BOVINE HERPESVIRUS-1-INDUCED APOPTOSIS - PHENOTYPIC CHARACTERIZATION OF SUSCEPTIBLE PERIPHERAL-BLOOD MONONUCLEAR-CELLS

Bovine herpesvirus 1 (BHV-1), a member of the Alphaherpesvirinae, indu ces apoptotic cell death in peripheral blood mononuclear cells (PBMC). To investigate the process by which BHV-1 induces apoptosis, we deter mined the susceptibility of the three main PBMC subpopulations to BHV- 1-induced apoptosis. This study shows that BHV-1 can induce apoptosis individually in T lymphocytes, B lymphocytes and monocytes. This concl usion is based on the following findings: (i) BHV-1 substantially redu ces the percentages of viable T and B lymphocytes in PBMCs, (ii) Conco mitant detection of cell phenotype and apoptosis indeed showed higher percentages of apoptotic T lymphocytes and B lymphocytes in BHV-1-infe cted PBMCs than in mock-infected cells. (iii) Each individual PBMC sub populations (B lymphocytes, T lymphocytes and monocytes) undergo apopt osis when incubated with UHV-1. These data also suggest that BHV-1 doe s not require the recruitment of one or more individual PBMC subpopula tions (e.g. cytotoxic cells) to induce apoptosis. Finally, we observed that BL-3 cells which have been characterized as bovine tumoral B lym phocytes also undergo apoptosis when incubated with BHV-1. Therefore, the use of the BL-3 cell line provides a new experimental model to inv estigate the apoptotic process induced by BHV-1 in vitro.