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3. Regulation of inducible nitric oxide synthase

Author

Feng, Gui-jie

Subjects
572, Immunology
Abstract

One of the major functions of macrophages is to provide the body with an immediate innate defence against pathogenic micro-organisms. This defence is largely dependent on the generation of nitric oxide (NO) and superoxide by macrophages which leads to the killing of these pathogens. NO is also important in many other biological functions. It is derived from L-arginine and molecular oxygen by the enzyme NO synthase (NOS). There are a number of classes of NOS including neuronal NOS (nNOS), endothelial NOS (eNOS) and cytokine-inducible NOS (iNOS). iNOS is upregulated and activated by several immunological stimuli including interferon gamma (IFN-gamma; lipopolysaccharide (LPS) and tumor necrosis factor-alpha (TNF-alpha), such activation leads to the production of large quantities of NO which can be cytotoxic. The potential toxicity of NO makes it important to understand the regulation of its production. In the study presented here, J774 cells, a murine macrophage cell line, were used as a model system for studying the induction and regulation of iNOS activation. These cells and murine peritoneal macrophages produce large amounts of NO in response to the T cell-derived lymphokine, IFN- and/or the potent macrophage activator, LPS in a dose-dependent manner. Northern and Western blotting revealed the process of induction of NO synthesis in J774 cells: The maximal induction of NO synthase mRNA was at 4 h while the maximum levels of NOS protein was observed at 8 to 12 h after treatment with IFN-gamma and LPS. IFN-? LPS-induced NO2- accumulation was abolished in the culture supernatants of samples that were pre-treated with cycloheximide. These suggest that iNOS is regulated transcriptionally in a manner that requires de novo protein synthesis. Protein phosphorylation plays a crucial role in regulating the signal transduction cascades leading to many biological responses in eukaryotes. Signals that are reversibly controlled by protein phosphorylation are modulated not only by a protein kinase but also by a protein phosphatase. In this project, I have shown that the induction of iNOS activity in J774 cells by IFN-gamma and LPS was reduced by more than 50% if the cells were pretreated with protein tyrosine kinase (PTK) inhibitors such as Tyrphostin 25, Tyrphostin AG126, and Herbimycin A. In contrast, iNOS was unaffected by pre-incubation with Tyrphostin 1, an inert analogue of these PTK inhibitors. Consistent with these findings, IFN-gamma and LPS-induced iNOS activity was enhanced by 30% in the presence of vanadate, a protein tyrosine phosphatase inhibitor. These results suggested that the activation of tyrosine kinase(s) plays a role in induction of NO synthesis.

Published
1997
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6. Contributors

