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1

Military defense strategies: An inspiration from game theoretic analysis of the immune defense  

Microsoft Academic Search

Based on our early studies on passive versus aggressive strategies, this paper proposes immune defense inspired game theoretic strategies for military defense. Similarities between the immune system and the military operations have been explored under a game theoretic framework and formulated as a min-max optimal control problem. This paper expands the early studies and offers detailed analysis of our predicted

Sharon Bewick; Jing Wu; William Hamel; Mingjun Zhang

2010-01-01

2

Body Defenses Immune System  

E-print Network

1 1 Body Defenses Immune System Part 2 2 Adaptive Immune Defenses When innate defenses have failed defenses respond to antigens Molecules the immune system recognizes as foreign to the body. Adaptive strongly to the body's own cells are eliminated in order to minimize an immune response against the body

Cochran-Stafira, D. Liane

3

Special issue on Avoidance, Resistance and Tolerance: Strategies in Host Defense Rethinking the role of immunity  

E-print Network

highlight growing evi- dence that the innate immune system with its host- specific antimicrobial peptides. A significant leap forward in scientific understanding of the natural forces and risk factors affecting to form natural symbiotic relationships with bacteria and eukaryotes [19­21] but also possess most

4

Innate Immune Defense Through RNA Interference  

NSDL National Science Digital Library

RNA interference (RNAi, also known as RNA silencing) has recently emerged as a fundamental and widespread regulator of gene expression. New developments in this field implicate RNAi in the innate immune response to infection in plants and animals. Evidence from plants, tissue culture cells, and Caenorhabditis elegans–based systems previously suggested that RNAi plays a role in the defense against viral infection, but definitive evidence using viruses and whole animals has been lacking. Two recent reports now show that both Drosophila embryos and adult flies mount a substantial innate immune response to insect viruses that requires the RNAi machinery. This innate response is distinct from known bacterial and fungal defense systems provided by the Toll and immune deficiency (Imd) pathways, thus defining a previously unrecognized strategy to fight viral infection. Whether RNAi, aside from its function in counteracting viruses, is also used to fight bacterial infection remained enigmatic. New evidence, however, now shows that in Arabidopsis, the bacterial component, flagellin, induces the expression of a specific microRNA, which in turn leads to the down-regulation of the signaling pathways that are implicated in disease susceptibility. This down-regulation then increases the plant's resistance to infection. Whether RNAi mechanisms also exist for combating bacterial diseases in animals remains an intriguing question for future studies.

Jorg H. Fritz (University of Toronto; Department of Immunology REV)

2006-06-13

5

Testicular defense systems: immune privilege and innate immunity  

PubMed Central

The mammalian testis possesses a special immunological environment because of its properties of remarkable immune privilege and effective local innate immunity. Testicular immune privilege protects immunogenic germ cells from systemic immune attack, and local innate immunity is important in preventing testicular microbial infections. The breakdown of local testicular immune homeostasis may lead to orchitis, an etiological factor of male infertility. The mechanisms underlying testicular immune privilege have been investigated for a long time. Increasing evidence shows that both a local immunosuppressive milieu and systemic immune tolerance are involved in maintaining testicular immune privilege status. The mechanisms underlying testicular innate immunity are emerging based on the investigation of the pattern recognition receptor-mediated innate immune response in testicular cells. This review summarizes our current understanding of testicular defense mechanisms and identifies topics that merit further investigation. PMID:24954222

Zhao, Shutao; Zhu, Weiwei; Xue, Shepu; Han, Daishu

2014-01-01

6

Improving immunization strategies  

NASA Astrophysics Data System (ADS)

We introduce an immunization method where the percentage of required vaccinations for immunity are close to the optimal value of a targeted immunization scheme of highest degree nodes. Our strategy retains the advantage of being purely local, without the need for knowledge on the global network structure or identification of the highest degree nodes. The method consists of selecting a random node and asking for a neighbor that has more links than himself or more than a given threshold and immunizing him. We compare this method to other efficient strategies on three real social networks and on a scale-free network model and find it to be significantly more effective.

Gallos, Lazaros K.; Liljeros, Fredrik; Argyrakis, Panos; Bunde, Armin; Havlin, Shlomo

2007-04-01

7

Defense display strategy and roadmaps  

NASA Astrophysics Data System (ADS)

The Department of Defense (DoD) is developing a new strategy for displays. The new displays science and technology roadmap will incorporate urgent warfighter needs as well as investment opportunities where military advantage is foreseen. Thrusts now ending include the High Definition System (HDS) program and related initiatives, like flexible displays, at the Defense Advanced Research Projects Agency (DARPA). Continuing thrusts include a variety of Serviceled programs to develop micro-displays for virtual image helmet-/rifle-mounted systems for pilots and soldiers, novel displays, materials, and basic research. New thrusts are being formulated for ultra-resolution, true 3D, and intelligent displays (integration of computers and communication functions into screens). The new strategy is Service-led.

Hopper, Darrel G.

2002-08-01

8

Evolving meningococcal immunization strategies.  

PubMed

Meningococcal disease is a major public health problem and immunization is considered the best strategy for prevention. The introduction of meningococcal C conjugate immunization schedules that targeted adolescents, with catch-up programs in several European countries, Australia and Canada proved to be highly effective, with dramatic reduction in the incidence of serogroup C disease, not only in vaccinated, but also in unvaccinated individuals. Meningococcal quadrivalent (A, C, W, Y) conjugate vaccines are now licensed and are being used in adolescent programs in North America and to control serogroup W disease in South America. In the African meningitis belt, a mass immunization campaign against serogroup A disease using a meningococcal A conjugate vaccine is now controlling the devastating epidemics of meningococcal disease. After introducing new immunization programs, it is of importance to maintain enhanced surveillance for a better understanding of the changing nature of disease epidemiology. This information is crucial for identifying optimal immunization policies. PMID:25494168

Sáfadi, Marco Aurélio; Bettinger, Julie A; Maturana, Gabriela Moreno; Enwere, Godwin; Borrow, Ray

2014-12-10

9

Defense strategies used by two sympatric vineyard moth pests.  

PubMed

Natural enemies including parasitoids are the major biological cause of mortality among phytophagous insects. In response to parasitism, these insects have evolved a set of defenses to protect themselves, including behavioral, morphological, physiological and immunological barriers. According to life history theory, resources are partitioned to various functions including defense, implying trade-offs among defense mechanisms. In this study we characterized the relative investment in behavioral, physical and immunological defense systems in two sympatric species of Tortricidae (Eupoecilia ambiguella, Lobesia botrana) which are important grapevine moth pests. We also estimated the parasitism by parasitoids in natural populations of both species, to infer the relative success of the investment strategies used by each moth. We demonstrated that larvae invest differently in defense systems according to the species. Relative to L. botrana, E. ambiguella larvae invested more into morphological defenses and less into behavioral defenses, and exhibited lower basal levels of immune defense but strongly responded to immune challenge. L. botrana larvae in a natural population were more heavily parasitized by various parasitoid species than E. ambiguella, suggesting that the efficacy of defense strategies against parasitoids is not equal among species. These results have implications for understanding of regulation in communities, and in the development of biological control strategies for these two grapevine pests. PMID:24662468

Vogelweith, Fanny; Thiéry, Denis; Moret, Yannick; Colin, Eloïse; Motreuil, Sébastien; Moreau, Jérôme

2014-05-01

10

Immune defense mechanisms of the dental pulp.  

PubMed

Defense reactions of the dentin/pulp complex involve a variety of biological systems, in which the immune system plays a pivotal role. The knowledge of the organization and function of pulpal immunocompetent cells has been sparse, but in recent years a significant body of information of immune mechanisms in general has provided a footing for substantial new knowledge of the immune mechanisms of the dental pulp. The identification of pulpal dendritic cells (DCs) has generated research activities which have led to a concept of how an antigenic challenge may evoke a pulpal inflammatory response. Although DCs are not able to identify foreign antigens specifically, they provide necessary signals to activate T-lymphocytes which in turn will orchestrate other immunocompetent cells to mount the local immune defense of the dental pulp. The purpose of this review is to accent the organization and function of pulpal DCs and other tissue and cellular components and to provide a basis for how they may interact to instigate pulpal defense mechanisms. PMID:9603235

Jontell, M; Okiji, T; Dahlgren, U; Bergenholtz, G

1998-01-01

11

Chemical defense strategies of marine organisms.  

PubMed

The diverse habitats of the marine environment and the adaptation required to live either in the open water or attached to a substrate resulted in various defense strategies. This review covers different ways how organisms from the plankton can maintain a chemical defense as well as the dynamic chemical defense strategies of benthic organisms. It opens with a detailed discussion of recent studies of chemical defenses among organisms floating in the open water. These defenses include the production of toxins by harmful algal blooms as well as the rapid production of defensive metabolites from non-toxic precursors upon cell disruption. A comprehensive account of recent advances in the field of dynamic chemical defense strategies of benthic organisms is then presented. It includes the known examples of activated defense based on the enzymatic transformation of storage metabolites as well as induced chemical defense strategies. These strategies depend on the recognition of signals from an herbivore or pathogen, followed by the up-regulation of the biosynthesis of metabolites involved in the chemical defense. PMID:22160234

Pohnert, Georg

2004-01-01

12

Chemical Defense Strategies of Marine Organisms  

Microsoft Academic Search

The diverse habitats of the marine environment and the adaptation required to live either in the open water or attached to\\u000a a substrate resulted in various defense strategies. This review covers different ways how organisms from the plankton can\\u000a maintain a chemical defense as well as the dynamic chemical defense strategies of benthic organisms. It opens with a detailed\\u000a discussion

Georg Pohnert

13

Hyaluronan Breakdown Contributes to Immune Defense against Group A Streptococcus*  

E-print Network

Hyaluronan Breakdown Contributes to Immune Defense against Group A Streptococcus* Received, La Jolla, California 92093 Background: The role of hyaluronan catabolism in group A Streptococcus be a previously unrecognized mechanism for host defense. Group A Streptococcus (GAS) commonly infects human skin

Nizet, Victor

14

Plant innate immunity: an updated insight into defense mechanism.  

PubMed

Plants are invaded by an array of pathogens of which only a few succeed in causing disease. The attack by others is countered by a sophisticated immune system possessed by the plants. The plant immune system is broadly divided into two, viz. microbial-associated molecular-patterns-triggered immunity (MTI) and effector-triggered immunity (ETI). MTI confers basal resistance, while ETI confers durable resistance, often resulting in hypersensitive response. Plants also possess systemic acquired resistance (SAR), which provides long-term defense against a broad-spectrum of pathogens. Salicylic-acid-mediated systemic acquired immunity provokes the defense response throughout the plant system during pathogen infection at a particular site. Trans-generational immune priming allows the plant to heritably shield their progeny towards pathogens previously encountered. Plants circumvent the viral infection through RNA interference phenomena by utilizing small RNAs. This review summarizes the molecular mechanisms of plant immune system, and the latest breakthroughs reported in plant defense. We discuss the plant–pathogen interactions and integrated defense responses in the context of presenting an integral understanding in plant molecular immunity. PMID:23660678

Muthamilarasan, Mehanathan; Prasad, Manoj

2013-06-01

15

Pattern Recognition Receptors in Innate Immunity, Host Defense, and Immunopathology  

ERIC Educational Resources Information Center

Infection by pathogenic microbes initiates a set of complex interactions between the pathogen and the host mediated by pattern recognition receptors. Innate immune responses play direct roles in host defense during the early stages of infection, and they also exert a profound influence on the generation of the adaptive immune responses that ensue.…

Suresh, Rahul; Mosser, David M.

