Regulated Assembly of Vacuolar ATPase Is Increased during Cluster Disruption-induced Maturation of Dendritic Cells through a Phosphatidylinositol 3-Kinase/mTOR-dependent Pathway

The vacuolar (H+)-ATPases (V-ATPases) are ATP-driven proton pumps composed of a peripheral V1 domain and a membrane-embedded V0 domain. Regulated assembly of V1 and V0 represents an important regulatory mechanism for controlling V-ATPase activity in vivo. Previous work has shown that V-ATPase assembly increases during maturation of bone marrow-derived dendritic cells induced by activation of Toll-like receptors. This increased assembly is essential for antigen processing, which is dependent upon an acidic lysosomal pH. Cluster disruption of dendritic cells induces a semi-mature phenotype associated with immune tolerance. Thus, semi-mature dendritic cells are able to process and present self-peptides to suppress autoimmune responses. We have investigated V-ATPase assembly in bone marrow-derived, murine dendritic cells and observed an increase in assembly following cluster disruption. This increased assembly is not dependent upon new protein synthesis and is associated with an increase in concanamycin A-sensitive proton transport in FITC-loaded lysosomes. Inhibition of phosphatidylinositol 3-kinase with wortmannin or mTORC1 with rapamycin effectively inhibits the increased assembly observed upon cluster disruption. These results suggest that the phosphatidylinositol 3-kinase/mTOR pathway is involved in controlling V-ATPase assembly during dendritic cell maturation.

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Mechanisms of Acute Eosinophil Mobilization from the Bone Marrow Stimulated by Interleukin 5: The Role of Specific Adhesion Molecules and Phosphatidylinositol 3-Kinase

Journal of Experimental Medicine ◽

10.1084/jem.188.9.1621 ◽

1998 ◽

Vol 188 (9) ◽

pp. 1621-1632 ◽

Cited By ~ 139

Author(s):

Roger T. Palframan ◽

Paul D. Collins ◽

Nicholas J. Severs ◽

Stephen Rothery ◽

Timothy J. Williams ◽

...

Keyword(s):

Bone Marrow ◽

Guinea Pig ◽

Light And Electron Microscopy ◽

Phosphatidylinositol 3 Kinase ◽

Release Process ◽

Blocking Antibody ◽

Β2 Integrin ◽

Phosphatidylinositol 3

Mobilization of bone marrow eosinophils is a critical early step in their trafficking to the lung during allergic inflammatory reactions. We have shown previously that the cytokine interleukin (IL)-5, generated during an allergic inflammatory reaction in the guinea pig, acts systemically to mobilize eosinophils from the bone marrow. Here, we have investigated the mechanisms underlying this release process. Examination by light and electron microscopy revealed the rapid migration of eosinophils from the hematopoietic compartment and across the bone marrow sinus endothelium in response to IL-5. Using an in situ perfusion system of the guinea pig hind limb, we showed that IL-5 stimulated a dose-dependent selective release of eosinophils from the bone marrow. Eosinophils released from the bone marrow in response to IL-5 expressed increased levels of β2 integrin and a decrease in L-selectin, but no change in α4 integrin levels. A β2 integrin–blocking antibody markedly inhibited the mobilization of eosinophils from the bone marrow stimulated by IL-5. In contrast, an α4 integrin blocking antibody increased the rate of eosinophil mobilization induced by IL-5. In vitro we demonstrated that IL-5 stimulates the selective chemokinesis of bone marrow eosinophils, a process markedly inhibited by two structurally distinct inhibitors of phosphatidylinositol 3-kinase, wortmannin and LY294002. Wortmannin was also shown to block eosinophil release induced by IL-5 in the perfused bone marrow system. The parallel observations on the bone marrow eosinophil release process and responses in isolated eosinophils in vitro suggest that eosinophil chemokinesis is the driving force for release in vivo and that this release process is regulated by α4 and β2 integrins acting in opposite directions.

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Insulin treatment stimulates the tyrosine phosphorylation of the alpha-type 85-kDa subunit of phosphatidylinositol 3-kinase in vivo.

Journal of Biological Chemistry ◽

10.1016/s0021-9258(18)41711-5 ◽

1992 ◽

Vol 267 (31) ◽

pp. 22575-22580

Author(s):

H Hayashi ◽

S Kamohara ◽

Y Nishioka ◽

F Kanai ◽

N Miyake ◽

...

