Nikhil Prasad Fact checked by:Thailand Medical News Team Aug 21, 2025 2 hours, 40 minutes ago
Medical News: Scientists Uncover the Role of CD9 in Viral Entry
A groundbreaking international study has revealed that a little-known protein called CD9, part of the tetraspanin family, may play a pivotal role in helping the SARS-CoV-2 virus infiltrate human cells. Found in microdomains of the plasma membrane, these proteins act as organizational hubs, clustering together critical cellular receptors and enzymes that viruses exploit to break into cells.
Hidden Viral Enabler CD9 Could Be the Missing Key in COVID-19 Spread
Researchers from Spain’s Centro Nacional de Biotecnología (CNB-CSIC) and the Health Research Institute of Asturias (ISPA) confirmed that CD9 not only supports the coronavirus in gaining entry but also stabilizes other key host proteins like ACE2, neuropilin-1 (NRP1), furin, and TMPRSS2—all vital for viral attachment and fusion.
Why This Discovery Matters
Viruses, including SARS-CoV-2, depend on complex interactions with host cells. The spike protein of the coronavirus must bind to ACE2, then undergo cleavage by proteases such as furin and TMPRSS2 to trigger infection. What researchers now show is that CD9 acts like a platform, gathering these players in the same location to streamline the invasion process. Without CD9, viral titers drop dramatically. In fact, when the scientists “knocked out” CD9 in cell lines, infection levels fell by as much as fivefold. This
Medical News report underscores that what once seemed like a minor structural protein could actually be a hidden enabler in viral spread.
Blocking CD9 Shows Therapeutic Potential
Perhaps the most striking finding is that an antibody designed to block CD9 significantly reduced the ability of the virus to infect cells. This not only highlights CD9’s central role but also opens the door to potential therapies. Antibodies or drugs targeting CD9 could, in theory, disrupt the virus’s ability to coordinate its entry machinery, providing doctors with new antiviral tools. Unlike vaccines, which target the virus directly, this approach interferes with the virus’s exploitation of host proteins, making it potentially effective against future coronavirus variants as well.
Broader Implications Beyond COVID
Tetraspanins like CD9 are not unique to SARS-CoV-2. Previous research has shown that they also assist in the entry of other dangerous viruses, including influenza, hepatitis C, and papillomaviruses. This makes CD9 a particularly interesting candidate for broad-spectrum antiviral therapies. By disrupting the very platforms viruses rely on, scientists could create treatments that offer a line of defense not just against COVID-19 but against future pandemics as well.
The Road Ahead
While these findings are promising, researchers stress that clinical translation will take time. Blocking CD9 must be carefully balanced, as the protein is also involved in normal cellular functions. Future work will need to explore safety, dosa
ge, and possible side effects in humans. Nonetheless, the evidence is mounting: CD9 may be one of the most critical yet overlooked players in viral infection biology. If harnessed correctly, targeting it could usher in a new era of host-directed antiviral strategies. The results strongly remind us that the battle against COVID-19 is not just about the virus itself but also about understanding and disrupting the human proteins it manipulates.
The discovery of CD9’s role in SARS-CoV-2 entry provides both a warning and a new pathway for intervention. It highlights how small molecular interactions can have large-scale consequences in global health. As scientists continue to probe these hidden viral enablers, the possibility emerges for a new class of antivirals that attack infection at its root. Such insights could dramatically reshape how we prepare for and fight pandemics in the future, giving humanity the upper hand in a battle too often dictated by viral adaptation.
The study findings were published in the peer reviewed journal: Viruses.
https://www.mdpi.com/1999-4915/17/8/1141
For the latest COVID-19 News, keep on logging to Thailand
Medical News.
Read Also:
https://www.thailandmedical.news/news/unraveling-the-role-of-tetraspanins-in-viral-infections-and-potential-therapeutic-strategies
https://www.thailandmedical.news/news/university-of-california-study-finds-that-tetraspanin-8-tspan8-is-a-mediator-in-in-sars-cov-2-infections
https://www.thailandmedical.news/news/breaking-brazil-study-provides-evidence-that-sars-cov-2-infects-the-astrocytes-of-the-human-brain-using-nrp1-receptors-and-causes-damage
https://www.thailandmedical.news/pages/thailand_doctors_listings
Share
Tweet
Share
