The release of the first human thymocyte map opens the door for a new type of cancer immunotherapy

White Dew On February 21, researchers from the Wellcome Sanger Institute, the University of Newcastle and the University of Ghent in Belgium published their latest findings in the journal Science They mapped thymocytes throughout the human life cycle to understand how thymus tissue develops and produces important immune cells called T cells Photo source: Science This map reveals new cell types and identifies signals that tell immature immune cells how to develop into T cells It can also help scientists understand diseases such as severe combined immunodeficiency (SCID) that affect the development of T cells, and join the human cell map project that is creating a "Google map" of the whole human body In the future, this information can help researchers create artificial thymus and design improved therapeutic T cells, which may lead to the birth of new immunotherapies for cancer and autoimmune diseases To construct human thymocyte map (picture source: Science) As we all know, thymus tissue is located in the chest and can produce T cells, the key leukocytes to resist infection and disease Then these T cells leave the thymus and enter the blood and other parts of the body to further mature, and start to search for and eliminate invading bacteria and viruses, while recognizing cancer cells and killing them Thymic development problems can lead to the production of defective T cells, which may lead to serious immune defects (such as SCID), making people vulnerable to infection Or, it can affect the regulation of T cells, leading to autoimmune diseases, such as type 1 diabetes Although mature T cells have been well studied, the development of human thymus and T cells in it has not been fully understood The researchers used a single cell technique to separate and analyze about 200000 cells from the developing thymus, as well as the thymus tissues of children and adults They studied which genes were active in each cell to identify cells, find new cell types, and use these genes as markers to locate each cell in its exact location in the thymus Dr jongeun Park, the lead author of the study, said: "we have produced the first human thymocyte map to understand what happens to healthy thymus in the whole human life cycle from development to adulthood, and how it provides the ideal environment to support the formation of T cells This publicly available resource will enable researchers around the world to understand how the immune system has developed to protect our bodies " Cell composition of developing human thymus tissue (picture source: Science) Therapeutic T cells are currently being used in clinical treatment of B-cell lymphoma and leukemia, but one of the main problems of these treatments is to produce the correct T cell subtypes Professor muzlifah Haniffa, one of the study's co authors, said: "with the human thymocyte map, we are unraveling cellular signals in the developing thymus and revealing which genes need to be turned on in order to convert early immune precursor cells into specific T cells This is really exciting, because in the future, this map can be used as a reference map to design and manufacture T cells with the right characteristics to attack and kill specific cancers in vitro, so as to provide customized treatment for tumors " Professor Tom taghong, another corresponding author, said: "we now have a very detailed understanding of the formation of T cells in healthy tissues We have been able to identify similar precursor cell groups in the developing thymus and liver We believe that these precursor cells are very important for the initiation of fetal T cell development and the establishment of a fully qualified thymic organ This helps us put together pieces of the puzzle to get a more comprehensive picture of how immunity develops " Thymic colonization and T cell differentiation of early thymic progenitor cells (picture source: Science) Thymus is special because it is the largest and most active in childhood, shrinking after puberty and almost disappearing by age 35 Understanding how the thymus develops and then shrinks can shed light on aging and how the immune system changes throughout its life cycle Dr Sarah TEICHMANN, CO chair of the human cell map organizing committee and the leader of the study, concluded: "this thymocyte map is an important part of the human cell map project designed to map every cell type in the human body It helps us to understand the development of the immune system in the body and the age-related decline of the immune system It can be applied to cell engineering and provide the possibility of creating artificial thymus in regenerative medicine Related literature: [1] J.E Park el al., A cell atlas of human thymic development defines T cell repertoire formation, Science (2020) reference material: