scholarly journals Rapid G protein-regulated activation event involved in lymphocyte binding to high endothelial venules.

1993 ◽  
Vol 178 (1) ◽  
pp. 367-372 ◽  
Author(s):  
R F Bargatze ◽  
E C Butcher
Keyword(s):  
G Protein ◽  
Pertussis Toxin ◽  
Critical Role ◽  
Lymphocyte Activation ◽  
Inhibitory Effect ◽  
Peyer's Patches ◽  
Peyer’S Patches ◽  
High Endothelial Venules ◽  
Activation Event

The homing of blood borne lymphocytes into lymph nodes and Peyer's patches is mediated in part by recognition and binding to specialized high endothelial venules (HEV). Here we demonstrate that a rapid pertussis toxin-sensitive lymphocyte activation event can participate in lymphocyte recognition of HEV. In situ video microscopic analyses of lymphocyte interactions with HEV in exteriorized mouse Peyer's patches reveal that pertussis toxin has no effect on an initial "rolling" displayed by many lymphocytes, but inhibits an activation-dependent "sticking" event required for lymphocyte arrest. This is the first demonstration that physiologic lymphocyte-endothelial interactions can involve sequential rolling, activation, and activation-dependent arrest, previously shown only for neutrophils. The inhibitory effect of the toxin is dependent on its G protein-modifying ADP-ribosyltransferase activity and can be reversed by phorbol myristic acetate, which bypasses cell surface receptors to trigger activation-dependent adhesion. Lymphocyte sticking can occur within 1-3 s after initiation of rolling. We conclude that a rapid receptor-mediated activation event involving G protein signaling can trigger stable lymphocyte attachment to HEV in vivo, and may play a critical role in regulating lymphocyte homing.

scholarly journals Rotavirus Infection Activates Dendritic Cells from Peyer's Patches in Adult Mice

2009 ◽  
Vol 84 (4) ◽  
pp. 1856-1866 ◽  
Author(s):  
Delia V. Lopez-Guerrero ◽  
Selene Meza-Perez ◽  
Oscar Ramirez-Pliego ◽  
Maria A. Santana-Calderon ◽  
Pavel Espino-Solis ◽  
...  
Keyword(s):  
Dendritic Cells ◽  
Critical Role ◽  
Cell Number ◽  
Peyer's Patches ◽  
Interleukin 12 ◽  
Peyer’S Patches ◽  
Necrosis Factor Alpha ◽  
Activation Markers ◽  
Rotavirus Infection

ABSTRACT This study used an in vivo mouse model to analyze the response of dendritic cells (DCs) in Peyer's patches (PPs) within the first 48 h of infection with the wild-type murine rotavirus EDIM (EDIMwt). After the infection, the absolute number of DCs was increased by 2-fold in the PPs without a modification of their relative percentage of the total cell number. Also, the DCs from PPs of infected mice showed a time-dependent migration to the subepithelial dome (SED) and an increase of the surface activation markers CD40, CD80, and CD86. This response was more evident at 48 h postinfection (p.i.) and depended on viral replication, since DCs from PPs of mice inoculated with UV-treated virus did not show this phenotype. As a result of the activation, the DCs showed an increase in the expression of mRNA for the proinflammatory cytokines interleukin-12/23p40 (IL-12/23p40), tumor necrosis factor alpha (TNF-α), and beta interferon (IFN-β), as well as for the regulatory cytokine IL-10. These results suggest that, a short time after rotavirus infection, the DCs from PPs play a critical role in controlling the infection and, at the same time, avoiding an excessive inflammatory immune response.

Vasoactive intestinal peptide modulates T lymphocyte migration in Peyer's patches of rat small intestine

1997 ◽  
Vol 272 (1) ◽  
pp. G92-G99 ◽  
Author(s):  
S. Miura ◽  
H. Serizawa ◽  
Y. Tsuzuki ◽  
I. Kurose ◽  
M. Suematsu ◽  
...  
Keyword(s):  
Vasoactive Intestinal Peptide ◽  
T Lymphocyte ◽  
Inhibitory Effect ◽  
Peyer's Patches ◽  
Peyer’S Patches ◽  
Intracellular Camp ◽  
Cell Trafficking ◽  
Lymphocyte Migration

Although vasoactive intestinal peptide (VIP) has been postulated to function in modulation of T cell trafficking, the exact mechanism has not been elucidated in vivo. In the present study, the effects of VIP on T lymphocyte migration were examined in rat Peyer's patches. T lymphocytes collected from intestinal lymph of rats were labeled with carboxyfluorescein diacetate succinimidyl ester and injected into the jugular vein. Peyer's patches of the recipient rats were observed with intravital fluorescence microscopy. In vivo intra-arterial infusion of or in vitro incubation with VIP did not affect the initial lymphocyte interaction with postcapillary venules of Peyer's patches. However, these treatments with VIP significantly inhibited transendothelial migration and also significantly blocked the interstitial migration of T cells and inhibited their subsequent appearance in the interfollicular lymphatics. Treatment with adenosine 3',5'-cyclic monophosphate (cAMP)-inducing agents resulted in similar inhibitory effect on T lymphocyte migration in Peyer's patches. In conclusion, VIP has significant inhibitory effects on T lymphocyte migration in Peyer's patches, possibly mediated by elevation of the intracellular cAMP concentrations.

