Infectibility of separated peripheral blood mononuclear cell subpopulations by varicella-zoster virus (VZV).

Varicella zoster-virus (VZV) is a humanpathogenic alpha-Herpesvirus that causes chickenpox after primary infection. The virus spreads by aerosol or direct contact with infectious vesical fluids, it enters the body via the respiratory tract. In a first viremic stage it replicates in local lymph nodes, followed by a secondary viremic stage. In the course it spreads through the body to endothelial cells in the periphery. During acute viremia of chickenpox viral DNA can be detected in peripheral blood mononuclear cells (PBMC) by PCR and in situ hybridization. Recently published results quantified the viral DNA load in PBMC and subpopulations by real-time PCR. In the animal SCID-hu mouse model system VZV showed a tropism for T-lymphocytes. The aim of this work was the investigation of viral ability to infect and to replicate in purified primary subtypes of PBMC, i.e., T-lymphocytes, B-lymphocytes, and monocytes. These cells were isolated from whole peripheral blood or tonsils and infected with cell-free VZV for different time periods. In all cell types, transcriptional activity was shown by amplification and detection of immediate early (IE) and late (L) viral mRNA by NASBA or RT-PCR. Expression of viral glycoproteins was analyzed and proved in lymphocytes by immunofluorescence microscopy.