Author

Abrams, John M., primary, Adelman, John P., additional, Alcorn, Joseph L., additional, Alessi, Dario R., additional, Alexov, Emil, additional, Alford, Simon, additional, Alitalo, Kari, additional, Allison, James P., additional, Almo, Steven C., additional, Alory, Christelle, additional, Al-Shamkhani, Aymen, additional, Amundson, Sally A., additional, Anderson, Carl W., additional, Andersen, Jannik N., additional, Angel, Peter, additional, Appella, Ettore, additional, Arendshorst, William J., additional, Arkinstall, Steve, additional, Audhya, Anjon, additional, Avruch, Joseph, additional, Bader, Gary D., additional, Bagala, Cinzia, additional, Balch, William E., additional, Balsinde, Jesus, additional, Banerjee, Utpal, additional, Barford, David, additional, Bar-Sagi, Dafna, additional, Bartlett, Perry F., additional, Bastiaens, Philippe I.H., additional, Battelli, Chiara, additional, Baudhuin, Linnea M., additional, Beavil, Andrew J., additional, Beavil, Rebecca L., additional, Beavo, Joseph A., additional, Bello-Reuss, Elsa, additional, Bellum, Stephen, additional, Belmonte, Juan Carlos Izpisúa, additional, Bennett, Craig B., additional, Benovic, Jeffrey L., additional, Berridge, Michael J., additional, Beuning, Penny J., additional, Bhandari, Rashna, additional, Bhattacharya, Ananya, additional, Biel, Martin, additional, Bielinski, Vincent A., additional, Bilak, Hana, additional, Birnbaumer, Lutz, additional, Birrell, Geoff, additional, Bishop, Gail A., additional, Blackmer, Trillium, additional, Blackshear, Perry J., additional, Blattner, Christine, additional, Blaustein, Mordecai P., additional, Bokoch, Gary M., additional, Bonewald, Lynda F., additional, Bonomi, Marco, additional, Booden, Michelle A., additional, Boone, Charles, additional, Bootman, Martin D., additional, Bos, Johannes L., additional, Bradbury, Jane M., additional, Bradshaw, Ralph A., additional, Bresnick, Anne R., additional, Brevnova, Lena, additional, Brinkworth, Ross I., additional, Brown, Michael S., additional, Brown, Steven A., additional, Brunet, Anne, additional, Bucki, Robert, additional, Burgoyne, Robert D., additional, Buss, Janice E., additional, Butow, Ronald A., additional, Capdevila, Javier, additional, Carafoli, Ernesto, additional, Carlson, Cathrine R., additional, Carpenter, Graham, additional, Carrillo, Juan J., additional, Casey, Patrick J., additional, Catterall, William A., additional, Cerione, Richard A., additional, Cesareni, Gianni, additional, Chan, Andrew C., additional, Chang, Geoffrey, additional, Chao, Moses V., additional, Charbonneau, Harry, additional, Chen, Philip, additional, Cheng, Alan, additional, Chiu, Chris, additional, Chow, Dar-chone, additional, Chrisman, Ted D., additional, Christensen, Anne Elisabeth, additional, Chung, Jee Y., additional, Churchill, Grant C., additional, Ciechanover, Aaron, additional, Cingolani, Gino, additional, Claeysen, Sylvie, additional, Closset, Jean, additional, Cockcroft, Shamshad, additional, Cohen, Patricia T.W., additional, Cohen, Philip, additional, Colbran, Roger J., additional, Comstock, Clay E.S., additional, Conti, Marco, additional, Corbin, Jackie D., additional, Corda, Daniela, additional, Costagliola, Sabine, additional, Cote, Rick H., additional, Coughlin, Shaun R., additional, Cowart, L. Ashley, additional, Cox, Adrienne D., additional, Cragg, Mark S., additional, Crespo, José L., additional, Crosio, Claudia, additional, Daly, Christopher, additional, Damak, Sami, additional, Dasso, Mary, additional, David, Michael, additional, Davis, Anthony J., additional, Davis, Roger J., additional, Day, Richard N., additional, Degerman, Eva, additional, DeLano, Warren L., additional, Dell'Acqua, Mark L., additional, Délot, Emmanuèle, additional, Demple, Bruce, additional, Dennis, Edward A., additional, Denu, John M., additional, DePaoli-Roach, Anna A., additional, Der, Channing J., additional, de Rooij, Johan, additional, de Sauvage, Frederic, additional, Devreotes, Peter N., additional, Dewaste, Valérie, additional, Dickson, Robert B., additional, Diebold, Becky A., additional, Fiori, Pier Paolo Di, additional, Girolamo, Maria Di, additional, Diplexcito, Julie, additional, Dixon, Jack E., additional, Doms, Robert W., additional, Donoghue, Daniel J., additional, Doolittle, Russell F., additional, Døskeland, Stein Ove, additional, Dostmann, Wolfgang R.G., additional, Dreyer, Matthias K., additional, Du, Guo Guang, additional, Du, Keyong, additional, Duchen, Michael R., additional, Dunphy, William G., additional, Durgan, Joanne, additional, Dustin, Michael L., additional, Edwards, Peter A., additional, Egen, Jackson G., additional, Eiden, Lee E., additional, Elion, Elaine