Spectroscopic detection and identification of infected cells with herpes viruses

Matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) and Fourier transform infrared (FTIR) microspectroscopy were previously applied for the identification of various biological samples. In the present study, normal cells in culture and cells infected with herpes simplex virus type 2 (HSV-2) or varicella-zoster virus (VZV) were analyzed by MALDI-TOF and FTIR microscopy. Specific spectral biomarkers for rapid and reliable monitoring and identification of infected cells and probably for the discrimination between these viruses were searched. The results show consistent spectral peaks in all examined normal uninfected human fibroblast cells both in MALDI-TOF and FTIR microscopy. In HSV-2- or VZV-infected cells, two unique peaks for each appeared at m/ z 5397 and 5813 or at m/z 3501 and 4951, respectively, in MALDI-TOF spectra. In addition, several peaks that appeared in control uninfected cells at the region m/z 13,000-20,000 disappeared completely in all examined infected samples. When these infected cells were examined by FTIR microscopy, a band at 859 cm^-1 in control uninfected cells was significantly shifted to 854 cm^-1 in both HSV2- and VZV-infected cells. In addition, phosphate levels were considerably increased in all infected cells compared to normal uninftcted cells. These parameters could be used as a basis for developing a spectral method for the detection and identification of cells infected with herpes virus.