Multi-system approach to analysis of T-lymphocyte activation by flow cytometry: Utilization of intracellular cytokine expression, cytokine receptor expression, and quantification of cytokine secretion as an indicator of activation

Production of and receptivity to cytokines is an essential component of T-cell activation.^1,4,5 Activation is a balance of cytokine expression, cytokine secretion, expression of cell surface cytokine receptors and secretion of soluble cytokine receptors. All of these factors interact to direct an immune response. The observed biological activity of in vitro activated cell cultures is influenced greatly by the presence of mixed cell populations and the method of activation. Control of responding cell populations and careful choice of activation methodology are important in designing experiments.⁹ In order to study fully the role of cytokines in activation and development of immunity, we have developed an inter-related and compatible group of products designed to work together to study cytokine biology as it relates to T-cell activation. The kits facilitate preparation of T-cell enriched cell suspensions, establishment of activated cells cultures, and measurement of biological activity based on cytokine biology. Our analysis methods are based on combining expression of intracytoplasmic cytokines, cell surface cytokine receptors, and secreted cytokines. Combining these analysis strategies can provide more information about cytokine non-responsiveness than any of the assays alone. Analysis of both intracellular cytokine and secreted cytokine complement each other providing confirmational data of each method of analysis. These assays can have a direct clinical impact when applied to the study of T-cell function in HIV and other viral infections, autoimmunity, and transplantation biology.