Specific Inhibition of Anti‐Self Reactivity following Exposure of Neonatal Rats to Lymphocytes with Anti‐Neural Activity

Not only did newborn rats prove to be resistant to the adoptive transfer of responses against central nervous system tissues following the injection of lymphocytes from rats sensitized against syngeneic spinal cord, but such recipients were also subsequently resistant as adults to the active induction of an immune response following challenge with syngeneic cord. This resistance to active immunization against syngeneic spinal cord as adults was associated with the absence of lymphocytes with anti‐neural activity and with the appearance of cells able to suppress such activity, after challenge. Interference by the lymphocytes of resistant rats with anti‐neural responses was restricted to those responses directed against syngeneic neural cells.