Protective responses against pathogens require a rapid mobilization of resting neutrophils and the timely removal of activated ones. Neutrophils are exceptionally short-lived leukocytes, yet it remains unclear whether the lifespan of pathogen-engaged neutrophils is regulated differently from that in the circulating steady-state pool. Here, we have found that under homeostatic conditions, the mRNA-destabilizing protein tristetraprolin (TTP) regulates apoptosis and the numbers of activated infiltrating murine neutrophils but not neutrophil cellularity. Activated TTP-deficient neutrophils exhibited decreased apoptosis and enhanced accumulation at the infection site. In the context of myeloid-specific deletion of
Florian Ebner, Vitaly Sedlyarov, Saren Tasciyan, Masa Ivin, Franz Kratochvill, Nina Gratz, Lukas Kenner, Andreas Villunger, Michael Sixt, Pavel Kovarik
Ajitha Thanabalasuriar, Bas G.J. Surewaard, Michelle E. Willson, Arpan S. Neupane, Charles K. Stover, Paul Warrener, George Wilson, Ashley E. Keller, Bret R. Sellman, Antonio DiGiandomenico, Paul Kubes
Type I IFNs promote cellular responses to viruses, and IFN receptor (IFNAR) signaling regulates the responses of endothelial cells of the blood-brain barrier (BBB) during neurotropic viral infection. However, the role of astrocytes in innate immune responses of the BBB during viral infection of the CNS remains to be fully elucidated. Here, we have demonstrated that type I IFNAR signaling in astrocytes regulates BBB permeability and protects the cerebellum from infection and immunopathology. Mice with astrocyte-specific loss of IFNAR signaling showed decreased survival after West Nile virus infection. Accelerated mortality was not due to expanded viral tropism or increased replication. Rather, viral entry increased specifically in the hindbrain of IFNAR-deficient mice, suggesting that IFNAR signaling critically regulates BBB permeability in this brain region. Pattern recognition receptors and IFN-stimulated genes had higher basal and IFN-induced expression in human and mouse cerebellar astrocytes than did cerebral cortical astrocytes, suggesting that IFNAR signaling has brain region–specific roles in CNS immune responses. Taken together, our data identify cerebellar astrocytes as key responders to viral infection and highlight the existence of distinct innate immune programs in astrocytes from evolutionarily disparate regions of the CNS.
Brian P. Daniels, Harsha Jujjavarapu, Douglas M. Durrant, Jessica L. Williams, Richard R. Green, James P. White, Helen M. Lazear, Michael Gale Jr., Michael S. Diamond, Robyn S. Klein
Cerebral malaria is characterized by cytoadhesion of
Julio Gallego-Delgado, Upal Basu-Roy, Maureen Ty, Matilde Alique, Cristina Fernandez-Arias, Alexandru Movila, Pollyanna Gomes, Ada Weinstock, Wenyue Xu, Innocent Edagha, Samuel C. Wassmer, Thomas Walther, Marta Ruiz-Ortega, Ana Rodriguez
Federico Iovino, Disa L. Hammarlöf, Genevieve Garriss, Sarah Brovall, Priyanka Nannapaneni, Birgitta Henriques-Normark
Patients with diabetic ketoacidosis (DKA) are uniquely predisposed to mucormycosis, an angioinvasive fungal infection with high mortality. Previously, we demonstrated that
Teclegiorgis Gebremariam, Lin Lin, Mingfu Liu, Dimitrios P. Kontoyiannis, Samuel French, John E. Edwards Jr., Scott G. Filler, Ashraf S. Ibrahim
IFN-γ is a critical mediator of host defense against
Andreas Kupz, Ulrike Zedler, Manuela Stäber, Carolina Perdomo, Anca Dorhoi, Roland Brosch, Stefan H.E. Kaufmann
In extrapulmonary tuberculosis, the most common site of infection is within the lymphatic system, and there is growing recognition that lymphatic endothelial cells (LECs) are involved in immune function. Here, we identified LECs, which line the lymphatic vessels, as a niche for
Thomas R. Lerner, Cristiane de Souza Carvalho-Wodarz, Urska Repnik, Matthew R.G. Russell, Sophie Borel, Collin R. Diedrich, Manfred Rohde, Helen Wainwright, Lucy M. Collinson, Robert J. Wilkinson, Gareth Griffiths, Maximiliano G. Gutierrez
The identification of the molecular events responsible for strain emergence, enhanced virulence, and epidemicity has been a long-pursued goal in infectious diseases research. A recent analysis of 3,615 genomes of serotype M1 group A
Luchang Zhu, Randall J. Olsen, Waleed Nasser, Stephen B. Beres, Jaana Vuopio, Karl G. Kristinsson, Magnus Gottfredsson, Adeline R. Porter, Frank R. DeLeo, James M. Musser
Toidi Adekambi, Chris C. Ibegbu, Stephanie Cagle, Ameeta S. Kalokhe, Yun F. Wang, Yijuan Hu, Cheryl L. Day, Susan M. Ray, Jyothi Rengarajan
Respiratory syncytial virus (RSV) is the most common cause of serious viral bronchiolitis in infants, young children, and the elderly. Currently, there is not an FDA-approved vaccine available for RSV, though the mAb palivizumab is licensed to reduce the incidence of RSV disease in premature or at-risk infants. The palivizumab epitope is a well-characterized, approximately 24-aa helix-loop-helix structure on the RSV fusion (F) protein (F254–277). Here, we genetically inserted this epitope and multiple site variants of this epitope within a versatile woodchuck hepadnavirus core–based virus-like particle (WHcAg-VLP) to generate hybrid VLPs that each bears 240 copies of the RSV epitope in a highly immunogenic arrayed format. A challenge of such an epitope-focused approach is that to be effective, the conformational F254–277 epitope must elicit antibodies that recognize the intact virus. A number of hybrid VLPs containing RSV F254–277 were recognized by palivizumab in vitro and elicited high-titer and protective neutralizing antibody in rodents. Together, the results from this proof-of-principle study suggest that the WHcAg-VLP technology may be an applicable approach to eliciting a response to other structural epitopes.
