T cell killing does not require the formation of a stable mature immunological synapse.
A notable feature of T lymphocyte recognition on other cell surfaces is the formation of a stable mature immunological synapse. Here we use a single-molecule labeling method to directly measure the number of ligands a cytotoxic T cell engages and track the consequences of that interaction by three-dimensional video microscopy. Like helper T cells, cytotoxic T cells were able to detect even a single foreign antigen but required about ten complexes of peptide-major histocompatibility complex (pMHC) to achieve full calcium increase and to form a mature synapse. Thus, cytotoxic T cells and helper T cells are more uniform in their antigen sensitivities than previously thought. Furthermore, only three pMHC complexes were required for killing, showing that stable synapse formation and complete signaling are not required for cytotoxicity.
Purbhoo
Marco A
MA
Department of Microbiology and Immunology and the Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, California 94305, USA.
Irvine
Darrell J
DJ
Huppa
Johannes B
JB
Davis
Mark M
MM
D000818:Animals; D016827:CD8 Antigens / Q000276:immunology; D006649:Histocompatibility Antigens / Q000276:immunology; D008213:Lymphocyte Activation / Q000276:immunology*; D051379:Mice; D008822:Mice, Transgenic; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology / Q000502:physiology*
D016827:CD8 Antigens; D006649:Histocompatibility Antigens