Varicella-zoster virus infection of human brain cells and ganglion cells in tissue culture.

The growth of varicella-zoster virus (VZV) in cultures of human brain (HB) and human ganglion (HG) cells was compared to VZV growth in human fibroblasts. Infected cultures were monitored by histologic, electron microscopic (EM), and virologic techniques. Two to three days after VZV infection of all cell cultures at a multiplicity of infection (MOI) of 0.1, a multifocal cytopathic effect (CPE) developed. CPE was characterized by multinucleated cells and virus-specific intranuclear inclusions as determined by immunofluorescence and EM. In VZV- infected HB and HG cells only, large vacuoles were also seen in the cytoplasm of dying cells. Some vacuoles were almost devoid of structures. Within and at the limiting membranes of other vacuoles, aggregates of VZV particles (measuring 210--230 nm) were seen enveloped in osmiophilic material. VZV infection of HB and HG cultures was strongly cell-associated. Clarified tissue culture medium removed at maximum CPE failed to infect homologous HB or HG cells. When an inoculum of VZV-infected HB or HG cells was transferred to homologous uninfected cultures for 10--15 passages, the incubation period for CPE remained constant, and the titer of VZV in cells sampled randomly corresponded to the amount of virus that was used for original infection.