Murine cortical brain cells are autoantigenic from a distinct developmental stage onwards.

The expression of autoantigens on murine cortical brain cells and their first appearance during development was studied. Autoreactivity was analyzed by weight increase and lymphocyte proliferation in the popliteal lymph node (PLN). Cortical brain cells or defined plasma membrane preparations were injected s.c. without adjuvant into syngeneic recipients. Weak, but significant T cell-dependent PLN enlargement was triggered with brain cells from adult mice. A stronger reaction could be elicited with one defined fraction of purified plasma membranes. The earliest appearance of the antigenic material in the plasma membrane fraction was observed on day 15 after birth. This time point correlates exactly with the completion of the blood-brain barrier in large parts of the central nervous system.