CHRONIC RELAPSING EXPERIMENTAL ALLERGIC ENCEPHALOMYELITIS IN THE GUINEA-PIG: IN-VITRO ANALYSIS OF MENINGEAL INFLAMMATORY CELLS

Inflammatory cells from the meninges of guinea-pigs with chronic relapsing experimental allergic encephalomyelitis (CREAE) have been isolated and compared to a similar cell population obtained from guinea-pigs with acute EAE. A mean of 6.2 x 10(6) cells were recovered from the brains of animals with CREAE while a similar number of cells (8.0 x 10(6)) was obtained from animals with acute EAE. Only 5.3% of the cells from animals with CREAE were found to be phagocytic in contrast with 28% of the cells obtained from animals with acute EAE. The meningeal inflammatory cells from guinea-pigs with CREAE did not respond, in the lymphocyte transformation test, to specific antigens or to mitogen. Peritoneal exudate cells (PECs) from these animals did, however, proliferate in the presence of tuberculin and of mitogen, but not with the brain antigen myelin basic protein (MBP). In contrast, the meningeal inflammatory cells from animals with acute EAE did respond to mitogen and PECs from the same animals responded to both the specific antigens and to the mitogen. The meningeal inflammatory cells and PECs from the guinea-pigs with CREAE did, however, behave in a similar manner to similar cell populations obtained from guinea-pigs fully protected against clinical signs of acute EAE.