A., additional, Emr, Scott, additional, Engelhardt, Othmar G., additional, Erneux, Christophe, additional, Espenshade, Peter J., additional, Esplin, Edward D., additional, Evers, B. Mark, additional, Eyles, Joanne L., additional, Fame, Sheelagh, additional, Farquhar, Marilyn, additional, Feil, Robert, additional, Feng, Gui-Jie, additional, Fields, Stanley, additional, Fiordalisi, James J., additional, Firtel, Richard A., additional, Fitzgerald, Garret A., additional, Flint, Andrew, additional, Foiani, Marco, additional, Forman, Barry Marc, additional, Fornace, Albert J., additional, Francis, Sharron H., additional, Fritz, Günter, additional, Fruman, David A., additional, Galione, Antony, additional, Gandhi, Chris S., additional, Garbers, David L., additional, Garcia, K. Christopher, additional, Geiger, Benjamin, additional, Gerace, Larry, additional, Gerstner, Andrea, additional, Giaccia, Amato J., additional, Giannattasio, Michele, additional, Giguère, Vincent, additional, Glass, Christopher K., additional, Glennie, Martin J., additional, Glick, Jennifer L., additional, Goldstein, Joseph L., additional, Gopal, Venkatesh, additional, Gorospe, Myriam, additional, Govaerts, Cedric, additional, Graves, Paul R., additional, Gray, Patrick W., additional, Graziani, Irene, additional, Green, Douglas R., additional, Greenberg, Michael E., additional, Greenwald, Iva, additional, Gu, Haihua, additional, Gueven, Nuri, additional, Gutkind, J. Silvio, additional, Haeggström, Jesper Z., additional, Hall, Alan, additional, Hall, Michael N., additional, Haller, Otto, additional, Hamm, Heidi E., additional, Hannun, Yusef A., additional, Hansen, Carl A., additional, Harden, T. Kendall, additional, Hardie, D. Grahame, additional, Hasegawa, Kiminori, additional, Hawkins, Phillip T., additional, Haystead, Timothy A.J., additional, He, Xiao-lin, additional, Heizmann, Claus W., additional, Heldin, Carl-Henrik, additional, Hermiston, Michelle L., additional, Herrlich, Peter, additional, Hewat, Elizabeth A., additional, Hille, Bertil, additional, Hilton, Douglas J., additional, Hinchliffe, K.A., additional, Ho, Steffan N., additional, Ho, Su-Chin, additional, Hochstrasser, Mark, additional, Hofmann, Franz, additional, Hogue, Christopher W., additional, Hol, Wim G.J., additional, Holash, Jocelyn, additional, Holmgren, Robert A., additional, Honig, Barry, additional, Hostager, Bruce S., additional, Hubbard, Stevan R., additional, Huber, Michael, additional, Hunter, Tony, additional, Huttenlocher, Anna, additional, Hymowitz, Sarah G., additional, Ihle, James N., additional, Imler, Jean-Luc, additional, Irvine, R.F., additional, Isacoff, Ehud Y., additional, Iturrioz, Xavier, additional, Iversen, Lars F., additional, Iyengar, Ravi, additional, Jackson, Stephen P., additional, Jan, Lily Yeh, additional, Janiak-Spens, Fabiola, additional, Janmey, Paul A., additional, Jansen, Peter Gildsig, additional, Jarriault, Sophie, additional, Javitch, Jonathan A., additional, Jensen, Elwood V., additional, Jepsen, Kristen, additional, Jones, E. Yvonne, additional, Jones, Katherine A., additional, Jordan, J. Dedrick, additional, Joseph, Jomon, additional, Justement, Louis B., additional, Kafri, Yariv, additional, Kahn, Richard A., additional, Kang, Shin W., additional, Karlin, Arthur, additional, Kast-Woelbern, Heidi R., additional, Kaufman, Randal J., additional, Kazlauskas, Andrius, additional, Keen, James H., additional, Kemler, Rolf, additional, Kemp, Bruce E., additional, Kennedy, Mary B., additional, Kennedy, Matthew A., additional, Kikkawa, Ushio, additional, Kim, Albert H., additional, Kim, Soo-A, additional, Kim, Sung-Hou, additional, Kim, Youngjoo, additional, King-Jones, Kirst, additional, Kintner, Chris, additional, Kivimäe, Saul, additional, Klee, Claude B., additional, Klein, Rüdiger, additional, Kleppisch, Thomas, additional, Kliewer, Steven A., additional, Klinghoffer, Richard A., additional, Knoblich, Juergen A., additional, Kobe, Bostjan, additional, Kochs, George, additional, Kong-Beltran, Monica, additional, König, Rolf, additional, Koong, Albert C., additional, Korc, Murray, additional, Kornitzer, Daniel, additional, Kossiakoff, Anthony A., additional, Kotera, Jun, additional, Kovalenko, M.V., additional, Kozasa, Tohru, additional, Kozlov, Sergei, additional, Kozminski, Keith G., additional, Krugmann, Sonja, additional, Kuriyan, John, additional, Kurokawa, Riki, additional, Kwong, Peter D., additional, Lai, Wi S., additional, Lamar, Elise, additional, Lambert, Millard H., additional, Lambright, David G., additional, Lancet, Doron, additional, Landry, Reiko, additional, Langdon, Wallace Y., additional, Langeberg, Lorene K., additional, Lasko, Paul, additional, Latham, Vaughn, additional, Lavin, Martin