Astrocyte cultures from human embryonic brain: characterization and modulation of surface molecules by inflammatory cytokines.
Astrocyte-enriched cultures were established upon passaging of primary cultures from the myelencephalon and mesencephalon of 7-9-week-old human embryos. Immunocytochemical analysis showed that third-fourth passage cultures were composed of a highly enriched population of proliferating, epithelioid cells, up to 90% of which expressed glial fibrillary acidic protein (GFAP); no macrophages and very few fibroblasts (less than 2%) were present. GFAP expression and proliferation declined upon further culturing in serum-containing medium but could be transiently reinduced by growing the cells in a serum-free chemically defined medium. Large numbers of GFAP+ astrocytes were obtained from each embryo and could be stored frozen and recultured. Using flow cytometric analysis, human astrocyte cultures were examined for basal and cytokine [interferon-gamma (IFN-gamma), interleukin-1 beta (IL-1 beta), and tumor necrosis factor-alpha (TNF-alpha)]-induced expression of molecules that may be involved in astrocyte-T-lymphocyte interactions. Cultured human astrocytes spontaneously expressed major histocompatibility complex (MHC) class I antigens and variable levels of MHC class II; MHC class I levels were increased upon IFN-gamma and TNF-alpha treatment, whereas MHC class II antigens were induced on most of the astrocytes by IFN-gamma. Among the molecules involved in antigen-independent interactions between T lymphocytes and target cells, lymphocyte function-associated molecule-3 (LFA-3) was spontaneously expressed by most cultured human astrocytes, whereas intercellular adhesion molecule-1 (ICAM-1) was present at variable levels in non-stimulated astrocytes and was greatly induced by IFN-gamma, TNF-alpha, and IL-1 beta. In this study we also show that the above cytokines upregulate astroglial expression of adhesion molecules of the integrin family (VLA-1, VLA-2, and VLA-6) that may be involved in astrocyte-extracellular matrix interaction and play a role in the astrocyte reactive changes occurring at sites of brain injury and inflammation. The human astrocyte cultures developed here represent a useful in vitro model to further investigate mechanisms involved in bidirectional communication between central glia and cells of the immune system.
Aloisi
F
F
Neurobiology Section, Istituto Superiore di Sanità, Rome, Italy.
Borsellino
G
G
Samoggia
P
P
Testa
U
U
Chelucci
C
C
Russo
G
G
Peschle
C
C
Levi
G
G
D001253:Astrocytes / Q000187:drug effects / Q000276:immunology / Q000378:metabolism*; D001921:Brain / Q000166:cytology*; D015815:Cell Adhesion Molecules / Q000378:metabolism; D016207:Cytokines / Q000494:pharmacology*; D004622:Embryo, Mammalian / Q000187:drug effects / Q000378:metabolism; D005260:Female; D005353:Fibronectins / Q000096:biosynthesis / Q000276:immunology; D005434:Flow Cytometry; D006801:Humans; D007150:Immunohistochemistry; D007249:Inflammation / Q000503:physiopathology*; D016023:Integrins / Q000276:immunology / Q000378:metabolism; D018799:Intercellular Adhesion Molecule-1; D016169:Lymphocyte Function-Associated Antigen-1 / Q000276:immunology / Q000378:metabolism; D008264:Macrophages / Q000187:drug effects / Q000378:metabolism; D008285:Major Histocompatibility Complex / Q000187:drug effects; D009457:Neuroglia / Q000187:drug effects / Q000378:metabolism; D011247:Pregnancy; D016029:Receptors, Very Late Antigen / Q000276:immunology / Q000378:metabolism
D015815:Cell Adhesion Molecules; D016207:Cytokines; D005353:Fibronectins; D016023:Integrins; D016169:Lymphocyte Function-Associated Antigen-1; D016029:Receptors, Very Late Antigen; D018799:Intercellular Adhesion Molecule-1