Beijing, March 26 (Xinhua) - A recent viral study published in the specialized academic journal Nature Microbiology, under Springer Nature, reveals that a molecule found on the surface of extracellular vesicles (EVs) in semen and saliva can block the infection of viruses such as Zika or dengue fever virus. These findings contribute to understanding why these viruses have a lower direct human-to-human transmission rate and why they are more easily spread through fluids lacking this molecule (such as blood) or via blood-sucking insects.
The paper outlines that viruses like dengue fever, Zika, chikungunya, Ebola, or Lassa fever viruses can infect various cell types. However, despite being present in various bodily fluids (including semen and saliva), oral or sexual transmission routes are notably limited. Previous research has shown that EVs present in semen and saliva can competitively block Zika virus binding to target cells and inhibit infection in laboratory experiments. However, the specific mechanism behind this has been unclear.
The lead author of the paper, Janis A. Müller from Philipps University Marburg in Germany, along with colleagues and collaborators, isolated EVs from five different human bodily fluids, including semen, saliva, urine, breast milk, and blood. They found that a molecule called phosphatidylserine (PS) was more common on the surface of EVs in semen compared to those in blood. In laboratory experiments, it was discovered that PS on the surface of EVs could block Zika virus infection of cells because these EVs would compete for the same PS receptors and interfere with virus attachment and entry. If EV concentrations similar to those found in the body are reached, infection by dengue fever, West Nile, chikungunya, Ebola, and herpes simplex viruses would all be inhibited.
However, viruses such as HIV, hepatitis C virus (HCV), severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and herpes simplex virus were not inhibited as they utilize different entry receptors. The efficacy of blocking infection also disappeared when researchers removed PS from the surface of EVs using enzymes.
The authors of the paper conclude that their research results could be utilized in developing novel antiviral drugs, but further studies are still needed. (End)
(Original title: How does the human body inhibit the spread of specific viruses? Latest international research makes significant progress)
