AP-64, Encoded by C5orf46, Exhibits Antimicrobial Activity against Gram-Negative Bacteria

Area of Science:

• Immunology
• Biochemistry
• Genetics

Background:

• Antimicrobial peptides (AMPs) are crucial for innate immunity, providing defense against microbes at body surfaces.
• The chromosome 5 open reading frame 46 (C5orf46) gene's role in antimicrobial defense was previously unexplored.

Purpose of the Study:

• To identify and characterize novel human antimicrobial peptides.
• To investigate the antimicrobial and cytotoxic properties of a newly identified peptide, AP-64.

Main Methods:

• Peptide identification and sequencing.
• In vitro antibacterial assays against Gram-negative bacteria.
• In vivo efficacy testing in a mouse infection model.
• Cytotoxicity assays against human cell lines.

Main Results:

• A novel human AMP, AP-64, was identified from the C5orf46 gene.
• AP-64 demonstrated significant antibacterial activity against various Gram-negative bacteria, including E. coli and P. aeruginosa.
• AP-64 showed efficacy in a mouse model of E. coli O157:H7 infection and exhibited cytotoxicity to human lymphoma cell lines.
• The mouse homolog, Gm94, displayed similar antibacterial properties.

Conclusions:

• AP-64 is a novel human AMP with distinct characteristics, including a long sequence, lack of cysteines, anionic nature, and cell toxicity.
• AP-64 represents a promising candidate for further research in antimicrobial therapeutics.