AS Lau, D Lehman, J Liu

Abstract

Cytokines are soluble signaling proteins responsible for cell-to-cell communication and play critical roles in many biological processes including growth and development, immunity, and hematopoiesis. In response to pathogen invasion, these pleiotropic molecules are produced by immune cells and other cells including fibroblasts and endothelia. Interaction among cytokines results in propagation of inflammation and host defense against pathogens. The biological functions of prototype cytokines including interferons, tumor necrosis factor-alpha, interleukins, and granulocyte colony stimulating factors are reviewed. With special references to children, therapeutic uses of interferon-α in viral diseases and interferon-γ in chronic granulomatous disease are discussed. The clinical applications of granulocyte/macrophage colony stimulating factors in patients with neutropenia due to cytotoxic chemotherapy, bone marrow transplantation, and congenital agranulocytosis are presented. We also examine the role of tumor necrosis factor-alpha and interleukins in the pathogenesis of septic shock and discuss the various possible strategies to suppress the undesirable effects of over-expression of proinflammatory cytokines. In summary, advances in biotechnology enable the use of interferons and colony stimulating factors to provide novel approaches to treat children and adults with viral infections, cancer, or autoimmune diseases. In addition, manipulating the cytokine systems by inhibiting the activity of proinflammatory cytokines may prove useful in the treatment of patients with sepsis.