VISUALIZATION OF PEPTIDE-SPECIFIC T-CELL IMMUNITY AND PERIPHERAL TOLERANCE INDUCTION IN-VIVO

An adoptive transfer system was used to monitor physically the behavio r of a trace population of TCR transgenic T cells in vivo. After subcu taneous injection of antigen in adjuvant, the antigen-specific cells a ccumulated first in the paracortical region of the draining lymph node s, proliferated there for several days, and then moved into lymph node follicles, where they accounted for most of the T cells. They then di sappeared slowly from the draining nodes, and the remaining cells were hypersensitive to antigenic stimulation in vitro. In contrast, when t he antigen was introduced into the blood, the antigen-specific cells r apidly accumulated in the paracortical regions of all lymph nodes, pro liferated there for a short time, but never entered follicles. Most of the cells then rapidly disappeared, leaving behind a population that was hyporesponsive to antigenic stimulation. These results provide a p hysical basis for the classical finding that antigen-specific memory a nd tolerance can be influenced by the form of antigen administration.