The Effect of Stimulated Macrophages on High Endothelial Venules and Germinal Centres in Lymph Nodes of Rat

Author(s):  
H. R. Hendriks ◽  
H. A. B. v. Hemert ◽  
M. v. d. Heijden
2004 ◽  
Vol 16 (7) ◽  
pp. 915-928 ◽  
Author(s):  
Hiroyuki Yoneyama ◽  
Kenjiro Matsuno ◽  
Yanyun Zhang ◽  
Tetsu Nishiwaki ◽  
Masahiro Kitabatake ◽  
...  

Blood ◽  
2004 ◽  
Vol 104 (13) ◽  
pp. 4104-4112 ◽  
Author(s):  
Jean-Marc Gauguet ◽  
Steven D. Rosen ◽  
Jamey D. Marth ◽  
Ulrich H. von Andrian

Abstract Blood-borne lymphocyte trafficking to peripheral lymph nodes (PLNs) depends on the successful initiation of rolling interactions mediated by L-selectin binding to sialomucin ligands in high endothelial venules (HEVs). Biochemical analysis of purified L-selectin ligands has identified posttranslational modifications mediated by Core2GlcNAcT-I and high endothelial cell GlcNAc-6-sulfotransferase (HECGlcNAc6ST). Consequently, lymphocyte migration to PLNs of C2GlcNAcT-I-/- and HEC-GlcNAc6ST-/- mice was reduced; however, B-cell homing was more severely compromised than T-cell migration. Accordingly, intravital microscopy (IVM) of PLN HEVs revealed a defect in B-cell tethering and increased rolling velocity (Vroll) in C2GlcNAcT-I-/- mice that was more pronounced than it was for T cells. By contrast, B- and T-cell tethering was normal in HEC-GlcNAc6ST-/- HEVs, but Vroll was accelerated, especially for B cells. The increased sensitivity of B cells to glycan deficiencies was caused by lower expression levels of L-selectin; L-selectin+/- T cells expressing L-selectin levels equivalent to those of B cells exhibited intravascular behavior similar to that of B cells. These results demonstrate distinct functions for C2GlcNAcT-I and HEC-GlcNAc6ST in the differential elaboration of HEV glycoproteins that set a threshold for the amount of L-selectin needed for lymphocyte homing. (Blood. 2004;104:4104-4112)


Blood ◽  
1994 ◽  
Vol 84 (8) ◽  
pp. 2554-2565 ◽  
Author(s):  
S Baumhueter ◽  
N Dybdal ◽  
C Kyle ◽  
LA Lasky

Abstract Extravasation of leukocytes into organized lymphoid tissues and into sites of inflammation is critical to immune surveillance. Leukocyte migration to peripheral lymph nodes (PLN), mesenteric lymph nodes (MLN) and Peyer's patches (PP) depends on L-selectin, which recognizes carbohydrate-bearing, sialomucin-like endothelial cell surface glycoproteins. Two of these ligands have been identified at the molecular level. One is the potentially soluble mucin, GlyCAM 1, which is almost exclusively produced by high endothelial venules (HEV) of PLN and MLN. The second HEV ligand for L-selectin is the membrane-bound sialomucin CD34. Historically, this molecule has been successfully used to purify human pluripotent bone marrow stem cells, and limited data suggest that human CD34 is present on the vascular endothelium of several organs. Here we describe a comprehensive analysis of the vascular expression of CD34 in murine tissues using a highly specific antimurine CD34 polyclonal antibody. CD34 was detected on vessels in all organs examined and was expressed during pancreatic and skin inflammatory episodes. A subset of HEV-like vessels in the inflamed pancreas of nonobese diabetic (NOD) mice are positive for both CD34 and GlyCAM 1, and bind to an L-selectin/immunoglobulin G (IgG) chimeric probe. Finally, we found that CD34 is present on vessels of deafferentiated PLN, despite the fact that these vessels are no longer able to interact with L-selectin or support lymphocyte binding in vitro or trafficking in vivo. Our data suggest that the regulation of posttranslational carbohydrate modifications of CD34 is critical in determining its capability to act as an L-selectin ligand. Based on its ubiquitous expression, we propose that an appropriately glycosylated form of vascular CD34 may act as a ligand for L-selectin-mediated leukocyte trafficking to both lymphoid and nonlymphoid sites.


