Neuroglial response after induction of experimental allergic encephalomyelitis in susceptible and resistant rat strains.
Experimental allergic encephalomyelitis (EAE), the animal model for multiple sclerosis in humans, a T-cell mediated disease of the central nervous system is characterized by inflammatory infiltrates of myelin antigen(s)-specific T cells and consecutive demyelination. Spinal cord tissue emulsified in complete Freund's adjuvant clinical disease in the genetically susceptible Dark Agouti rats (DA) but not in Albino Oxford (AO) rats although similar inflammatory infiltrates in the CNS are observed in both strains 10-12 days after induction. We have shown that the resistance to clinical disease of AO rats is associated with rapid clearance of infiltrating mononuclear cells by a mechanism of apoptosis. Here, we demonstrate by immunohistochemical and FACS analyses of the expression of CD11b/c that microglial cells respond differently to disease induction in the two strains. Whereas microglial cells are activated throughout the period of day 10-28 days after EAE induction in AO rats they are only activated at the inception and resolution phases but not at the peak of clinical disease in DA rats when there is the highest level of CD4+ T cell infiltration. Our findings are compatible with the notion that microglia terminate effector T cells by apoptosis and that lack of this mechanism as evidenced by the lack of CD11b/c expression, support T cell survival and clinical expression of disease.
Mensah-Brown
E P K
EP
Faculty of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates.
Shahin
A
A
Garey
L J
LJ
Lukic
M L
ML
D000818:Animals; D039481:CD11b Antigen / Q000096:biosynthesis; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology / Q000473:pathology; D002465:Cell Movement / Q000276:immunology; D015536:Down-Regulation / Q000276:immunology; D004681:Encephalomyelitis, Autoimmune, Experimental / Q000235:genetics* / Q000276:immunology* / Q000473:pathology; D020022:Genetic Predisposition to Disease; D007113:Immunity, Innate / Q000235:genetics; D009457:Neuroglia / Q000276:immunology* / Q000378:metabolism; D051381:Rats; D013116:Spinal Cord / Q000276:immunology / Q000473:pathology; D016176:T-Lymphocyte Subsets / Q000378:metabolism
D039481:CD11b Antigen