1
|
Van Itallie CM, Tietgens AJ, Aponte A, Gucek M, Cartagena-Rivera AX, Chadwick RS, Anderson JM. MARCKS-related protein regulates cytoskeletal organization at cell-cell and cell-substrate contacts in epithelial cells. J Cell Sci 2018; 131:jcs.210237. [PMID: 29222109 DOI: 10.1242/jcs.210237] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2017] [Accepted: 12/04/2017] [Indexed: 01/14/2023] Open
Abstract
Treatment of epithelial cells with interferon-γ and TNF-α (IFN/TNF) results in increased paracellular permeability. To identify relevant proteins mediating barrier disruption, we performed proximity-dependent biotinylation (BioID) of occludin and found that tagging of MARCKS-related protein (MRP; also known as MARCKSL1) increased ∼20-fold following IFN/TNF administration. GFP-MRP was focused at the lateral cell membrane and its overexpression potentiated the physiological response of the tight junction barrier to cytokines. However, deletion of MRP did not abrogate the cytokine responses, suggesting that MRP is not required in the occludin-dependent IFN/TNF response. Instead, our results reveal a key role for MRP in epithelial cells in control of multiple actin-based structures, likely by regulation of integrin signaling. Changes in focal adhesion organization and basal actin stress fibers in MRP-knockout (KO) cells were reminiscent of those seen in FAK-KO cells. In addition, we found alterations in cell-cell interactions in MRP-KO cells associated with increased junctional tension, suggesting that MRP may play a role in focal adhesion-adherens junction cross talk. Together, our results are consistent with a key role for MRP in cytoskeletal organization of cell contacts in epithelial cells.
Collapse
Affiliation(s)
- Christina M Van Itallie
- Laboratory of Tight Junction Structure and Function, National Institutes of Health, Building 50, Room 4525, 50 South Drive, Bethesda, MD 20892, USA
| | - Amber Jean Tietgens
- Laboratory of Tight Junction Structure and Function, National Institutes of Health, Building 50, Room 4525, 50 South Drive, Bethesda, MD 20892, USA
| | - Angel Aponte
- Proteomics Core, National Heart, Lung and Blood Institute, National Institutes of Health, Building 50, Room 4525, 50 South Drive, Bethesda, MD 20892, USA
| | - Marjan Gucek
- Proteomics Core, National Heart, Lung and Blood Institute, National Institutes of Health, Building 50, Room 4525, 50 South Drive, Bethesda, MD 20892, USA
| | - Alexander X Cartagena-Rivera
- Section on Auditory Mechanics, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Building 50, Room 4525, 50 South Drive, Bethesda, MD 20892, USA
| | - Richard S Chadwick
- Section on Auditory Mechanics, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Building 50, Room 4525, 50 South Drive, Bethesda, MD 20892, USA
| | - James M Anderson
- Laboratory of Tight Junction Structure and Function, National Institutes of Health, Building 50, Room 4525, 50 South Drive, Bethesda, MD 20892, USA
| |
Collapse
|
2
|
Micheva-Viteva SN, Shou Y, Ganguly K, Wu TH, Hong-Geller E. PKC-η-MARCKS Signaling Promotes Intracellular Survival of Unopsonized Burkholderia thailandensis. Front Cell Infect Microbiol 2017. [PMID: 28638804 PMCID: PMC5461351 DOI: 10.3389/fcimb.2017.00231] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Pathogenic Burkholderia rely on host factors for efficient intracellular replication and are highly refractory to antibiotic treatment. To identify host genes that are required by Burkholderia spp. during infection, we performed a RNA interference (RNAi) screen of the human kinome and identified 35 host kinases that facilitated Burkholderia thailandensis intracellular survival in human monocytic THP-1 cells. We validated a selection of host kinases using imaging flow cytometry to assess efficiency of B. thailandensis survival in the host upon siRNA-mediated knockdown. We focused on the role of the novel protein kinase C isoform, PKC-η, in Burkholderia infection and characterized PKC-η/MARCKS signaling as a key event that promotes the survival of unopsonized B. thailandensis CDC2721121 within host cells. While infection of lung epithelial cells with unopsonized Gram-negative bacteria stimulated phosphorylation of Ser175/160 in the MARCKS effector domain, siRNA-mediated knockdown of PKC-η expression reduced the levels of phosphorylated MARCKS by >3-fold in response to infection with Bt CDC2721121. We compared the effect of the conventional PKC-α and novel PKC-η isoforms on the growth of B. thailandensis CDC2721121 within monocytic THP-1 cells and found that ≥75% knock-down of PRKCH transcript levels reduced intracellular bacterial load 100% more efficiently when compared to growth in cells siRNA-depleted of the classical PKC-α, suggesting that the PKC-η isoform can specifically mediate Burkholderia intracellular survival. Based on imaging studies of intracellular B. thailandensis, we found that PKC-η function stimulates phagocytic pathways that promote B. thailandensis escape into the cytoplasm leading to activation of autophagosome flux. Identification of host kinases that are targeted by Burkholderia during infection provides valuable molecular insights in understanding Burkholderia pathogenesis, and ultimately, in designing effective host-targeted therapies against infectious disease caused by intracellular pathogens.
