Nat Immunol: identification of T cells against specific targets

November 21, 2019 / BIOON / -- when the immune system is activated after vaccination, or after the release of allergens and microbial pathogens, the generated T cell subsets will recognize and remove "foreign invaders" Some of these T cells are able to play an immediate role, while others develop into "memory T cells" that circulate throughout the body while protecting the host from the re emergence of invaders Now, MIT researchers have designed a method to identify T cells with specific targets Through high-throughput single cell RNA sequencing, the authors can determine the gene expression of a cell at a given time, and then reveal the unique functions of T cells In the new study, the researchers used the technique to identify specific inflammatory T cells in patients with peanut allergy (image source: www Pixabay Com) by using this method to study the characteristics of peanut allergy of patients' T cells, researchers can help develop specific therapies and determine whether they are effective for specific patients Such research can also help guide researchers in developing and testing new therapies The results were recently published in Nature Immunology The main authors of this paper are ang Andy Tu, a graduate student, and Todd gierahn, a postdoctoral student The researchers' new approach builds on the technology they developed in their previous work, which enables rapid single cell RNA sequencing on a large number of cells By sequencing messenger RNA, scientists can discover genes that are expressed at a given time, allowing them to understand the function of a single cell RNA sequencing on immune cells such as T cells is of great interest because T cells have many different roles in immune response However, previous sequencing studies have not been able to accurately find T cell populations that respond to specific targets or antigens This is determined by the sequence characteristics of T cell receptor (TCR) Single cell RNA sequencing usually only marks and sequencing one end of each RNA molecule, while most of the variation of T cell receptor gene is located at the other end of the sequence, so conventional sequencing methods can not recognize these differences "For a long time, this traditional method has been used to analyze the characteristics of T cells and their transcriptome, but the receptor information of T cells cannot be determined." In a single T cell, the RNA encoding the T cell receptor is less than 1% of the total RNA of the cell, so the MIT team proposed a way to amplify these specific RNA molecules and then "pull" them out of the total sample Each RNA molecule is labeled with a barcode to reveal its cell source information, so researchers can match the target of a T cell with its RNA expression This allows them to determine which genes are active in T cell populations that target specific antigens "To understand the function of T cells, it is necessary to understand the target information recognized by their receptors The method we developed can take advantage of the existing single cell RNA sequencing library and extract the related sequences that we want to characterize " Another advantage of the technology, the researchers say, is that it does not require expensive chemicals, relies on equipment already in many laboratories, and can be applied to many previously processed samples In this paper, the researchers demonstrated that after mice were vaccinated against human papillomavirus, the technology could be used to select mouse T cells with activity against human papillomavirus They found that although all these T cells responded to the virus, they had different TCRs and were at different stages of development: some of them were activated to kill the infected cells, while others focused on growth and division Then, the researchers analyzed T cells from four people who were allergic to peanuts After exposing the cells to peanut allergens, they were able to identify T cells that were active against those allergens They also showed which subsets of T cells were the most active, and found that some inflammatory cytokines were being produced, usually associated with allergic reactions "We can now begin to stratify the data to reveal what the most important cells are, which previously could not be identified by RNA sequencing alone." Source of information: technical identifications T cells primed for certain energies or influences original source: ang A Tu, Todd M gierahn, Brenda monitor, Duncan M Morgan, Naveen K Mehta, Bert ruiter, Wayne g shreffer, Alex K Shalek, J Christopher love TCR sequencing paid with massively parallel 3 ′ RNA SEQ signals clottypic t cell signatures
Nature Immunology , 2019; 20 (12): 1692 DOI: 10.1038/s41590-019-0544-5