With 20 years of recognition, Science today reveals a new mechanism for immune T-cells to identify risks.

▎ academic latitude / report ▎ today, the top academic journal Science published a new research paper from Australia.the official introduction to science points out that the study "redefines the nature of T cell antigen recognition.".as we know, T cells are important guards in the immune system and are active in the first line of anti pathogen.they can not only protect us from bacteria and viruses, but also effectively attack cancer cells.therefore, if we can understand how these cells recognize the dangerous molecules in the body, it is expected to bring us better anti infection or anti-cancer therapy.in the current mainstream models, T cells recognize potential threats through the surface "T cell receptor" (TCR).for example, when viruses and bacteria infect the human body, their surface specific proteins are loaded into a structure called the major histocompatibility complex (MHC) for T cells to recognize.it's like copying hundreds of thousands of portraits of suspects and distributing them to the grassroots investigators.it will be easier for the police to arrest the suspects if they know what they look like.} in the current mainstream models, MHC and TCR bind "head to head" (image source: Cecilia tejero Garc í a [CC by-sa 4.0(), in the past, we knew a lot about α - β T cell receptor.it is believed that T cell receptors are able to recognize specific signals from pathogens by binding to MHC or MHC like molecules in a "head-to-head" manner.in this study, the scientists focused on their relatives, the gamma delta T cell receptors.specifically, the researchers obtained a three-dimensional structure in which the gamma delta T cell receptor binds to a molecule similar to MHC.surprisingly, some receptors bind not to the top of the molecule, but to the bottom! Dr. J é R ô me le nours, one of the co authors of this study, made a vivid analogy: "imagine that (MHC molecule) is like a flag on a cell.we always thought that T cells would sit on the top of the flagpole and read the information on the flag.however, we found that some T cells first bind to the bottom."} some T cell receptors first bind to the bottom of MHC like molecules (photo source: reference [1]). Researchers believe that this unusual recognition system is expected to help us understand how TCR binds to target molecules. considering that T cells are an important weapon for the body to fight diseases, these insights are expected to lead to more effective therapies. due to the role of δ T cells in anti-cancer, the existing anti-cancer immunotherapy may be further enhanced. according to its official news, researchers will further explore this mechanism and strive to apply it to the treatment of diseases. References: [1] J é R ô me le nours et al., (2019), a class of γ δ T cell receptors recognize the under of the anti presenting molecular MR1, science, DOI: 10.1126/ science.aav3900 [2] Advanced imaging tips T cell target recognition on its head, Retrieved December, 19, 2019, from