scholarly journals Large G protein α-subunit XLαs limits clathrin-mediated endocytosis and regulates tissue iron levels in vivo

2017 ◽  
Vol 114 (45) ◽  
pp. E9559-E9568 ◽  
Author(s):  
Qing He ◽  
Richard Bouley ◽  
Zun Liu ◽  
Marc N. Wein ◽  
Yan Zhu ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
G Protein ◽  
Critical Role ◽  
Hek293 Cells ◽  
Activity Levels ◽  
Α Subunit ◽  
Proteomic Screen ◽  
Protein Levels ◽  
G Protein Α Subunit

Alterations in the activity/levels of the extralarge G protein α-subunit (XLαs) are implicated in various human disorders, such as perinatal growth retardation. Encoded by GNAS, XLαs is partly identical to the α-subunit of the stimulatory G protein (Gsα), but the cellular actions of XLαs remain poorly defined. Following an initial proteomic screen, we identified sorting nexin-9 (SNX9) and dynamins, key components of clathrin-mediated endocytosis, as binding partners of XLαs. Overexpression of XLαs in HEK293 cells inhibited internalization of transferrin, a process that depends on clathrin-mediated endocytosis, while its ablation by CRISPR/Cas9 in an osteocyte-like cell line (Ocy454) enhanced it. Similarly, primary cardiomyocytes derived from XLαs knockout (XLKO) pups showed enhanced transferrin internalization. Early postnatal XLKO mice showed a significantly higher degree of cardiac iron uptake than wild-type littermates following iron dextran injection. In XLKO neonates, iron and ferritin levels were elevated in heart and skeletal muscle, where XLαs is normally expressed abundantly. XLKO heart and skeletal muscle, as well as XLKO Ocy454 cells, showed elevated SNX9 protein levels, and siRNA-mediated knockdown of SNX9 in XLKO Ocy454 cells prevented enhanced transferrin internalization. In transfected cells, XLαs also inhibited internalization of the parathyroid hormone and type 2 vasopressin receptors. Internalization of transferrin and these G protein-coupled receptors was also inhibited in cells expressing an XLαs mutant missing the Gα portion, but not Gsα or an N-terminally truncated XLαs mutant unable to interact with SNX9 or dynamin. Thus, XLαs restricts clathrin-mediated endocytosis and plays a critical role in iron/transferrin uptake in vivo.

scholarly journals Arachidonic acid release from rat Leydig cells: the involvement of G protein, phospholipase A2 and regulation of cAMP production

2002 ◽  
Vol 172 (1) ◽  
pp. 95-104 ◽  
Author(s):  
AM Ronco ◽  
PF Moraga ◽  
MN Llanos
Keyword(s):  
Arachidonic Acid ◽  
Fatty Acid ◽  
G Protein ◽  
G Proteins ◽  
Pertussis Toxin ◽  
Leydig Cells ◽  
Inhibitory Effect ◽  
Receptor Interaction ◽  
Dependent Manner ◽  
Camp Production

We have previously demonstrated that the release of arachidonic acid (AA) from human chorionic gonadotropin (hCG)-stimulated Leydig cells occurs in a dose- and time-dependent manner. In addition, the amount of AA released was dependent on the hormone-receptor interaction and the concentration of LH-hCG binding sites on the cell surface. The present study was conducted to evaluate the involvement of phospholipase A(2) (PLA(2)) and G proteins in AA release from hormonally stimulated rat Leydig cells, and the possible role of this fatty acid in cAMP production. Cells were first prelabelled with [(14)C]AA to incorporate the fatty acid into cell phospholipids, and then treated in different ways to evaluate AA release. hCG (25 mIU) increased the release of AA to 180+/-12% when compared with AA released from control cells, arbitrarily set as 100%. Mepacrine and parabromophenacyl bromide (pBpB), two PLA(2) inhibitors, decreased the hormone-stimulated AA release to 85+/-9 and 70+/-24% respectively. Conversely, melittin, a PLA(2) stimulator, increased the release of AA up to 200% over control. The inhibitory effect of mepacrine on the release of AA was evident in hCG-treated Leydig cells, but not in the melittin-treated cells. To determine if the release of AA was also mediated through a G protein, cells were first permeabilized and subsequently treated with pertussis toxin or GTPgammaS, a non-hydrolyzable analog of GTP. Results demonstrate that GTPgammaS was able to induce a similar level of the release of AA as hCG. In addition, pertussis toxin completely abolished the stimulatory effect of hCG on the release of AA, indicating that a member of the G(i) family was involved in the hCG-dependent release of AA. Cells treated with PLA(2) inhibitors did not modify cAMP production, but exogenously added AA significantly reduced cAMP production from hCG-treated Leydig cells, in a manner dependent on the concentration of AA and hCG. Results presented here suggest an involvement of PLA(2) and G proteins in the release of AA from hCG-stimulated Leydig cells, and under particular conditions, regulation of cAMP production by this fatty acid in these cells.

scholarly journals Eosinophilia in transgenic mice expressing interleukin 5.

