title: Long-term commitment to inflammation-seeking homing in CD4+ effector cells.
abstract: Access of T effector cells to sites of inflammation is a prerequisite for an efficient action in immune defense and is mediated by different, partly tissue-specific sets of adhesion molecules. To what extent lymphocytes memorize the site of initial priming and develop organ-specific homing properties is still a matter of debate. Notably, data on the stability of homing receptor expression on T cells in vivo are largely lacking. We approached this question by the adoptive transfer of CD4(+) T cells sorted for the expression of P-selectin ligands, which contribute to migration into inflamed sites in skin and other tissues. We observed long-term expression of P-selectin ligands on roughly one-third of effector cells. On those cells that had lost P-selectin ligands, re-expression upon Ag challenge was observed but only within pLNs, similar to the organ-selective induction upon the primary activation of naive T cells. The frequency of cells stably expressing P-selectin ligands was higher when cells were repeatedly stimulated under permissive conditions in the presence of IL-12, indicating a gradual fixation of this phenotype. In line with that finding, isolated P-selectin ligand positive memory T cells showed the highest frequency of long-term expressing cells. A tissue-specific environment was not required for the long-term maintenance of P-selectin ligand expression on the subfraction of effector cells. These data indicate that the expression of selectin ligands can become clonally imprinted under certain conditions, but also that a major fraction of the cells remains flexible and subject to environmental modulation upon restimulation.
authors.affiliation: Charité, Campus Mitte, Experimentelle Rheumatologie, c/o Deutsches Rheumaforschungszentrum, 12200 Berlin, Germany.
authors.forename: Silke
authors.initials: S
authors.lastname: Jennrich
authors.forename: Boris A
authors.initials: BA
authors.lastname: Ratsch
authors.forename: Alf
authors.initials: A
authors.lastname: Hamann
authors.forename: Uta
authors.initials: U
authors.lastname: Syrbe
mesh_terms: D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000737:chemistry / Q000187:drug effects / Q000276:immunology*; D002465:Cell Movement; D002478:Cells, Cultured; D003872:Dermatitis / Q000276:immunology*; D007156:Immunologic Memory; D007249:Inflammation / Q000276:immunology; D016023:Integrins / Q000032:analysis / Q000378:metabolism*; D008562:Membrane Glycoproteins / Q000032:analysis / Q000378:metabolism*; D051379:Mice; D016176:T-Lymphocyte Subsets / Q000737:chemistry / Q000187:drug effects / Q000276:immunology*; D014212:Tretinoin / Q000494:pharmacology
chemical_list: D016023:Integrins; D008562:Membrane Glycoproteins; C084882:P-selectin ligand protein; C071777:integrin alpha4beta7; D014212:Tretinoin