F., additional, Lease, Kevin A., additional, Leffler, Hakon, additional, Lemmon, Mark A., additional, Leonard, Ann E., additional, Levitzki, Alexander, additional, Liao, Hong-Jun, additional, Liaw, Lucy, additional, Liberi, Giordano, additional, Lickert, Heiko, additional, Liddington, Robert C., additional, Lincoln, Thomas M., additional, Linder, Jürgen U., additional, Linder, Maurine E., additional, Liu, Hui, additional, Liu, Zhengchang, additional, Lohela, Marja K., additional, Louie, Sarah H., additional, Luttrell, Deirdre K., additional, Luttrell, Louis M., additional, Lyons, Karen M., additional, Macaulay, S. Lance, additional, Maceyka, Michael, additional, Maciag, Thomas, additional, Macian, Fernando, additional, MacKintosh, Carol, additional, MacLennan, David H., additional, Mahmood, Nadir A., additional, Malbon, Craig C., additional, Malik, Sohail, additional, Man, Orna, additional, Manahan, Carol L., additional, Mandinova, Anna, additional, Manganiello, Vincent C., additional, Manley, James L., additional, Mann, Matthias, additional, Manning, Gerald, additional, Manser, Ed, additional, Margeta-Mitrovic, Marta, additional, Margolskee, Robert F., additional, Marinissen, Julia, additional, Mariuzza, Roy A., additional, Marmor, Mina D., additional, Martin, G. Steven, additional, Martin, Karen H., additional, Martinez, Sergio E., additional, Mathews, Michael B., additional, Mayer, Bruce J., additional, Mayer, Mark L., additional, Mazzoni, Maria R., additional, McCormick, Frank, additional, McGowan, Clare H., additional, McKay, Melissa M., additional, McKeehan, Wallace L., additional, McLean, Alison J., additional, Means, Anthony R., additional, Meili, Ruedi, additional, Meng, Jingwei, additional, Merchant, Mark, additional, Mercurio, Frank, additional, Milligan, Graeme, additional, Ming, Guo-Li, additional, Minor, Daniel L., additional, Moghal, Nadeem, additional, Møller, Neils Peter H., additional, Mongillo, Marco, additional, Montminy, Marc, additional, Moon, Randall T., additional, Morimoto, Richard I., additional, Moss, Stephen E., additional, Mott, Helen R., additional, Mouta, Carla, additional, Muda, Marco, additional, Mumby, Marc C., additional, Murphy, Gretchen A., additional, Muzi-Falconi, Marco, additional, Nagaraj, Raghavendra, additional, Nahorski, Stefan R., additional, Nairn, Angus C., additional, Nash, Piers, additional, Neel, Benjamin G., additional, Newton, Alexandra C., additional, Nishizuka, Yasutomi, additional, Noel, Joseph P., additional, Nollen, Ellen A.A., additional, Nooren, Irene M.A., additional, O'Connor, Rodney, additional, Offermanns, Stefan, additional, Olender, Tsviya, additional, Ong, Shao-En, additional, Owen, Darerca, additional, Pagliari, Lisa J., additional, Pao, Lily, additional, Papaconstantinou, John, additional, Pardo, Leonardo, additional, Park, Hay-Oak, additional, Park, Young Chul, additional, Parker, Peter J., additional, Parsons, J. Thomas, additional, Passner, J.M., additional, Pawson, Tony, additional, Pelliccioli, Achille, additional, Perez-Polo, J. Regino, additional, Perrimon, Norbert, additional, Petite, Fabrice G., additional, Petroulakis, Emmanuel, additional, Pfaff, Samuel L., additional, Piehler, Jacob, additional, Pike, Linda J., additional, Pinkoski, Michael J., additional, Pixley, Fiona J., additional, Plevani, Paolo, additional, Poo, Mu-ming, additional, Pozzan, Tullioi, additional, Prescott, Stephen M., additional, Prudovsky, Igor, additional, Putney, James W., additional, Radimerski, Thomas, additional, Radzio-Andzelm, Elzbieta, additional, Ram, Prahlad T., additional, Rameh, Lucia, additional, Ramljak, Danica, additional, Ranscht, Barbara, additional, Rao, Anjana, additional, Raport, Carol J., additional, Reeves, Jacqueline D., additional, Rehman, Holger, additional, Reichman, Trevor W., additional, Reiter, Eric, additional, Resnick, Michael A., additional, Reth, Michael, additional, Rhee, Sue Goo, additional, Richter, Joel D., additional, Rietze, Rodney L., additional, Rini, James M., additional, Ripperger, Jürgen A., additional, Rizo, Josep, additional, Robishaw, Janet D., additional, Roderick, H. Llewelyn, additional, Roeder, Robert G., additional, Rohrschneider, Larry R., additional, Ron, David, additional, Rosenfeld, Michael G., additional, Rosenfeldt, Hans, additional, Rossman, Kent L., additional, Roth, Christopher B., additional, Rudolph, Markus G., additional, Ruppelt, Anja, additional, Saez, Lino, additional, Sakmar, Thomas P., additional, Salvesen, Guy S., additional, Sassone-Corsi, Paolo, additional, Saxe, Charles L., additional, Schäfer, Beat W., additional, Schibler, Ueli, additional, Schindler, Christian W., additional, Schmelzle, Tobias, additional, Schmid, Sandra