title: Evolution of lymphoid tissues.
abstract: Lymphoid organs are integral parts of all vertebrate adaptive immune systems. Primary lymphoid tissues exhibit a remarkable functional dichotomy: T cells develop in specialized thymopoietic tissues located in the pharynx, whereas B cells develop in distinct areas of general hematopoietic areas, such as the kidney or bone marrow. Among secondary lymphoid tissues, the spleen is present in all vertebrates, whereas lymph nodes represent an innovation particular to mammals and some birds. A comparative analysis of anatomical, functional and genomic features thus reveals the core components of adaptive immune systems. Such information has guided recent attempts at reconstructing lymphopoietic functions in vivo and in the future might inspire the development of new strategies for medical interventions restoring and modulating immune functions.
authors.affiliation: Department of Developmental Immunology, Max Planck Institute of Immunobiology and Epigenetics, Stuebeweg 51, D-79108 Freiburg, Germany. boehm@immunbio.mpg.de
authors.forename: Thomas
authors.initials: T
authors.lastname: Boehm
authors.forename: Isabell
authors.initials: I
authors.lastname: Hess
authors.forename: Jeremy B
authors.initials: JB
authors.lastname: Swann
mesh_terms: D056704:Adaptive Immunity; D000818:Animals; D005075:Biological Evolution; D002454:Cell Differentiation; D006801:Humans; D008221:Lymphoid Tissue / Q000166:cytology / Q000276:immunology*; D013601:T-Lymphocytes / Q000166:cytology / Q000276:immunology