A research team led by the Fisabio Foundation announced on Mar. 30 that a naturally occurring peptide found in sweat, saliva, tears, and the nasopharynx could help prevent influenza infection before symptoms develop. The study identifies dermcidin, an antimicrobial peptide previously known for its antibacterial and antifungal properties, as also having antiviral activity against the influenza virus.
The findings are significant because they point to a potential new approach for developing antivirals that target parts of viruses less likely to mutate. This could reduce the risk of resistance that is often seen with current antiviral drugs.
Researchers from several institutions collaborated on this work, including CIBERESP, the Institute of Biomedicine of Valencia (IBV-CSIC), CIBERER, IDiBE at University Miguel Hernández, University of Valencia, and Margarita Salas Biological Research Center (CIB-CSIC). Dr. María D. Ferrer of Fisabio said: "Dermcidin, which is present in sweat and known for its antibacterial and antifungal activity, also exhibits antiviral activity against the influenza virus and can interfere with infection, as we have observed in in vitro and in vivo models." Dr. Álex Mira from Fisabio added: "These results show that our own bodies have natural mechanisms capable of curbing viral infection, which opens the door to the development of new, more effective antivirals."
The study demonstrated that dermcidin binds to hemagglutinin—a protein crucial for viral entry—at a conserved region involved in cell fusion. This binding causes changes in hemagglutinin's structure that stop the virus from fusing with cell membranes and starting an infection. Unlike most current antivirals targeting neuraminidase (a different viral protein), this mechanism targets regions less prone to change between flu subtypes.
Dr. Ferrer explained: "By acting on regions of the virus that hardly change between subtypes-known as highly conserved regions-dermcidin could contribute to defense against different variants of the influenza virus." Dr. Mira suggested this principle might apply beyond flu: "This same principle could be extended to other respiratory viruses... suggesting a possible broad-spectrum effect." The team also found higher baseline levels of dermcidin—up to six times greater—in people who did not develop flu-like symptoms compared to those who did; levels rose further during respiratory infections.
Dr. Paula Corell said: "The results show that baseline levels of dermcidin are up to six times higher in people who do not develop flu-like symptoms... Altogether these findings reinforce the idea that dermcidin is part of the innate immune system's first line of defense against this type of infection." Researchers are now exploring whether dermcidin may help regulate immune responses during infections.
Funding for this research came from multiple sources including grants from Valencian Innovation Agency (AVI), European Regional Development Fund (ERDF), Carlos III Health Institute (ISCIII), and Spain’s Ministry of Economy and Competitiveness.
