Elephant Cathelicidin-Derived Peptides Inhibit Herpes Simplex Virus 1 Infection

Area of Science:

• Virology and Immunology
• Antimicrobial Peptide Therapeutics
• Innate Immune Response Modulation

Background:

• Herpes simplex virus type 1 (HSV-1) is a widespread pathogen with limited effective treatments for latency and recurrence.
• Antimicrobial peptides (AMPs), such as cathelicidins, exhibit broad-spectrum antiviral activity and are key components of the innate immune system.

Purpose of the Study:

• To design and optimize elephant cathelicidin (EM) derived peptides for anti-HSV-1 activity.
• To evaluate the antiviral efficacy, toxicity, and underlying mechanisms of these peptides against HSV-1.
• To assess the therapeutic potential of EM-derived peptides in a preclinical mouse model.

Main Methods:

• Design and synthesis of four EM-derived peptides (EM-1 to EM-4).
• Hemolytic and cytotoxicity assays to determine peptide safety.
• In vitro anti-HSV-1 activity assessment (IC50 determination) and mechanism investigation (RT-qPCR).
• In vivo efficacy studies in C57BL/6J mice, including viral load quantification and histological analysis.

Main Results:

• Peptide EM-1 demonstrated significant inhibition of HSV-1 replication in cell culture with low toxicity.
• In vivo, EM-1 administration reduced viral loads in multiple organs (brain, lung, heart) and alleviated inflammatory responses.
• EM-1 treatment mitigated HSV-1-induced tissue damage and upregulated host antiviral immunity by enhancing interferon-gamma and downstream gene expression (ISG15, MX1).

Conclusions:

• EM-1 is a potent dual-function peptide effective against HSV-1 replication and capable of boosting host antiviral immunity.
• Elephant cathelicidin-derived peptides represent a promising new class of therapeutics for managing HSV-1 infections.
• Further development of EM-1 could lead to novel strategies for combating viral latency and recurrent disease.