Collapse
Affiliation(s)
| | - Yulin Shou
- Bioscience Division, Los Alamos National LaboratoryLos Alamos, NM, United States
| | - Kumkum Ganguly
- Bioscience Division, Los Alamos National LaboratoryLos Alamos, NM, United States
| | - Terry H Wu
- Center for Infectious Disease and Immunity and Department of Internal Medicine, University of New Mexico Health Sciences CenterAlbuquerque, NM, United States
| | | |
Collapse
|
3
|
Johnston DGW, Kearney J, Zasłona Z, Williams MA, O'Neill LAJ, Corr SC. MicroRNA-21 Limits Uptake of Listeria monocytogenes by Macrophages to Reduce the Intracellular Niche and Control Infection. Front Cell Infect Microbiol 2017; 7:201. [PMID: 28589100 PMCID: PMC5440467 DOI: 10.3389/fcimb.2017.00201] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Accepted: 05/05/2017] [Indexed: 12/19/2022] Open
Abstract
MiRNAs are important post-transcriptional regulators of gene expression. MiRNA expression is a crucial part of host responses to bacterial infection, however there is limited knowledge of their impact on the outcome of infections. We investigated the influence of miR-21 on macrophage responses during infection with Listeria monocytogenes, which establishes an intracellular niche within macrophages. MiR-21 is induced following infection of bone marrow-derived macrophages (BMDMs) with Listeria. MiR-21−/− macrophages display an increased bacterial burden with Listeria at 30 min and 2 h post-infection. This phenotype was reversed by the addition of synthetic miR-21 mimics to the system. To assess the immune response of wildtype (WT) and miR-21−/− macrophages, BMDMs were treated with bacterial LPS or infected with Listeria. There was no difference in IL-10 and IL-6 between WT and miR-21−/− BMDMs in response to LPS or Listeria. TNF-α was increased in miR-21−/− BMDMs stimulated with LPS or Listeria compared to WT macrophages. We next assessed the production of nitric oxide (NO), a key bactericidal factor in Listeria infection. There was no significant difference in NO production between WT and miR-21−/− cells, indicating that the increased bacterial burden may not be due to impaired killing. As the increased bacterial load was observed early following infection (30 min), we questioned whether this is due to differences in uptake of Listeria by WT and miR-21−/− macrophages. We show that miR-21-deficiency enhances uptake of FITC-dextran and FITC-Escherichia coli bioparticles by macrophages. The previously observed Listeria burden phenotype was ablated by pre-treatment of cells with the actin polymerization inhibitor cytochalasin-D. From analysis of miR-21 targets, we selected the pro-phagocytic regulators myristoylated alanine-rich C-kinase substrate (MARCKS) and Ras homolog gene family, member B (RhoB) for further investigation. MARCKS and RhoB are increased in miR-21−/− BMDMs, correlating with increased uptake of Listeria. Finally, intra-peritoneal infection of mice with Listeria led to increased bacterial burden in livers of miR-21−/− mice compared to WT mice. These findings suggest a possible role for miR-21 in regulation of phagocytosis during infection, potentially by repression of MARCKS and RhoB, thus serving to limit the availability of the intracellular niche of pathogens like L. monocytogenes.
Collapse
Affiliation(s)
- Daniel G W Johnston
- School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College DublinDublin, Ireland.,Department of Microbiology, Moyne Institute of Preventive Medicine, School of Genetics and Microbiology, Trinity College DublinDublin, Ireland
| | - Jay Kearney
- School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College DublinDublin, Ireland
| | - Zbigniew Zasłona
- School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College DublinDublin, Ireland
| | - Michelle A Williams
- Department of Microbiology, Moyne Institute of Preventive Medicine, School of Genetics and Microbiology, Trinity College DublinDublin, Ireland
| | - Luke A J O'Neill
- School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College DublinDublin, Ireland
| | - Sinéad C Corr
- Department of Microbiology, Moyne Institute of Preventive Medicine, School of Genetics and Microbiology, Trinity College DublinDublin, Ireland
| |
Collapse
|
4
|
Kim BR, Lee SH, Park MS, Seo SH, Park YM, Kwon YJ, Rho SB. MARCKSL1 exhibits anti-angiogenic effects through suppression of VEGFR-2-dependent Akt/PDK-1/mTOR phosphorylation. Oncol Rep 2015; 35:1041-8. [PMID: 26555156 DOI: 10.3892/or.2015.4408] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Accepted: 08/10/2015] [Indexed: 11/06/2022] Open
Abstract
Myristoylated alanine-rich C kinase substrate-like 1 (MARCKSL1) plays a pivotal role in the regulation of apoptosis and has been shown to maintain antitumor and metastasis-suppressive properties. In the present study, we examined the effects of MARCKSL1 as a novel anti-angiogenic agent on the inhibition of angiogenesis-mediated cell migration. MARCKSL1 also reduced vascular endothelial growth factor (VEGF)-induced human umbilical vein endothelial cell (HUVEC) proliferation, as well as capillary-like tubular structure formation in vitro. MARCKSL1 disrupted phosphorylation of vascular endothelial growth factor receptor-2 (VEGFR-2) in ovarian tumorigenesis. In addition, MARCKSL1 showed potent anti-angiogenic activity and reduced the levels of VEGF and hypoxia-inducible factor 1α (HIF-1α) expression, an essential regulator of angiogenesis. Consistently, MARCKSL1 decreased VEGF‑induced phosphorylation of the PI3K/Akt signaling pathway components, including phosphoinositide-dependent protein kinase 1 (PDK-1), mammalian target of rapamycin (mTOR), tuberous sclerosis complex 2 (TSC-2), p70 ribosomal protein S6 kinase (p70S6K), and glycogen synthase kinase 3β (GSK-3β) protein. Collectively, our results provide evidence for the physiological/biological function of an endothelial cell system involved in angiogenesis through suppression of Akt/PDK-1/mTOR phosphorylation by interaction with VEGFR-2.
Collapse
Affiliation(s)
- Boh-Ram Kim
- Research Institute, National Cancer Center, Ilsandong-gu, Goyang-si, Gyeonggi-do 410‑769, Republic of Korea
| | - Seung-Hoon Lee
- Department of Life Science, Yong In University, Cheoin-gu, Yongin-si, Gyeonggi‑do 449‑714, Republic of Korea
| | - Mi-Sun Park
- Research Institute, National Cancer Center, Ilsandong-gu, Goyang-si, Gyeonggi-do 410‑769, Republic of Korea
| | - Seung-Hee Seo
- Research Institute, National Cancer Center, Ilsandong-gu, Goyang-si, Gyeonggi-do 410‑769, Republic of Korea
| | - Young-Min Park
- Department of Biological Sciences, Sung Kyun Kwan University, Jangan-gu, Suwon‑si, Gyeonggi‑do 440‑746, Republic of Korea
| | - Young-Joo Kwon
- College of Pharmacy, Graduate School of Pharmaceutical Sciences, Ewha Global Top 5 Program, Ewha Womans University, Seoul 120-750, Republic of Korea
| | - Seung-Bae Rho
- Research Institute, National Cancer Center, Ilsandong-gu, Goyang-si, Gyeonggi-do 410‑769, Republic of Korea
| |
Collapse
|
5
|
Kim BR, Dong SM, Seo SH, Lee JH, Lee JM, Lee SH, Rho SB. Lysyl oxidase-like 2 (LOXL2) controls tumor-associated cell proliferation through the interaction with MARCKSL1. Cell Signal 2014; 26:1765-73. [DOI: 10.1016/j.cellsig.2014.05.010] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2014] [Accepted: 05/15/2014] [Indexed: 01/25/2023]
|
6
|
Wang Y, He H, Li S, Liu D, Lan B, Hu M, Cao Y, Wang C. All-optical regulation of gene expression in targeted cells. Sci Rep 2014; 4:5346. [PMID: 24939233 PMCID: PMC4061554 DOI: 10.1038/srep05346] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2014] [Accepted: 05/30/2014] [Indexed: 12/20/2022] Open
Abstract
Controllable gene expression is always a challenge and of great significance to biomedical research and clinical applications. Recently, various approaches based on extra-engineered light-sensitive proteins have been developed to provide optogenetic actuators for gene expression. Complicated biomedical techniques including exogenous genes engineering, transfection, and material delivery are needed. Here we present an all-optical method to regulate gene expression in targeted cells. Intrinsic or exogenous genes can be activated by a Ca(2+)-sensitive transcription factor nuclear factor of activated T cells (NFAT) driven by a short flash of femtosecond-laser irradiation. When applied to mesenchymal stem cells, expression of a differentiation regulator Osterix can be activated by this method to potentially induce differentiation of them. A laser-induced "Ca(2+)-comb" (LiCCo) by multi-time laser exposure is further developed to enhance gene expression efficiency. This noninvasive method hence provides an encouraging advance of gene expression regulation, with promising potential of applying in cell biology and stem-cell science.