L., additional, Schmidt, Anja, additional, Schmidt, Eric F., additional, Schreiber, Gideon, additional, Schultz, Joachim E., additional, Schwaller, Beat, additional, Schwamborn, Klaus, additional, Schwartz, Thue, additional, Schwindinger, William F., additional, Scita, Giorgio, additional, Scott, John D., additional, Scott, Shaun, additional, Seebeck, Thomas, additional, Serhan, Charles N., additional, Shabb, John B., additional, Shaw, Andrey S., additional, Shears, Stephen B., additional, Shenolikar, Shirish, additional, Shi, Lei, additional, Shin, Chanseok, additional, Shiozaki, Kazuhiro, additional, Shokat, Kevan M., additional, Shuttleworth, Trevor J., additional, Siderovski, David P., additional, Siegelbaum, Steven A., additional, Silverstein, Adam M., additional, Singer, Robert H., additional, Skinner, Michael K., additional, Slack-Davis, Jill K., additional, Smerdon, Stephen J., additional, Smith, Graeme C.M., additional, Smits, Guillaume, additional, Smolik, Sarah M., additional, Smotrys, Jessica E., additional, Smyth, Emer M., additional, Snyder, Jason T., additional, Sogame, Naoko, additional, Soldi, Raffaella, additional, Sondek, John, additional, Sonenberg, Nahum, additional, Sonneberg, Erica Dutil, additional, Sparrow, Lindsay G., additional, Spiegel, Sarah, additional, Sprang, Stephen R., additional, Srivastava, Deepak, additional, Stanfield, Robyn L., additional, Stanley, E. Richard, additional, Stauber, Deborah J., additional, Stefan, Christopher, additional, Stenson-Holst, Lena, additional, Stephens, Len, additional, Sternberg, Paul W., additional, Sternweis, Paul C., additional, Steward, Ruth, additional, Stickney, John T., additional, Stoker, Andrew W., additional, Strittmatter, Stephen M., additional, Stronach, Beth E., additional, Strong, Roland K., additional, Stroud, Robert M., additional, Südhof, Thomas C., additional, Sunahara, Roger K., additional, Sutton, Brian J., additional, Szabolcs, Sipeki, additional, Tang, Xiao-Bo, additional, Taskén, Kjetil, additional, Tatebe, Hisashi, additional, Tauszig-Delamasure, Servane, additional, Taylor, Colin W., additional, Taylor, Garry L., additional, Taylor, Laura J., additional, Taylor, Susan S., additional, Thomas, George, additional, Thomas, Robert P., additional, Thompson, E. Brad, additional, Thompson, Michael J., additional, Thornton, Janet M., additional, Thummel, Carl S., additional, Togashi, Hideaki, additional, Tong, Amy Hin Yan, additional, Tonks, Nicholas K., additional, Tontonoz, Peter, additional, Topham, M.K., additional, Torgersen, Knut Martin, additional, Tran, Hien, additional, Tremblay, Michel L., additional, Tsai, Ming-Jer, additional, Tsai, Sophia Y., additional, Tsunoda, Susan, additional, Turley, Stewart, additional, Tyson, Darren, additional, Van Etten, Robert L., additional, Vassart, Gilbert, additional, Verveer, Peter J., additional, Vlaeminck, Virginie, additional, de Vos, Abraham M., additional, Voss, Ty C., additional, Walczak, Robert, additional, Walker, Graham C., additional, Walker, John C., additional, Walter, Gernot, additional, Walter, Mark R., additional, Wang, Fen, additional, Wang, Jean Y.J., additional, Wang, Weiru, additional, Ward, Richard J., additional, Wedegaertner, Philip, additional, Wehrle, Christian, additional, Weiss, Arthur, additional, Weiss, Jamie L., additional, Wells, Alan, additional, Werner, Claudia, additional, West, Ann H., additional, Weston, Marie C., additional, Westwick, John K., additional, Wetterholm, Anders, additional, White, Morris F., additional, Whitman, Malcolm, additional, Whorton, Matt R., additional, Wiesmann, Christian, additional, Williams, Roger L., additional, Willis, William D., additional, Willson, Timothy M., additional, Wilson, Ian A., additional, Wiser, Ofer, additional, Wishart, Matthew J., additional, Wittinghofer, Alfred, additional, Woodgett, James R., additional, Worthylake, David K., additional, Wrana, Jeffrey L., additional, Wu, Hao, additional, Xiao, Yijin, additional, Xu, H. Eric, additional, Xu, Yan, additional, Xu, Zheng, additional, Yaffe, Michael B., additional, Yamada, Kenneth M., additional, Yang, Seun-Ah, additional, Yang, Wannian, additional, Yarden, Yosef, additional, Ye, Hong, additional, Ye, Weilan, additional, Yeates, Todd O., additional, Yin, Helen L., additional, York, John D., additional, Young, Edgar C., additional, Young, Kenneth W., additional, Young, Matthew A., additional, Young, Michael W., additional, Yu, Minmin, additional, Zaccai, Nathan R., additional, Zaccolo, Manuela, additional, Zamir, Eli, additional, von Zastrow, Mark, additional, Zhang, Chao, additional, Zhang, Xuewu, additional, Zhang, Zhong-Yin, additional, Zhou, Wenhong, additional, and Zoraghi, Roya, additional

