TY - JOUR
AB - Lymphocyte motility in lymph nodes is regulated by chemokines, but the contribution of integrins to this motility remains obscure. Here we examined lymphocyte migration over CCR7-binding chemokines that 'decorate' lymph node stroma. In a shear-free environment, surface-bound lymph node chemokines but not their soluble counterparts promoted robust and sustained T lymphocyte motility. The chemokine CCL21 induced compartmentalized clustering of the integrins LFA-1 and VLA-4 in motile lymphocytes, but both integrins remained nonadhesive to ligands on lymphocytes, dendritic cells and stroma. The application of shear stress to lymphocytes interacting with CCL21 and integrin ligands promoted robust integrin-mediated adhesion. Thus, lymph node chemokines that promote motility and strongly activate lymphocyte integrins under shear forces fail to stimulate stable integrin adhesiveness in extravascular shear-free environments.
AU - Woolf, Eilon
AU - Grigorova, Irina
AU - Sagiv, Adi
AU - Grabovsky, Valentin
AU - Feigelson, Sara W
AU - Shulman, Ziv
AU - Hartmann, Tanja
AU - Michael Sixt
AU - Cyster, Jason G
AU - Alon, Ronen
ID - 3937
IS - 10
JF - Nature Immunology
TI - Lymph node chemokines promote sustained T lymphocyte motility without triggering stable integrin adhesiveness in the absence of shear forces
VL - 8
ER -
TY - JOUR
AB - RhoH is a small GTPase expressed only in the hematopoietic system. With the use of mice with targeted disruption of the RhoH gene, we demonstrated that RhoH is crucial for thymocyte maturation during DN3 to DN4 transition and during positive selection. Furthermore, the differentiation and expansion of DN3 and DN4 thymocytes in vitro were severely impaired. These defects corresponded to defective TCR signaling. Although RhoH is not required for TCR-induced activation of ZAP70 and ZAP70-mediated activation of p38, it is crucial for the tyrosine phosphorylation of LAT, PLCgamma1, and Vav1 and for the activation of Erk and calcium influx. These data suggest that RhoH is important for pre-TCR and TCR signaling because it allows the efficient interaction of ZAP70 with the LAT signalosome, thus regulating thymocyte development.
AU - Dorn, Tatjana
AU - Kuhn, Ursula
AU - Bungartz, Gerd
AU - Stiller, Sebastian
AU - Bauer, Martina
AU - Ellwart, Joachim
AU - Peters, Thorsten
AU - Scharffetter-Kochanek, Karin
AU - Semmrich, Monika
AU - Laschinger, Melanie
AU - Holzmann, Bernhard
AU - Klinkert, Wolfgang E
AU - Straten, Per Thor
AU - Køllgaard, Tania
AU - Michael Sixt
AU - Brakebusch, Cord
ID - 3938
IS - 6
JF - Blood
TI - RhoH is important for positive thymocyte selection and T-cell receptor signaling
VL - 109
ER -
TY - JOUR
AB - The persistence diagram of a real-valued function on a topological space is a multiset of points in the extended plane. We prove that under mild assumptions on the function, the persistence diagram is stable: small changes in the function imply only small changes in the diagram. We apply this result to estimating the homology of sets in a metric space and to comparing and classifying geometric shapes.
AU - Cohen-Steiner, David
AU - Herbert Edelsbrunner
AU - Harer, John
ID - 3972
IS - 1
JF - Discrete & Computational Geometry
TI - Stability of persistence diagrams
VL - 37
ER -
TY - JOUR
AB - In this paper we bound the difference between the total mean curvatures of two closed surfaces in R-3 in terms of their total absolute curvatures and the Frechet distance between the volumes they enclose. The proof relies on a combination of methods from algebraic topology and integral geometry. We also bound the difference between the lengths of two curves using the same methods.
AU - Cohen-Steiner, David
AU - Herbert Edelsbrunner
ID - 3973
IS - 4
JF - Foundations of Computational Mathematics
TI - Inequalities for the curvature of curves and surfaces
VL - 7
ER -
TY - CONF
AB - We study the reconstruction of a stratified space from a possibly noisy point sample. Specifically, we use the vineyard of the distance function restricted to a I-parameter family of neighborhoods of a point to assess the local homology of the stratified space at that point. We prove the correctness of this assessment under the assumption of a sufficiently dense sample. We also give an algorithm that constructs the vineyard and makes the local assessment in time at most cubic in the size of the Delaunay triangulation of the point sample.
AU - Paul Bendich
AU - Cohen-Steiner, David
AU - Herbert Edelsbrunner
AU - Harer, John
AU - Morozov, Dmitriy
ID - 3975
TI - Inferring local homology from sampled stratified spaces
ER -