Collapse
Affiliation(s)
- Yisen Wang
- Ultrafast Laser Laboratory, Key Laboratory of Optoelectronic Information Technology (Ministry of Education), College of Precision Instrument and Optoelectronics Engineering, Tianjin University, Tianjin, 300072, P.R. China
| | - Hao He
- Ultrafast Laser Laboratory, Key Laboratory of Optoelectronic Information Technology (Ministry of Education), College of Precision Instrument and Optoelectronics Engineering, Tianjin University, Tianjin, 300072, P.R. China
- Med-X Research Institute, School of Biomedical Engineering, Shanghai Jiaotong University, Shanghai, 200030, P.R. China
| | - Shiyang Li
- Key Laboratory of microbial functional genomics of Ministry of Education, College of Life Sciences, Nankai University, Tianjin, 300072, P.R. China
- Current address: Department of Microbiology-Immunology, Feiberg School of Medicine, Northwestern University
| | - Dayong Liu
- Department of Endodontics, School of Stomatology, Tianjin Medical University, Tianjin, 300072, P.R. China
| | - Bei Lan
- Key Laboratory of microbial functional genomics of Ministry of Education, College of Life Sciences, Nankai University, Tianjin, 300072, P.R. China
| | - Minglie Hu
- Ultrafast Laser Laboratory, Key Laboratory of Optoelectronic Information Technology (Ministry of Education), College of Precision Instrument and Optoelectronics Engineering, Tianjin University, Tianjin, 300072, P.R. China
| | - Youjia Cao
- Key Laboratory of microbial functional genomics of Ministry of Education, College of Life Sciences, Nankai University, Tianjin, 300072, P.R. China
| | - Chingyue Wang
- Ultrafast Laser Laboratory, Key Laboratory of Optoelectronic Information Technology (Ministry of Education), College of Precision Instrument and Optoelectronics Engineering, Tianjin University, Tianjin, 300072, P.R. China
| |
Collapse
|
7
|
Glass AM, Wolf BJ, Schneider KM, Princiotta MF, Taffet SM. Connexin43 is dispensable for phagocytosis. THE JOURNAL OF IMMUNOLOGY 2013; 190:4830-5. [PMID: 23554311 DOI: 10.4049/jimmunol.1202884] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Macrophages that lack connexin43 (Cx43), a gap junction protein, have been reported to exhibit dramatic deficiencies in phagocytosis. In this study, we revisit these findings using well-characterized macrophage populations. Cx43 knockout (Cx43(-/-)) mice die soon after birth, making the harvest of macrophages from adult Cx43(-/-) mice problematic. To overcome this obstacle, we used several strategies: mice heterozygous for the deletion of Cx43 were crossed to produce Cx43(+/+) (wild type [WT]) and Cx43(-/-) fetuses. Cells isolated from 12- to 14-d fetal livers were used to reconstitute irradiated recipient animals. After reconstitution, thioglycollate-elicited macrophages were collected by peritoneal lavage and bone marrow was harvested. Bone marrow cells and, alternatively, fetal liver cells were cultured in media containing M-CSF for 7-10 d, resulting in populations of cells that were >95% macrophages based on flow cytometry. Phagocytic uptake was detected using flow cytometric and microscopic techniques. Quantification of phagocytic uptake of IgG-opsonized sheep erythrocytes, zymosan particles, and Listeria monocytogenes failed to show any significant difference between WT and Cx43(-/-) macrophages. Furthermore, the use of particles labeled with pH-sensitive dyes showed equivalent acidification of phagosomes in both WT and Cx43(-/-) macrophages. Our findings suggest that modulation of Cx43 levels in cultured macrophages does not have a significant impact on phagocytosis.
Collapse
Affiliation(s)
- Aaron M Glass
- Department of Microbiology and Immunology, State University of New York Upstate Medical University, Syracuse, NY 13210, USA
| | | | | | | | | |
Collapse
|
8
|
Park H, Ishihara D, Cox D. Regulation of tyrosine phosphorylation in macrophage phagocytosis and chemotaxis. Arch Biochem Biophys 2011; 510:101-11. [PMID: 21356194 PMCID: PMC3114168 DOI: 10.1016/j.abb.2011.02.019] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2010] [Revised: 02/15/2011] [Accepted: 02/18/2011] [Indexed: 12/22/2022]
Abstract
Macrophages display a large variety of surface receptors that are critical for their normal cellular functions in host defense, including finding sites of infection (chemotaxis) and removing foreign particles (phagocytosis). However, inappropriate regulation of these processes can lead to human diseases. Many of these receptors utilize tyrosine phosphorylation cascades to initiate and terminate signals leading to cell migration and clearance of infection. Actin remodeling dominates these processes and many regulators have been identified. This review focuses on how tyrosine kinases and phosphatases regulate actin dynamics leading to macrophage chemotaxis and phagocytosis.
