T-Cell Activation Phase

Another Fascinating Episode in the Epic Story of Human Immunity

This latest visual vignette envisioned by Audra Geras is a close-up taken within a lymph node. It represents another stage in the story of how the human immune system responds to a tumor or viral infection.

An MHC Class I molecule (gray-blue) on an antigen-presenting cell (APC), is depicted presenting its bound peptide antigen to a T cell receptor (TCR) on a 'naive' T cell (above). The other molecular pair next to the MHC/TCR pair are co-stimulatory molecules.

Close-up view of antigen presentation

Migration of cytotoxic CD8+ T cells out of a lymph node via a capillary

Antigen presentation by APCs to naive T cells leads to the transformation and cloning of naive T cells into cytotoxic, CD8+ T cells. In the background, cytotoxic T cells are shown migrating into a lymphatic vessel (or capillary) to travel back to areas identified by the presence of the specific antigen. The T cells have been primed and are ready for battle! The next exciting installment in this story will be coming soon!