JC virus can infect human immune and nervous system progenitor cells: implications for pathogenesis

Recent advances in stem cell biology have called attention to the role these cells may play in the pathogenesis of systemic and nervous system diseases. Although not capable of indefinite self renewal and pluripotentiality as stem cells are, progenitor cells can give rise to cells of different lineages. It is infection of these differentiated cells that has traditionally been associated with the pathology and symptoms of viral-induced disease. However, neural progenitor cells have been shown, in vitro, to be susceptible to infection by neurotropic viruses such as the human polyomavirus, JCV, and the lentivirus, HIV-1. These progenitor cells, which exist during development as well as in the fully developed adult brain, could therefore be involved in neuropathogenesis. Morever, JCV can also infect progenitor cells of the hematopoietic system, derivatives of which have been implicated in the trafficking of virus from the periphery to the brain. Interestingly, susceptibility to and molecular regulation of JCV infection in hematopoietic cells closely parallels what has been observed in glial cells. The biological interaction between the immune and nervous systems that exists in the dissemination of virus from periphery to nervous system and the susceptibility of both systems to JCV infection provide potential for hematopoietic and neural progenitor cell involvement in JCV pathogenesis.