Easily and efficiently isolate highly purified human CD8+ T cells from fresh or previously frozen human peripheral blood mononuclear cells (PBMCs) or lysed leukapheresis samples by immunomagnetic negative selection, with the EasySep™ Human CD8+ T Cell Enrichment Kit. Widely used in published research for more than 20 years, EasySep™ combines the specificity of monoclonal antibodies with the simplicity of a column-free magnetic system.
In this EasySep™ negative selection procedure, unwanted cells are labeled with antibody complexes and magnetic particles. Unwanted cells expressing the following markers are targeted for removal: CD4, CD14, CD16, CD19, CD20, CD36, CD56, CD66b, TCRgd, and GlyA. The magnetically labeled cells are then separated from the untouched desired CD8+ T cells by using an EasySep™ magnet and simply pouring or pipetting the desired cells into a new tube. Following magnetic cell isolation, the desired CD4+ T cells are ready for downstream applications such as flow cytometry, culture, or DNA/RNA extraction.
Learn more about how immunomagnetic EasySep™ technology works or how to fully automate immunomagnetic cell isolation with RoboSep™. Alternatively, choose ready-to-use, ethically sourced, primary Human Peripheral Blood CD8+ T Cells, Frozen isolated with EasySep™ Human CD8+ T Cell Enrichment Kit. Explore additional products optimized for your workflow, including culture media, supplements, antibodies, and more.
This product is designed for use in the following research area(s) as part of the highlighted workflow stage(s). Explore these workflows to learn more about the other products we offer to support each research area.
Can EasySep™ be used for either positive or negative selection?
Yes. The EasySep™ kits use either a negative selection approach by targeting and removing unwanted cells or a positive selection approach targeting desired cells. Depletion kits are also available for the removal of cells with a specific undesired marker (e.g. GlyA).
How does the separation work?
Magnetic particles are crosslinked to cells using Tetrameric Antibody Complexes (TAC). When placed in the EasySep™ Magnet, labeled cells migrate to the wall of the tube. The unlabeled cells are then poured off into a separate fraction.
Which columns do I use?
The EasySep™ procedure is column-free. That's right - no columns!
How can I analyze the purity of my enriched sample?
The Product Information Sheet provided with each EasySep™ kit contains detailed staining information.
Can EasySep™ separations be automated?
Yes. RoboSep™, the fully automated cell separator, automates all EasySep™ labeling and cell separation steps.
Can EasySep™ be used to isolate rare cells?
Yes. We recommend a cell concentration of 2x108 cells/mL and a minimum working volume of 100 µL. Samples containing 2x107 cells or fewer should be suspended in 100 µL of buffer.
Are the EasySep™ magnetic particles FACS-compatible?
Yes, the EasySep™ particles are flow cytometry-compatible, as they are very uniform in size and about 5000X smaller than other commercially available magnetic beads used with column-free systems.
Can the EasySep™ magnetic particles be removed after enrichment?
No, but due to the small size of these particles, they will not interfere with downstream applications.
Can I alter the separation time in the magnet?
Yes; however, this may impact the kit's performance. The provided EasySep™ protocols have already been optimized to balance purity, recovery and time spent on the isolation.
For positive selection, can I perform more than 3 separations to increase purity?
Yes, the purity of targeted cells will increase with additional rounds of separations; however, cell recovery will decrease.
How does the binding of the EasySep™ magnetic particle affect the cells? is the function of positively selected cells altered by the bound particles?
Hundreds of publications have used cells selected with EasySep™ positive selection kits for functional studies. Our in-house experiments also confirm that selected cells are not functionally altered by the EasySep™ magnetic particles.
If particle binding is a key concern, we offer two options for negative selection. The EasySep™ negative selection kits can isolate untouched cells with comparable purities, while RosetteSep™ can isolate untouched cells directly from whole blood without using particles or magnets.
Identification of cross-reactive CD8+ T cell receptors with high functional avidity to a SARS-CoV-2 immunodominant epitope and its natural mutant variants. C. Hu et al. Genes & diseases 2022 jan
Abstract
Despite the growing knowledge of T cell responses in COVID-19 patients, there is a lack of detailed characterizations for T cell-antigen interactions and T cell functions. Here, with a predicted peptide library from SARS-CoV-2 S and N proteins, we found that specific CD8+ T cell responses were identified in over 75% of COVID-19 convalescent patients (15/20) and an epitope from the N protein, N361-369 (KTFPPTEPK), was the most dominant epitope from our selected peptide library. Importantly, we discovered 2 N361-369-specific T cell receptors (TCRs) with high functional avidity that were independent of the CD8 co-receptor. These TCRs exhibited complementary cross-reactivity to several presently reported N361-369 mutant variants, as to the wild-type epitope. Further, the natural functions of these TCRs in the cytotoxic immunity against SARS-CoV-2 were determined with dendritic cells (DCs) and the lung organoid model. We found that the N361-369 epitope could be normally processed and endogenously presented by these different types of antigen presenting cells, to elicit successful activation and effective cytotoxicity of CD8+ T cells ex vivo. Our study evidenced potential mechanisms of cellular immunity to SARS-CoV-2, and illuminated potential ways of viral clearance in COVID-19 patients. These results indicate that utilizing CD8-independent TCRs against SARS-CoV-2-associated antigens may provide functional superiority that is beneficial for the adoptive cell immunotherapies based on natural or genetically engineered T cells. Additionally, this information is highly relevant for the development of the next-generation vaccines with protections against continuously emerged SARS-CoV-2 mutant strains.