2013-01-01

16

Immunity and other defenses in pea aphids, Acyrthosiphon pisum  

E-print Network

(Acyrthosiphon pisum), we conducted the first extensive annotation of the immune and stress gene repertoire- 1 - Immunity and other defenses in pea aphids, Acyrthosiphon pisum N.M. Gerardo1,§ , B elements underlying responses to pathogens, parasites and stresses. At the center of pathogen

Paris-Sud XI, Université de

17

Strategies in Oral Immunization  

Microsoft Academic Search

Development of mucosal vaccine delivery system is an important area for improving public health. Oral vaccines have large\\u000a implications for rural and remote populations since the access to trained medical staff to administer vaccines by injection\\u000a is limited. New mucosal vaccine strategies are focused on development of non-replicating subunit vaccines, DNA, plant, and\\u000a other types of recombinant vaccines. The conjugation

Pavla Simerska; Peter Moyle; Colleen Olive; Istvan Toth

18

Innate Immune Evasion Strategies by Human Immunodeficiency Virus Type 1  

PubMed Central

Host immune components play both beneficial and pathogenic roles in human immunodeficiency virus type 1 (HIV-1) infection. During the initial stage of viral infection, a complex network of innate immune factors are activated. For instance, the immune cells express a number of inflammatory proteins including cytokines, chemokines, and antiviral restriction factors. These factors, specifically, interferons (IFNs) play a crucial role in antiviral defense system by modulating the downstream signaling events, by inducing maturation of dendritic cells (DCs), and by activation of macrophages, natural killer (NK) cells, and B and T cells. However, HIV-1 has evolved to utilize a number of strategies to overcome the antiviral effects of the host innate immune system. This review discusses the pathways and strategies utilized by HIV-1 to establish latent and persistent infection by defeating host's innate defense system. PMID:24052891

Guha, Debjani; Ayyavoo, Velpandi

2013-01-01

19

A Chromosome-based Evaluation Model for Computer Defense Immune Systems  

E-print Network

- 1 - A Chromosome-based Evaluation Model for Computer Defense Immune Systems Zejun Wu, Hongbin,hbdong}@whu.edu.cn rim@cs.adfa.edu.au Abstract- The Computer Defense Immune System (CDIS) is an artificial immune system on systems in which they were incorporated. 1 Introduction The Computer Defense Immune System (CDIS

McKay, Robert Ian

20

Phylogenetic escalation and decline of plant defense strategies  

E-print Network

Phylogenetic escalation and decline of plant defense strategies Anurag A. Agrawal* and Mark the fact that most milkweed herbivores are specialists and have adaptations to cope with each defense (4, 5 ability (a measure of tolerance) trade off as alternative defensive strategies to cope with herbivores (16

Agrawal, Anurag

21

A recent perspective on alcohol, immunity and host defense  

PubMed Central

Overview Multiple line of clinical and experimental evidence demonstrates that both acute, moderate and chronic, excessive alcohol use result in various abnormalities in the functions of the immune system. Altered inflammatory cell and adaptive immune responses in turn result in increased incidence and poor outcome of infections and other organ effects after alcohol use. This review article summarizes recent findings relevant to immunomodulation by alcohol and its consequences on host defense against microbial pathogens and tissue injury. PMID:19053973

Szabo, Gyongyi; Mandrekar, Pranoti

2013-01-01

22

Trained immunity: a memory for innate host defense.  

PubMed

Immune responses in vertebrates are classically divided into innate and adaptive, with only the latter being able to build up immunological memory. However, although lacking adaptive immune responses, plants and invertebrates are protected against reinfection with pathogens, and invertebrates even display transplant rejection. In mammals, past "forgotten" studies demonstrate cross-protection between infections independently of T and B cells, and more recently memory properties for NK cells and macrophages, prototypical cells of innate immunity, have been described. We now posit that mammalian innate immunity also exhibits an immunological memory of past insults, for which we propose the term "trained immunity." Understanding trained immunity will revolutionize our view of host defense and immunological memory, and could lead to defining a new class of vaccines and immunotherapies. PMID:21575907

Netea, Mihai G; Quintin, Jessica; van der Meer, Jos W M

2011-05-19

23

Immune Building Technology and Bioterrorism Defense  

NSDL National Science Digital Library

In the wake of the 2001 anthrax scare, a research project at Pennsylvania State University has garnered significant attention. This paper introduces immune buildings, which have advanced ventilation and air filtration systems that can mitigate the danger caused by airborne pathogens. Experimental results from the project are also presented.

Bahnfleth, William P. (William Parry), 1957-; Kowalski, Wladyslaw J.

2008-01-04

24

Immune defense and biological responses induced by toxics in Annelida  

Microsoft Academic Search

The phylum Annelida comprises primitive coelomates that possess specially developed cellular immunity against pathogens. Active phagocytosis by coelomocytes occurs in the struggle against bacteria in Polychaeta and Oligochaeta. Encapsulation plays an important role in defense against parasites, and experimental studies have demon- strated that cooperation between different coelomocyte populations occurs in this process. Spontaneous cytotoxicity of coelomocytes against xenogenic or

André Dhainaut; Patrick Scaps

2001-01-01

25

Immunity and defense in pea aphids, Acyrthosiphon pisum  

Technology Transfer Automated Retrieval System (TEKTRAN)

Recent genomic analyses of arthropod defense mechanisms suggest conservation of key elements underlying responses to pathogens, parasites, and stresses. At the center of pathogen-induced immune response are signaling pathways triggered by the recognition of fungal, bacterial, and viral signatures. T...

26

T Cell–Mediated Host Immune Defenses in the Lung  

PubMed Central

Evidence has increasingly shown that the lungs are a major site of immune regulation. A robust and highly regulated immune response in the lung protects the host from pathogen infection, whereas an inefficient or deleterious response can lead to various pulmonary diseases. Many cell types, such as epithelial cells, dendritic cells, macrophages, neutrophils, eosinophils, and B and T lymphocytes, contribute to lung immunity. This review focuses on the recent advances in understanding how T lymphocytes mediate pulmonary host defenses against bacterial, viral, and fungal pathogens. PMID:23516986

Chen, Kong; Kolls, Jay K.

2014-01-01

27

Immunity and other defenses in pea aphids, Acyrthosiphon pisum  

PubMed Central

Background Recent genomic analyses of arthropod defense mechanisms suggest conservation of key elements underlying responses to pathogens, parasites and stresses. At the center of pathogen-induced immune responses are signaling pathways triggered by the recognition of fungal, bacterial and viral signatures. These pathways result in the production of response molecules, such as antimicrobial peptides and lysozymes, which degrade or destroy invaders. Using the recently sequenced genome of the pea aphid (Acyrthosiphon pisum), we conducted the first extensive annotation of the immune and stress gene repertoire of a hemipterous insect, which is phylogenetically distantly related to previously characterized insects models. Results Strikingly, pea aphids appear to be missing genes present in insect genomes characterized to date and thought critical for recognition, signaling and killing of microbes. In line with results of gene annotation, experimental analyses designed to characterize immune response through the isolation of RNA transcripts and proteins from immune-challenged pea aphids uncovered few immune-related products. Gene expression studies, however, indicated some expression of immune and stress-related genes. Conclusions The absence of genes suspected to be essential for the insect immune response suggests that the traditional view of insect immunity may not be as broadly applicable as once thought. The limitations of the aphid immune system may be representative of a broad range of insects, or may be aphid specific. We suggest that several aspects of the aphid life style, such as their association with microbial symbionts, could facilitate survival without strong immune protection. PMID:20178569

2010-01-01

28

Stealth Proteins: In Silico Identification of a Novel Protein Family Rendering Bacterial Pathogens Invisible to Host Immune Defense  

Microsoft Academic Search

There are a variety of bacterial defense strategies to survive in a hostile environment. Generation of extracellular polysaccharides has proved to be a simple but effective strategy against the host's innate immune system. A comparative genomics approach led us to identify a new protein family termed Stealth, most likely involved in the synthesis of extracellular polysaccharides. This protein family is

Peter Sperisen; Christoph D. Schmid; Philipp Bucher; Olav Zilian

2005-01-01

29

Contrasting adaptive immune defenses and blood parasite prevalence in closely related Passer sparrows  

Microsoft Academic Search

Immune system components differ in their functions and costs, and immune defense profiles are likely to vary among species with differing ecologies. We compared adaptive immune defenses in two closely related species that have contrasting inflammatory immune responses, the widespread and abundant house sparrow (Passer domesticus) and the less abundant tree sparrow (Passer montanus). We found that the house sparrow,

Kelly A. Lee; Lynn B. Martin II; Dennis Hasselquist; Robert E. Ricklefs; Martin Wikelski

2006-01-01

30

Optimizing Defense Strategies for Complex MultiState Systems  

Microsoft Academic Search

This chapter presents a generalized model of damage caused to a complex multi-state series-parallel system by intentional attacks. The model takes into account a defense strategy that presumes both separation and protection of system elements, and also deployment of false targets. Protection importance indices are introduced that can be used for tracing bottlenecks in defense strategy, and for identifying the

J. M. P Cardoso; P. C Diniz

31

Dynamical immunization strategy for seasonal epidemics  

NASA Astrophysics Data System (ADS)

The topic of finding an effective strategy to halt virus in a complex network is of current interest. We propose an immunization strategy for seasonal epidemics that occur periodically. Based on the local information of the infection status from the previous epidemic season, the selection of vaccinated nodes is optimized gradually. The evolution of vaccinated nodes during iterations demonstrates that the immunization tends to locate in both global hubs and local hubs. We analyze the epidemic prevalence using a heterogeneous mean-field method, and we present numerical simulations of our model. This immunization performs better than some other previously known strategies. Our work highlights an alternative direction in immunization for seasonal epidemics.

Yan, Shu; Tang, Shaoting; Pei, Sen; Jiang, Shijin; Zheng, Zhiming

2014-08-01

32

Thermoregulatory strategy may shape immune investment in Drosophila melanogaster.  

PubMed

As temperatures change, insects alter the amount of melanin in their cuticle to improve thermoregulation. However, melanin is also central to insect immunity, suggesting that thermoregulatory strategy may indirectly impact immune defense by altering the abundance of melanin pathway components (a hypothesis we refer to as thermoregulatory-dependent immune investment). This may be the case in the cricket Allonemobius socius, where warm environments (both seasonal and geographical) produced crickets with lighter cuticles and increased pathogen susceptibility. Unfortunately, the potential for thermoregulatory strategy to influence insect immunity has not been widely explored. Here we address the relationships between temperature, thermoregulatory strategy and immunity in the fruit fly Drosophila melanogaster. To this end, flies from two separate Canadian populations were reared in either a summer- or autumn-like environment. Shortly after adult eclosion, flies were moved to a common environment where their cuticle color and susceptibility to a bacterial pathogen (Pseudomonas aeruginosa) were measured. As with A. socius, individuals from summer-like environments exhibited lighter cuticles and increased pathogen susceptibility, suggesting that the thermoregulatory-immunity relationship is evolutionarily conserved across the hemimetabolous and holometabolous clades. If global temperatures continue to rise as expected, then thermoregulation might play an important role in host infection and mortality rates in systems that provide critical ecosystem services (e.g. pollination), or influence the prevalence of insect-vectored disease (e.g. malaria). PMID:25147243

Kutch, Ian C; Sevgili, Hasan; Wittman, Tyler; Fedorka, Kenneth M

2014-10-15

33

Comparison of immunization strategies in geographical networks  

NASA Astrophysics Data System (ADS)

The epidemic spread and immunizations in geographically embedded scale-free (SF) and Watts-Strogatz (WS) networks are numerically investigated. We make a realistic assumption that it takes time which we call the detection time, for a vertex to be identified as infected, and implement two different immunization strategies: one is based on connection neighbors (CN) of the infected vertex with the exact information of the network structure utilized and the other is based on spatial neighbors (SN) with only geographical distances taken into account. We find that the decrease of the detection time is crucial for a successful immunization in general. Simulation results show that for both SF networks and WS networks, the SN strategy always performs better than the CN strategy, especially for more heterogeneous SF networks at long detection time. The observation is verified by checking the number of the infected nodes being immunized. We found that in geographical space, the distance preferences in the network construction process and the geographically decaying infection rate are key factors that make the SN immunization strategy outperforms the CN strategy. It indicates that even in the absence of the full knowledge of network connectivity we can still stop the epidemic spread efficiently only by using geographical information as in the SN strategy, which may have potential applications for preventing the real epidemic spread.

Wang, Bing; Aihara, Kazuyuki; Kim, Beom Jun

2009-10-01

34

Ontogeny of innate and adaptive immune defense components in free-living tree swallows, Tachycineta bicolor.  

PubMed

Little is known about the development of immune function in wild animals. We investigated the ontogeny of immune defense in a free-living bird, the tree swallow. We assessed total and differential leukocyte counts, natural antibodies, complement activity, in vivo skin swelling response, and in vitro lymphocyte proliferation and compared the levels of development between nestlings and young adults. We also assessed whether body condition explained variation in these immune components. We found some support for the prediction that innate defenses, which do not need to generate a broad repertoire of specific receptors, would reach adult levels earlier than adaptive defenses. In contrast, we found limited support for the prediction that adaptive defenses, which are thought to be more costly to develop, would be more related to body condition than innate defenses. We discuss our findings in the context of other studies on the ontogeny of immune function. PMID:18848578

Palacios, Maria G; Cunnick, Joan E; Vleck, David; Vleck, Carol M

2009-04-01

35

Chemical defense of an exotic coral as invasion strategy  

Microsoft Academic Search

The invasion success of exotic species has been frequently correlated to abiotic and biotic features of the receptor region and to the biological aspects of the invasive organism. There is, however, no information about defensive chemicals found in invasive species as strategy that could promote or facilitate an invasion in a marine environment. We conducted experimental field assays to verify

Bruno G. Lages; Beatriz G. Fleury; Carlos E. L. Ferreira; Renato C. Pereira

2006-01-01

36

Ecological immunology in a fluctuating environment: an integrative analysis of tree swallow nestling immune defense  

PubMed Central

Evolutionary ecologists have long been interested by the link between different immune defenses and fitness. Given the importance of a proper immune defense for survival, it is important to understand how its numerous components are affected by environmental heterogeneity. Previous studies targeting this question have rarely considered more than two immune markers. In this study, we measured seven immune markers (response to phytohemagglutinin (PHA), hemolysis capacity, hemagglutination capacity, plasma bactericidal capacity, percentage of lymphocytes, percentage of heterophils, and percentage of eosinophils) in tree swallow (Tachycineta bicolor) nestlings raised in two types of agro-ecosystems of contrasted quality and over 2 years. First, we assessed the effect of environmental heterogeneity (spatial and temporal) on the strength and direction of correlations between immune measures. Second, we investigated the effect of an immune score integrating information from several immune markers on individual performance (including growth, mass at fledging and parasite burden). Both a multivariate and a pair-wise approach showed variation in relationships between immune measures across years and habitats. We also found a weak association between the integrated score of nestling immune function and individual performance, but only under certain environmental conditions. We conclude that the ecological context can strongly affect the interpretation of immune defenses in the wild. Given that spatiotemporal variations are likely to affect individual immune defenses, great caution should be used when generalizing conclusions to other study systems. PMID:23610646

Pigeon, Gabriel; Bélisle, Marc; Garant, Dany; Cohen, Alan A; Pelletier, Fanie

2013-01-01

37

Ecological immunology in a fluctuating environment: an integrative analysis of tree swallow nestling immune defense.  