Collapse
Affiliation(s)
- Haein Park
- Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, NY, 10461, USA
| | - Dan Ishihara
- Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, NY, 10461, USA
| | - Dianne Cox
- Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, NY, 10461, USA
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, Bronx, NY, 10461, USA
| |
Collapse
|
9
|
Abstract
Receptor-mediated phagocytosis is a complex process that mediates the internalization, by a cell, of other cells and large particles; this is an important physiological event not only in mammals, but in a wide diversity of organisms. Of simple unicellular organisms that use phagocytosis to extract nutrients, to complex metazoans in which phagocytosis is essential for the innate defence system, as a first line of defence against invading pathogens, as well as for the clearance of damaged, dying or dead cells. Evolution has armed multicellular organisms with a range of receptors expressed on many cells that serve as the molecular basis to bring about phagocytosis, regardless of the organism or the specific physiological event concerned. Key to all phagocytic processes is the finely controlled rearrangement of the actin cytoskeleton, in which Ca(2+) signals play a major role. Ca(2+) is involved in cytoskeletal changes by affecting the actions of a number of contractile proteins, as well as being a cofactor for the activation of a number of intracellular signalling molecules, which are known to play important roles during the initiation, progression and resolution of the phagocytic process. In mammals, the requirement of Ca(2+) for the initial steps in phagocytosis, and the subsequent phagosome maturation, can be quite different depending on the type of cell and on the type of receptor that is driving phagocytosis. In this review we discuss the different receptors that mediate professional and non-professional phagocytosis, and discuss the role of Ca(2+) in the different steps of this complex process.
Collapse
|
10
|
Chun KR, Bae EM, Kim JK, Suk K, Lee WH. Suppression of the lipopolysaccharide-induced expression of MARCKS-related protein (MRP) affects transmigration in activated RAW264.7 cells. Cell Immunol 2009; 256:92-8. [PMID: 19246034 DOI: 10.1016/j.cellimm.2009.01.011] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2008] [Revised: 01/14/2009] [Accepted: 01/25/2009] [Indexed: 01/01/2023]
Abstract
The molecular action mechanism of MRP, one of the protein kinase C (PKC) substrates, has been under intense investigation, but reports on its role in macrophage function remain controversial. The treatment of macrophage cell lines with bacterial lipopolysaccharide (LPS) induced a high level of MRP expression suggesting that MRP plays a role in the function of activated macrophages. In order to investigate the role of MRP in activated RAW264.7 cells, we stably transfected MRP-specific shRNA expression constructs and tested for alterations in macrophage-related functions. The down-regulation of MRP expression resulted in a marked reduction in chemotaxis toward MCP-1 or extracellular matrix proteins. Furthermore, pharmacological inhibitors of PKC significantly inhibited the chemotaxis in RAW264.7 cells. These data reveals the pivotal role of MRP in the transmigration of activated RAW264.7 cells.
Collapse
Affiliation(s)
- Kwang-Rok Chun
- Department of Genetic Engineering, Kyungpook National University, Daegu, Republic of Korea
| | | | | | | | | |
Collapse
|
11
|
Honing H, van Rooijen N, van den Berg T. Manipulation of Macrophage Activities Using Liposomes. J Liposome Res 2008. [DOI: 10.3109/08982100009031105] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
|
12
|
Terahara K, Yoshida M, Igarashi O, Nochi T, Pontes GS, Hase K, Ohno H, Kurokawa S, Mejima M, Takayama N, Yuki Y, Lowe AW, Kiyono H. Comprehensive gene expression profiling of Peyer's patch M cells, villous M-like cells, and intestinal epithelial cells. THE JOURNAL OF IMMUNOLOGY 2008; 180:7840-6. [PMID: 18523247 DOI: 10.4049/jimmunol.180.12.7840] [Citation(s) in RCA: 128] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Separate populations of M cells have been detected in the follicle-associated epithelium of Peyer's patches (PPs) and the villous epithelium of the small intestine, but the traits shared by or distinguishing the two populations have not been characterized. Our separate study has demonstrated that a potent mucosal modulator cholera toxin (CT) can induce lectin Ulex europaeus agglutinin-1 and our newly developed M cell-specific mAb NKM 16-2-4-positive M-like cells in the duodenal villous epithelium. In this study, we determined the gene expression of PP M cells, CT-induced villous M-like cells, and intestinal epithelial cells isolated by a novel approach using FACS. Additional mRNA and protein analyses confirmed the specific expression of glycoprotein 2 and myristoylated alanine-rich C kinase substrate (MARCKS)-like protein by PP M cells but not CT-induced villous M-like cells. Comprehensive gene profiling also suggested that CT-induced villous M-like cells share traits of both PP M cells and intestinal epithelial cells, a finding that is supported by their unique expression of specific chemokines. The genome-wide assessment of gene expression facilitates discovery of M cell-specific molecules and enhances the molecular understanding of M cell immunobiology.
Collapse
Affiliation(s)
- Kazutaka Terahara
- Division of Mucosal Immunology, Graduate School of Frontier Science, The University of Tokyo, Tokyo, Japan
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
13
|
Zhang W, Sato T, Smith SO. NMR spectroscopy of basic/aromatic amino acid clusters in membrane proteins. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2006. [PMCID: PMC7112282 DOI: 10.1016/j.pnmrs.2006.04.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Affiliation(s)
| | | | - Steven O. Smith
- Corresponding author. Tel.: +1 631 632 1210; fax: +1 631 632 8575.
| |
Collapse
|
14
|
Hardin AO, Meals EA, Yi T, Knapp KM, English BK. SHP-1 inhibits LPS-mediated TNF and iNOS production in murine macrophages. Biochem Biophys Res Commun 2006; 342:547-55. [PMID: 16487932 DOI: 10.1016/j.bbrc.2006.02.005] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2006] [Accepted: 02/02/2006] [Indexed: 12/27/2022]
Abstract
Several lines of evidence have suggested that protein tyrosine phosphatases, including CD45 and SHP-1, regulate macrophage activation. Macrophages from mice lacking SHP-1 (motheaten mice) are hyper-responsive to many stimuli, suggesting that SHP-1 may negatively regulate macrophage activation. Herein we report that the repressible/inducible over-expression of wild-type SHP-1 in a subclone of RAW 264.7 macrophages (RAW-TT10 cells) inhibited both TNF secretion and iNOS protein accumulation in response to stimulation with lipopolysaccharide (LPS) and recombinant murine interferon-gamma and led to diminished LPS-mediated tyrosine phosphorylation of vav1. In contrast, expression of a truncated SHP-1 construct previously shown to interfere with endogenous SHP-1 function modestly augmented LPS-mediated TNF and iNOS production and did not inhibit vav1 tyrosine phosphorylation. Taken together, these data provide the first direct evidence that SHP-1 inhibits macrophage activation by LPS and suggest that this effect may be mediated in part by dephosphorylation of vav1.
