Multiparametric Flow Cytometry Analysis of Naïve, Memory, and Effector T Cells.

Polychromatic flow cytometry enables the detection and characterization of markers which are helpful in defining phenotype of various cell subsets. Here we describe flow cytometry-based method to characterize phenotype of naïve, memory, and effector T cells. Being able to differentiate these cells is crucial in understanding immune response, and immune profiling. Naïve T cells enable the body to fight off new, unrecognized infections and diseases, and memory T cells are enriched for response to recall antigens. Furthermore, the antigen-experienced T cell populations can be broadly divided into effector and memory cell compartments, both of which are needed for sustaining a responsive immune system. Simplistically, the effector T cells require active antigenic stimulation to eliminate pathogens. On the other hand, memory T cells are described as cells which remain present in the absence of antigenic stimulation and have the capacity to expand rapidly upon secondary challenges. Recently, with the identification of central and effector memory T cell subsets, tremendous efforts have been devoted to characterize markers on the surfaces of these cells. Though, various markers have been used to identify the subsets, no single marker that segregates one subset from the other has been described. Thus, multiple markers are needed to subset the cells in order to characterize them. Here we report the verification of a nine-color panel (CD3, CD4, CD8, CD45RO, CD28, CD95, CCR7, Live/Dead Aqua, dump channel-CD19, CD14, CD56, CD16) that can successfully identify six distinct CD4 and CD8 T cell populations within the naïve and effector cell subsets from human donors.