PubMed

Evolutionary ecologists have long been interested by the link between different immune defenses and fitness. Given the importance of a proper immune defense for survival, it is important to understand how its numerous components are affected by environmental heterogeneity. Previous studies targeting this question have rarely considered more than two immune markers. In this study, we measured seven immune markers (response to phytohemagglutinin (PHA), hemolysis capacity, hemagglutination capacity, plasma bactericidal capacity, percentage of lymphocytes, percentage of heterophils, and percentage of eosinophils) in tree swallow (Tachycineta bicolor) nestlings raised in two types of agro-ecosystems of contrasted quality and over 2 years. First, we assessed the effect of environmental heterogeneity (spatial and temporal) on the strength and direction of correlations between immune measures. Second, we investigated the effect of an immune score integrating information from several immune markers on individual performance (including growth, mass at fledging and parasite burden). Both a multivariate and a pair-wise approach showed variation in relationships between immune measures across years and habitats. We also found a weak association between the integrated score of nestling immune function and individual performance, but only under certain environmental conditions. We conclude that the ecological context can strongly affect the interpretation of immune defenses in the wild. Given that spatiotemporal variations are likely to affect individual immune defenses, great caution should be used when generalizing conclusions to other study systems. PMID:23610646

Pigeon, Gabriel; Bélisle, Marc; Garant, Dany; Cohen, Alan A; Pelletier, Fanie

2013-04-01

38

Accessory cells in the immune defense of the dental pulp.  

PubMed

This communication focuses on the participation of accessory cells in the initial recognition and processing of antigenic substances in the dental pulp. Immunohistochemical analyses have demonstrated the presence of two types of accessory cells--one with a dendritic morphology located in the periphery of the pulp and one with a macrophage-like appearance located more centrally. Functional studies in vitro have provided evidence for the dendritic cells being the most significant of the two cells regarding their capacity to induce T-cell proliferation. Studies on ontogeny have revealed that the appearance of pulp accessory cells is delayed compared to other peripheral tissues. In experimentally induced pulp lesions a rapid increase of cells with morphologic and phenotypic features similar to normally occurring accessory cells was found. These data demonstrate that the dental pulp contains the necessary cellular constituents to mount an immunologic defense reaction. Future studies should focus on elucidating possible interactions between these immune cells and the neurovascular system of the pulp. PMID:1508890

Jontell, M; Bergenholtz, G

1992-01-01

39

Phylogenetic escalation and decline of plant defense strategies.  

PubMed

As the basal resource in most food webs, plants have evolved myriad strategies to battle consumption by herbivores. Over the past 50 years, plant defense theories have been formulated to explain the remarkable variation in abundance, distribution, and diversity of secondary chemistry and other defensive traits. For example, classic theories of enemy-driven evolutionary dynamics have hypothesized that defensive traits escalate through the diversification process. Despite the fact that macroevolutionary patterns are an explicit part of defense theories, phylogenetic analyses have not been previously attempted to disentangle specific predictions concerning (i) investment in resistance traits, (ii) recovery after damage, and (iii) plant growth rate. We constructed a molecular phylogeny of 38 species of milkweed and tested four major predictions of defense theory using maximum-likelihood methods. We did not find support for the growth-rate hypothesis. Our key finding was a pattern of phyletic decline in the three most potent resistance traits (cardenolides, latex, and trichomes) and an escalation of regrowth ability. Our neontological approach complements more common paleontological approaches to discover directional trends in the evolution of life and points to the importance of natural enemies in the macroevolution of species. The finding of macroevolutionary escalating regowth ability and declining resistance provides a window into the ongoing coevolutionary dynamics between plants and herbivores and suggests a revision of classic plant defense theory. Where plants are primarily consumed by specialist herbivores, regrowth (or tolerance) may be favored over resistance traits during the diversification process. PMID:18645183

Agrawal, Anurag A; Fishbein, Mark

2008-07-22

40

Immune evasion strategies used by Helicobacter pylori  

PubMed Central

Helicobacter pylori (H. pylori) is perhaps the most ubiquitous and successful human pathogen, since it colonizes the stomach of more than half of humankind. Infection with this bacterium is commonly acquired during childhood. Once infected, people carry the bacteria for decades or even for life, if not treated. Persistent infection with this pathogen causes gastritis, peptic ulcer disease and is also strongly associated with the development of gastric cancer. Despite induction of innate and adaptive immune responses in the infected individual, the host is unable to clear the bacteria. One widely accepted hallmark of H. pylori is that it successfully and stealthily evades host defense mechanisms. Though the gastric mucosa is well protected against infection, H. pylori is able to reside under the mucus, attach to gastric epithelial cells and cause persistent infection by evading immune responses mediated by host. In this review, we discuss how H. pylori avoids innate and acquired immune response elements, uses gastric epithelial cells as mediators to manipulate host T cell responses and uses virulence factors to avoid adaptive immune responses by T cells to establish a persistent infection. We also discuss in this review how the genetic diversity of this pathogen helps for its survival. PMID:25278676

Lina, Taslima T; Alzahrani, Shatha; Gonzalez, Jazmin; Pinchuk, Irina V; Beswick, Ellen J; Reyes, Victor E

2014-01-01

41

Immune evasion strategies used by Helicobacter pylori.  

PubMed

Helicobacter pylori (H. pylori) is perhaps the most ubiquitous and successful human pathogen, since it colonizes the stomach of more than half of humankind. Infection with this bacterium is commonly acquired during childhood. Once infected, people carry the bacteria for decades or even for life, if not treated. Persistent infection with this pathogen causes gastritis, peptic ulcer disease and is also strongly associated with the development of gastric cancer. Despite induction of innate and adaptive immune responses in the infected individual, the host is unable to clear the bacteria. One widely accepted hallmark of H. pylori is that it successfully and stealthily evades host defense mechanisms. Though the gastric mucosa is well protected against infection, H. pylori is able to reside under the mucus, attach to gastric epithelial cells and cause persistent infection by evading immune responses mediated by host. In this review, we discuss how H. pylori avoids innate and acquired immune response elements, uses gastric epithelial cells as mediators to manipulate host T cell responses and uses virulence factors to avoid adaptive immune responses by T cells to establish a persistent infection. We also discuss in this review how the genetic diversity of this pathogen helps for its survival. PMID:25278676

Lina, Taslima T; Alzahrani, Shatha; Gonzalez, Jazmin; Pinchuk, Irina V; Beswick, Ellen J; Reyes, Victor E

2014-09-28

42

Agent-based modeling approach of immune defense against spores of opportunistic human pathogenic fungi.  

PubMed

Opportunistic human pathogenic fungi like the ubiquitous fungus Aspergillus fumigatus are a major threat to immunocompromised patients. An impaired immune system renders the body vulnerable to invasive mycoses that often lead to the death of the patient. While the number of immunocompromised patients is rising with medical progress, the process, and dynamics of defense against invaded and ready to germinate fungal conidia are still insufficiently understood. Besides macrophages, neutrophil granulocytes form an important line of defense in that they clear conidia. Live imaging shows the interaction of those phagocytes and conidia as a dynamic process of touching, dragging, and phagocytosis. To unravel strategies of phagocytes on the hunt for conidia an agent-based modeling approach is used, implemented in NetLogo. Different modes of movement of phagocytes are tested regarding their clearing efficiency: random walk, short-term persistence in their recent direction, chemotaxis of chemokines excreted by conidia, and communication between phagocytes. While the short-term persistence hunting strategy turned out to be superior to the simple random walk, following a gradient of chemokines released by conidial agents is even better. The advantage of communication between neutrophilic agents showed a strong dependency on the spatial scale of the focused area and the distribution of the pathogens. PMID:22557995

Tokarski, Christian; Hummert, Sabine; Mech, Franziska; Figge, Marc Thilo; Germerodt, Sebastian; Schroeter, Anja; Schuster, Stefan

2012-01-01

43

Agent-Based Modeling Approach of Immune Defense Against Spores of Opportunistic Human Pathogenic Fungi  

PubMed Central

Opportunistic human pathogenic fungi like the ubiquitous fungus Aspergillus fumigatus are a major threat to immunocompromised patients. An impaired immune system renders the body vulnerable to invasive mycoses that often lead to the death of the patient. While the number of immunocompromised patients is rising with medical progress, the process, and dynamics of defense against invaded and ready to germinate fungal conidia are still insufficiently understood. Besides macrophages, neutrophil granulocytes form an important line of defense in that they clear conidia. Live imaging shows the interaction of those phagocytes and conidia as a dynamic process of touching, dragging, and phagocytosis. To unravel strategies of phagocytes on the hunt for conidia an agent-based modeling approach is used, implemented in NetLogo. Different modes of movement of phagocytes are tested regarding their clearing efficiency: random walk, short-term persistence in their recent direction, chemotaxis of chemokines excreted by conidia, and communication between phagocytes. While the short-term persistence hunting strategy turned out to be superior to the simple random walk, following a gradient of chemokines released by conidial agents is even better. The advantage of communication between neutrophilic agents showed a strong dependency on the spatial scale of the focused area and the distribution of the pathogens. PMID:22557995

Tokarski, Christian; Hummert, Sabine; Mech, Franziska; Figge, Marc Thilo; Germerodt, Sebastian; Schroeter, Anja; Schuster, Stefan

2012-01-01

44

Immune Defense Reactions of Myriapoda — A Brief Presentation of Recent Results  

Microsoft Academic Search

A short review of immune defense mechanisms of diplopods and chilopods (with special ref- erence to the species Rhapidostreptus virgator (SILVESTRI), Chicobolus spec, Scolopendra spec, and Lithobius forficatus (L.)) is given. Myriapods have different types of hemocytes which are able to detect between self and non-self and phagocytize or encapsulate foreign material. As humoral defense systems myriapods have different antibacterial

Willi E. R. XYLANDER

45

Ontogeny of innate and adaptive immune defense components in free-living tree swallows, Tachycineta bicolor  

Microsoft Academic Search

Little is known about the development of immune function in wild animals. We investigated the ontogeny of immune defense in a free-living bird, the tree swallow. We assessed total and differential leukocyte counts, natural antibodies, complement activity, in vivo skin swelling response, and in vitro lymphocyte proliferation and compared the levels of development between nestlings and young adults. We also

Maria G. Palacios; Joan E. Cunnick; David Vleck; Carol M. Vleck

2009-01-01

46

An engineered innate immune defense protects grapevines from Pierce disease  

PubMed Central

We postulated that a synergistic combination of two innate immune functions, pathogen surface recognition and lysis, in a protein chimera would lead to a robust class of engineered antimicrobial therapeutics for protection against pathogens. In support of our hypothesis, we have engineered such a chimera to protect against the Gram-negative Xylella fastidiosa (Xf), which causes diseases in multiple plants of economic importance. Here we report the design and delivery of this chimera to target the Xf subspecies fastidiosa (Xff), which causes Pierce disease in grapevines and poses a great threat to the wine-growing regions of California. One domain of this chimera is an elastase that recognizes and cleaves MopB, a conserved outer membrane protein of Xff. The second domain is a lytic peptide, cecropin B, which targets conserved lipid moieties and creates pores in the Xff outer membrane. A flexible linker joins the recognition and lysis domains, thereby ensuring correct folding of the individual domains and synergistic combination of their functions. The chimera transgene is fused with an amino-terminal signal sequence to facilitate delivery of the chimera to the plant xylem, the site of Xff colonization. We demonstrate that the protein chimera expressed in the xylem is able to directly target Xff, suppress its growth, and significantly decrease the leaf scorching and xylem clogging commonly associated with Pierce disease in grapevines. We believe that similar strategies involving protein chimeras can be developed to protect against many diseases caused by human and plant pathogens. PMID:22355130