Collapse
Affiliation(s)
- Amy O Hardin
- Children's Foundation Research Center at Le Bonheur Children's Medical Center, Room 301 West Patient Tower, 50 North Dunlap, Memphis, TN 38103, USA
| | | | | | | | | |
Collapse
|
15
|
Godambe SA, Knapp KM, Meals EA, English BK. Role of vav1 in the lipopolysaccharide-mediated upregulation of inducible nitric oxide synthase production and nuclear factor for interleukin-6 expression activity in murine macrophages. CLINICAL AND DIAGNOSTIC LABORATORY IMMUNOLOGY 2005; 11:525-31. [PMID: 15138177 PMCID: PMC404562 DOI: 10.1128/cdli.11.3.525-531.2004] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
vav1 has been shown to play a key role in lymphocyte development and activation, but its potential importance in macrophage activation has received little attention. We have previously reported that exposure of macrophages to bacterial lipopolysaccharide (LPS) leads to increased activity of hck and other src-related tyrosine kinases and to the prompt phosphorylation of vav1 on tyrosine. In this study, we tested the role of vav1 in macrophage responses to LPS, focusing on the upregulation of nuclear factor for interleukin-6 expression (NF-IL-6) activity and inducible nitric oxide synthase (iNOS) protein accumulation in RAW-TT10 murine macrophages. We established a series of stable cell lines expressing three mutant forms of vav1 in a tetracycline-regulatable fashion: (i) a form producing a truncated protein, vavC; (ii) a form containing a point mutation in the regulatory tyrosine residue, vavYF174; and (iii) a form with an in-frame deletion of 6 amino acids required for the guanidine nucleotide exchange factor (GEF) activity of vav1 for rac family GTPases, vavGEFmt. Expression of the truncated mutant (but not the other two mutants) has been reported to interfere with T-cell activation. In contrast, we now demonstrate that expression of any of the three mutant forms of vav1 in RAW-TT10 cells consistently inhibited LPS-mediated increases in iNOS protein accumulation and NF-IL-6 activity. These data provide direct evidence for a role for vav1 in LPS-mediated macrophage activation and iNOS production and suggest that vav1 functions in part via activation of NF-IL-6. Furthermore, these findings indicate that the GEF activity of vav1 is required for its ability to mediate macrophage activation by LPS.
Collapse
Affiliation(s)
- Sandip A Godambe
- Department of Pediatrics, Children's Foundation Research Center, Le Bonheur Children's Medical Center, 50 N. Dunlap, Memphis, TN 38103, USA
| | | | | | | |
Collapse
|
16
|
Stovall SH, Yi AK, Meals EA, Talati AJ, Godambe SA, English BK. Role of vav1- and src-related tyrosine kinases in macrophage activation by CpG DNA. J Biol Chem 2004; 279:13809-16. [PMID: 14749335 DOI: 10.1074/jbc.m311434200] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Macrophage activation by CpG DNA requires toll-like receptor 9 and the adaptor protein MyD88. Gram-negative bacterial lipopolysaccharide also activates macrophages via a toll-like receptor pathway (TLR-4), but we and others have reported that lipopolysaccharide also stimulates tyrosine phosphorylation in macrophages. Herein we report that exposure of RAW 264.7 murine macrophages to CpG DNA (but not non-CpG DNA) provoked the rapid tyrosine phosphorylation of vav1. PP1, a selective inhibitor of src-related tyrosine kinases, blocked both the CpG DNA-mediated tyrosine phosphorylation of vav1 and the CpG DNA-mediated up-regulation of macrophage tumor necrosis factor secretion and inducible nitric-oxide synthase protein accumulation. Furthermore, we found that the inducible expression of any of three dominant interfering mutants of vav1 (a truncated protein, vavC; a form containing a point mutation in the regulatory tyrosine residue, vavYF174; and a form with an in-frame deletion of six amino acids required for the guanidine nucleotide exchange factor (GEF) activity of vav1 for rac family GTPases, vavGEFmt) consistently inhibited CpG DNA-mediated up-regulation of tumor necrosis factor secretion and inducible nitric-oxide synthase protein accumulation in RAW-TT10 macrophages. Finally, we determined that CpG DNA-mediated up-regulation of NF-kappaB activity (but not mitogen-activated protein kinase activation) was inhibited by preincubation with PP1 or by expression of the truncated vavC mutant. Taken together, our results indicate that the tyrosine phosphorylation of vav1 by a src-related tyrosine kinase or kinases plays an important role in the macrophage response to CpG DNA.
Collapse
Affiliation(s)
- Stephanie H Stovall
- Children's Foundation Research Center at Le Bonheur Children's Medical Center, University of Tennessee Health Science Center, Memphis, Tennessee 38103, USA
| | | | | | | | | | | |
Collapse
|
17
|
Zhang W, Crocker E, McLaughlin S, Smith SO. Binding of peptides with basic and aromatic residues to bilayer membranes: phenylalanine in the myristoylated alanine-rich C kinase substrate effector domain penetrates into the hydrophobic core of the bilayer. J Biol Chem 2003; 278:21459-66. [PMID: 12670959 DOI: 10.1074/jbc.m301652200] [Citation(s) in RCA: 98] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Electrostatic interactions with positively charged regions of membrane-associated proteins such as myristoylated alanine-rich C kinase substrate (MARCKS) may have a role in regulating the level of free phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2) in plasma membranes. Both the MARCKS protein and a peptide corresponding to the effector domain (an unstructured region that contains 13 basic residues and 5 phenylalanines), MARCKS-(151-175), laterally sequester the polyvalent lipid PI(4,5)P2 in the plane of a bilayer membrane with high affinity. We used high resolution magic angle spinning NMR to establish the location of MARCKS-(151-175) in membrane bilayers, which is necessary to understand the sequestration mechanism. Measurements of cross-relaxation rates in two-dimensional nuclear Overhauser enhancement spectroscopy NMR experiments show that the five Phe rings of MARCKS-(151-175) penetrate into the acyl chain region of phosphatidylcholine bilayers containing phosphatidylglycerol or PI(4,5)P2. Specifically, we observed strong cross-peaks between the aromatic protons of the Phe rings and the acyl chain protons of the lipids, even for very short (50 ms) mixing times. The position of the Phe rings implies that the adjacent positively charged amino acids in the peptide are close to the level of the negatively charged lipid phosphates. The deep location of the MARCKS peptide in the polar head group region should enhance its electrostatic sequestration of PI(4,5)P2 by an "image charge" mechanism. Moreover, this location has interesting implications for membrane curvature and local surface pressure effects and may be relevant to a wide variety of other proteins with basic-aromatic clusters, such as phospholipase D, GAP43, SCAMP2, and the N-methyl-d-aspartate receptor.
