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A vaccine against the disease associated with a virus carried by migrating wildebeest
7/3/13

In order to obtain confirmation, he identified all the genes expressed during the illness. “In order to mimic natural conditions as much as possible, we carried out an experiment by infecting calves with the disease. We looked at the lymph nodes to read the virus transcriptome, that is to say, we wanted to know what viral RNA was expressed during the illness,” he recalls.

 For this it was necessary to carry out a “microarray” analysis of the entire genome of AlHV1, in order to compare the RNA that came from the transcriptome of the infected cell with the one identified when the calves became sick. “In the genome, certain genes are really essential for the replication of the virus and therefore to the formation of the infected particle.  We noticed that some of these genes we not expressed at all. On the other hand, the expression of the gene that was essential for latency was similar from both points of view. Thus we were able to formulate the theory that we were dealing with an infection that was truly latent”.

Summary figure wildebeest

Circular protection

The majority of viral genomes present in the calves had a circular shape. This is a characteristic that is not only a “physical” detail: the genome of the herpesvirus has a linear shape in the infectious particles. During the illness, on the other hand, AlHV1 takes the shape of an episome (a circular genome), which is a characteristic of latency in these types of viruses.

Benjamin Dewals also discovered that the latency of this illness was made possible by a protein named ORF73. “This protein is capable of acting as a pressure button between the virus episome and the chromosome, he explains. In other words, when a host cell divides, ORF73 tethers the genetic material of the virus to the daughter cells created. Proliferation is then in Progress…

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