Published
2003
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7. Altered immune responses in mice lacking inducible nitric oxide synthase

Author

Wei, Xiao-qing, Charles, Ian G., Smith, AUstin, Ure, Jan, Feng, GUi-Jie, Huang, Fang-ping, Xu, Damo, Muller, Werner, Moncada, Salvador, and Liew, Foo Y.

Subjects
Immune response -- Genetic aspects, Nitric oxide -- Physiological aspects, Cytokines -- Physiological aspects, Mice, mutant strains -- Genetic aspects, Environmental issues, Science and technology, Zoology and wildlife conservation
Abstract

A study using mutant mice without the gene for cytokine-inducible nitric oxide synthase (iNOS) was conducted to characterize the biological role of iNOS. The results showed that mutant mice were fertile, viable and without obvious histopathological abnormalities, but were uniformly susceptible to infection by the protozoan parasite Leishmania major compared to wild-type and heterozygous mice. Infected mice also exhibited stronger Th1 type immune response, reduced nonspecific inflammatory response to carrageenin and resistance to lipopolysaccharide-induced mortality.

Published
1995

16. Extracellular Signal-Related Kinase (ERK) and p38 Mitogen-Activated Protein (MAP) Kinases Differentially Regulate the Lipopolysaccharide-Mediated Induction of Inducible Nitric Oxide Synthase and IL-12 in Macrophages:LeishmaniaPhosphoglycans Subvert Macrophage IL-12 Production by Targeting ERK MAP Kinase

Author

Feng, Gui-Jie, primary, Goodridge, Helen S., additional, Harnett, Margaret M., additional, Wei, Xiao-Qing, additional, Nikolaev, Andrei V., additional, Higson, Adrian P., additional, and Liew, Foo-Y., additional

Published
1999
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18. Regulation of macrophage IL-12 synthesis byLeishmania phosphoglycans

Author

Piedrafita, David, primary, Proudfoot, Lorna, additional, Nikolaev, Andrei V., additional, Xu, Damo, additional, Sands, William, additional, Feng, Gui-Jie, additional, Thomas, Elaine, additional, Brewer, James, additional, Ferguson, Michael A. J., additional, Alexander, James, additional, and Liew, Foo Y., additional

Published
1999
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20. Lipopolysaccharide-Induced M2 to M1 Macrophage Transformation for IL-12p70 Production Is Blocked by Candida albicans Mediated Up-Regulation of EBI3 Expression

Author

Zheng, Xing-Feng, Hong, Yu-Xiao, Feng, Gui-Jie, Zhang, Gao-Feng, Rogers, Helen, Lewis, Michael A. O., Williams, David W., Xia, Zhao-Fan, Song, Bing, and Wei, Xiao-Qing

Subjects
CANDIDA albicans, MACROPHAGES, FUNGAL gene expression, GENETIC regulation in plants, IMMUNOLOGICAL tolerance, LIPOPOLYSACCHARIDES, MONOCYTES, CYTOKINES
Abstract