Collapse
Affiliation(s)
- Wenyi Zhang
- Department of Biochemistry and Cell Biology, Center for Structural Biology, State University of New York, Stony Brook, NY 11794-5115, USA
| | | | | | | |
Collapse
|
18
|
Wang J, Gambhir A, Hangyás-Mihályné G, Murray D, Golebiewska U, McLaughlin S. Lateral sequestration of phosphatidylinositol 4,5-bisphosphate by the basic effector domain of myristoylated alanine-rich C kinase substrate is due to nonspecific electrostatic interactions. J Biol Chem 2002; 277:34401-12. [PMID: 12097325 DOI: 10.1074/jbc.m203954200] [Citation(s) in RCA: 175] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
A peptide corresponding to the basic (+13), unstructured effector domain of myristoylated alanine-rich C kinase substrate (MARCKS) binds strongly to membranes containing phosphatidylinositol 4,5-bisphosphate (PIP(2)). Although aromatic residues contribute to the binding, three experiments suggest the binding is driven mainly by nonspecific local electrostatic interactions. First, peptides with 13 basic residues, Lys-13 and Arg-13, bind to PIP(2)-containing vesicles with the same high affinity as the effector domain peptide. Second, removing basic residues from the effector domain peptide reduces the binding energy by an amount that correlates with the number of charges removed. Third, peptides corresponding to a basic region in GAP43 and MARCKS effector domain-like regions in other proteins (e.g. MacMARCKS, adducin, Drosophila A kinase anchor protein 200, and N-methyl-d-aspartate receptor) also bind with an energy that correlates with the number of basic residues. Kinetic measurements suggest the effector domain binds to several PIP(2). Theoretical calculations show the effector domain produces a local positive potential, even when bound to a bilayer with 33% monovalent acidic lipids, and should thus sequester PIP(2) laterally. This electrostatic sequestration was observed experimentally using a phospholipase C assay. Our results are consistent with the hypothesis that MARCKS could reversibly sequester much of the PIP(2) in the plasma membrane.
Collapse
Affiliation(s)
- Jiyao Wang
- Department of Physiology and Biophysics, State University of New York, Stony Brook, New York 11794-8661, USA
| | | | | | | | | | | |
Collapse
|
19
|
Abstract
The proteins of the MARCKS (myristoylated alanine-rich C kinase substrate) family were first identified as prominent substrates of protein kinase C (PKC). Since then, these proteins have been implicated in the regulation of brain development and postnatal survival, cellular migration and adhesion, as well as endo-, exo- and phago-cytosis, and neurosecretion. The effector domain of MARCKS proteins is phosphorylated by PKC, binds to calmodulin and contributes to membrane binding. This multitude of mutually exclusive interactions allows cross-talk between the signal transduction pathways involving PKC and calmodulin. This review focuses on recent, mostly biophysical and biochemical results renewing interest in this protein family. MARCKS membrane binding is now understood at the molecular level. From a structural point of view, there is a consensus emerging that MARCKS proteins are "natively unfolded". Interestingly, domains similar to the effector domain have been discovered in other proteins. Furthermore, since the effector domain enhances the polymerization of actin in vitro, MARCKS proteins have been proposed to mediate regulation of the actin cytoskeleton. However, the recent observations that MARCKS might serve to sequester phosphatidylinositol 4,5-bisphosphate in the plasma membrane of unstimulated cells suggest an alternative model for the control of the actin cytoskeleton. While myristoylation is classically considered to be a co-translational, irreversible event, new reports on MARCKS proteins suggest a more dynamic picture of this protein modification. Finally, studies with mice lacking MARCKS proteins have investigated the functions of these proteins during embryonic development in the intact organism.
Collapse
Affiliation(s)
- Anna Arbuzova
- Department of Physiology and Biophysics, Health Sciences Center, State University of New York, Stony Brook, NY 11794-8661, U.S.A
| | | | | |
Collapse
|
20
|
Abstract
The process of engulfing a foreign particle - phagocytosis - is of fundamental importance for a wide diversity of organisms. From simple unicellular organisms that use phagocytosis to obtain their next meal, to complex metazoans in which phagocytic cells represent an essential branch of the immune system, evolution has armed cells with a fantastic repertoire of molecules that serve to bring about this complex event. Regardless of the organism or specific molecules concerned, however, all phagocytic processes are driven by a finely controlled rearrangement of the actin cytoskeleton. A variety of signals can converge to locally reorganise the actin cytoskeleton at a phagosome, and there are significant similarities and differences between different organisms and between different engulfment processes within the same organism. Recent advances have demonstrated the complexity of phagocytic signalling, such as the involvement of phosphoinostide lipids and multicomponent signalling complexes in transducing signals from phagocytic receptors to the cytoskeleton. Similarly, a wide diversity of ‘effector molecules’ are now implicated in actin-remodelling downstream of these receptors.
