medwireNews: Primitive human stem cells are resistant to human cytomegalovirus (HCMV), say researchers who believe this finding could provide further insight into disease pathology.
Vishwajit Nimgaonkar (University of Pittsburgh, Pennsylvania, USA) and team found that as stem cells and other primitive cells mature into neurons, they become more susceptible to HCMV, one of the leading prenatal causes of intellectual disability, deafness, and deformity worldwide.
"Previous studies have focused on other species and other cells types, but those studies did not evaluate what the [CMV] does to human brain cells," remarked Nimgaonkar in a press statement. "This study is the first of its kind, and the first to discover that primitive stem cells are actually resistant to HCMV."
As reported in PLoS One, Nimgaonkar and team derived live human-induced pluripotent (iPS) cells by reprogramming fibroblasts obtained from human skin biopsies. The iPS cells were induced to mature through several stages into neurons.
The results showed that human iPS cells prevent a full viral replication cycle, indicating for the first time that these cells can resist CMV infection.
However, CMV infection with HCMV strain Ad169 distorted iPS cell differentiation into neurons. The authors say that this may be a mechanism by which infected babies develop impairments of brain maturation and intellectual ability.
The authors say that iPS-derived mature neurons are more susceptible to CMV infection than their primitive counterparts and once infected, show effects such as defective function that have also been shown in other animal studies and human tissues. The neurons die a few days after infection, reflecting the impact of CMV on the human brain.
"The findings were quite surprising, but this is only the first in a series of studies on HCMV," added Nimgaonkar. "There is a lot of interest in what we can do to treat the infection, and current work is already underway to screen for new drugs that could be used to treat these viruses."
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