Prevention of tolerance in differentiating B lymphocytes by T cells.

Normal, but not tolerant, adult thymocytes prevented particulate antigen inducing tolerance in differentiating B lymphocytes. This was demonstrated by measuring the emergence of responsive B cells (identified by their allotype) developing from a foetal liver innoculum in irradiated hosts with or without the addition of antigen, thymocytes or tolerant thymocytes. The relevance of these findings to the recruitment of B lymphocytes in adult animals and to the development of those autoreactive B cells found in normal animals is discussed.