Experimental allergic encephalomyelitis: characterization of T lymphocytes that bind myelin basic protein and...

The immuno phenotypic profile of the mononuclear cells that bind myelin basic protein (MBP) and synapsin was investigated in lymph node cells from rats with experimental allergic encephalomyelitis induced by injection with MBP. Using a double immunofluorescent labeling technique, purified cells that bind one or both antigens were analyzed in different stages of the disease. The total MBP-bound lymphocytes increased at 14 days post-inoculation (dpi), had a CD4+/CD8+ ratio of two and were present until 29 dpi. Conversely, the apportionment of cells specific for MBP that also recognize synapsin reached a maximum value at 14 dpi coincidentally with the expression of the paralysis symptoms and then, they disappeared when the animal began to recover. This population amounted to about 40% of the total lymph node MBP-bound cells and had a CD4+/CD8+ ratio of one, indicating that the lymphocytes with MBP-synapsin crossreactivity could be principally implicated in a cytotoxic or suppressor activity.