During the last two decades, a number of approaches for the activation of the immune system against
cancer has been developed. These include highly specific interventions, such as
monoclonal antibodies,
vaccines and cell-based
therapies, as well as relatively unselective strategies, such as the systemic administration of adjuvants and immunomodulatory
cytokines.
Cytokines constitute a huge group of
proteins that, taken together, regulate not only virtually all the aspects of innate and cognate immunity, but also several other cellular and organismal functions.
Cytokines operate via specific transmembrane receptors that are expressed on the plasma membrane of target cells and, depending on multiple variables, can engage autocrine, paracrine or endocrine signaling pathways. The most appropriate term for defining the
cytokine network is "pleiotropic":
cytokines are produced by - and operate on - multiple, often overlapping, cell types, triggering context-depend biological outcomes as diverse as cell proliferation, chemotaxis, differentiation,
inflammation, elimination of pathogens and cell death. Moreover,
cytokines often induce the release of additional
cytokines, thereby engaging self-amplificatory or self-inhibitory signaling cascades. In this Trial Watch, we will summarize the biological properties of
cytokines and discuss the progress of ongoing clinical studies evaluating their safety and efficacy as
immunomodulatory agents against
cancer.