Dandekar, Abhaya M.; Gouran, Hossein; Ibáñez, Ana María; Uratsu, Sandra L.; Agüero, Cecilia B.; McFarland, Sarah; Borhani, Yasmin; Feldstein, Paul A.; Bruening, George; Nascimento, Rafael; Goulart, Luiz R.; Pardington, Paige E.; Chaudhary, Anu; Norvell, Meghan; Civerolo, Edwin; Gupta, Goutam

2012-01-01

47

Plant mating system transitions drive the macroevolution of defense strategies  

PubMed Central

Understanding the factors that shape macroevolutionary patterns in functional traits is a central goal of evolutionary biology. Alternative strategies of sexual reproduction (inbreeding vs. outcrossing) have divergent effects on population genetic structure and could thereby broadly influence trait evolution. However, the broader evolutionary consequences of mating system transitions remain poorly understood, with the exception of traits related to reproduction itself (e.g., pollination). Across a phylogeny of 56 wild species of Solanaceae (nightshades), we show here that the repeated, unidirectional transition from ancestral self-incompatibility (obligate outcrossing) to self-compatibility (increased inbreeding) leads to the evolution of an inducible (vs. constitutive) strategy of plant resistance to herbivores. We demonstrate that inducible and constitutive defense strategies represent evolutionary alternatives and that the magnitude of the resulting macroevolutionary tradeoff is dependent on the mating system. Loss of self-incompatibility is also associated with the evolution of increased specificity in induced plant resistance. We conclude that the evolution of sexual reproductive variation may have profound effects on plant–herbivore interactions, suggesting a new hypothesis for the evolution of two primary strategies of plant defense. PMID:23431190

Campbell, Stuart A.; Kessler, André

2013-01-01

48

Age and Sex Differences in Strategies of Coping and Defense Across the Life Span  

Microsoft Academic Search

Age and sex differences in the use of coping and defense strategies were examined in a life-span sample of 381 individuals. Participants responded to 2 self-report measures assessing mechanisms of coping and defense and measures assessing their level of cognitive complexity. Older adults used a combination of coping and defense strategies indicative of greater impulse control and the tendency to

Manfred Diehl; Nathan Coyle; Gisela Labouvie-Vief

1996-01-01

49

Probing the Unknowns in Cytokinin-Mediated Immune Defense in Arabidopsis with Systems Biology Approaches  

PubMed Central

Plant hormones involving salicylic acid (SA), jasmonic acid (JA), ethylene (Et), and auxin, gibberellins, and abscisic acid (ABA) are known to regulate host immune responses. However, plant hormone cytokinin has the potential to modulate defense signaling including SA and JA. It promotes plant pathogen and herbivore resistance; underlying mechanisms are still unknown. Using systems biology approaches, we unravel hub points of immune interaction mediated by cytokinin signaling in Arabidopsis. High-confidence Arabidopsis protein–protein interactions (PPI) are coupled to changes in cytokinin-mediated gene expression. Nodes of the cellular interactome that are enriched in immune functions also reconstitute sub-networks. Topological analyses and their specific immunological relevance lead to the identification of functional hubs in cellular interactome. We discuss our identified immune hubs in light of an emerging model of cytokinin-mediated immune defense against pathogen infection in plants. PMID:24558299

Naseem, Muhammad; Kunz, Meik; Dandekar, Thomas

2014-01-01

50

Control Systems Cyber Security:Defense in Depth Strategies  

SciTech Connect

Information infrastructures across many public and private domains share several common attributes regarding IT deployments and data communications. This is particularly true in the control systems domain. A majority of the systems use robust architectures to enhance business and reduce costs by increasing the integration of external, business, and control system networks. However, multi-network integration strategies often lead to vulnerabilities that greatly reduce the security of an organization, and can expose mission-critical control systems to cyber threats. This document provides guidance and direction for developing ‘defense-in-depth’ strategies for organizations that use control system networks while maintaining a multi-tier information architecture that requires: Maintenance of various field devices, telemetry collection, and/or industrial-level process systems Access to facilities via remote data link or modem Public facing services for customer or corporate operations A robust business environment that requires connections among the control system domain, the external Internet, and other peer organizations.

David Kuipers; Mark Fabro

2006-05-01

51

Control Systems Cyber Security: Defense-in-Depth Strategies  

SciTech Connect

Information infrastructures across many public and private domains share several common attributes regarding IT deployments and data communications. This is particularly true in the control systems domain. A majority of the systems use robust architectures to enhance business and reduce costs by increasing the integration of external, business, and control system networks. However, multi-network integration strategies often lead to vulnerabilities that greatly reduce the security of an organization, and can expose mission-critical control systems to cyber threats. This document provides guidance and direction for developing ‘defense-in-depth’ strategies for organizations that use control system networks while maintaining a multi-tier information architecture that requires: • Maintenance of various field devices, telemetry collection, and/or industrial-level process systems • Access to facilities via remote data link or modem • Public facing services for customer or corporate operations • A robust business environment that requires connections among the control system domain, the external Internet, and other peer organizations.

Mark Fabro

2007-10-01

52

Inducible defenses stay up late: temporal patterns of immune gene expression in Tenebrio molitor.  

PubMed

The course of microbial infection in insects is shaped by a two-stage process of immune defense. Constitutive defenses, such as engulfment and melanization, act immediately and are followed by inducible defenses, archetypically the production of antimicrobial peptides, which eliminate or suppress the remaining microbes. By applying RNAseq across a 7-day time course, we sought to characterize the long-lasting immune response to bacterial challenge in the mealworm beetle Tenebrio molitor, a model for the biochemistry of insect immunity and persistent bacterial infection. By annotating a hybrid de novo assembly of RNAseq data, we were able to identify putative orthologs for the majority of components of the conserved insect immune system. Compared with Tribolium castaneum, the most closely related species with a reference genome sequence and a manually curated immune system annotation, the T. molitor immune gene count was lower, with lineage-specific expansions of genes encoding serine proteases and their countervailing inhibitors accounting for the majority of the deficit. Quantitative mapping of RNAseq reads to the reference assembly showed that expression of genes with predicted functions in cellular immunity, wound healing, melanization, and the production of reactive oxygen species was transiently induced immediately after immune challenge. In contrast, expression of genes encoding antimicrobial peptides or components of the Toll signaling pathway and iron sequestration response remained elevated for at least 7 days. Numerous genes involved in metabolism and nutrient storage were repressed, indicating a possible cost of immune induction. Strikingly, the expression of almost all antibacterial peptides followed the same pattern of long-lasting induction, regardless of their spectra of activity, signaling possible interactive roles in vivo. PMID:24318927

Johnston, Paul R; Makarova, Olga; Rolff, Jens

2014-06-01

53

A unique host defense pathway: TRIF mediates both antiviral and antibacterial immune responses  

PubMed Central

Both anti-viral and anti-bacterial host defense mechanisms involve TRIF signaling. TRIF provides early clearance of pathogens and coordination of a local inflammatory ensemble through an interferon cascade, while it may trigger organ damage. The multipotentiality of TRIF-mediated immune machinery may direct the fate of our continuous battle with microbes. PMID:23116944

Hyun, Jinhee; Kanagavelu, Saravana; Fukata, Masayuki

2012-01-01

54

WHY INDUCED DEFENSES MAY BE FAVORED OVER CONSTITUTIVE STRATEGIES IN PLANTS  

E-print Network

Chapter 3 WHY INDUCED DEFENSES MAY BE FAVORED OVER CONSTITUTIVE STRATEGIES IN PLANTS Anurag A defenses seems to be the obvious next step in understanding why so many plants employ induction. #12;Introduction This chapter examines the potential of induced responses to maximize plant defense and focuses

Agrawal, Anurag

55

[Modulation of host immune defenses by cytomegalovirus: advanced insights from evolutionary game theory].  

PubMed

Human cytomegalovirus (HCMV) is an ubiquitous pathogen that infects a majority of the world's population. The virus can establish lifelong infection once the human body is infected by HCMV and virus can be reactivated from a latent state in immune suppressed individuals. HCMV has developed several strategies to evade host immune surveillance after millions of years of co-evolution with mankind. One of the classical tricks is encoding homologous to human immune factors or stealing host cellular genes that have significant functions in immune system. Virus encoded immune modulators which participate in regulating the major histocompatibility complex, cellular immunity, humoral immunity, cytokines and chemokines are supposed to play a significant role in the pathogenesis of HCMV. Evaluation of "mutually assured survival" relationship between virus and host provides important insights into viral immunopathogenesis and study of viral immunomodulatory proteins might help us to uncover new human genes that control immunity. PMID:23547385

Zheng, Qi; Tao, Ran; Shang, Shi-Qiang

2013-01-01

56

Self/nonself perception in plants in innate immunity and defense  

PubMed Central

The ability to distinguish ‘self’ from ‘nonself’ is the most fundamental aspect of any immune system. The evolutionary solution in plants to the problems of perceiving and responding to pathogens involves surveillance of nonself, damaged-self and altered-self as danger signals. This is reflected in basal resistance or non-host resistance, which is the innate immune response that protects plants against the majority of pathogens. In the case of surveillance of nonself, plants utilize receptor-like proteins or -kinases (RLP/Ks) as pattern recognition receptors (PRRs), which can detect conserved pathogen/microbe-associated molecular pattern (P/MAMP) molecules. P/MAMP detection serves as an early warning system for the presence of a wide range of potential pathogens and the timely activation of plant defense mechanisms. However, adapted microbes express a suite of effector proteins that often interfere or act as suppressors of these defenses. In response, plants have evolved a second line of defense that includes intracellular nucleotide binding leucine-rich repeat (NB-LRR)-containing resistance proteins, which recognize isolate-specific pathogen effectors once the cell wall has been compromised. This host-immunity acts within the species level and is controlled by polymorphic host genes, where resistance protein-mediated activation of defense is based on an ‘altered-self’ recognition mechanism. PMID:21559176

Sanabria, Natasha M; Huang, Ju-Chi

2010-01-01

57

Nonsense-mediated mRNA decay modulates immune receptor levels to regulate plant antibacterial defense.  

PubMed

Nonsense-mediated mRNA decay (NMD) is a conserved eukaryotic RNA surveillance mechanism that degrades aberrant mRNAs. NMD impairment in Arabidopsis is linked to constitutive immune response activation and enhanced antibacterial resistance, but the underlying mechanisms are unknown. Here we show that NMD contributes to innate immunity in Arabidopsis by controlling the turnover of numerous TIR domain-containing, nucleotide-binding, leucine-rich repeat (TNL) immune receptor-encoding mRNAs. Autoimmunity resulting from NMD impairment depends on TNL signaling pathway components and can be triggered through deregulation of a single TNL gene, RPS6. Bacterial infection of plants causes host-programmed inhibition of NMD, leading to stabilization of NMD-regulated TNL transcripts. Conversely, constitutive NMD activity prevents TNL stabilization and impairs plant defense, demonstrating that host-regulated NMD contributes to disease resistance. Thus, NMD shapes plant innate immunity by controlling the threshold for activation of TNL resistance pathways. PMID:25211079

Gloggnitzer, Jiradet; Akimcheva, Svetlana; Srinivasan, Arunkumar; Kusenda, Branislav; Riehs, Nina; Stampfl, Hansjörg; Bautor, Jaqueline; Dekrout, Bettina; Jonak, Claudia; Jiménez-Gómez, José M; Parker, Jane E; Riha, Karel

2014-09-10

58

Community-based Immunization Strategies for Epidemic Control  

E-print Network

Understanding the epidemic dynamics, and finding out efficient techniques to control it, is a challenging issue. A lot of research has been done on targeted immunization strategies, exploiting various global network topological properties. However, in practice, information about the global structure of the contact network may not be available. Therefore, immunization strategies that can deal with a limited knowledge of the network structure are required. In this paper, we propose targeted immunization strategies that require information only at the community level. Results of our investigations on the SIR epidemiological model, using a realistic synthetic benchmark with controlled community structure, show that the community structure plays an important role in the epidemic dynamics. An extensive comparative evaluation demonstrates that the proposed strategies are as efficient as the most influential global centrality based immunization strategies, despite the fact that they use a limited amount of informatio...

Gupta, Naveen; Cherifi, Hocine

2014-01-01

59

An experimental heat wave changes immune defense and life history traits in a freshwater snail  

PubMed Central

The predicted increase in frequency and severity of heat waves due to climate change is expected to alter disease dynamics by reducing hosts' ability to resist infections. This could take place via two different mechanisms: (1) through general reduction in hosts' performance under harsh environmental conditions and/or (2) through altered resource allocation that reduces expression of defense traits in order to maintain other traits. We tested these alternative hypotheses by measuring the effect of an experimental heat wave (25 vs. 15°C) on the constitutive level of immune defense (hemocyte concentration, phenoloxidase [PO]-like activity, antibacterial activity of hemolymph), and life history traits (growth and number of oviposited eggs) of the great pond snail Lymnaea stagnalis. We also manipulated the exposure time to high temperature (1, 3, 5, 7, 9, or 11 days). We found that if the exposure to high temperature lasted <1 week, immune function was not affected. However, when the exposure lasted longer than that, the level of snails' immune function (hemocyte concentration and PO-like activity) was reduced. Snails' growth and reproduction increased within the first week of exposure to high temperature. However, longer exposures did not lead to a further increase in cumulative reproductive output. Our results show that short experimental heat waves do not alter immune function but lead to plastic responses that increase snails' growth and reproduction. Thus, although the relative expression of traits changes, short experimental heat waves do not impair snails' defenses. Negative effects on performance get pronounced when the heat waves are prolonged suggesting that high performance cannot be maintained over long time periods. This ultimately reduces the levels of defense traits. PMID:24455121

Leicht, Katja; Jokela, Jukka; Seppälä, Otto

2013-01-01

60

The damage threshold hypothesis and the immune strategies of insects.  

