title: Cytokines and their role in lymphoid development, differentiation and homeostasis.
abstract: OBJECTIVE
  The development of lymphoid tissues as well as the ultimate differentiation of naïve and memory T cells are dependent on cytokines. In this review, we will focus on recent advances in the understanding of molecular mechanisms that regulate lymphoid development, homeostasis and tolerance.
  
  
  RESULTS
  Cytokines play a critical role in the development and differentiation of lymphoid cells. In addition, newer data indicate important roles of interleukin-7 and interleukin-15 in lymphoid homeostasis and memory. Furthermore, a new family of heterodimeric cytokines comprising interleukin-12, interleukin-23 and -27 is important for differentiation of helper T cells and cell-mediated immunity. Finally the importance of tumor necrosis factor superfamily members in the development of lymphoid organs has recently been elucidated and will be discussed in detail.
  
  
  CONCLUSIONS
  New cytokines and receptors continue to be identified. The discovery and characterization of cytokines, their receptors and signaling molecules will provide a more complete understanding of normal lymphoid development, differentiation and function. In addition, this knowledge should improve our understanding of the pathogenesis of immunological diseases and hopefully will provide new treatment strategies.
authors.affiliation: Molecular Immunology and Inflammation Branch, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA.
authors.forename: Sigrun R
authors.initials: SR
authors.lastname: Hofmann
authors.forename: Rachel
authors.initials: R
authors.lastname: Ettinger
authors.forename: Yong-Jie
authors.initials: YJ
authors.lastname: Zhou
authors.forename: Massimo
authors.initials: M
authors.lastname: Gadina
authors.forename: Peter
authors.initials: P
authors.lastname: Lipsky
authors.forename: Richard
authors.initials: R
authors.lastname: Siegel
authors.forename: Fabio
authors.initials: F
authors.lastname: Candotti
authors.forename: John J
authors.initials: JJ
authors.lastname: O'Shea
mesh_terms: D016207:Cytokines / Q000378:metabolism*; D006706:Homeostasis / Q000502:physiology*; D006801:Humans; D007156:Immunologic Memory; D018664:Interleukin-12 / Q000378:metabolism; D053759:Interleukin-23; D053760:Interleukin-23 Subunit p19; D015847:Interleukin-4 / Q000378:metabolism; D016906:Interleukin-9 / Q000378:metabolism; D007378:Interleukins / Q000378:metabolism; D008221:Lymphoid Tissue / Q000276:immunology / Q000502:physiology*; D018121:Receptors, Cytokine / Q000032:analysis / Q000378:metabolism; D012680:Sensitivity and Specificity; D015398:Signal Transduction; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology / Q000502:physiology*; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: D016207:Cytokines; C508840:IL23A protein, human; D053759:Interleukin-23; D053760:Interleukin-23 Subunit p19; D016906:Interleukin-9; D007378:Interleukins; D018121:Receptors, Cytokine; D014409:Tumor Necrosis Factor-alpha; D018664:Interleukin-12; D015847:Interleukin-4