T-cell activation is an essential step in the immune response. CD4+ T cells play a vital role in adaptive immunity and regulate both cytotoxic T cell- and antibody-mediated immune responses. The CD4+ T cells play a central role in the recognition and elimination of infected and malignant cells. In addition, CD4+ regulatory T cells (Tregs) are needed to maintain and support self-tolerance and to inhibit immune responses that could damage the host.
Five subsets of CD4+ T cells have been identified: the Th1, Th2, and Th17 cells that target specific classes of pathogens; the regulatory T cells that are required to maintain self-tolerance; the follicular helper T cells (TFH) that provide help to B cells for antibody production (REF)
Human peripheral blood CD4 T lymphocytes are isolated from blood mononuclear cells of single donor.
Plasticity of human CD4 T cell subsets. Jens Geginat, Moira Paroni, Stefano Maglie, Johanna Sophie Alfen, Ilko Kastirr, Paola Gruarin, Marco De Simone, Massimiliano Pagani and Sergio Abrignani. Front. Immunol., 16 December 2014. https://doi.org/10.3389/fimmu.2014.00630