In a
recent report (1), using mice deficient in both perforin and
IFN- (PKO/GKO) it was shown, by the same group, that
clearance by perforin requires the presence of IFN-, which
plays an important role in upregulating major histocompatibility
complex class I on astrocytes and microglia, a requirement
for obtaining a good cytolytic T-cell response. In our study, the
lack of clearance in PKO mice is not due to the lack of IFN-,
since a normal IFN- response was observed in CD8 T cells