Detection of T cell cytokine production as a tool for monitoring immunotherapy

There are many complex relationships between tu-\ud mour cells and effector cells in the immune system.\ud These interactions are controlled predominantly by cy-\ud tokines, either within the tumour environment, or sys-\ud temically where the effector cells may be stimulated as\ud a response to the presence of the tumour. Favourable\ud clinical responses in cancer patients have been shown\ud to be associated with enhanced cell-mediated immunity\ud as well as T cell infiltration in tumours. This status\ud is controlled in part by a predominantly Th1 cytokine\ud profile e.g. IFN γ , TNF α and IL-12. Conversely, pa-\ud tients with advancing cancer may have impaired cell-\ud mediated immunity as a result of an imbalance of Th1\ud and Th2 cytokines e.g. IL-4 and IL-10 [6,9,15]. Whilst\ud cytokines have long been known to orchestrate the im-\ud mune system by allowing communication between reg-\ud ulatory and effector cells, the pleiotropic nature of these\ud molecules results in a very complex environment in\ud which to study any single molecule’s properties. Several\ud in vitro protocols have been developed,which aim to closely reflect cytokine production and T cell function in vivo. However, these assays have been developed in artificial settings and as such only allow conclusions to be drawn within a defined context [11]. The aim of this report is to outline the basic proto-cols and applications for the detection of intracellular cytokines by flow cytometry, in the context of disease monitoring.