Astrocyte differentiation induced by Junín virus in rat brain cell cultures.

Morphological and immunocytochemical differentiation was observed in astroglial cell cultures of the rat infected with Junín virus. From days 3 to 6 postinoculation (p.i.), GFAP immunostaining was observed in both the perikaryon and processes of maturated astrocytes, whereas it was limited to the perikaryon in less differentiated cells. The rather slow spontaneous differentiation usually occurring in astroglial cell cultures was seen to be accelerated by viral infection, mimicking the astrocytic reaction formerly described in Junín virus-inoculated mice. Infected cell monolayers showed orderly development, maintenance of contact inhibition, and exhaustion of cell cultures beyond the 6th-7th passages. The morphological and immunocytochemical maturation effects of Junín virus on astroglial cells were evident, but to a significantly lesser degree than those caused by rat brain extract. The glial cell cultures proved a valuable tool for the study of virus-cell interaction, since the immune response and the structural complexity of the whole animal can thus be avoided.