Analysis of T cell subsets after induction of experimental autoimmune encephalomyelitis in susceptible and resistant strains of rats

T cell subsets in the peripheral blood, draining lymph node (DLN) and spinal cord lesions were analysed after the induction of experimental autoimmune encephalomyelitis (EAE) in susceptible (DA) and relatively resistant (AO) rats. In DA rats, a significantly higher number of CD4 + cells were generated in the DLN, in response to both nervous tissue antigens and complete Freund's adjuvant (CFA), compared to AO rats. In the peripheral blood of DA rats, the percentage as well as absolute number of CD4 + cells increased in the preclinical phase of EAE, but declined as the disease developed. The percentage of CD8 + cells decreased in both these phases of EAE. In resistant AO rats, however, there were no significant changes in the T lymphocyte subset percentage after EAE induction, although the absolute number of peripheral blood CD4 + cells again increased in the preclinical stage of EAE. In the CFA-treated control DA rats, the absolute number of CD4 + cells was increased in the preclinical phase. However, no decline comparable to that seen in diseased animals followed. It is concluded that the generation of CD4 + cells in response to this antigen is strain specific and, since the cells are released into the circulation, will affect the balance between the T cell subsets in the peripheral blood during the development of EAE.