Restricted replication of herpes simplex virus in satellite glial cell cultures clonally derived from adult mice.

To determine the possible influence of satellite glial cells on restricting the spread of herpes simplex virus in the peripheral nervous system, HSV replication was studied in clonally derived cultures of satellite glial cells from adult animals. Satellite cells were purified by exploiting their close anatomical association with primary sensory neurons. Dissociated neurons from dorsal root ganglia were micro-manipulated to remove all but one of the attached satellite cells and cultured in the presence of the mitogenic stimulators bovine pituitary extract and cholera toxin. Following a lag phase of 20-30 days some of the individual satellite cells began to proliferate. Initial cultures demonstrated bipolar morphology similar to cultured Schwann cells, some of which differentiated into large astrocytic whorl-like cells on subsequent passage. Immunocytochemical and molecular studies demonstrated that these cells, designated Sat.1, express glial fibrillary acidic protein, confirming their glial origin and by electron microscopy they were shown to be phagocytic. Under single step viral growth conditions Sat.1 cells were restrictive for HSV replication, producing in the order of 1000 times less infectious virus than Vero cells, a standard permissive cell line. These results suggest that satellite cells, which tightly encase sensory neurons, play a role in restricting interneural spread of HSV within the peripheral nervous system.