A Compartmentalized Reduction in Membrane-Proximal Calmodulin Reduces the Immune Surveillance Capabilities of CD8+ T Cells in Head and Neck Cancer. A. A. Chimote et al. Frontiers in pharmacology 2020
Abstract
The limited ability of cytotoxic CD8+ T cells to infiltrate solid tumors and function within the tumor microenvironment presents a major roadblock to effective immunotherapy. Ion channels and Ca2+-dependent signaling events control the activity of T cells and are implicated in the failure of immune surveillance in cancer. Reduced KCa3.1 channel activity mediates the heightened inhibitory effect of adenosine on the chemotaxis of circulating T cells from head and neck squamous cell carcinoma (HNSCC) patients. Herein, we conducted experiments that elucidate the mechanisms of KCa3.1 dysfunction and impaired chemotaxis in HNSCC CD8+ T cells. The Ca2+ sensor calmodulin (CaM) controls multiple cellular functions including KCa3.1 activation. Our data showed that CaM expression is lower in HNSCC than healthy donor (HD) T cells. This reduction was due to an intrinsic decrease in the genes encoding CaM combined to the failure of HNSCC T cells to upregulate CaM upon activation. Furthermore, the reduction in CaM was confined to the plasma membrane and resulted in decreased CaM-KCa3.1 association and KCa3.1 activity (which was rescued by the delivery of CaM). IFN$\gamma$ production, also Ca2+- and CaM-dependent, was instead not reduced in HNSCC T cells, which maintained intact cytoplasmic CaM and Ca2+ fluxing ability. Knockdown of CaM in HD T cells decreased KCa3.1 activity, but not IFN$\gamma$ production, and reduced their chemotaxis in the presence of adenosine, thus recapitulating HNSCC T cell dysfunction. Activation of KCa3.1 with 1-EBIO restored the ability of CaM knockdown HD T cells to chemotax in the presence of adenosine. Additionally, 1-EBIO enhanced INF$\gamma$ production. Our data showed a localized downregulation of membrane-proximal CaM that suppressed KCa3.1 activity in HNSCC circulating T cells and limited their ability to infiltrate adenosine-rich tumor-like microenvironments. Furthermore, they indicate that KCa3.1 activators could be used as positive CD8+ T cell modulators in cancers.
Multifactorial heterogeneity of virus-specific T cells and association with the progression of human chronic hepatitis B infection. Y. Cheng et al. Science immunology 2019 feb
Abstract
Associations between chronic antigen stimulation, T cell dysfunction, and the expression of various inhibitory receptors are well characterized in several mouse and human systems. During chronic hepatitis B virus (HBV) infection (CHB), T cell responses are blunted with low frequencies of virus-specific T cells observed, making these parameters difficult to study. Here, using mass cytometry and a highly multiplexed combinatorial peptide-major histocompatibility complex (pMHC) tetramer strategy that allows for the detection of rare antigen-specific T cells, we simultaneously probed 484 unique HLA-A*1101-restricted epitopes spanning the entire HBV genome on T cells from patients at various stages of CHB. Numerous HBV-specific T cell populations were detected, validated, and profiled. T cells specific for two epitopes (HBVpol387 and HBVcore169) displayed differing and complex heterogeneities that were associated with the disease progression, and the expression of inhibitory receptors on these cells was not linearly related with their extent of T cell dysfunction. For HBVcore169-specific CD8+ T cells, we found cellular markers associated with long-term memory, polyfunctionality, and the presence of several previously unidentified public TCR clones that correlated with viral control. Using high-dimensional trajectory analysis of these cellular phenotypes, a pseudo-time metric was constructed that fit with the status of viral infection in corresponding patients. This was validated in a longitudinal cohort of patients undergoing antiviral therapy. Our study uncovers complex relationships of inhibitory receptors between the profiles of antigen-specific T cells and the status of CHB with implications for new strategies of therapeutic intervention.
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