PubMed

The insect immune response strategy has generally been considered bipolar: either resistance or death. Lately, a much broader and subtler landscape has emerged: occurrence of tolerance and resistance has been described as a host-regulated immune response. However, little is known about the interplay between the immune response strategy mounted by the insect during infection and the damage produced by the pathogen. Based on the Matzinger model of danger/damage, we propose a quantitative model to explain the occurrence of either resistance or tolerance. We discuss the features to be analyzed and describe the terms of reference by which, with basic models, we distinguish between immune strategies. Pathogen type and mixed infections are also contemplated. We hope this analysis will give new perspective, from an evolutionary ecology standpoint, on immune response measurements in the context of insect infection, and on the importance of (non-self or self) damage. PMID:24614506

Moreno-García, Miguel; Condé, Renaud; Bello-Bedoy, Rafael; Lanz-Mendoza, Humberto

2014-06-01

61

Psychological Defense Strategies According to the Defense Mechanism Test Among Patients with Severe Conversion Disorder  

Microsoft Academic Search

Nineteen patients with a diagnosis of conversion disorder (according to DSM-IV criteria), and 32 healthy nonpatients, were assessed using the Defense Mechanism Test (DMT), which is a projective perception test that examines psychodynamic defense operations according to psychoanalytical theory. The conversion group was significantly separated from the non-patient group. The nonpatients showed better reality testing and the ability to perceive

Elisabet Sundbom; Michael Binzer; Gunnar Kullgren

1999-01-01

62

Protein Poly(ADP-ribosyl)ation Regulates Arabidopsis Immune Gene Expression and Defense Responses  

PubMed Central

Perception of microbe-associated molecular patterns (MAMPs) elicits transcriptional reprogramming in hosts and activates defense to pathogen attacks. The molecular mechanisms underlying plant pattern-triggered immunity remain elusive. A genetic screen identified Arabidopsis poly(ADP-ribose) glycohydrolase 1 (atparg1) mutant with elevated immune gene expression upon multiple MAMP and pathogen treatments. Poly(ADP-ribose) glycohydrolase (PARG) is predicted to remove poly(ADP-ribose) polymers on acceptor proteins modified by poly(ADP-ribose) polymerases (PARPs) with three PARPs and two PARGs in Arabidopsis genome. AtPARP1 and AtPARP2 possess poly(ADP-ribose) polymerase activity, and the activity of AtPARP2 was enhanced by MAMP treatment. AtPARG1, but not AtPARG2, carries glycohydrolase activity in vivo and in vitro. Importantly, mutation (G450R) in atparg1 blocks its activity and the corresponding residue is highly conserved and essential for human HsPARG activity. Consistently, mutant atparp1atparp2 plants exhibited compromised immune gene activation and enhanced susceptibility to pathogen infections. Our study indicates that protein poly(ADP-ribosyl)ation plays critical roles in plant immune gene expression and defense to pathogen attacks. PMID:25569773

Feng, Baomin; Liu, Chenglong; de Oliveira, Marcos V. V.; Intorne, Aline C.; Li, Bo; Babilonia, Kevin; de Souza Filho, Gonçalo A.; Shan, Libo; He, Ping

2015-01-01

63

Increased activity correlates with reduced ability to mount immune defenses to endotoxin in zebra finches.  

PubMed

When suffering from infection, animals experience behavioral and physiological alterations that potentiate the immune system's ability to fight pathogens. The behavioral component of this response, termed "sickness behavior," is characterized by an overall reduction in physical activity. A growing number of reports demonstrate substantial flexibility in these sickness behaviors, which can be partially overcome in response to mates, intruders and parental duties. Since it is hypothesized that adopting sickness behaviors frees energetic resources for mounting an immune response, we tested whether diminished immune responses coincided with reduced sickness behaviors by housing male zebra finches (Taeniopygia guttata) in social conditions that alter their behavioral response to an endotoxin. To facilitate our data collection, we developed and built a miniaturized sensor capable of detecting changes in dorsoventral acceleration and categorizing them as different behaviors when attached to the finches. We found that the immune defenses (quantified as haptoglobin-like activity, ability to change body temperature and bacterial killing capacity) increased as a function of increased time spent resting. The findings indicate that when animals are sick attenuation of sickness behaviors may exact costs, such as reduced immune function. The extent of these costs depends on how relevant the affected components of immunity are for fighting a specific infection. PMID:24888267

Lopes, Patricia C; Springthorpe, Dwight; Bentley, George E

2014-10-01

64

Adolescent Humor and Its Relationship to Coping, Defense Strategies, Psychological Distress, and Well-Being  

ERIC Educational Resources Information Center

Objective: This study investigated the psychometric properties of the Humor Styles Questionnaire (HSQ) in measuring adolescent humor, including the relationship between humor and coping style, defense style, depressive symptoms, and adjustment in a non-clinical sample of adolescents. Method: Humor, coping, defense strategies, depressive symptoms,…

Erickson, Sarah J.; Feldstein, Sarah W.

2007-01-01

65

Phenotypic plasticity in seedling defense strategies: compensatory growth and chemical induction  

Microsoft Academic Search

Phenotypic plasticity in growth (leading to compensation) and secondary chemical production (leading to induction) in response to herbivory are key defense strategies in adult plants, but their role in seedling defense remains unclear. A pair of greenhouse studies was conducted to investigate compensation and induction in seedlings and juvenile plants, using Plantago lanceolata (Plantaginaceae) and the specialist buckeye caterpillar Junonia

Kasey E. Barton

2008-01-01

66

EVOLUTION OF MIXED STRATEGIES OF PLANT DEFENSE ALLOCATION AGAINST NATURAL ENEMIES  

Microsoft Academic Search

In this study we present a simple optimization model for the evolution of defensive strategies (tolerance and resistance) of plants against their natural enemies. The model specifically evaluates the consequences of introducing variable costs and benefits of tolerance and resistance and nonlinear cost-and-benefit functions for tolerance and resistance. Incorporating these assumptions, the present model of plant defense predicts different evolutionary

Juan Fornoni; Juan Núñez-Farfán; Pedro Luis Valverde; Mark D. Rausher

2004-01-01

67

Degree based attacks and defense strategies in complex networks Aviv Yehezkel1  

E-print Network

that many real world networks, af- fecting almost every part of the modern life, from brain and biological using analytical results and simulations that the mid degree nodes defense strategy leads to the largest

Cohen, Reuven

68

Isonitrosoacetophenone Drives Transcriptional Reprogramming in Nicotiana tabacum Cells in Support of Innate Immunity and Defense  

PubMed Central

Plants respond to various stress stimuli by activating broad-spectrum defense responses both locally as well as systemically. As such, identification of expressed genes represents an important step towards understanding inducible defense responses and assists in designing appropriate intervention strategies for disease management. Genes differentially expressed in tobacco cell suspensions following elicitation with isonitrosoacetophenone (INAP) were identified using mRNA differential display and pyro-sequencing. Sequencing data produced 14579 reads, which resulted in 198 contigs and 1758 singletons. Following BLAST analyses, several inducible plant defense genes of interest were identified and classified into functional categories including signal transduction, transcription activation, transcription and protein synthesis, protein degradation and ubiquitination, stress-responsive, defense-related, metabolism and energy, regulation, transportation, cytoskeleton and cell wall-related. Quantitative PCR was used to investigate the expression of 17 selected target genes within these categories. Results indicate that INAP has a sensitising or priming effect through activation of salicylic acid-, jasmonic acid- and ethylene pathways that result in an altered transcriptome, with the expression of genes involved in perception of pathogens and associated cellular re-programming in support of defense. Furthermore, infection assays with the pathogen Pseudomonas syringae pv. tabaci confirmed the establishment of a functional anti-microbial environment in planta. PMID:25658943

Djami-Tchatchou, Arnaud T.; Maake, Mmapula P.; Piater, Lizelle A.; Dubery, Ian A.

2015-01-01

69

Salmonella exploits NLRP12-dependent innate immune signaling to suppress host defenses during infection  

PubMed Central

The nucleotide-binding oligomerization domain (NOD)-like receptor family pyrin domain containing 12 (NLRP12) plays a protective role in intestinal inflammation and carcinogenesis, but the physiological function of this NLR during microbial infection is largely unexplored. Salmonella enterica serovar Typhimurium (S. typhimurium) is a leading cause of food poisoning worldwide. Here, we show that NLRP12-deficient mice were highly resistant to S. typhimurium infection. Salmonella-infected macrophages induced NLRP12-dependent inhibition of NF-?B and ERK activation by suppressing phosphorylation of I?B? and ERK. NLRP12-mediated down-regulation of proinflammatory and antimicrobial molecules prevented efficient clearance of bacterial burden, highlighting a role for NLRP12 as a negative regulator of innate immune signaling during salmonellosis. These results underscore a signaling pathway defined by NLRP12-mediated dampening of host immune defenses that could be exploited by S. typhimurium to persist and survive in the host. PMID:24347638

Zaki, Md. Hasan; Man, Si Ming; Vogel, Peter; Lamkanfi, Mohamed; Kanneganti, Thirumala-Devi

2014-01-01

70

Immunization strategy for epidemic spreading on multilayer networks  

NASA Astrophysics Data System (ADS)

In many real-world complex systems, individuals have many kinds of interactions among them, suggesting that it is necessary to consider a layered-structure framework to model systems such as social interactions. This structure can be captured by multilayer networks and can have major effects on the spreading of process that occurs over them, such as epidemics. In this letter we study a targeted immunization strategy for epidemic spreading over a multilayer network. We apply the strategy in one of the layers and study its effect in all layers of the network disregarding degree-degree correlation among layers. We found that the targeted strategy is not as efficient as in isolated networks, due to the fact that in order to stop the spreading of the disease it is necessary to immunize more than 80% of the individuals. However, the size of the epidemic is drastically reduced in the layer where the immunization strategy is applied compared to the case with no mitigation strategy. Thus, the immunization strategy has a major effect on the layer were it is applied, but does not efficiently protect the individuals of other layers.

Buono, C.; Braunstein, L. A.

2015-01-01

71

Global Security: Comparative Assessment II The modules in this class will examine the homeland security and defense strategies and operational  

E-print Network

1 Russia's National Security Russia's Approach to Counterterrorism The United Kingdom's National Defense Strategy The United Kingdom's Approach to Counterterrorism The United Kingdom's CONTEST 2009 Module 2 Israel's Unique National Defense and Counter-Terrorism Challenges Israel's Border Issues

Rhode Island, University of

72

Optimal Defensive Strategies under Varying Consumer Distributional Patterns and Market Maturity  

Microsoft Academic Search

In this paper we describe a simulation approach to explore optimal defensive strategies concerning an entrant situation in an artificial consumer market. There are two questions of interest concerning the adaptation of the strategy to obtain maximal profits¡Xthe effects of (1) varying heterogeneity of the considered consumer aspiration points and (2) the maturity of the market at the time of

Ulrike Schuster

2005-01-01

73

Role of Analytical Chemistry in Defense Strategies Against Chemical and Biological Attack  

NASA Astrophysics Data System (ADS)

Analytical chemistry plays a role in the two strategies of defense against chemical or biological weapons that are discussed in this review: the detect-to-protect and the prevent-and-detect strategies. The detect-to-protect method, which is based on detection of a known chemical agent with a specific chemical sensor designed for said agent, has serious flaws. I argue that this approach should be replaced with the prevent-and-detect strategy. Such a change in the defense paradigm would require reallocation of resources, but it is necessary for effective protection of enclosed civilians from chemical and/or biological attack.

Janata, Jiri

2009-07-01

74

Defense mechanisms and coping strategies in conjugal relationships: An integration  

Microsoft Academic Search

Coping strategies and defence mechanisms are used to describe people's responses to stressful situations. The concept of coping strategies comes from the social psychological tradition, whereas the concept of defence mechanisms comes from the psychoanalytic tradition. According to the traditional view, the two concepts are very different. However, recently, a growing number of researchers suggested that coping strategies and defence

Geneviéve Bouchard; Vicky Thériault

2003-01-01

75

Complex interplay of body condition, life history, and prevailing environment shapes immune defenses of garter snakes in the wild.  

