A team of scientists, led by Dr. Reed Shabman of the J. Craig Venter Institute and Prof. Christopher Basler of the Icahn School of Medicine at Mount Sinai, New York, has isolated a novel gammaherpesvirus — bat gammaherpesvirus 8 — from the cells of the cave bat Myotis velifer incautus.
Electron microscopy of the bat cell line identifies viral particles that appear to be BGHV8: black and red boxes highlight enlarged regions directly below the image above; both areas identify budding and fully budded herpesvirus virions. Image credit: Reed S. Shabman et al.
Dr. Shabman, Prof. Basler and their colleagues set out to study bats’ immune response to infection, looking at cells from a tumor taken from the wing of an adult female bat found in a cave in Texas.
While using a technique called next-generation sequencing to study genetic material from the bat cells, they quickly noticed that a large number of genes expressed weren’t bat genes but instead were genes related to herpes viruses.
Through further tests, they isolated and characterized a previously unknown virus — bat gammaherpesvirus 8 (BGHV8). In humans, gammaherpesviruses like Epstein-Barr virus are known for causing diseases like infectious mononucleosis and some cancers.
The team was able to assemble a genome of nearly 130,000 base pairs of genetic material for BGHV8, and to show that the virus was capable of multiplying in the lab and of infecting human and animal cell lines.
“The cool thing about this study is that it was so surprising. We didn’t go looking for a virus and really, by accident, we found this new virus, and it turned out to be the first replicating bat gammaherpesvirus,” said Prof. Basler, senior author on a paper published in the journal mSphere.
“We think it’s exciting for people interested in studying how bats interact with viruses.”
During the lab studies, investigators took liquid growing on top of the bat cell line and put it onto another line of cells called Vero cells that allow viruses to reproduce.
“Within 18 hours, the Vero cells were dead. BGHV8 cells also were able to infect isolated human lung and human liver cells,” Dr. Shabman said.
Not only could the team see viral particles in the bat cells using an electron microscope, but studying the virus’ family tree, they determined that BGHV8 is similar to but distinct from other gammaherpesviruses.
“This is the first replicating bat gammaherpesvirus that’s been isolated. Most labs just have bits and pieces of a virus,” Dr. Shabman said.
“A big question is why bats are repeatedly associated with infections that transfer to humans,” Prof. Basler said.
“We have very few tools to study bats’ immune response to viruses. This natural bat virus is actually going to prove to be useful in understanding and probing how bats respond to natural infections and microorganisms that can cause disease.”
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Reed S. Shabman et al. Isolation and Characterization of a Novel Gammaherpesvirus from a Microbat Cell Line. mSphere, published online February 17, 2016; doi: 10.1128/mSphere.00070-15
