Introduction to Cytokines as Tissue Regulators in Health and Disease

Cytokines are powerful mediators of several biological processes and are highly regulated in the body. Chronic uncontrolled levels of such proteins can initiate and potentiate many pathologies, including autoimmunity and cancer. Cytokines shares basic properties: they are pleiotropic-a given cytokine may drive proliferation of a cell type and induce growth arrest in another cell type, they are redundant, and the cytokine network is tightly regulated and its alteration may lead to impaired tissue and cellular physiology. Currently, there is an emerging understanding of the role of cytokine in tissue homeostatic functional regulation and it is becoming clear that pathological conditions may develop from dysregulation of cytokines. Some organs seem more vulnerable to dysregulated cytokines networks than others, so it is becoming more and more important to study the cytokine network in the contest of tissue specificity. In addition, cytokines can act in concert with other tissue-specific signals. Therefore, unraveling the complexity of such network is extremely challenging as different organs have developed diverse strategies to cope with immune cell migration. Here, I summarize the basic knowledge on functional groups of cytokines and the role played in the context of tissue regulation in health and disease.