Keyword(s):

Tyrosine Phosphorylation ◽

Insulin Treatment ◽

Phosphatidylinositol 3 Kinase ◽

Alpha Type ◽

Phosphatidylinositol 3

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Dendritic cells differentiate into osteoclasts in bone marrow microenvironment in vivo

Blood ◽

10.1182/blood-2008-09-180836 ◽

2009 ◽

Vol 113 (1) ◽

pp. 264-265 ◽

Cited By ~ 11

Author(s):

Mawadda Alnaeeli ◽

Yen-Tung A. Teng

Keyword(s):

Bone Marrow ◽

Dendritic Cells ◽

Bone Marrow Microenvironment

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Morin Promotes the Production of Th2 Cytokine by Modulating Bone Marrow-Derived Dendritic Cells

The American Journal of Chinese Medicine ◽

10.1142/s0192415x06004193 ◽

2006 ◽

Vol 34 (04) ◽

pp. 667-684 ◽

Cited By ~ 10

Author(s):

Chia-Yang Li ◽

Jau-Ling Suen ◽

Bor-Luen Chiang ◽

Pei-Dawn Lee Chao ◽

Shih-Hua Fang

Keyword(s):

Bone Marrow ◽

T Cells ◽

Dendritic Cells ◽

Interleukin 12 ◽

Th2 Response ◽

Necrosis Factor Alpha ◽

Tnf Α ◽

Th Differentiation ◽

Th1 And Th2 Responses

Our previous studies had reported that morin decreased the interleukin-12 (IL-12) and tumor necrosis factor-alpha (TNF-α) production in lipopolysaccharide (LPS)-activated macrophages, suggesting that morin may promote helper T type 2 (Th2) response in vivo. Dendritic cells (DCs) are the most potent antigen presenting cells and known to play a major role in the differentiation of helper T type 1 (Th1) and Th2 responses. This study aimed to reveal whether morin is able to control the Th differentiation through modulating the maturation and functions of DCs. Bone marrow-derived dendritic cells (BM-DCs) were incubated with various concentrations of morin and their characteristics were studied. The results indicated that morin significantly affects the phenotype and cytokine expression of BM-DCs. Morin reduced the production of IL-12 and TNF-α in BM-DCs, in response to LPS stimulation. In addition, the proliferative response of stimulated alloreactive T cells was significantly decreased by morin in BM-DCs. Furthermore, allogeneic T cells secreted higher IL-4 and lower IFN-γ in response to morin in BM-DCs. In conclusion, these results suggested that morin favors Th2 cell differentiation through modulating the maturation and function of BM-DCs.

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Insulin-like growth factor-1-mediated association of p85 phosphatidylinositol 3-kinase with pp 185: requirement of SH2 domains for in vivo interaction.

Molecular Endocrinology ◽

10.1210/mend.8.9.7838146 ◽

1994 ◽

Vol 8 (9) ◽

pp. 1139-1146

Author(s):

D Altschuler ◽

K Yamamoto ◽

E G Lapetina

Keyword(s):

Growth Factor ◽

Insulin Like Growth Factor ◽

Phosphatidylinositol 3 Kinase ◽

Sh2 Domains ◽

Phosphatidylinositol 3

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An In Vivo Mouse Model to Measure Naïve CD4 T Cell Activation, Proliferation and Th1 Differentiation Induced by Bone Marrow-derived Dendritic Cells

Journal of Visualized Experiments ◽

10.3791/58118 ◽

2018 ◽

Cited By ~ 1

Author(s):

Raquel Toribio-Fernandez ◽

Virginia Zorita ◽

Beatriz Herrero-Fernandez ◽

Jose M. Gonzalez-Granado

Keyword(s):

Bone Marrow ◽

Dendritic Cells ◽

T Cell ◽

Mouse Model ◽

T Cell Activation ◽

Cell Activation ◽

Cd4 T Cell

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Tyrosine 1101 of Tie2 Is the Major Site of Association of p85 and Is Required for Activation of Phosphatidylinositol 3-Kinase and Akt

Molecular and Cellular Biology ◽

10.1128/mcb.18.7.4131 ◽

1998 ◽

Vol 18 (7) ◽

pp. 4131-4140 ◽

Cited By ~ 154

Author(s):

Christopher D. Kontos ◽

Thomas P. Stauffer ◽

Wen-Pin Yang ◽

John D. York ◽

Liwen Huang ◽

...

Keyword(s):

Fluorescent Protein ◽

Vascular Development ◽

Pi3 Kinase ◽

Pleckstrin Homology Domain ◽

Phosphatidylinositol 3 Kinase ◽

Lipid Kinase ◽

Embryonic Vascular Development ◽

Phosphatidylinositol 3

ABSTRACT Tie2 is an endothelium-specific receptor tyrosine kinase that is required for both normal embryonic vascular development and tumor angiogenesis and is thought to play a role in vascular maintenance. However, the signaling pathways responsible for the function of Tie2 remain unknown. In this report, we demonstrate that the p85 subunit of phosphatidylinositol 3-kinase (PI3-kinase) associates with Tie2 and that this association confers functional lipid kinase activity. Mutation of tyrosine 1101 of Tie2 abrogated p85 association both in vitro and in vivo in yeast. Tie2 was found to activate PI3-kinase in vivo as demonstrated by direct measurement of increases in cellular phosphatidylinositol 3-phosphate and phosphatidylinositol 3,4-bisphosphate, by plasma membrane translocation of a green fluorescent protein-Akt pleckstrin homology domain fusion protein, and by downstream activation of the Akt kinase. Activation of PI3-kinase was abrogated in these assays by mutation of Y1101 to phenylalanine, consistent with a requirement for this residue for p85 association with Tie2. These results suggest that activation of PI3-kinase and Akt may in part account for Tie2’s role in both embryonic vascular development and pathologic angiogenesis, and they are consistent with a role for Tie2 in endothelial cell survival.

