Most people believe the body only reacts after a virus enters, but this is not entirely accurate. Concealed defense systems are already working in the background, and one of them may be stronger than we assumed.
Scientists from the Fisabio Foundation and several research centers have discovered an interesting feature of a molecule called dermcidin. This molecule is always present in the body and is typically associated with sweat. The study results were published in the journal Proceedings of the National Academy of Sciences.
Previously, researchers knew that it could kill bacteria and fungi. Now, studies show that it can also fight the influenza virus.
The influenza virus uses a protein called hemagglutinin to enter human cells. Without this entry step, the virus cannot survive or spread. Dermcidin interrupts this process in a direct and effective manner.
“Dermcidin, present in sweat and known for its antibacterial and antifungal activity, also exhibits antiviral activity against the influenza virus and can prevent infection, as we observed in in vitro and in vivo models,” noted study co-author Maria D. Ferrer.
Instead of attacking the virus after infection, dermcidin acts at an early stage. It attaches to hemagglutinin and alters its shape. Once this shape changes, the virus loses its ability to fuse with the cell. Simply put, the virus is blocked at the threshold.
Many antiviral drugs target another protein called neuraminidase. This approach is effective, but viruses often adapt over time. Drug resistance becomes a genuine problem, and treatment stops working properly.
Dermcidin offers a different approach. It targets a part of the virus that remains largely unchanged across different strains. Scientists call this a highly conserved region. Because this area stays stable, dermcidin may be effective against many varieties of the influenza virus.
“These results show that our bodies have natural mechanisms capable of restraining viral infection, which opens up opportunities for developing new, more effective antiviral drugs,” notes Alex Mira from Fisabio. “This same principle could be extended to other respiratory viruses, such as the measles virus and coronaviruses that cause colds, suggesting a possible broad-spectrum effect.”
This idea opens up broader possibilities. If one molecule can target stable regions of viruses, future treatments may be effective against multiple infections, not just one.
Dermcidin is found not only in sweat. Researchers have located it in places where viruses typically enter, such as the nose, saliva, and even tears. This placement is not accidental. It allows dermcidin to act as an early defense.
“The results show that baseline dermcidin levels are six times higher in people who do not develop flu-like symptoms compared to those susceptible to the disease,” said study co-author Paula Corell.
This difference matters. Higher dermcidin levels appear to provide better protection, which may explain why some individuals avoid illness even after exposure to the pathogen.
When an infection begins, dermcidin levels rise. This increase indicates that the body actively uses this molecule during a viral attack. It is not simply present passively in the body.
“Overall, these results support the idea that dermcidin is part of the first line of defense of the innate immune system against this type of infection,” noted Corell.
The innate immune system acts quickly and does not wait for prior exposure to the pathogen. Dermcidin fits perfectly into this system by intervening at an early stage and reducing the likelihood of further infection spread.
This discovery points to a new direction in flu treatment. Instead of developing drugs from scratch, scientists can study molecules that already exist in the body.
Currently, researchers are investigating whether dermcidin can not only block viruses but also guide the immune response. A balanced response could prevent unnecessary damage during infections.
The work conducted by the Fisabio Foundation and its partner organizations demonstrates something simple yet very important. The human body already possesses tools capable of effectively fighting infections. Science is only beginning to understand how to best utilize them.
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