Defensin HNP-1 is a naturally occurring antimicrobial peptide involved in the innate immune response. It plays a key role in host defense by disrupting the membranes of bacteria, viruses, and fungi, leading to their inactivation or death. It is particularly effective against Gram-negative and Gram-positive bacteria, making it a critical component in early immune responses at sites of infection.

This peptide is found in high concentrations in neutrophil granules and is released at sites of inflammation or tissue injury. Its ability to attract immune cells such as dendritic cells and T-cells also gives it immunomodulatory functions, linking innate and adaptive immunity.

Due to its broad-spectrum antimicrobial activity and low propensity for inducing resistance, Defensin HNP-1 is being studied for potential use in developing new anti-infective therapies, especially in the context of multidrug-resistant pathogens. It may also have applications in wound healing, mucosal immunity, and as a biomarker for certain inflammatory or infectious diseases.