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11C-Labeled Pictilisib (GDC-0941) as a Molecular Tracer Targeting Phosphatidylinositol 3-Kinase (PI3K) for Breast Cancer Imaging

Contrast Media & Molecular Imaging ◽

10.1155/2019/1760184 ◽

2019 ◽

Vol 2019 ◽

pp. 1-11 ◽

Cited By ~ 2

Author(s):

Na Han ◽

Yaqun Jiang ◽

Yongkang Gai ◽

Qingyao Liu ◽

Lujie Yuan ◽

...

Keyword(s):

Breast Cancer ◽

Pik3ca Mutation ◽

Phosphatidylinositol 3 Kinase ◽

Pet Tracer ◽

Positron Emission ◽

Pet Scans ◽

Mcf 7 ◽

Phosphatidylinositol 3

Pictilisib (GDC-0941) is an inhibitor of phosphatidylinositol 3-kinase (PI3K), part of a signaling cascade involved in breast cancer development. The purpose of this study was to evaluate the pharmacokinetics of pictilisib noninvasively by radiolabeling it with 11C and to assess the usability of the resulting [11C]-pictilisib as a positron-emission tomography (PET) tracer to screen for pictilisib-sensitive tumors. In this study, pictilisib was radiolabeled with [11C]-methyl iodide to obtain 11C-methylated pictilisib ([11C]-pictilisib) using an automated synthesis module with a high radiolabeling yield. Considerably higher uptake ratios were observed in MCF-7 (PIK3CA mutation, pictilisib-sensitive) cells than those in MDA-MB-231 (PIK3CA wild-type, pictilisib-insensitive) cells at all evaluated time points, indicating good in vitro binding of [11C]-pictilisib. Dynamic micro-PET scans in mice and biodistribution results showed that [11C]-pictilisib was mainly excreted via the hepatobiliary tract into the intestines. MCF-7 xenografts could be clearly visualized on the static micro-PET scans, while MDA-MB-231 tumors could not. Biodistribution results of two xenograft models showed significantly higher uptake and tumor-to-muscle ratios in the MCF-7 xenografts than those in MDA-MB-231 xenografts, exhibiting high in vivo targeting specificity. In conclusion, [11C]-pictilisib was first successfully prepared, and it exhibited good potential to identify pictilisib-sensitive tumors noninvasively, which may have a great impact in the treatment of cancers with an overactive PI3K/Akt/mTOR signal pathway. However, the high activity in hepatobiliary system and intestines needs to be addressed.

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Dendritic cell progenitors phagocytose particulates, including bacillus Calmette-Guerin organisms, and sensitize mice to mycobacterial antigens in vivo.

Journal of Experimental Medicine ◽

10.1084/jem.178.2.479 ◽

1993 ◽

Vol 178 (2) ◽

pp. 479-488 ◽

Cited By ~ 332

Author(s):

K Inaba ◽

M Inaba ◽

M Naito ◽

R M Steinman

Keyword(s):

T Cells ◽

Dendritic Cells ◽

Antigen Processing ◽

Blood Stream ◽

Active Immunization ◽

Bacillus Calmette Guerin ◽

Antigen Uptake ◽

Gm Csf ◽

Mycobacterial Antigens

Dendritic cells, while effective in sensitizing T cells to several different antigens, show little or no phagocytic activity. To the extent that endocytosis is required for antigen processing and presentation, it is not evident how dendritic cells would present particle-associated peptides. Evidence has now been obtained showing that progenitors to dendritic cells can internalize particles, including Bacillus Calmette-Guerin (BCG) mycobacteria. The particulates are applied for 20 h to bone marrow cultures that have been stimulated with granulocyte/macrophage colony-stimulating factor (GM-CSF) to induce aggregates of growing dendritic cells. Cells within these aggregates are clearly phagocytic. If the developing cultures are exposed to particles, washed, and "chased" for 2 d, the number of major histocompatibility complex class II-rich dendritic cells increases substantially and at least 50% contain internalized mycobacteria or latex particles. The mycobacteria-laden, newly developed dendritic cells are much more potent in presenting antigens to primed T cells than corresponding cultures of mature dendritic cells that are exposed to a pulse of organisms. A similar situation exists when the BCG-charged dendritic cells are injected into the footpad or blood stream of naive mice. Those dendritic cells that have phagocytosed organisms induce the strongest T cell responses to mycobacterial antigens in draining lymph node and spleen. The administration of antigens to GM-CSF-induced, developing dendritic cells (by increasing both antigen uptake and cell numbers) will facilitate the use of these antigen-presenting cells for active immunization in situ.

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