2020 ◽  
Vol 11 ◽  
Author(s):  
Lutz Menzel ◽  
Uta E. Höpken ◽  
Armin Rehm

Tumor-induced remodeling of the microenvironment in lymph nodes (LNs) includes the formation of blood vessels, which goes beyond the regulation of metabolism, and shaping a survival niche for tumor cells. In contrast to solid tumors, which primarily rely on neo-angiogenesis, hematopoietic malignancies usually grow within pre-vascularized autochthonous niches in secondary lymphatic organs or the bone marrow. The mechanisms of vascular remodeling in expanding LNs during infection-induced responses have been studied in more detail; in contrast, insights into the conditions of lymphoma growth and lodging remain enigmatic. Based on previous murine studies and clinical trials in human, we conclude that there is not a universal LN-specific angiogenic program applicable. Instead, signaling pathways that are tightly connected to autochthonous and infiltrating cell types contribute variably to LN vascular expansion. Inflammation related angiogenesis within LNs relies on dendritic cell derived pro-inflammatory cytokines stimulating vascular endothelial growth factor-A (VEGF-A) expression in fibroblastic reticular cells, which in turn triggers vessel growth. In high-grade B cell lymphoma, angiogenesis correlates with poor prognosis. Lymphoma cells immigrate and grow in LNs and provide pro-angiogenic growth factors themselves. In contrast to infectious stimuli that impact on LN vasculature, they do not trigger the typical inflammatory and hypoxia-related stroma-remodeling cascade. Blood vessels in LNs are unique in selective recruitment of lymphocytes via high endothelial venules (HEVs). The dissemination routes of neoplastic lymphocytes are usually disease stage dependent. Early seeding via the blood stream requires the expression of the homeostatic chemokine receptor CCR7 and of L-selectin, both cooperate to facilitate transmigration of tumor and also of protective tumor-reactive lymphocytes via HEV structures. In this view, the HEV route is not only relevant for lymphoma cell homing, but also for a continuous immunosurveillance. We envision that HEV functional and structural alterations during lymphomagenesis are not only key to vascular remodeling, but also impact on tumor cell accessibility when targeted by T cell–mediated immunotherapies.


2020 ◽  
Vol 133 (16) ◽  
pp. jcs242883
Author(s):  
Xuan Luo ◽  
Valentine Seveau de Noray ◽  
Laurene Aoun ◽  
Martine Biarnes-Pelicot ◽  
Pierre-Olivier Strale ◽  
...  

ABSTRACTCell guidance by anchored molecules, or haptotaxis, is crucial in development, immunology and cancer. Adhesive haptotaxis, or guidance by adhesion molecules, is well established for mesenchymal cells such as fibroblasts, whereas its existence remains unreported for amoeboid cells that require less or no adhesion in order to migrate. We show that, in vitro, amoeboid human T lymphocytes develop adhesive haptotaxis mediated by densities of integrin ligands expressed by high endothelial venules. Moreover, lymphocytes orient towards increasing adhesion with VLA-4 integrins (also known as integrin α4β1), like all mesenchymal cells, but towards decreasing adhesion with LFA-1 integrins (also known as integrin αLβ4), which has not previously been observed. This counterintuitive ‘reverse haptotaxis’ cannot be explained by existing mechanisms of mesenchymal haptotaxis involving either competitive anchoring of cell edges under tension or differential integrin-activated growth of lamellipodia, because they both favor orientation towards increasing adhesion. The mechanisms and functions of amoeboid adhesive haptotaxis remain unclear; however, multidirectional integrin-mediated haptotaxis might operate around transmigration ports on endothelia, stromal cells in lymph nodes, and inflamed tissue where integrin ligands are spatially modulated.


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