t cells (IMAGE) University of California - San Diego Caption T cells are a type of white blood cell and play a central role in the immune response. Credit National Institute of Allergy and Infectious Diseases Usage Restrictions Use photo credit License Original 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.