Macrophages are heterogeneous cell populations that are present in all tissues. Macrophages can be divided into classically activated inflammatory macrophages (M1) and alternatively activated anti-inflammatory macrophages (M2). It has been generally accepted that M1 macrophages are polarised in an inflammatory environment to produce pro-inflammatory cytokines, whilst M2 macrophages are involved in anti-inflammation and aid tissue repair in wound healing. Bacterial endotoxin (lipopolysaccharide; LPS) is a potent factor in infection, which induces M1 macrophages resulting in higher levels of iNOS, TNFα and IL-12p70 which dictate inflammatory T cell responses. M2 macrophages can be transformed into M1 macrophages following LPS stimulation to promote inflammation. Candida albicans is a commensal fungal microorganism, which has been suggested to induce immune tolerance; however, the mechanism of C. albicans-induced immune tolerance has not been investigated in detail. IL-35 is a recently identified anti-inflammatory cytokine which is a heterodimeric protein consisting of the Epstein-Barr virus-induced gene 3 (EBI3) and IL-12p35. IL-35 shares the protein subunit p35, with IL-12p70. IL-12p70 is the most potent cytokine to induce Th1 responses during inflammation. In this study, we demonstrate that heat-killed C. albicans (HKC) strongly suppressed LPS-induced IL-12p70 production in M2 macrophages. Candida albicans induced a high level of EBI3 expression in M2 macrophages, which served as a mechanism for IL-12p70 suppression by competitive binding of the common protein subunit (p35) of IL-35 and IL-12p70. To demonstrate that EBI3 expression had the ability to block IL-12p70 production intracellularly, a Chinese Hamster Ovary (CHO) cell line with biscistronic expression of IL-12p40 and p35 was constructed, followed by ectopic over-expression of EBI3. The over-expression of EBI3 in the IL-12p70 producing cell line effectively suppressed IL-12p70 production. IL-35 secretion was also detected in the cell line, with suppressed IL-12p70 production by immune-precipitation Western blotting. However, this secretion was not evident in M2 macrophages following stimulation by HKC. This can be explained by the constitutive expression of IL-35 receptors (gp130 and IL-12Rβ2) in M2 macrophages for cytokine consumption. Our results have indicated that C. albicans can suppress host inflammatory responses in mucosal skin by suppressing LPS-induced IL-12p70 production. Lower IL-12p70 production may avoid an unnecessary Th1 response in order to retain immune tolerance, which may be one of the mechanisms by which C. albicans achieves a successful commensal lifestyle without having a detrimental effect on the host’s health. [ABSTRACT FROM AUTHOR]

Published
2013
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21. Role of Bacterial Lipopolysaccharide in Enhancing Host Immune Response to Candida albicans.

Author

Rogers, Helen, Williams, David W., Feng, Gui-Jie, Lewis, Michael A. O., and Xiao-Qing Wei

Subjects
LIPOPOLYSACCHARIDES, MONOCYTES, LEUCOCYTES, IMMUNE response, PROKARYOTES, IMMUNOLOGY
Abstract

Human infections involving yeast of the genus Candida often occur in the presence of bacteria, and, as such, it is important to understand how these bacteria influence innate host immunity towards Candida. Dectin-1 is a cell receptor of macrophages for Candida albicans recognition. The aim of this study was to examine dectin-1 expression by monocytes after stimulation with bacterial lipopolysaccharide (LPS), followed by heat-killed C. albicans (HKC). Freshly isolated human peripheral blood monocytes (PBMCs) and human monocytes cell line (THP-1) cells expressed low levels of dectin-1. Stimulation with LPS and GM-CSF/IL-4 was found to increase dectin-1 expression in both CD14+ human PBMC and THP-1 cells. Enhanced dectin-1 expression resulted in increased phagocytosis of Candida. When THP-1 cells were challenged only with HKC, detectable levels of IL-23 were not evident. However, challenge by LPS followed by varying concentrations of HKC resulted in increased IL-23 expression by THP-1 cells in HKC dose-dependent manner. Increased expression of IL-17 by PBMC also occurred after stimulation with Candida and LPS. In conclusion, bacterial LPS induces an enhanced immune response to Candida by immune cells, and this occurs through increasing dectin-1 expression. [ABSTRACT FROM AUTHOR]

Published
2013
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22. Engineering a V2 Vasopressin Receptor Agonist- and Regulator of G-Protein-Signaling-Sensitive G Protein

