Microglial cells qualify as the stimulators of unprimed CD4 super(+) and CD8 super(+) T lymphocytes in the central nervous system

• Published in: Clinical and experimental immunology Vol. 98; no. 2; pp. 313 - 318
• Main Authors: Cash, E, Rott, O
• Format: Journal Article
• Language: English
• Published: 01.01.1994
• ISSN: 0009-9104

The potential of central nervous system (CNS)-derived cells for initiating T cell responses is not known. Using the capacity of unprimed T cells to respond to allogeneic determinants on antigen-presenting cells (APC), we assessed the ability of microglial cells to act as stimulators of primary T cell responses in vitro. For this purpose, microglial cells were activated with lipopolysaccharide (LPS), interferon-gamma (IFN- gamma ), or by phagocytosis of progenitor oligodendrocytes and subsequently tested for their ability to induce a proliferative response of naive, resting T cells. Activated microglial cells induced a significant proliferation of virgin, alloreactive CD4 super(+) and CD8 super(+) T lymphocytes, with a more substantial response of highly purified CD4 super(+) than of CD8-expressing T cells. Phagocytosis activation was the most efficient stimulus to induce this APC competence on microglial cells. By contrast, IFN- gamma -pretreated, MHC-expressing astrocytes were unable to induce similar responses of alloreactive CD4 super(+) or CD8 super(+) T cells under the same experimental conditions. Collectively, our data suggest the role of activated microglia as the fully immunocompetent accessory cell population of the CNS.