Experimental autoimmune encephalomyelitis in mice. Antigen binding lymphocytes to basic protein of myelin in susceptible and resistant strains.

SUMMARY Antigen-binding lymphocytes (ABL) to basic protein of myelin (BPM) were demonstrable in the thymus and spleen of various strains of mice. Counts of ABL did not differ in strains resistant and susceptible to EAE, and did not differ when human or murine 125I-labelled BPM was used as a labelled antigen to detect ABL. After injection with mouse spinal cord and adjuvants, under conditions known to be immunogenic and encephalitogenic for susceptible strains of mice, counts of ABL increased two- to four-fold in susceptible strains but did not increase in resistant strains. Antigen binding could not be accounted for by the attachment to cells of cytophilic antibody with specificity for BPM, because such antibody was seldom demonstrable even after immunization. Inferences from the study were: (i) that tolerance (non-responsiveness) to certain autoantigens at least must depend on control over continually present antigen-reactive lymphocytes rather than on any lack of capacity to recognize antigen; (ii) differences in susceptible and resistant strains are evident after, rather than before, immunization.