Study on mechanisms of viral infection in live cells by Raman spectroscopy and chemometrics

Viral invasion process in live cell is studied by Raman spectroscopy

Abstract Text:

There is a demand for the development a technique to detect human infectious viruses rapidly in environment. The techniques commonly used, such as PCR and antibody test, are merely applied to detect the virus in human patients. In contrast, there are varied viruses in the environment, of which host are any animals, plants and even bacteria. It is difficult to apply the conventional methods to screen and detect only the human infectious viruses. We have developed a technique to employ human cultured cell for the host of the human infectious viruses and observe the reaction of the live cell to detect the viral invasion by Raman spectroscopy. The technique successfully detected the invasion of model viruses into the cells within 3 hours after the infection. The spectral changes were so small that we developed a new spectral pre-treatment technique to optimize the small spectral differences. A model virus, recombinant adenovirus (rAV) is able to propagate in a model cell, HEK293 cell. In contrast, a model virus, recombinant lentivirus (rLV) is not able to do. The cell with rAV showed spectral changes keeping for 48 hours but that with rLV did that the spectral alteration disappeared after 24 hours. The results suggested that the cell “forgot” the invasion of rLV. The reaction of the live cells at the very early state of the virus infection gives insight into activity of the cells, which is even earlier than any gene expression taking place.