PubMed

The immunocompetence "pace-of-life" hypothesis proposes that fast-living organisms should invest more in innate immune defenses and less in adaptive defenses compared to slow-living ones. We found some support for this hypothesis in two life-history ecotypes of the snake Thamnophis elegans; fast-living individuals show higher levels of innate immunity compared to slow-living ones. Here, we optimized a lymphocyte proliferation assay to assess the complementary prediction that slow-living snakes should in turn show stronger adaptive defenses. We also assessed the "environmental" hypothesis that predicts that slow-living snakes should show lower levels of immune defenses (both innate and adaptive) given the harsher environment they live in. Proliferation of B- and T-lymphocytes of free-living individuals was on average higher in fast-living than slow-living snakes, opposing the pace-of-life hypothesis and supporting the environmental hypothesis. Bactericidal capacity of plasma, an index of innate immunity, did not differ between fast-living and slow-living snakes in this study, contrasting the previously documented pattern and highlighting the importance of annual environmental conditions as determinants of immune profiles of free-living animals. Our results do not negate a link between life history and immunity, as indicated by ecotype-specific relationships between lymphocyte proliferation and body condition, but suggest more subtle nuances than those currently proposed. PMID:23995485

Palacios, Maria G; Cunnick, Joan E; Bronikowski, Anne M

2013-01-01

76

Neisseria gonorrhoeae Modulates Iron-Limiting Innate Immune Defenses in Macrophages  

PubMed Central

Neisseria gonorrhoeae is a strict human pathogen that causes the sexually transmitted infection termed gonorrhea. The gonococcus can survive extracellularly and intracellularly, but in both environments the bacteria must acquire iron from host proteins for survival. However, upon infection the host uses a defensive response by limiting the bioavailability of iron by a number of mechanisms including the enhanced expression of hepcidin, the master iron-regulating hormone, which reduces iron uptake from the gut and retains iron in macrophages. The host also secretes the antibacterial protein NGAL, which sequesters bacterial siderophores and therefore inhibits bacterial growth. To learn whether intracellular gonococci can subvert this defensive response, we examined expression of host genes that encode proteins involved in modulating levels of intracellular iron. We found that N. gonorrhoeae can survive in association (tightly adherent and intracellular) with monocytes and macrophages and upregulates a panel of its iron-responsive genes in this environment. We also found that gonococcal infection of human monocytes or murine macrophages resulted in the upregulation of hepcidin, NGAL, and NRAMP1 as well as downregulation of the expression of the gene encoding the short chain 3-hydroxybutyrate dehydrogenase (BDH2); BDH2 catalyzes the production of the mammalian siderophore 2,5-DHBA involved in chelating and detoxifying iron. Based on these findings, we propose that N. gonorrhoeae can subvert the iron-limiting innate immune defenses to facilitate iron acquisition and intracellular survival. PMID:24489950

Zughaier, Susu M.; Kandler, Justin L.; Shafer, William M.

2014-01-01

77

Neisseria gonorrhoeae modulates iron-limiting innate immune defenses in macrophages.  

PubMed

Neisseria gonorrhoeae is a strict human pathogen that causes the sexually transmitted infection termed gonorrhea. The gonococcus can survive extracellularly and intracellularly, but in both environments the bacteria must acquire iron from host proteins for survival. However, upon infection the host uses a defensive response by limiting the bioavailability of iron by a number of mechanisms including the enhanced expression of hepcidin, the master iron-regulating hormone, which reduces iron uptake from the gut and retains iron in macrophages. The host also secretes the antibacterial protein NGAL, which sequesters bacterial siderophores and therefore inhibits bacterial growth. To learn whether intracellular gonococci can subvert this defensive response, we examined expression of host genes that encode proteins involved in modulating levels of intracellular iron. We found that N. gonorrhoeae can survive in association (tightly adherent and intracellular) with monocytes and macrophages and upregulates a panel of its iron-responsive genes in this environment. We also found that gonococcal infection of human monocytes or murine macrophages resulted in the upregulation of hepcidin, NGAL, and NRAMP1 as well as downregulation of the expression of the gene encoding the short chain 3-hydroxybutyrate dehydrogenase (BDH2); BDH2 catalyzes the production of the mammalian siderophore 2,5-DHBA involved in chelating and detoxifying iron. Based on these findings, we propose that N. gonorrhoeae can subvert the iron-limiting innate immune defenses to facilitate iron acquisition and intracellular survival. PMID:24489950

Zughaier, Susu M; Kandler, Justin L; Shafer, William M

2014-01-01

78

Multiagent-Based Defensive Strategy System for Military Simulation  

Microsoft Academic Search

In ubiquitous computing, it needs to manage dynamic and various information from various sources and aware the situation.\\u000a In the same way, it needs same capabilities including detecting and analyzing data from various sources, and recommending\\u000a behaviors to a commander in a national defense domain. In this paper, we describe the adaptation of an open-source multi-agent\\u000a architecture for a military

Seheon Song; Seokcheol Shin; Minkoo Kim

2007-01-01

79

Aggregation and cnidae development as early defensive strategies in Favia fragum and Porites astreoides  

NASA Astrophysics Data System (ADS)

To survive, corals possess a variety of active and passive defenses. This study examined the effectiveness of aggregation and cnidae development as defensive strategies in enhancing post-settlement survival and growth of two brooding corals, Favia fragum and Porites astreoides, in Bermuda. Growth and survival of solitary and aggregated spat were monitored over seven weeks; cnidae were extracted from surviving spat. F. fragum aggregated spat had higher mortality, slower growth, and more cnidae than solitary spat. On the other hand, aggregation proved beneficial for P. astreoides spat, which had significantly lower mortality, faster growth, and fewer cnidae. Aggregated and solitary F. fragum spat displayed negative correlations between cnidae density and growth, suggesting a trade-off between defense and growth; however, P. astreoides spat did not demonstrate such a trade-off. These differing responses suggest that early patterns of survivorship and defensive strategies are highly species specific and complex.

Rivera, H. E.; Goodbody-Gringley, G.

2014-12-01

80

Immune defense of rats immunized with fennel honey, propolis, and bee venom against induced staphylococcal infection.  

PubMed

The objective of this work was to evaluate the potency of bee product-immunized rats to overcome an induced Staphylococcus aureus infection. Forty rats were divided to eight groups: T1, T3, and T5 received, respectively, fennel honey, ethanol, and aqueous propolis extracts orally, and T2, T4, and T6 were administered the respective materials intraperitoneally; T7 received bee venom by the bee sting technique; and T8 was the control group. All groups were challenged by a bovine clinical mastitis isolate of S. aureus. Each rat received 2 mL of broth inoculated with 1 x 10(5) colony-forming units/mL intraperitoneally. Two weeks post-induced infection all rats were sacrificed and eviscerated for postmortem inspection and histopathological study. Three rats from T8 and one rat from T7 died before sacrifice. Another two rats, one each in T4 and T5, had morbidity manifestations. The remaining experimental animals showed apparently healthy conditions until time of sacrifice. Postmortem inspection revealed that all T8 rats showed different degrees of skeletal muscle and internal organ paleness with scattered focal pus nodules mainly on lungs and livers. All rats of the treated groups showed normal postmortem features except three rats. A dead rat in group T7 showed focal pus nodules on the lung surface only, whereas the affected two rats in groups T4 and T5 appeared normal except with some pus nodules, but much smaller than in the control, scattered on the hepatic surface and mesentery. Histopathological studies revealed that T8 rats had typical suppurative bronchopneumonia and or severe degenerative and necrobiotic changes in hepatic tissues. Three affected rats of the treated groups showed slight bronchopneumonia or degenerative hepatic changes only. The other animals of the treated groups showed completely normal parenchymatous organs with stimulated lymphatic tissues. It was concluded that all tested previously bee product-immunized rats could significantly challenge the induced S. aureus infection (P < .01). The effects were more pronounced in rats that had received fennel honey solution. PMID:19627205

Sayed, S M; Abou El-Ella, Ghada A; Wahba, Nahed M; El Nisr, Neveen A; Raddad, Khaled; Abd El Rahman, M F; Abd El Hafeez, M M; Abd El Fattah Aamer, Ahmed

2009-06-01

81

Optimal treatment strategy for a tumor model under immune suppression.  

PubMed

We propose a mathematical model describing tumor-immune interactions under immune suppression. These days evidences indicate that the immune suppression related to cancer contributes to its progression. The mathematical model for tumor-immune interactions would provide a new methodology for more sophisticated treatment options of cancer. To do this we have developed a system of 11 ordinary differential equations including the movement, interaction, and activation of NK cells, CD8(+)T-cells, CD4(+)T cells, regulatory T cells, and dendritic cells under the presence of tumor and cytokines and the immune interactions. In addition, we apply two control therapies, immunotherapy and chemotherapy to the model in order to control growth of tumor. Using optimal control theory and numerical simulations, we obtain appropriate treatment strategies according to the ratio of the cost for two therapies, which suggest an optimal timing of each administration for the two types of models, without and with immunosuppressive effects. These results mean that the immune suppression can have an influence on treatment strategies for cancer. PMID:25140193

Kim, Kwang Su; Cho, Giphil; Jung, Il Hyo

2014-01-01

82

Optimal Treatment Strategy for a Tumor Model under Immune Suppression  

PubMed Central

We propose a mathematical model describing tumor-immune interactions under immune suppression. These days evidences indicate that the immune suppression related to cancer contributes to its progression. The mathematical model for tumor-immune interactions would provide a new methodology for more sophisticated treatment options of cancer. To do this we have developed a system of 11 ordinary differential equations including the movement, interaction, and activation of NK cells, CD8+T-cells, CD4+T cells, regulatory T cells, and dendritic cells under the presence of tumor and cytokines and the immune interactions. In addition, we apply two control therapies, immunotherapy and chemotherapy to the model in order to control growth of tumor. Using optimal control theory and numerical simulations, we obtain appropriate treatment strategies according to the ratio of the cost for two therapies, which suggest an optimal timing of each administration for the two types of models, without and with immunosuppressive effects. These results mean that the immune suppression can have an influence on treatment strategies for cancer. PMID:25140193

Kim, Kwang Su; Cho, Giphil; Jung, Il Hyo

2014-01-01

83

Natural History of Innate Host Defense Peptides  

Microsoft Academic Search

Host defense peptides act on the forefront of innate immunity, thus playing a central role in the survival of animals and\\u000a plants. Despite vast morphological changes in species through evolutionary history, all animals examined to date share common\\u000a features in their innate immune defense strategies, hereunder expression of host defense peptides (HDPs). Most studies on\\u000a HDPs have focused on humans,

A. Linde; B. Wachter; O. P. Höner; L. Dib; C. Ross; A. R. Tamayo; F. Blecha; T. Melgarejo

2009-01-01

84

Quantitative proteomics of the human skin secretome reveal a reduction in immune defense mediators in ectodermal dysplasia patients.  

PubMed

In healthy human skin host defense molecules such as antimicrobial peptides (AMPs) contribute to skin immune homeostasis. In patients with the congenital disease ectodermal dysplasia (ED) skin integrity is disturbed and as a result patients have recurrent skin infections. The disease is characterized by developmental abnormalities of ectodermal derivatives and absent or reduced sweating. We hypothesized that ED patients have a reduced skin immune defense because of the reduced ability to sweat. Therefore, we performed a label-free quantitative proteome analysis of wash solution of human skin from ED patients or healthy individuals. A clear-cut difference between both cohorts could be observed in cellular processes related to immunity and host defense. In line with the extensive underrepresentation of proteins of the immune system, dermcidin, a sweat-derived AMP, was reduced in its abundance in the skin secretome of ED patients. In contrast, proteins involved in metabolic/catabolic and biosynthetic processes were enriched in the skin secretome of ED patients. In summary, our proteome profiling provides insights into the actual situation of healthy versus diseased skin. The systematic reduction in immune system and defense-related proteins may contribute to the high susceptibility of ED patients to skin infections and altered skin colonization. PMID:25347115

Burian, Marc; Velic, Ana; Matic, Katarina; Günther, Stephanie; Kraft, Beatrice; Gonser, Lena; Forchhammer, Stephan; Tiffert, Yvonne; Naumer, Christian; Krohn, Michael; Berneburg, Mark; Yazdi, Amir S; Ma?ek, Boris; Schittek, Birgit

2015-03-01

85

Immune response  

MedlinePLUS

... INNATE IMMUNITY Innate, or nonspecific, immunity is the defense system with which you were born. It protects ... body. These barriers form the first line of defense in the immune response. Examples of innate immunity ...

86

An alternative to present United States defense strategy  

E-print Network

-Allied Relationships Page 73 76 85 VI GREENLAND: GEOSTRATEGY Implications for Deterrence Greenland: The Site, Use, Design and Tactical Organization VII CONCLUSIONS BIBLIOGRAPHY 'PPENDIX VITA 101 106 113 ?6 140 PREFACE "P ' V' D d ~Ph'1 h ', " i...: provided that the act will not be too great for the nation to accept. As part of their military strategy, nations have devised nuclear strategies of various types. Basically they are tactics of reprisal in reply to the initial strike. All involve a...

