The role of apoptosis in Listeria monocytogenes neural infection: Listeriolysin O interaction with neuroblastoma Neuro-2a cells

Listeria monocytogenes is the etiological agent of meningitis that affects individuals at high risk such as pregnant women, neonates, the elderly and immunocompromised individuals. Infection by this intracellular pathogen can be lethal if not diagnosed and treated. Mouse neuroblastoma Neuro-2a cells, a neuron-like cell line, were infected with L. monocytogenes. In this study apoptotic changes of neuroblastoma Neuro-2a cells infected with strains of Listeria producing different listeriolysin O levels are investigated by cytotoxicity assay, cellular viability assay, DAPI staining, intranucleosomal DNA fragmentation test, and monoclonal antibodies against ss-DNA. Results show that after internalization, the bacteria induced morphological, functional and genetic changes in the cells characteristic of apoptosis, which was dose-and time-dependent on listeriolysin O. Neuroblastoma Neuro-2a cells represent an interesting model cell line to further the understanding of Listeria pathogenesis within the central nervous system.