Scientists Discover Herpesvirus Sometimes Leads to Cancer in Different Parts of the World

You may not be aware of the fact, but most of us are infected with the herpesvirus known as Epstein-Barr virus (EBV). For most of us, this virus will lead at worst to a case of infectious mononucleosis. But now, scientists have discovered that this virus can have deadlier impacts; it turns out that in some parts of the world, these viruses are found in association with cancer.

In order to better understand EBV, the researchers sequenced the DNA of a viral strain dubbed M81. This strain was isolated from a Chinese patient with nasopharyngeal carcinoma (NPC). After analyzing the strain, the scientists discovered that M81 is highly similar to other viruses isolated from NPCs and profoundly different from Western strains in terms of its ability to replicate in cells.

In fact, the researchers found that the M81 strain can infect epithelial cells and multiply spontaneously at a very high level in all cells that it infects, including B lymphocytes. These are the cells in which the viruses hide. That said, it remains to be seen exactly how infected epithelial cells become cancerous.

"EBV is an important but neglected pathogen," said Henri-Jacques Delecluse, one of the researchers, in a news release. "We have made an important step in recognizing that EBV is actually a family of viruses that have different properties, some of which are very likely to cause disease. So, the consequences of being infected with EBV might be different, depending on the strain one carries."

The results actually offer some of the first evidence for the existence of distinct EBV subtypes with very different public health risks. Vaccination or other strategies for preventing EBV infection will need to be designed with these most pathogenic, cancer-causing strains in mind.

"Our results have made me radically change my strategy to address the problem of EBV-associated diseases," said Delecluse in a news release. "The current view is that the virus is essentially the same all over the world and that local conditions explain the different consequences of EBV infection. We now show that the type of EBV also plays an important role."

The findings are published in the journal Cell Reports.