Anthony, William Wallace

1971-01-01

87

Immune Evasion Strategies of Ranaviruses and Innate Immune Responses to These Emerging Pathogens  

PubMed Central

Ranaviruses (RV, Iridoviridae) are large double-stranded DNA viruses that infect fish, amphibians and reptiles. For ecological and commercial reasons, considerable attention has been drawn to the increasing prevalence of ranaviral infections of wild populations and in aquacultural settings. Importantly, RVs appear to be capable of crossing species barriers of numerous poikilotherms, suggesting that these pathogens possess a broad host range and potent immune evasion mechanisms. Indeed, while some of the 95–100 predicted ranavirus genes encode putative evasion proteins (e.g., vIF?, vCARD), roughly two-thirds of them do not share significant sequence identity with known viral or eukaryotic genes. Accordingly, the investigation of ranaviral virulence and immune evasion strategies is promising for elucidating potential antiviral targets. In this regard, recombination-based technologies are being employed to knock out gene candidates in the best-characterized RV member, Frog Virus (FV3). Concurrently, by using animal infection models with extensively characterized immune systems, such as the African clawed frog, Xenopus laevis, it is becoming evident that components of innate immunity are at the forefront of virus-host interactions. For example, cells of the macrophage lineage represent important combatants of RV infections while themselves serving as targets for viral infection, maintenance and possibly dissemination. This review focuses on the recent advances in the understanding of the RV immune evasion strategies with emphasis on the roles of the innate immune system in ranaviral infections. PMID:22852041

Grayfer, Leon; Andino, Francisco De Jesús; Chen, Guangchun; Chinchar, Gregory V.; Robert, Jacques

2012-01-01

88

Latitudinal variation of immune defense and sickness behavior in the white-crowned sparrow (Zonotrichia leucophrys).  

PubMed

There is a general trend that parasitism risk declines as latitude increases. Host populations breeding at high latitudes should therefore invest less in costly immune defenses than populations breeding in temperate or tropical zones, although it is unknown if such an effect is mediated by environmental (photoperiodic) or genetic factors or both. Acquired immune function (humoral, cell-mediated) and behavioral sickness responses to lipopolysaccharide (LPS; mimics bacterial infection) were assessed in two subspecies of white-crowned sparrow (Zonotrichia leucophrys) that breed at different latitudes in western North America. Zonotrichia l. gambelii (GWCS) is a high-latitude breeder (47-68 degrees N) while Z. l. pugetensis (PWCS) breeds at temperate latitudes (40-49 degrees N). Captive males of each subspecies were acclimated to (1) a short day (non-breeding) photoperiod (8L:16D), (2) the breeding photoperiod of PWCS (16L:8D), or (3) the breeding photoperiod of GWCS (20L:4D). Photoperiod was manipulated because shorter day lengths may enhance immune function. In support of a genetic effect, humoral responses to diphtheria-tetanus vaccination were significantly higher in PWCS compared to GWCS, regardless of photoperiod. There were no differences in cell-mediated responses to phytohemagglutinin (PHA) between subspecies or among photoperiods. For sickness responses to LPS, a significant interaction between photoperiod and subspecies was found, with long day GWCS producing stronger sickness responses (losing more weight, eating less) than short day GWCS and PWCS on all day lengths. However, these effects were influenced by photoperiodic changes in body condition. In conclusion, we find evidence for genetic control of immune responses across latitude, but no support for environmental (photoperiodic) regulation. PMID:18255257

Owen-Ashley, Noah T; Hasselquist, Dennis; Råberg, Lars; Wingfield, John C

2008-05-01

89

Social marketing as a strategy to increase immunization rates.  

PubMed

Today in the United States, outbreaks of vaccine-preventable disease are often traced to susceptible children whose parents have claimed an exemption from school or child care immunization regulations. The origins of this immunization hesitancy and resistance have roots in the decline of the threat of vaccine-preventable disease coupled with an increase in concerns about the adverse effects of vaccines, the emergence of mass media and the Internet, and the intrinsic limitations of modern medicine. Appeals to emotion have drowned out thoughtful discussion in public forums, and overall, public trust in immunizations has declined. We present an often overlooked behavior change strategy-social marketing-as a way to improve immunization rates by addressing the important roots of immunization hesitancy and effectively engaging emotions. As an example, we provide a synopsis of a social marketing campaign that is currently in development in Washington state and that is aimed at increasing timely immunizations in children from birth to age 24 months. PMID:19414689

Opel, Douglas J; Diekema, Douglas S; Lee, Nancy R; Marcuse, Edgar K

2009-05-01

90

Induced immunity against belowground insect herbivores- activation of defenses in the absence of a jasmonate burst.  

PubMed

Roots respond dynamically to belowground herbivore attack. Yet, little is known about the mechanisms and ecological consequences of these responses. Do roots behave the same way as leaves, or do the paradigms derived from aboveground research need to be rewritten? This is the central question that we tackle in this article. To this end, we review the current literature on induced root defenses and present a number of experiments on the interaction between the root herbivore Diabrotica virgifera and its natural host, maize. Currently, the literature provides no clear evidence that plants can recognize root herbivores specifically. In maize, mild mechanical damage is sufficient to trigger a root volatile response comparable to D. virgifera induction. Interestingly, the jasmonate (JA) burst, a highly conserved signaling event following leaf attack, is consistently attenuated in the roots across plant species, from wild tobacco to Arabidopsis. In accordance, we found only a weak JA response in D. virgifera attacked maize roots. Despite this reduction in JA-signaling, roots of many plants start producing a distinct suite of secondary metabolites upon attack and reconfigure their primary metabolism. We, therefore, postulate the existence of additional, unknown signals that govern induced root responses in the absence of a jasmonate burst. Surprisingly, despite the high phenotypic plasticity of plant roots, evidence for herbivore-induced resistance below ground is virtually absent from the literature. We propose that other defensive mechanisms, including resource reallocation and compensatory growth, may be more important to improve plant immunity below ground. PMID:22527052

Erb, Matthias; Glauser, Gaetan; Robert, Christelle A M

2012-06-01

91

A Role for Host Activation-Induced Cytidine Deaminase in Innate Immune Defense against KSHV  

PubMed Central

Activation-induced cytidine deaminase (AID) is specifically induced in germinal center B cells to carry out somatic hypermutation and class-switch recombination, two processes responsible for antibody diversification. Because of its mutagenic potential, AID expression and activity are tightly regulated to minimize unwanted DNA damage. Surprisingly, AID expression has been observed ectopically during pathogenic infections. However, the function of AID outside of the germinal centers remains largely uncharacterized. In this study, we demonstrate that infection of human primary naïve B cells with Kaposi's sarcoma-associated herpesvirus (KSHV) rapidly induces AID expression in a cell intrinsic manner. We find that infected cells are marked for elimination by Natural Killer cells through upregulation of NKG2D ligands via the DNA damage pathway, a pathway triggered by AID. Moreover, without having a measurable effect on KSHV latency, AID impinges directly on the viral fitness by inhibiting lytic reactivation and reducing infectivity of KSHV virions. Importantly, we uncover two KSHV-encoded microRNAs that directly regulate AID abundance, further reinforcing the role for AID in the antiviral response. Together our findings reveal additional functions for AID in innate immune defense against KSHV with implications for a broader involvement in innate immunity to other pathogens. PMID:24244169

Bekerman, Elena; Jeon, Diana; Ardolino, Michele; Coscoy, Laurent

2013-01-01

92

A role for host activation-induced cytidine deaminase in innate immune defense against KSHV.  

PubMed

Activation-induced cytidine deaminase (AID) is specifically induced in germinal center B cells to carry out somatic hypermutation and class-switch recombination, two processes responsible for antibody diversification. Because of its mutagenic potential, AID expression and activity are tightly regulated to minimize unwanted DNA damage. Surprisingly, AID expression has been observed ectopically during pathogenic infections. However, the function of AID outside of the germinal centers remains largely uncharacterized. In this study, we demonstrate that infection of human primary naïve B cells with Kaposi's sarcoma-associated herpesvirus (KSHV) rapidly induces AID expression in a cell intrinsic manner. We find that infected cells are marked for elimination by Natural Killer cells through upregulation of NKG2D ligands via the DNA damage pathway, a pathway triggered by AID. Moreover, without having a measurable effect on KSHV latency, AID impinges directly on the viral fitness by inhibiting lytic reactivation and reducing infectivity of KSHV virions. Importantly, we uncover two KSHV-encoded microRNAs that directly regulate AID abundance, further reinforcing the role for AID in the antiviral response. Together our findings reveal additional functions for AID in innate immune defense against KSHV with implications for a broader involvement in innate immunity to other pathogens. PMID:24244169

Bekerman, Elena; Jeon, Diana; Ardolino, Michele; Coscoy, Laurent

2013-01-01

93

An Abscisic Acid-Independent Oxylipin Pathway Controls Stomatal Closure and Immune Defense in Arabidopsis  

PubMed Central

Plant stomata function in innate immunity against bacterial invasion and abscisic acid (ABA) has been suggested to regulate this process. Using genetic, biochemical, and pharmacological approaches, we demonstrate that (i) the Arabidopsis thaliana nine-specific-lipoxygenase encoding gene, LOX1, which is expressed in guard cells, is required to trigger stomatal closure in response to both bacteria and the pathogen-associated molecular pattern flagellin peptide flg22; (ii) LOX1 participates in stomatal defense; (iii) polyunsaturated fatty acids, the LOX substrates, trigger stomatal closure; (iv) the LOX products, fatty acid hydroperoxides, or reactive electrophile oxylipins induce stomatal closure; and (v) the flg22-mediated stomatal closure is conveyed by both LOX1 and the mitogen-activated protein kinases MPK3 and MPK6 and involves salicylic acid whereas the ABA-induced process depends on the protein kinases OST1, MPK9, or MPK12. Finally, we show that the oxylipin and the ABA pathways converge at the level of the anion channel SLAC1 to regulate stomatal closure. Collectively, our results demonstrate that early biotic signaling in guard cells is an ABA-independent process revealing a novel function of LOX1-dependent stomatal pathway in plant immunity. PMID:23526882

Mondy, Samuel; Tranchimand, Sylvain; Rumeau, Dominique; Boudsocq, Marie; Garcia, Ana Victoria; Douki, Thierry; Bigeard, Jean; Laurière, Christiane; Chevalier, Anne; Castresana, Carmen; Hirt, Heribert

2013-01-01

94

Role of Analytical Chemistry in Defense Strategies Against Chemical and Biological Attack  

Microsoft Academic Search

Analytical chemistry plays a role in the two strategies of defense against chemical or biological weapons that are discussed in this review: the detect-to-protect and the prevent-and-detect strategies. The detect-to-protect method, which is based on detection of a known chemical agent with a specific chemical sensor designed for said agent, has serious flaws. I argue that this approach should be

Jiri Janata

2009-01-01

95

Understanding SMS Spam in a Large Cellular Network: Characteristics, Strategies and Defenses  

E-print Network

Understanding SMS Spam in a Large Cellular Network: Characteristics, Strategies and Defenses Nan (June 2011 to May 2012) of user reported SMS spam messages together with SMS network records collected from a large US based cellular carrier, we carry out a comprehensive study of SMS spamming. Our

Zhang, Zhi-Li

96

Evolution of mixed strategies of plant defense allocation against natural enemies.  

PubMed

In this study we present a simple optimization model for the evolution of defensive strategies (tolerance and resistance) of plants against their natural enemies. The model specifically evaluates the consequences of introducing variable costs and benefits of tolerance and resistance and nonlinear cost-and-benefit functions for tolerance and resistance. Incorporating these assumptions, the present model of plant defense predicts different evolutionary scenarios, not expected by previous work. Basically, the presence of an adaptive peak corresponding to intermediate levels of allocation to tolerance and resistance can arise when the shape parameter of the cost function is higher than the corresponding of the benefit function. The presence of two alternatives peaks of maximum tolerance and maximum resistance occurs only when benefits of tolerance and resistance interact less than additive. Finally, the presence of one peak of maximum resistance or maximum tolerance depends on the relative values of the magnitude of costs for tolerance and resistance. An important outcome of our model is that under a plausible set of conditions, variable costs of tolerance and resistance can represent an important aspect involved in the maintenance of intermediate levels of tolerance and resistance, and in favoring adaptive divergence in plant defensive strategies among populations. The model offers a framework for future theoretical and empirical work toward understanding spatial variation in levels of allocation to different defensive strategies. PMID:15446423

Fornoni, Juan; Núñez-Farfán, Juan; Valverde, Pedro Luis; Rausher, Mark D

2004-08-01

97

Adolescent Humor and its Relationship to Coping, Defense Strategies, Psychological Distress, and Well-Being  

Microsoft Academic Search

Objective  This study investigated the psychometric properties of the Humor Styles Questionnaire (HSQ) in measuring adolescent humor,\\u000a including the relationship between humor and coping style, defense style, depressive symptoms, and adjustment in a non-clinical\\u000a sample of adolescents.\\u000a \\u000a \\u000a \\u000a Method  Humor, coping, defense strategies, depressive symptoms, and adjustment were investigated in 94 adolescents aged 12–15.\\u000a \\u000a \\u000a \\u000a Results  The HSQ demonstrated adequate internal consistency. Inter-scale correlational patterns

Sarah J. Erickson; Sarah W. Feldstein

2007-01-01

98

Hybrid advantage in skin peptide immune defenses of water frogs (Pelophylax esculentus) at risk from emerging pathogens.  

