title: Intravital microscopy comparing T lymphocyte trafficking to the spleen and the mesenteric lymph node.
abstract: Lymphocyte rolling velocity is determined largely by interactions between leukocyte alpha(4)-integrin (CD49d) and L-selectin and mucosal addressin cell adhesion molecule-1 (MAdCAM-1) in mesenteric postcapillary venules and Peyer's patch high endothelial venules (HEVs). The role of these interactions in other tissue sites of lymphocyte emigration is not known. With the use of real-time intravital confocal microscopy, we found that rolling velocities of T lymphocytes in the murine mesenteric lymph node (MLN) HEV also depend on L-selectin and CD49d. However, in the murine spleen, rolling velocities of T lymphocytes are not influenced by the loss of L-selectin and CD49d. With the use of FITC-dextran and TIE2-GFP mice, we further defined the microvascular compartments of the spleen and showed that adherence of T cells is localized to regions in the white pulp that are not lined by endothelial cells and have shear rates similar to bone marrow sinusoids. These results establish that T cell trafficking to the spleen differs from trafficking to other secondary lymphoid organs and suggest that the mechanical properties of the blood-filtering role of the spleen are important in T cell accumulation in the organ.
authors.affiliation: Division of Allergy and Immunology, Washington University School of Medicine, St. Louis, Missouri 63110, USA. wheeze@allergist.com
authors.forename: Mitchell H
authors.initials: MH
authors.lastname: Grayson
authors.forename: Richard S
authors.initials: RS
authors.lastname: Hotchkiss
authors.forename: Irene E
authors.initials: IE
authors.lastname: Karl
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Holtzman
authors.forename: David D
authors.initials: DD
authors.lastname: Chaplin
mesh_terms: D000818:Animals; D002448:Cell Adhesion / Q000502:physiology; D015815:Cell Adhesion Molecules; D002469:Cell Separation; D016650:Fluorescein-5-isothiocyanate; D005456:Fluorescent Dyes; D007136:Immunoglobulins / Q000502:physiology; D019041:L-Selectin / Q000235:genetics / Q000502:physiology; D008198:Lymph Nodes / Q000098:blood supply / Q000166:cytology* / Q000502:physiology*; D008643:Mesentery / Q000166:cytology / Q000502:physiology; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D018613:Microscopy, Confocal; D008863:Microspheres; D009088:Mucoproteins / Q000502:physiology; D037342:Pertussis Toxin / Q000494:pharmacology; D012039:Regional Blood Flow / Q000502:physiology; D012212:Rheology; D013154:Spleen / Q000098:blood supply / Q000166:cytology* / Q000502:physiology*; D013601:T-Lymphocytes / Q000502:physiology*
chemical_list: D015815:Cell Adhesion Molecules; D005456:Fluorescent Dyes; D007136:Immunoglobulins; C489082:Madcam1 protein, mouse; D009088:Mucoproteins; D019041:L-Selectin; D037342:Pertussis Toxin; D016650:Fluorescein-5-isothiocyanate