T CELL 1 (IMAGE) Rice University Caption Rice University scientists' simple model of T cell activation of the immune response shows the T cell binding, via a receptor (TCR) to an antigen-presenting cell (APC). If an invader is identified as such, the response is activated, but only if the "relaxation" time of the binding is long enough. Credit Hamid Teimouri/Rice University Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.