title: Tissue trafficking patterns of effector memory CD4+ T cells in rheumatoid arthritis.
abstract: OBJECTIVE
  Clonal populations of CD4+,CD28- T cells accumulating in rheumatoid arthritis functionally resemble end-differentiated, nondividing, short-lived effector memory cells that reside in peripheral tissues. We undertook this study to examine the tissue niche for CD4+,CD28- T cells and the signals regulating their survival and tissue homing patterns.
  
  
  METHODS
  Chemokine receptor expression on CD4+,CD28- T cell clones and peripheral blood lymphocytes was assessed by multicolor cytometry. In vitro chemotaxis and transendothelial migration were examined in a Transwell system. In vivo tissue-homing patterns were established by adoptively transferring fluorescence-labeled T cell clones into SCID mice engrafted either with rheumatoid synovium or with human lymph nodes.
  
  
  RESULTS
  CD4+,CD28- T cell clones adoptively transferred into human tissue-SCID mouse chimeras infiltrated rheumatoid synovium but preferentially homed to lymph nodes. Such T cells coexpressed the chemokine receptors CCR7, CCR5, and CXCR4 and migrated in response to both inflammatory chemokines (CCL5) and homing chemokines (CXCL12). T cell receptor crosslinking abrogated chemotactic responsiveness. In contrast, interleukin-12 stimulation induced the up-regulation of CCR5 and a shift in the in vivo homing pattern away from the lymph nodes toward the inflamed synovium.
  
  
  CONCLUSIONS
  CD4+,CD28- T cells resemble both short-lived effector memory cells and long-lived central memory cells, and they find a niche both in inflamed synovium and in lymph nodes. Nonspecific cytokine stimulation, not antigen recognition, triggers the transition from the lymph node to the synovium. By maintaining CCR7 expression, these end-differentiated T cells can home to lymphoid organs, enhance their survival, support clonal expansion, and perpetuate autoreactivity.
authors.affiliation: Mayo Clinic, Rochester, Minnesota, USA.
authors.forename: Xiaoyu
authors.initials: X
authors.lastname: Zhang
authors.forename: Takako
authors.initials: T
authors.lastname: Nakajima
authors.forename: Jörg J
authors.initials: JJ
authors.lastname: Goronzy
authors.forename: Cornelia M
authors.initials: CM
authors.lastname: Weyand
mesh_terms: D019264:Adoptive Transfer; D000818:Animals; D001172:Arthritis, Rheumatoid / Q000276:immunology*; D018106:CD28 Antigens / Q000378:metabolism; D015704:CD4 Antigens / Q000378:metabolism; D015496:CD4-Positive T-Lymphocytes / Q000166:cytology / Q000276:immunology* / Q000378:metabolism; D002465:Cell Movement / Q000276:immunology; D002678:Chimera; D006801:Humans; D007156:Immunologic Memory / Q000276:immunology*; D018664:Interleukin-12 / Q000378:metabolism; D051379:Mice; D016688:Mice, Inbred NOD; D016513:Mice, SCID; D019713:Receptors, CCR5 / Q000378:metabolism; D054400:Receptors, CCR7; D019718:Receptors, CXCR4 / Q000378:metabolism; D019707:Receptors, Chemokine / Q000378:metabolism
chemical_list: C515370:CCR7 protein, human; D018106:CD28 Antigens; D015704:CD4 Antigens; C515371:Ccr7 protein, mouse; D019713:Receptors, CCR5; D054400:Receptors, CCR7; D019718:Receptors, CXCR4; D019707:Receptors, Chemokine; D018664:Interleukin-12