Cells, PBMC, CD4+ Helper T cells, Negative Selection, BioPrimary(TM)

BioPrimary(TM) Cells are derived using technology including advanced protocols and adjuvants that ehance the viability of our cells to over >90% total post-thaw viability.\n\nCD4+ T helper cells are a sub-group of lymphocytes that play a crucial role in establishing and maximizing the capabilities of the immune system. These cells are unusual in that they have no cytotoxic or phagocytic activity; they cannot kill infected host cells (also known as somatic cells) or pathogens. CD4+ T cells are essential in determining B cell antibody class switching, in the activation and growth of cytotoxic T cells, and in maximizing bactericidal activity of phagocytes such as macrophages. It is this diversity in function and their role in influencing other cells that gives T helper cells their name.\n\nRole in Disease:\nPerhaps the best example of the importance of CD4+ T cells is demonstrated with HIV infection. HIV targets cells that express CD4, and can infect macrophages, dendritic cells (both groups express CD4 at low levels) and CD4+ T cells.\n\nIt has been proposed that during the non-symptomatic phase of HIV infection, the virus has a relatively low affinity towards T cells (and has a higher affinity for macrophages), resulting in a slow kill rate of CD4+ T cells by the immune system. This is initially compensated for via the production of new helper T cells from the thymus (originally from the bone marrow). Once the virus becomes lymphotropic (or T-tropic) however, it begins to infect CD4+ T cells far more efficiently (likely due to a change in the co-receptors it binds to during infection), and the immune system is overwhelmed.\n\nAt this point, functional CD4+ T cell levels begin to decrease, eventually to a point where the CD4+ T cell population is too small to recognize the full range of antigens that could potentially be detected. The lack of full antigen cover results in the core symptoms of AIDS.\nCD4+ T cell depletion during AIDS allows various pathogens to escape T cell recognition, thus allowing opportunistic infections that would normally elicit a helper T cell response to bypass the immune system. While these complete bypass situations only occur when the helper T cell response is absolutely necessary for infection clearance, most infections increase in severity and/or duration because the immune system's helper T cells provide a weaker contribution to a less efficient immune response.\n\nAll products are shipped on dry ice with: 1) Certificate of Analysis (with viability and purity results), and 2) Thawing instructions\n\nStorage and Stability: \nIt is recommended that cells are used as soon as possible following receipt to ensure optimal viability. Cells may be stored at -80 C for up to one month (minimize storage length at -80 C in order to maximize viability).\n

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SPECIFICATIONS

Catalog Number

C2600-190

Size

5M Cells

References

Chevalier, N. et al., CXCR5 Expressing Human Central Memory CD4 T Cells and Their Relevance for Humoral Immune Responses, J. Immunol (2011) 186; 5556-5568. \n