Surface phenotypic changes of spleen cells on acquisition of encephalitogenicity

The relationship between surface marker expression and encephalitogenicity of spleen cells was studied in Lewis rats. Donors were sensitized with either BP/CFA or BP/IFA, or given BP-cultured naive spleen cells. The adoptive transfer of EAE was successfully achieved in every case after culture with BP, although only spleen cells from BP/CFA-sensitized rats proliferated significantly in response to BP. The observed encephalitogenicities were BP/CFA-sensitized cells greater than BP/IFA-sensitized cells much greater than cells from recipients of BP-cultured naive cells in descending order. In BP/CFA-sensitized cells, the expression of both W3/25 and OX-3 antigens on T cells increased markedly after culture with BP, but the expression of neither OX-19 nor OX-8 antigen increased significantly. Cells from neither BP/IFA-sensitized rats nor recipients of BP-cultured naive cells showed a significant change in the surface marker expression after culture with BP. Therefore, the generation of T cells coexpressing large amounts of both W3/25 and OX-3 antigens after culture with BP seems to correspond to the acquisition of the strong encephalitogenicity in vivo.