WST (Dojindo, Kumamoto, Japan) according to the manufacturer’s protocol and the Clinical and Laboratory Standards Institute guidelines (2018) [ 44 , 48 , 49 , 50 ]. Briefly, four colonies of each bacterium were inoculated into 5 mL LB medium at 37 °C for 4–6 h, allowing the bacteria to reach the log phase.…”

Characterisation of Antiviral Activity of Cathelicidins from Naked Mole Rat and Python bivittatus on Human Herpes Simplex Virus 1

“…This is the case for the chicken Cathelicidin B1, which inhibited the Influenza A virus (IAV) infection by blocking viral entry [ 26 ]. ModoCath5, a cathelicidin from the grey short-tailed opossum, has exhibited antiviral activity against West Nile virus, while the bovine cathelicidin BMAP-18 reduced ZIKV replication in human primary keratinocytes and in Vero cells, respectively [ 27 , 28 ]. Finally, a cathelicidin isolated from the venom of the Bungarus fasciatus snake has been reported to possess strong antiviral effects on IAV and ZIKV [ 29 , 30 ].…”

Koala cathelicidin PhciCath5 has antimicrobial activity, including against Chlamydia pecorum

“…They have both immunomodulatory and antimicrobial functions, and display activity against a range of bacteria, fungi and viruses [ 24 ]. Throughout evolution cathelicidins have expanded in marsupials, compared to eutherian mammals, resulting in numerous diverse peptides [ 25 – 28 ]. For example, the gray short-tailed opossum has 19 cathelicidin genes [ 27 , 28 ], while humans have only one [ 29 ].…”

“…Throughout evolution cathelicidins have expanded in marsupials, compared to eutherian mammals, resulting in numerous diverse peptides [ 25 – 28 ]. For example, the gray short-tailed opossum has 19 cathelicidin genes [ 27 , 28 ], while humans have only one [ 29 ]. Expansions within marsupials are likely driven by the need to protect immunologically naive young during pouch life [ 25 , 30 ].…”