Collapse
Affiliation(s)
- R C May
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | | |
Collapse
|
21
|
Affiliation(s)
- J C Patel
- MRC Laboratory for Molecular Cell Biology, University College London, England, United Kingdom
| | | | | |
Collapse
|
22
|
Mita Y, Dobashi K, Nakazawa T, Mori M. Induction of Toll-like receptor 4 in granulocytic and monocytic cells differentiated from HL-60 cells. Br J Haematol 2001; 112:1041-7. [PMID: 11298604 DOI: 10.1046/j.1365-2141.2001.02658.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Toll-like receptor 4 (TLR4) is the main protein expressed on the cell surface and is an essential receptor for lipopolysaccharide (LPS) signalling in human peripheral blood leucocytes. We examined TLR4 expression and the functional response to LPS in retinoic acid-treated HL-60 cells (HL-60-derived granulocytic cells) and interferon-gamma-treated HL-60 cells (HL-60-derived monocytic cells). Slight TLR4 expression was induced in HL-60-derived granulocytic cells, while strong induction was seen in HL-60-derived monocytic cells. LPS induced interleukin 1beta (IL-1beta) production and TLR4 expression in HL-60-derived monocytic cells, but not HL-60-derived granulocytic cells. These data indicate different responses to LPS in the cells. TLR4 surface expression paralleled LPS-induced phagocytosis and TLR4-neutralizing antibody partially inhibited LPS-induced IL-8 production in HL-60-derived monocytic cells, but not in HL-60-derived granulocytic cells. These results suggest that HL-60-derived monocytic cells are partially activated via TLR4, but that HL-60-derived granulocytic cells are not activated via TLR4.
Collapse
Affiliation(s)
- Y Mita
- First Department of Internal Medicine, Gunma University Faculty of Medicine, 3-39-15, Showa-machi, Maebashi, Gunma 371-8511, Japan.
| | | | | | | |
Collapse
|
23
|
Breton A, Descoteaux A. Protein kinase C-alpha participates in FcgammaR-mediated phagocytosis in macrophages. Biochem Biophys Res Commun 2000; 276:472-6. [PMID: 11027499 DOI: 10.1006/bbrc.2000.3511] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Phagocytosis of IgG-opsonized particles by macrophages requires the activation of protein kinase C (PKC), a family of protein serine/threonine kinases. In the present study, we have investigated the role of the PKC-alpha isoenzyme in FcgammaR-mediated phagocytosis using clones of the mouse macrophage cell line RAW 264. 7 overexpressing a dominant-negative (DN) mutant of PKC-alpha. Overexpression of DN PKC-alpha had no effect on the attachment of IgG-opsonized sheep red blood cells, but inhibited their internalization. Further analysis of the signaling events induced by IgG-opsonized sheep red blood cells revealed that whereas tyrosine phosphorylation of Syk was normal, phosphorylation of ERK 1/2 (p42/44) was impaired in DN PKC-alpha-overexpressing macrophages. These observations suggest a role for PKC-alpha in the regulation of FcgammaR-induced phagocytosis and signal transduction.
Collapse
Affiliation(s)
- A Breton
- INRS-Institut Armand-Frappier, Laval, Québec, H7V 1B7, Canada
| | | |
Collapse
|
24
|
Underhill DM, Ozinsky A, Smith KD, Aderem A. Toll-like receptor-2 mediates mycobacteria-induced proinflammatory signaling in macrophages. Proc Natl Acad Sci U S A 1999; 96:14459-63. [PMID: 10588727 PMCID: PMC24458 DOI: 10.1073/pnas.96.25.14459] [Citation(s) in RCA: 584] [Impact Index Per Article: 23.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
The recognition of mycobacterial cell wall components causes macrophages to secrete tumor necrosis factor alpha (TNF-alpha) and other cytokines that are essential for the development of a protective inflammatory response. We show that toll-like receptors are required for the induction of TNF-alpha in macrophages by Mycobacterium tuberculosis. Expression of a dominant negative form of MyD88 (a signaling component required for toll-like receptor signaling) in a mouse macrophage cell line blocks TNF-alpha production induced by M. tuberculosis. We identify toll-like receptor-2 (TLR2) as the specific toll-like receptor required for this induction by showing that expression of an inhibitory TLR2 (TLR2-P681H) blocks TNF-alpha production induced by whole M. tuberculosis. Further, we show that TLR2-dependent signaling mediates responses to mycobacterial cell wall fractions enriched for lipoarrabinomannan, mycolylarabinogalactan-peptidoglycan complex, or M. tuberculosis total lipids. Thus, although many mycobacterial cell wall fractions are identified to be inflammatory, all require TLR2 for induction of TNF-alpha in macrophages. These data suggest that TLR2 is essential for the induction of a protective immune response to mycobacteria.
Collapse
Affiliation(s)
- D M Underhill
- Department of Immunology, University of Washington, Seattle, WA 98195, USA
| | | | | | | |
Collapse
|
25
|
The Toll-like receptor 2 is recruited to macrophage phagosomes and discriminates between pathogens. Nature 1999. [DOI: 10.1038/35005543] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
|
26
|
Underhill DM, Ozinsky A, Hajjar AM, Stevens A, Wilson CB, Bassetti M, Aderem A. The Toll-like receptor 2 is recruited to macrophage phagosomes and discriminates between pathogens. Nature 1999; 401:811-5. [PMID: 10548109 DOI: 10.1038/44605] [Citation(s) in RCA: 1036] [Impact Index Per Article: 41.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Macrophages orchestrate innate immunity by phagocytosing pathogens and coordinating inflammatory responses. Effective defence requires the host to discriminate between different pathogens. The specificity of innate immune recognition in Drosophila is mediated by the Toll family of receptors; Toll mediates anti-fungal responses, whereas 18-wheeler mediates anti-bacterial defence. A large number of Toll homologues have been identified in mammals, and Toll-like receptor 4 is critical in responses to Gram-negative bacteria. Here we show that Toll-like receptor 2 is recruited specifically to macrophage phagosomes containing yeast, and that a point mutation in the receptor abrogates inflammatory responses to yeast and Gram-positive bacteria, but not to Gram-negative bacteria. Thus, during the phagocytosis of pathogens, two classes of innate immune receptors cooperate to mediate host defence: phagocytic receptors, such as the mannose receptor, signal particle internalization, and the Toll-like receptors sample the contents of the vacuole and trigger an inflammatory response appropriate to defence against the specific organism.
