Abstract
The inducibility of major histocompatibility complex class II (Ia) antigens on glial cells of the brain suggests that neuroglia have immunoregulatory functions within the central nervous system (CNS), i.e., recognition and presentation of antigens. The aim of the present study was to investigate rat recombinant-interferon-γ (r-IFN-γ) induced la antigen expression in rat cerebral cultures containing type-1 astrocytes and macrophages, and in rat spinal cord cultures enriched in type-2 astrocytes or oligodendrocytes. We compared induction of la antigen expression in glial cell cultures derived from Lewis rats, which are very susceptible to experimental allergic encephalomyelitis (EAE), with those from Wistar rats, which are but modestly EAE susceptible.
After 5 days in culture we found in Wistar rat type-1 astrocyte-enriched cultures that la antigens were expressed by 19% of the astrocytes, whereas we found that in Lewis rat type-1 astrocyte cultures a considerably higher number of astrocytes expressed la antigens (53%). However, no significant difference were found in la antigen expression between type-2 astrocytes derived from Wistar rat spinal cord (49%) and Lewis rat type-2 astrocytes (56%). In contrast, in oligodendrocyte-enriched cell cultures derived from either Lewis of Wistar rats no la antigen expression was found.
Interestingly, we found in type-1 astrocyte-enriched cerebral cultures a large number (approx, 46% of the cells) of brain macrophages (amoeboid microglia), all expressing la antigens after treatment with r-IFN-γ.