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CD4+ Naive T Cell Sorting Service
Leukopak is a concentrated blood fraction collected using a apheresis machine, primarily intended for the isolation of white blood cells (WBCs) from peripheral blood. WBCs are highly enriched in peripheral blood mononuclear cells (PBMCs), which consist mainly of T cells, B cells, NK cells, and monocytes. The WBC concentration in Leukopak is substantially higher—approximately 4–7 × 10^8 WBCs per milliliter—than that in whole blood, where the average is 5–7 × 10^6 WBCs per milliliter. In addition, the red blood cell (RBC) count in Leukopak is markedly reduced, with a ratio of about 2 RBCs to 1 WBC, whereas in whole blood the ratio is roughly 1,000 RBCs to 1 WBC. Moreover, the purity and quality of the WBC fraction in Leukopak are far superior to those in whole blood, typically containing more than 20-fold the amount of PBMCs. PBMCs are highly valued for their applications in immunotherapy research, cell therapy process development, and clinical settings. Consequently, WBCs have become the preferred starting material for cell therapy research and drug development.
PBMC (peripheral blood mononuclear cell) refers to mononuclear cells in peripheral blood, including lymphocytes, monocytes, dendritic cells, and a small number of other cell types such as hematopoietic stem cells. Based on the source of the sample, PBMC can be classified as whole-blood–derived PBMC or apheresis–derived PBMC. Apheresis–derived PBMC is a component blood product obtained by leukapheresis using an apheresis machine; the majority of cells in this fraction are PBMC, with only a small proportion of granulocytes and erythrocytes.
CD3 is an important leukocyte differentiation antigen that is expressed on the surface of nearly all T cells. It consists of four genetic loci and six polypeptide chains, and serves as a membrane-associated antigen that forms part of the T-cell antigen receptor (TCR). Upon antigen–TCR engagement, CD3 mediates intracellular signal transduction, regulates T-cell differentiation—including the lineage commitment and activation of helper T cells and cytotoxic T cells—facilitates cytokine secretion and apoptosis, and influences ligand-receptor interactions, thereby playing a critical role in the diverse functional activities of T cells.
CD4 cells refer to T lymphocytes that express the CD4 molecule on their surface; they are a crucial type of immune cell in the human body. Because HIV primarily targets CD4+ T cells, the results of CD4 cell count testing play an important role in assessing the efficacy of AIDS treatment and evaluating the patient’s immune function.
CD4+ Naive T Cell Sorting Service
Among helper T cells, naïve CD4+ T cells that have not yet been stimulated by antigens are designated as Th0. Upon maturation and activation, these cells can execute a variety of antigen-dependent effector functions. Based on their distinct functional profiles, CD4+ T cells can be classified into several Th cell subsets, including Th1, Th2, Th3, Treg, Tr1, Tfh, Th17, Th9, and Th22. These Th subsets engage in intricate interplay and coordinate their activities to exert immunoregulatory effects, thereby maintaining homeostasis of the organism.
CD8+ cytotoxic T cells are considered the primary effector cells of anti-tumor immunity. Their restricted and antigen-specific recognition of tumor-associated antigens (TA) via class I MHC molecules, combined with their ability to produce perforin and other cytotoxins upon activation, enables them to induce tumor cell death while sparing normal cells.