Isolation and characterization of the inflammatory infiltrate in the central nervous system of the guinea-pig with experimental allergic encephalomyelitis.

The inflammatory infiltrate of the central nervous system in acute experimental allergic encephalomyelitis (EAE) in the guinea-pig has been isolated and characterized. Inflammatory cells found over the surface of the brain and spinal cord and within the leptomeninges have been isolated by washing, and were subsequently identified by a number of methods. By light microscopy approximately 60% were lymphocytes, 30% were cells of the mononuclear phagocyte series, and 5% were neutrophils: the occasional plasma cell and eosinophil were also identified. E, EA and EAC rosetting tests were used to determine the proportions of T lymphocytes (both early and late), and cells with Fc and C3 receptors respectively. Particular attention was paid to cells of the mononuclear phagocyte series bearing Fc and C3 receptors to determine whether any change or loss of these receptors was apparent. The percentage of phagocytic cells from the brain and spinal cord washes was also determined. Transmission and scanning electron microscopy showed that a large proportion of the inflammatory infiltrate consisted of cells of the mononuclear phagocyte series. This study therefore confirms that the cells of the mononuclear phagocyte series play a predominant role in EAE.