Jeanne H. Schickli, David C. Whitacre, Roderick S. Tang, Jasmine Kaur, Heather Lawlor, Cory J. Peters, Joyce E. Jones, Darrell L. Peterson, Michael P. McCarthy, Gary Van Nest, David R. Milich
Chronic wasting disease (CWD) is a fatal prion disease of North American deer and elk and poses an unclear risk for transmission to humans. Human exposure to CWD occurs through hunting activities and consumption of venison from prion-infected animals. Although the amino acid residues of the prion protein (PrP) that prevent or permit human CWD infection are unknown, NMR-based structural studies suggest that the β2-α2 loop (residues 165–175) may impact species barriers. Here we sought to define PrP sequence determinants that affect CWD transmission to humans. We engineered transgenic mice that express human PrP with four amino acid substitutions that result in expression of PrP with a β2-α2 loop (residues 165–175) that exactly matches that of elk PrP. Compared with transgenic mice expressing unaltered human PrP, mice expressing the human-elk chimeric PrP were highly susceptible to elk and deer CWD prions but were concurrently less susceptible to human Creutzfeldt-Jakob disease prions. A systematic in vitro survey of amino acid differences between humans and cervids identified two additional residues that impacted CWD conversion of human PrP. This work identifies amino acids that constitute a substantial structural barrier for CWD transmission to humans and helps illuminate the molecular requirements for cross-species prion transmission.
Timothy D. Kurt, Lin Jiang, Natalia Fernández-Borges, Cyrus Bett, Jun Liu, Tom Yang, Terry R. Spraker, Joaquín Castilla, David Eisenberg, Qingzhong Kong, Christina J. Sigurdson
While 30%–70% of RSV-infected infants develop bronchiolitis, 2% require hospitalization. It is not clear why disease severity differs among healthy, full-term infants; however, virus titers, inflammation, and Th2 bias are proposed explanations. While TLR4 is associated with these disease phenotypes, the role of this receptor in respiratory syncytial virus (RSV) pathogenesis is controversial. Here, we evaluated the interaction between TLR4 and environmental factors in RSV disease and defined the immune mediators associated with severe illness. Two independent populations of infants with RSV bronchiolitis revealed that the severity of RSV infection is determined by the
Mauricio T. Caballero, M. Elina Serra, Patricio L. Acosta, Jacqui Marzec, Luz Gibbons, Maximiliano Salim, Andrea Rodriguez, Andrea Reynaldi, Alejandro Garcia, Daniela Bado, Ursula J. Buchholz, Diego R. Hijano, Silvina Coviello, Dawn Newcomb, Miguel Bellabarba, Fausto M. Ferolla, Romina Libster, Ada Berenstein, Susana Siniawaski, Valeria Blumetti, Marcela Echavarria, Leonardo Pinto, Andrea Lawrence, M. Fabiana Ossorio, Arnoldo Grosman, Cecilia G. Mateu, Carola Bayle, Alejandra Dericco, Mariana Pellegrini, Ignacio Igarza, Horacio A. Repetto, Luciano Alva Grimaldi, Prathyusha Gudapati, Norberto R. Polack, Fernando Althabe, Min Shi, Fernando Ferrero, Eduardo Bergel, Renato T. Stein, R. Stokes Peebles, Mark Boothby, Steven R. Kleeberger, Fernando P. Polack
The phagocytosis of apoptotic cells and associated vesicles (efferocytosis) by DCs is an important mechanism for both self tolerance and host defense. Although some of the engulfment ligands involved in efferocytosis have been identified and studied in vitro, the contributions of these ligands in vivo remain ill defined. Here, we determined that during
Fanny Tzelepis, Mark Verway, Jamal Daoud, Joshua Gillard, Kimya Hassani-Ardakani, Jonathan Dunn, Jeffrey Downey, Marilena Elena Gentile, Joanna Jaworska, Anthony Michel Jean Sanchez, Yohann Nédélec, Hojatollah Vali, Maryam Tabrizian, Arnold Scott Kristof, Irah Luther King, Luis Bruno Barreiro, Maziar Divangahi