Author

Feng, Gui-Jie, Cavalli, Antonella, and Milligan, Graeme

Subjects
*VASOPRESSIN, *GUANOSINE triphosphatase, *G proteins
Abstract

It is extremely difficult to detect guanine nucleotide exchange or hydrolysis stimulated by receptors which couple to Gsα. Furthermore, Gsα is largely resistant to the GTPase-activating properties of RGS proteins. Coexpression of the vasopressin V2 receptor with a series of chimeric G protein α subunits in which the C-terminal 6–12 amino acids of Gi1α were replaced with the equivalent sequence of Gsα allowed robust vasopressin-stimulated [35S]GTPγS binding. Vasopressin did not stimulate the GTPase activity of fusion proteins between the V2 receptor and either Gsα or Gi1α. However, it produced a concentration-dependent stimulation of Vmax for a V2 receptor-Gi1α/Gs6α fusion protein. This construct bound [3H]vasopressin with high affinity and this was competed by other ligands with rank order anticipated for the V2 receptor. RGS1 enhanced vasopressin stimulation of V2 receptor-Gi1α/Gs6α in a concentration-dependent manner. RGS-GAIP was substantially less potent. Enzyme kinetic analysis demonstrated that RGS1 increased both Vmax of the GTPase activity and the observed Km for GTP, consistent with RGS1 accelerating the rate of GTP hydrolysis of the chimeric G protein, whereas the agonist vasopressin accelerates guanine nucleotide exchange. This approach provides a sensitive assay for V2 receptor agonist ligands and may be amenable to many other Gsα-coupled receptors. [Copyright &y& Elsevier]

Published
2002
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24. Regulation of inducible nitric oxide synthase

Author

Feng, Gui-jie and Feng, Gui-jie

Abstract

One of the major functions of macrophages is to provide the body with an immediate innate defence against pathogenic micro-organisms. This defence is largely dependent on the generation of nitric oxide (NO) and superoxide by macrophages which leads to the killing of these pathogens. NO is also important in many other biological functions. It is derived from L-arginine and molecular oxygen by the enzyme NO synthase (NOS). There are a number of classes of NOS including neuronal NOS (nNOS), endothelial NOS (eNOS) and cytokine-inducible NOS (iNOS). iNOS is upregulated and activated by several immunological stimuli including interferon gamma (IFN-gamma; lipopolysaccharide (LPS) and tumor necrosis factor-alpha (TNF-alpha), such activation leads to the production of large quantities of NO which can be cytotoxic. The potential toxicity of NO makes it important to understand the regulation of its production. In the study presented here, J774 cells, a murine macrophage cell line, were used as a model system for studying the induction and regulation of iNOS activation. These cells and murine peritoneal macrophages produce large amounts of NO in response to the T cell-derived lymphokine, IFN- and/or the potent macrophage activator, LPS in a dose-dependent manner. Northern and Western blotting revealed the process of induction of NO synthesis in J774 cells: The maximal induction of NO synthase mRNA was at 4 h while the maximum levels of NOS protein was observed at 8 to 12 h after treatment with IFN-gamma and LPS. IFN-? LPS-induced NO2- accumulation was abolished in the culture supernatants of samples that were pre-treated with cycloheximide. These suggest that iNOS is regulated transcriptionally in a manner that requires de novo protein synthesis. Protein phosphorylation plays a crucial role in regulating the signal transduction cascades leading to many biological responses in eukaryotes. Signals that are reversibly controlled by protein phosphorylation are modulated not only by

26. Isolation of Murine Hematopoietic Stem Cells.

Author

Menendez-Gonzalez JB, Saleh L, Feng GJ, and Rodrigues NP

Subjects
Animals, Bone Marrow Transplantation, Hematopoietic Stem Cell Transplantation, Humans, Mice, Cell Separation methods, Flow Cytometry methods, Hematopoietic Stem Cells cytology
Abstract

Bone marrow resident hematopoietic stem cells (HSCs) are responsible for the lifetime generation of the wide profusion of blood and immune cell types found in the body. In addition, therapeutically, in the context of bone marrow transplantation, HSCs have been successfully deployed to restore normal blood-forming capacity in patients being treated with high-dose chemotherapy for hematologic malignancies. The known ability of bone marrow transplantation to either restore or reset the immune system and to engender immune tolerance has suggested that HSCs may be applied therapeutically for a wider range of clinical conditions, including immunological/autoimmune disorders and allogeneic organ transplantation. Herein, we describe a flow-cytometry-based method to isolate mouse HSCs for continued experimental investigation into such therapeutic uses.

Published
2019
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