Collapse
Affiliation(s)
- D M Underhill
- Department of Immunology, University of Washington, Seattle 98195, USA
| | | | | | | | | | | | | |
Collapse
|
27
|
Corradin S, Ransijn A, Corradin G, Roggero MA, Schmitz AA, Schneider P, Mauël J, Vergères G. MARCKS-related protein (MRP) is a substrate for the Leishmania major surface protease leishmanolysin (gp63). J Biol Chem 1999; 274:25411-8. [PMID: 10464270 DOI: 10.1074/jbc.274.36.25411] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Myristoylated alanine-rich C kinase substrate (MARCKS) and MARCKS-related protein (MRP; MacMARCKS) are protein kinase C substrates in diverse cell types. Activation of murine macrophages by cytokines increases MRP expression, but infection with Leishmania promastigotes during activation results in MRP depletion. We therefore examined the effect of Leishmania major LV39 on recombinant MRP. Both live promastigotes and a soluble fraction of LV39 lysates degraded MRP to yield lower molecular weight fragments. Degradation was independent of MRP myristoylation and was inhibited by protein kinase C-dependent phosphorylation of MRP. MRP was similarly degraded by purified leishmanolysin (gp63), a Leishmania surface metalloprotease. Degradation was evident at low enzyme/substrate ratios, over a broad pH range, and was inhibited by 1,10-phenanthroline and by a hydroxamate dipeptide inhibitor of leishmanolysin. Using mass spectrometric analysis, cleavage was shown to occur within the effector domain of MRP between Ser(92) and Phe(93), in accordance with the substrate specificity of leishmanolysin. Moreover, an MRP construct in which the effector domain had been deleted was resistant to cleavage. Thus, Leishmania infection may result in leishmanolysin-dependent hydrolysis of MRP, a major protein kinase C substrate in macrophages.
Collapse
Affiliation(s)
- S Corradin
- Institute of Biochemistry, University of Lausanne, 1066 Epalinges, Switzerland.
| | | | | | | | | | | | | | | |
Collapse
|
28
|
Carballo E, Pitterle DM, Stumpo DJ, Sperling RT, Blackshear PJ. Phagocytic and macropinocytic activity in MARCKS-deficient macrophages and fibroblasts. THE AMERICAN JOURNAL OF PHYSIOLOGY 1999; 277:C163-73. [PMID: 10409119 DOI: 10.1152/ajpcell.1999.277.1.c163] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Macrophages express high levels of the myristoylated, alanine-rich, C kinase substrate (MARCKS), an actin cross-linking protein. To investigate a possible role of MARCKS in macrophage function, fetal liver-derived macrophages were generated from wild-type and MARCKS knockout mouse embryos. No differences between the wild-type and MARCKS-deficient macrophages with respect to morphology (Wright's stain) or actin distribution (staining with rhodamine-phalloidin, under basal conditions or after treatment with phorbol esters, lipopolysaccharide, or both) were observed. We then evaluated phagocytosis mediated by different receptors: Fc receptors tested with IgG-coated sheep red blood cells, complement C3b receptors tested with C3b-coated yeast, mannose receptors tested with unopsonized zymosan, and nonspecific phagocytosis tested with latex beads. We also studied fluid phase endocytosis in macrophages and mouse embryo fibroblasts by using FITC-dextran to quantitate this process. In most cases, there were no differences between the cells derived from wild-type and MARCKS-deficient mice. However, a minor but significant and reproducible difference in rates of zymosan phagocytosis at 45-60 min was observed, with lower rates of phagocytosis in the MARCKS-deficient cells. Our data indicate that MARCKS deficiency may lead to slightly decreased rates of zymosan phagocytosis.
Collapse
Affiliation(s)
- E Carballo
- Office of Clinical Research and Laboratory of Signal Transduction, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina 27709, USA
| | | | | | | | | |
Collapse
|
29
|
Corradin S, Mauël J, Ransijn A, Stürzinger C, Vergères G. Down-regulation of MARCKS-related protein (MRP) in macrophages infected with Leishmania. J Biol Chem 1999; 274:16782-7. [PMID: 10358020 DOI: 10.1074/jbc.274.24.16782] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Leishmania, a protozoan parasite of macrophages, has been shown to interfere with host cell signal transduction pathways including protein kinase C (PKC)-dependent signaling. Myristoylated alanine-rich C kinase substrate (MARCKS) and MARCKS-related protein (MRP, MacMARCKS) are PKC substrates in diverse cell types. MARCKS and MRP are thought to regulate the actin network and thereby participate in cellular responses involving cytoskeletal rearrangement. Because MRP is a major PKC substrate in macrophages, we examined its expression in response to infection by Leishmania. Activation of murine macrophages by cytokines increased MRP expression as determined by Western blot analysis. Infection with Leishmania promastigotes at the time of activation or up to 48 h postactivation strongly decreased MRP levels. Leishmania-dependent MRP depletion was confirmed by [3H]myristate labeling and by immunofluorescence microscopy. All species or strains of Leishmania parasites tested, including lipophosphoglycan-deficient Leishmania major L119, decreased MRP levels. MRP depletion was not obtained with other phagocytic stimuli including zymosan, latex beads, or heat-killed Streptococcus mitis, a Gram-positive bacterium. Experiments with [3H]myristate labeled proteins revealed the appearance of lower molecular weight fragments in Leishmania-infected cells suggesting that MRP depletion may be due to proteolytic degradation.
Collapse
Affiliation(s)
- S Corradin
- Institute of Biochemistry, University of Lausanne, 1066 Epalinges, Switzerland.
| | | | | | | | | |
Collapse
|
30
|
Abstract
Phagocytosis of pathogens by macrophages initiates the innate immune response, which in turn orchestrates the adaptive response. In order to discriminate between infectious agents and self, macrophages have evolved a restricted number of phagocytic receptors, like the mannose receptor, that recognize conserved motifs on pathogens. Pathogens are also phagocytosed by complement receptors after relatively nonspecific opsonization with complement and by Fc receptors after specific opsonization with antibodies. All these receptors induce rearrangements in the actin cytoskeleton that lead to the internalization of the particle. However, important differences in the molecular mechanisms underlying phagocytosis by different receptors are now being appreciated. These include differences in the cytoskeletal elements that mediate ingestion, differences in vacuole maturation, and differences in inflammatory responses. Infectious agents, such as M. tuberculosis, Legionella pneumophila, and Salmonella typhimurium, enter macrophages via heterogeneous pathways and modify vacuolar maturation in a manner that favors their survival. Macrophages also play an important role in the recognition and clearance of apoptotic cells; a notable feature of this process is the absence of an inflammatory response.
Collapse
Affiliation(s)
- A Aderem
- Department of Immunology, University of Washington, Seattle 98195, USA.
| | | |
Collapse
|
31
|
|