Ticks are notorious hematophagous ectoparasites and vectors of many deadly pathogens. As an effective vector, ticks must break the strong barrier provided by the skin of their host during feeding, and their saliva contains a complex mixture of bioactive molecules that paralyze host defenses. The receptor for advanced glycation end products (RAGE) mediates immune cell activation at inflammatory sites and is constitutively and highly expressed in skin. Here, we demonstrate that longistatin secreted with saliva of the tick
Anisuzzaman, Takeshi Hatta, Takeharu Miyoshi, Makoto Matsubayashi, M. Khyrul Islam, M. Abdul Alim, M. Abu Anas, M. Mehedi Hasan, Yasunobu Matsumoto, Yasuhiko Yamamoto, Hiroshi Yamamoto, Kozo Fujisaki, Naotoshi Tsuji
Many pathogens, including viruses, bacteria, and protozoan parasites, suppress cellular immune responses through activation of type I IFN signaling. Recent evidence suggests that immune suppression and susceptibility to the malaria parasite,
Ashraful Haque, Shannon E. Best, Marcela Montes de Oca, Kylie R. James, Anne Ammerdorffer, Chelsea L. Edwards, Fabian de Labastida Rivera, Fiona H. Amante, Patrick T. Bunn, Meru Sheel, Ismail Sebina, Motoko Koyama, Antiopi Varelias, Paul J. Hertzog, Ulrich Kalinke, Sin Yee Gun, Laurent Rénia, Christiane Ruedl, Kelli P.A. MacDonald, Geoffrey R. Hill, Christian R. Engwerda
Lyme disease, caused by the spirochete
Kenneth K.C. Bramwell, Ying Ma, John H. Weis, Xinjian Chen, James F. Zachary, Cory Teuscher, Janis J. Weis
Michail S. Lionakis, Muthulekha Swamydas, Brett G. Fischer, Theo S. Plantinga, Melissa D. Johnson, Martin Jaeger, Nathaniel M. Green, Andrius Masedunskas, Roberto Weigert, Constantinos Mikelis, Wuzhou Wan, Chyi-Chia Richard Lee, Jean K. Lim, Aymeric Rivollier, John C. Yang, Greg M. Laird, Robert T. Wheeler, Barbara D. Alexander, John R. Perfect, Ji-Liang Gao, Bart-Jan Kullberg, Mihai G. Netea, Philip M. Murphy
Rotavirus-induced diarrhea is a life-threatening disease in immunocompromised individuals and in children in developing countries. We have developed a system for prophylaxis and therapy against rotavirus disease using transgenic rice expressing the neutralizing variable domain of a rotavirus-specific llama heavy-chain antibody fragment (MucoRice-ARP1). MucoRice-ARP1 was produced at high levels in rice seeds using an overexpression system and RNAi technology to suppress the production of major rice endogenous storage proteins. Orally administered MucoRice-ARP1 markedly decreased the viral load in immunocompetent and immunodeficient mice. The antibody retained in vitro neutralizing activity after long-term storage (>1 yr) and boiling and conferred protection in mice even after heat treatment at 94°C for 30 minutes. High-yield, water-soluble, and purification-free MucoRice-ARP1 thus forms the basis for orally administered prophylaxis and therapy against rotavirus infections.
Daisuke Tokuhara, Beatriz Álvarez, Mio Mejima, Tomoko Hiroiwa, Yuko Takahashi, Shiho Kurokawa, Masaharu Kuroda, Masaaki Oyama, Hiroko Kozuka-Hata, Tomonori Nochi, Hiroshi Sagara, Farah Aladin, Harold Marcotte, Leon G.J. Frenken, Miren Iturriza-Gómara, Hiroshi Kiyono, Lennart Hammarström, Yoshikazu Yuki
Vaccine development for the blood stages of malaria has focused on the induction of antibodies to parasite surface antigens, most of which are highly polymorphic. An alternate strategy has evolved from observations that low-density infections can induce antibody-independent immunity to different strains. To test this strategy, we treated parasitized red blood cells from the rodent parasite
Michael F. Good, Jennifer M. Reiman, I. Bibiana Rodriguez, Koichi Ito, Stephanie K. Yanow, Ibrahim M. El-Deeb, Michael R. Batzloff, Danielle I. Stanisic, Christian Engwerda, Terry Spithill, Stephen L. Hoffman, Moses Lee, Virginia McPhun
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