Neurons which reactivate a cycle of cell division

What is FPV doing in tissues where the cells are no longer dividing? To find an answer to this question, the researchers started from the theory that these cells had perhaps reactivated the cycle of cell division. ‘And they do so either by themselves or are driven by the virus’, specifies Mutien Garigliany. ‘Professor Luc Poncelet from ULB used a p27 marker of cell ‘rest’ and was able to observe that this marker had disappeared in neurons infected by FPV’, explains the scientist. ‘The neurons therefore effectively re-enter, at least in the initial phases of the cell division cycle, which enables the replication of the FPV’. At this stage, the researchers do not know whether this is caused by the virus or not. ‘In order to multiply, this virus, which consists of DNA and a capsid, needs to use the machinery of a dividing cell’, recalls Mutien Garigliany. It is therefore not impossible that the virus has evolved and can now reactivate this machinery in certain cells, in this case, the neurons. ‘The mutation that we have identified in this strain of the virus affects a protein whose role in controlling the cell cycle has been established for other parvoviruses. We therefore suggest, although we cannot demonstrate it at this point, that a cause and effect exists between this mutation and the acquisition of the neuronal tropism that we have highlighted’, specifies the researcher.

Parvovirus and the fight against cancer: proceed with care!

This theory, which remains to be verified, may be vitally important for other research into parvoviruses. Scientists are studying the effect of using certain parvoviruses to fight cancer. ‘Given the tropism of this virus for cells which are rapidly dividing, cancerous cells are a dream territory for the virus which, as it multiplies, kills these cells’, continues the vet. 

But caution is required because the frontier between activation of the cell cycle and the destruction of cancer cells remains permeable. Recent results from Mutien Garigliany et al.’s study, published in the BMC Veterinary Research (1), are a good example of this. If parvoviruses evolve and acquire the capacity to reactivate cell division, they could potentially cause more harm than good, by attacking healthy tissues, such as the central nervous system, in addition to the tumour. ‘A well-known virus which presents this ability to push cells to divide is the papillomavirus, which is responsible for cervical cancer(2)’, indicates the scientist. Things are, therefore, not as straightforward as they may appear and extreme caution should be taken in terms of using the virus as a therapeutic tool. This study is interesting for at least two reasons: it provides insight into unusual cases of feline panleukopenia which were reported during the 2013 outbreak and it contributes towards improving knowledge of the interaction between parvoviruses and the cells they infect.

(1) Mutien Garigliany · Gautier Gilliaux · Sandra Jolly · Tomas Casanova · Calixte Bayrou · Kris Gommeren · Thomas Fett · Axel Mauroy · Etienne Lévy · Dominique Cassart · Dominique Peeters · Luc Poncelet · Daniel Desmecht. Feline panleukopenia virus in cerebral neurons of young and adult cats. BMC Veterinary Research. 12/2016; 12(1). DOI: 10.1186/s12917-016-0657-0 

(2) On this topic, read  The origins of cervical cancer