1990 ◽  
Vol 172 (5) ◽  
pp. 1425-1431 ◽  
Author(s):  
L A Dent ◽  
M Strath ◽  
A L Mellor ◽  
C J Sanderson
Keyword(s):  
Bone Marrow ◽  
Transgenic Mice ◽  
Lymph Nodes ◽  
Peyer's Patches ◽  
Peyer’S Patches ◽  
Mesenteric Lymph Nodes ◽  
Gene Encoding ◽  
Interleukin 5

Experiments in vitro suggest that although interleukin 5 (IL-5) stimulates the late stages of eosinophil differentiation, other cytokines are required for the generation of eosinophil progenitor cells. In this study transgenic mice constitutively expressing the IL-5 gene were established using a genomic fragment of the IL-5 gene coupled to the dominant control region from the gene encoding human CD2. Four independent eosinophilic transgenic lines have thus far been established, two of which with 8 and 49 transgene copies, are described in detail. These mice appeared macroscopically normal apart from splenomegaly. Eosinophils were at least 65- and 265-fold higher in blood from transgenics, relative to normal littermates, and approximately two- or sevenfold more numerous relative to blood from mice infected with the helminth Mesocestoides corti. Much more modest increases in blood neutrophil, lymphocyte, and monocyte numbers were noted in transgenics, relative to normal littermates (less than threefold). Thus IL-5 in vivo is relatively specific for the eosinophil lineage. Large numbers of eosinophils were present in spleen, bone marrow, and peritoneal exudate, and were highest in the line with the greatest transgene copy number. Eosinophilia was also noted in histological sections of transgenic lungs, Peyer's patches, mesenteric lymph nodes, and gut lamina propria but not in other tissues examined. IL-5 was detected in the sera of transgenics at levels comparable to those seen in sera from parasite-infected animals. IL-3 and granulocyte/macrophage colony-stimulating factor (GM-CSF) were not found. IL-5 mRNA was detected in transgenic thymus, Peyer's patches, and superficial lymph nodes, but not in heart, liver, brain, or skeletal muscle or in any tissues from nontransgenics. Bone marrow from transgenic mice was rich in IL-5-dependent eosinophil precursors. These data indicate that induction of the IL-5 gene is sufficient for production of eosinophilia, and that IL-5 can induce the full pathway of eosinophil differentiation. IL-5 may therefore not be restricted in action to the later stages of eosinophil differentiation, as suggested by earlier in vitro studies.

scholarly journals Association of Lactobacillus spp. with Peyer's Patches in Mice

2001 ◽  
Vol 8 (2) ◽  
pp. 320-324 ◽  
Author(s):  
Laura Plant ◽  
Patricia Conway
Keyword(s):  
Peyer's Patches ◽  
Peyer’S Patches ◽  
Adhesion Assay ◽  
Scanning Electron Micrographs ◽  
Intestinal Tissue ◽  
High Adhesion ◽  
Preferential Binding ◽  
Scanning Electron

ABSTRACT Sixteen strains of Lactobacillus isolated from humans, mice, and food products were screened for their capacity to associate with Peyer's patches in mice. In preliminary experiments, in vitro binding to tissue pieces was assessed by scanning electron microscopy, and it was demonstrated qualitatively that 5 of the 16 strains showed some affinity for the Peyer's patches, irrespective of their association with the nonlymphoid intestinal tissue. Lactobacillus fermentum KLD was selected for further study, since, in addition to its intrinsically high adhesion rate, this organism was found to exhibit a preferential binding to the follicle-associated epithelium of the Peyer's patches compared with its level of binding to the mucus-secreting regions of the small intestine. Quantitative assessment of scanning electron micrographs of tissue sections which had been incubated with L. fermentum KLD or a nonbinding control strain, Lactobacillus delbruckii subsp.bulgaricus, supported these observations, since a marked difference in adhesion was noted (P < 0.05). This preferential association of strain KLD with the Peyer's patches was also confirmed with radiolabeled lactobacilli incubated with intestinal tissue in the in vitro adhesion assay. Direct recovery of L. fermentum KLD from washed tissue following oral dosing of mice revealed a distinct association (P < 0.05) between this organism and the Peyer's patch tissue. In contrast, L. delbruckii subsp. bulgaricus showed negligible binding to both tissue types in both in vitro and in vivo adhesion assays. It was concluded that L. fermentum KLD bound preferentially to Peyer's patches of BALB/c mice.

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