Immunoregulation in clinical diseases: an overview.

The quality, magnitude, and persistence of each immune response results from the net balance of different influences that may amplify or decrease it. The complex interaction between such influences underlies the concept of immunoregulation. Comprehension of the complex mechanisms of immunoregulation has the potential to yield important insights into the genetic and the molecular basis of the physiology of immune responses and of the pathophysiology of a wide number of clinical diseases. The principal basic mechanisms of immunoregulation comprise the systems of recognition structures regulating antigen specificity of immune responses and the interconnecting systems involved in the overall regulation of immune responses. Such regulatory interconnecting systems include regulatory T cells, idiotypic network, isotopic network, and the intricate web of interactions between cytokines (cytokine network). In addition, there is now evidence that these highly complex and sophisticated regulatory systems are not only interrelated to each other, but are themselves regulated by signals originated outside the immune system (e.g., from the nervous or the endocrine apparatus). These alterations of immunoregulatory mechanisms are involved in the pathogensis of many groups of human diseases, such as immunodeficiencies, neoplastic and immunoproliferative disorders, many infectious diseases, atopic disease, and autoimmune disorders. A rational knowledge of immunoregulation will hopefully have great practical implications for future strategies of diagnosis and treatment of diseases in which deranged immune functions play a major role.