Infection of rat brain primary cell cultures with an avirulent A7 strain of semliki forest virus

Abstract

The ability of A7 Semliki Forest Virus (SFV) to infect primary brain cell cultures has been examined using cultures prepared from 1–2-day neonatal rat cerebral hemispheres. These cultures, characterised immunocytochemically using cell-specified markers, contain mainly GFAP + protoplasmic astrocytes and smaller multiprocessed A2B5 + cells, probably fibrous astrocytes. 10% of the cells are GC + oligodendrocytes and some neurones are also present. These cultures support virus growth and a cytopathic effect was observed. Using double labelling techniques with the cell-specific markers and anti-SFV antibody A7 has been shown to readily infect cells which carry either the A2B5 + antigen or galactocerebroside marker. Protoplasmic astrocytes ( GFAP + A2 B5 − ) are not readily infected under the conditions used. The protein labelling studies using [ 35S]methionine show that host cell protein synthesis is not completely shut off and continues in the astrocyte protein region. These results suggest that cells derived from a common A2B5 +, GFAP −, GC − progenitor glial cell, i.e. GC + oligodendrocytes and A2 B5 + GFAP + fibrous astrocytes, are more readily infected than other brain cell types including the protoplasmic astrocytes.