|[Frontiers in Bioscience 2, d88-125, March 1, 1997]|
CROSS-TALK SIGNALS IN THE CNS: ROLE OF NEUROTROPHIC AND HORMONAL FACTORS, ADHESION MOLECULES AND INTERCELLULAR SIGNALING AGENTS IN LUTEINIZING HORMONE-RELEASING HORMONE (LHRH)-ASTROGLIAL INTERACTIVE NETWORK|
Department of Pharmacology, Medical School, University of Catania, 95125 Catania, Laboratory of Biotech. Neuropharmacology, OASI Institute for Research and Care (IRCCS) on Mental Retardation and Brain Aging (IRCCS) Troina, (EN), Italy.
Received 8/2/96; Accepted 2/20/97; On-line 3/1/97
Since astrocytes and microglial cells produce a variety of cytokines, some of which may have a role during maturation and differentiation of the glial cells (241), we have tested a possible immunological nature of glial soluble factors (44). For this aim thymic lymphocytes were treated with ACM at different stages of glial differentiation. As observed in Fig. 13, thymocytes show a biphasic pattern of response to ACM: 8 and 12 DIV astroglial cell culture medium induced a significant increase in 3H-thymidine incorporation comparable or even greater than the one observed following a subactive dose of the lectin polyclonal mitogen, concanavalin A (Con-A, 0.3 mg/ml). At later stages of glial maturation (40 DIV) ACM produced a sharp inhibition in T-cell proliferation (44).
Figure 13. Astroglial-derived factors modulate lymphocyte proliferation. In order to test the ability of astroglia CM to modulate immune cell proliferation, thymocyte cell preparations were treated with either a subactive dose of the T-cell mitogen, concanavalin A (Con-A, 0.3 mg/ml) and/or ACM of 8, 12 and 40 DIV. Note the marked [3H]thymidine incorporation after treatment of murine thymocyte with 8 and 12 DIV ACM, at 40 DIV however, ACM is no longer stimulatory, and a significant inhibition of proliferative capacity was measured.