Enhanced response to antigen within lymph nodes of SJL/J mice that were protected against experimental allergic encephalomyelitis by T cell vaccination

The effects of T cell vaccination on peripheral immune responsiveness are not yet fully understood. We have induced resistance to rat spinal cord homogenate (RSCH)-induced experimental allergic encephalomyelitis (EAE) in SJL/J mice by vaccination with four T cell lines (RZ8, RZ15, RZ16, and A51) which were reactive to myelin basic protein (MBP) but not to proteolipid protein (PLP). The effect was relatively neuroantigen-specific since vaccination with ovalbumin (OVA)-reactive and alloantigen-specific cells did not prevent EAE induction. Alloantigen-reactive cells reduced the rate of relapse. The number of central nervous system (CNS) infiltrates and mean clinical EAE scores were significantly reduced. This is the first report demonstrating T cell vaccination in the SJL/J mouse, a strain in which PLP is the predominant encephalitogen in RSCH. The vaccinating cells were of the memory/effector (CD44^high, CD45RB^low) surface phenotype. We examined the effect of T cell vaccination on lymph node T cell proliferative responses to MBP, encephalitogenic peptides of PLP and MBP, OVA and anti-CD3. With the exception of polyclonal cytokine responses to anti-CD3, which remained unchanged, vaccination led to a 5–10-fold augmentation in all, including background, responses. By comparison with lymph node cell (LNC) responses from naive mice and mice primed with OVA, it appeared that T cell vaccination restored cellular activation levels which had been depleted in peripheral lymphoid tissues of unvaccinated animals with EAE.