PubMed

Heterogeneity in immune defense effectors can benefit hosts encountering a variety of parasites and pathogens. Antimicrobial peptides (AMPs) are a diverse set of immune defense effectors in many amphibians, and are secreted from dermal granular glands to protect the skin from infection. Over 50 different skin peptides have been reported from the European water frog hybridogenic complex (Pelophylax esculentus complex), consisting of the hybrid P. esculentus, and the parent species Pelophylax lessonae and Pelophylax ridibundus. In central Europe the hybrid is sympatric with only P. lessonae, while in other areas all three species can co-occur. Amphibian immune defenses are likely under selective pressure from emerging pathogens such as the chytrid fungus Batrachochytrium dendrobatidis (Bd). To assess if hybridization affects immune defenses against Bd, we compared skin peptides of the three species in terms of (i) quantity, (ii) activity against Bd, (iii) repertoire, and (iv) stability. Hybrids secreted AMPs at higher quantities and with greater fungicidal activity compared to cohabiting P. lessonae. Compared to P. ridibundus, AMPs from hybrids were of similar quantity but slightly greater antifungal activity. Mass spectrometric analyses (MALDI-TOF) revealed that of all three species P. esculentus has the greatest peptide diversity, a repertoire inclusive of peptides occurring in either one or the other parent species. Measurements of degradation dynamics indicate that peptides remain relatively stable on the skin of all species for over an hour after induction of skin gland secretions. Our data demonstrate that the hybrid has more effective peptide defenses against Bd and a richer peptide repertoire than either parent species. Hybrid advantage in environments hosting virulent pathogens may contribute to disassortative mating preferences, and we suggest that AMP diversity may be analogous to major histocompatibility complex (MHC) heterozygosity by benefiting hosts encountering multiple parasites. PMID:22940461

Daum, Janine M; Davis, Leyla R; Bigler, Laurent; Woodhams, Douglas C

2012-12-01

99

Chapter 13 Adaptive Defense Responses to Pathogens and Insects  

Microsoft Academic Search

The relative resistance of a plant to pathogens is determined by preformed, constitutive defenses, and the quality and diversity of the induced defenses deployed upon attack. Pathogens have evolved strategies to breach structural barriers and avoid or counter preformed and induced chemical defenses of their host plants. Plants have evolved sensitive mechanisms to perceive bioagressors and innate immune responses are

Linda L. Walling

2009-01-01

100

The Impact of High-Fat Diet on Metabolism and Immune Defense in Small Intestine Mucosa.  

PubMed

Improved procedures for sample preparation and proteomic data analysis allowed us to identify 7700 different proteins in mouse small intestinal mucosa and calculate the concentrations of >5000 proteins. We compared protein concentrations of small intestinal mucosa from mice that were fed for two months with normal diet (ND) containing 34.4% carbohydrates, 19.6% protein, and 3.3% fat or high-fat diet (HFD) containing 25.3% carbohydrates, 24.1% protein, and 34.6% fat. Eleven percent of the quantified proteins were significantly different between ND and HFD. After HFD, we observed an elevation of proteins involved in protein synthesis, protein N-glycosylation, and vesicle trafficking. Proteins engaged in fatty acid absorption, fatty acid ?-oxidation, and steroid metabolism were also increased. Enzymes of glycolysis and pentose phosphate cycle were decreased, whereas proteins of the respiratory chain and of ATP synthase were increased. The protein concentrations of various nutrient transporters located in the enterocyte plasma membrane including the Na(+)-d-glucose cotransporter SGLT1, the passive glucose transporter GLUT2, and the H(+)-peptide cotransporter PEPT1 were decreased. The concentration of the Na(+),K(+)-ATPase, which turned out to be the most strongly expressed enterocyte transporter, was also decreased. HFD also induced concentration changes of drug transporters and of enzymes involved in drug metabolism, which suggests effects of HFD on pharmacokinetics and toxicities. Finally, we observed down-regulation of antibody subunits and of components of the major histocompatibility complex II that may reflect impaired immune defense and immune tolerance in HFD. Our work shows dramatic changes in functional proteins of small intestine mucosa upon excessive fat consumption. PMID:25285821

Wi?niewski, Jacek R; Friedrich, Alexandra; Keller, Thorsten; Mann, Matthias; Koepsell, Hermann

2014-10-23

101

Considerations for developing an immunization strategy with enterovirus 71 vaccine.  

PubMed

Enterovirus 71 (EV71) is a common pathogen for hand, foot, and mouth disease (HFMD), which has significant morbidity and mortality, and for which children aged 6-59 months age are at highest risk. Due to lack of effective treatment options, control of EV71 epidemics has mainly focused on development of EV71 vaccines. Clinical trials have been completed on 3 EV71 vaccines, with trial results demonstrating good vaccine efficacy and safety. When EV71 vaccine is approved by China's national regulatory authority, an evidence-based strategy should be developed to optimize impact and safety. An immunization strategy for EV71 vaccine should consider several factors, including the target population age group, the number of doses for primary immunization, the need for a booster dose, concomitant administration of other vaccines, economic value, program capacity and logistics, and public acceptance. Once EV71 vaccines are in use, vaccine effectiveness and safety must be monitored in large populations, and the epidemiology of HFMD must be evaluated to assure a match between vaccination strategy and epidemiology. Evaluation in China is especially important because there are no other EV71 vaccines globally. PMID:25444807

Li, Li; Yin, Hongzhang; An, Zhijie; Feng, Zijian

2014-11-01

102

Invertebrate and avian predators as drivers of chemical defensive strategies in tenthredinid sawflies  

PubMed Central

Background Many insects are chemically defended against predatory vertebrates and invertebrates. Nevertheless, our understanding of the evolution and diversity of insect defenses remains limited, since most studies have focused on visual signaling of defenses against birds, thereby implicitly underestimating the impact of insectivorous insects. In the larvae of sawflies in the family Tenthredinidae (Hymenoptera), which feed on various plants and show diverse lifestyles, two distinct defensive strategies are found: easy bleeding of deterrent hemolymph, and emission of volatiles by ventral glands. Here, we used phylogenetic information to identify phylogenetic correlations among various ecological and defensive traits in order to estimate the relative importance of avian versus invertebrate predation. Results The mapping of 12 ecological and defensive traits on phylogenetic trees inferred from DNA sequences reveals the discrete distribution of easy bleeding that occurs, among others, in the genus Athalia and the tribe Phymatocerini. By contrast, occurrence of ventral glands is restricted to the monophyletic subfamily Nematinae, which are never easy bleeders. Both strategies are especially effective towards insectivorous insects such as ants, while only Nematinae species are frequently brightly colored and truly gregarious. Among ten tests of phylogenetic correlation between traits, only a few are significant. None of these involves morphological traits enhancing visual signals, but easy bleeding is associated with the absence of defensive body movements and with toxins occurring in the host plant. Easy bleeding functions through a combination of attributes, which is corroborated by an independent contrasts test indicating a statistically significant negative correlation between species-level integument mechanical resistance and hemolymph feeding deterrence against ants. Conclusions Our analyses evidence a repeated occurrence of easy bleeding, and no phylogenetic correlation including specific visual signals is significant. We conclude that the evolution of chemically-based defenses in tenthredinids may have been driven by invertebrate as much as by avian predation. The clear-cut visual signaling often encountered in the Nematinae would be linked to differential trends of habitat use by prey and predators. Further studies on (prey) insect groups should include visual signals and other traits, as well as several groups of natural enemies, to better interpret their relative significance and to refine our understanding of insect chemical defenses. PMID:24041372

2013-01-01

103

Influence of diet on fecundity, immune defense and content of 2-isopropyl-3-methoxypyrazine in Harmonia axyridis Pallas.  

PubMed

Food type can affect all functional aspects of an insect's life. We investigated the effects of different diet regimes on life history parameters of the ladybird beetle Harmonia axyridis. Furthermore, we tested the importance of elytral color, sex, and diet on chemical and immune defense in this species. We also compared hemolymph from cohorts of H. axyridis and Coccinella septempunctata (Coleoptera: Coccinellidae) fed different diets to examine effects on the 2-isopropyl-3-methoxypyrazine (IPMP) content in these beetles. No effects of diet on the duration of larval development and on adult weight were found. We detected, however, significantly higher fecundity and oviposition rates when female H. axyridis were reared on pea aphids than when reared on eggs of Ephestia kuehniella. Males and females did not differ in their immune response. Elytral color affected both immune defense and chemical defense. The antimicrobial activity of the hemolymph differed only when morphotypes were tested against E. coli. Moreover, we observed an effect of elytral pigmentation on IPMP content. The succinea 2 type (orange without dots) had the lowest IPMP content in two out of three feeding regimes compared to the succinea 1 (orange with dots) type. Depending on diet, IPMP contents differed in both species leading to higher contents either in H. axyridis or C. septempunctata. Furthermore, aphid species ingested during larval development significantly affected IPMP content in adult beetles. These results implicate new aspects for risk assessment of H. axyridis in viticulture. PMID:22648506

Kögel, Susanne; Eben, Astrid; Hoffmann, Christoph; Gross, Jürgen

2012-07-01

104

Partitioning, repressing and derepressing: dynamic regulations in MLA immune receptor triggered defense signaling  

PubMed Central

Plants and animals have evolved intracellular nucleotide-binding domain and leucine-rich repeat-containing immune receptors (NLRs) to perceive non-self and trigger immune responses. Plant NLRs detect strain-specific pathogen effectors and activate immune signaling leading to extensive transcriptional reprogramming and termination of pathogen infection. Here we review the recent findings in barley MLA immune receptor mediated immune responses against the barley powdery mildew fungus. We focus on nucleocytoplasmic partitioning of immune receptor, bifurcation of immune signaling, transcriptional repression and derepression connecting receptor activation to immune responses. We also discuss similar findings from other plant NLRs where appropriate. PMID:24115952

Chang, Cheng; Zhang, Ling; Shen, Qian-Hua

2013-01-01

105

Stimulatory effects of chitinase on growth and immune defense of orange-spotted grouper (Epinephelus coioides).  

PubMed

Chitinase, belonging to either family 18 or family 19 of the glycosylhydrolases, hydrolyze chitin into oligosaccharides. In the present study, the cDNA fragment encoding orange-spotted grouper (Epinephelus coioides) chitinase1 was subcloned into pPIC3.5K vector and expressed in Pichia pastoris GS115. The results showed that a band with the size of about 53 kDa could be detected by SDS-PAGE and Western blot. The recombinant protein of grouper chitinase1 (rgChi1) was added into the fish diet containing shrimp shell chitin for feeding experiment lasting 8 weeks. The weight of orange-spotted grouper, fed with diets containing rgChi1 at 0, 5, 10 and 20 ?g/g was calculated on the 2nd, 4th, 6th and 8th weeks, and difference in growth rates was first observed in the 6th week of the feeding period and it kept until the end of the feeding experiment. At the end of 8 weeks feeding trial, the percent weight gain (PWG), growth rate (GR) and specific growth rate (SGR) of fish fed with 10 and 20 ?g rgChi1/g feed were significantly higher compared to the control group. The neuropeptide Y (NPY), growth-hormone-releasing hormone (GHRH), growth-hormone (GH), interleukin-1beta (IL-1?), cyclooxygenase-2 (COX-2), superoxide dismutase (SOD) (Cu/Zn) and SOD (Mn) mRNA expression of fish fed with diet containing 10 ?g/g or/and 20 ?g/g rgChi1 were obviously higher than the control group. The lysozyme (LZM) and total SOD activity of fish fed with diet containing rgChi1 at 10 and 20 ?g/g were significantly higher than that of the control. The aspartate aminotransferase (AST)/glutamic oxalacetic transaminases (GOT) activity in 20 ?g/g group decreased compared to the control group. These results indicated that the grouper chitinase1 was successfully produced using the P. pastoris expression system and the recombinant protein had obvious effects on growth and immune defense. The mRNA expression and protein secretion of grouper chitinase1 and chitinase2 were significantly stimulated in spleen in response to bacterial lipopolysaccharide (LPS) challenge, strongly suggesting the existence of an innate pathway for local defense against chitin-containing organisms. Moreover, the pathogen such as Escherichia coli and Staphylococcus aureus could be inhibited by the recombinant protein of grouper chitinase1 to a certain extent. PMID:22365990

Zhang, Yanhong; Feng, Shaozhen; Chen, Jun; Qin, Chaobin; Lin, Haoran; Li, Wensheng

2012-05-01

106

Pipecolic Acid, an Endogenous Mediator of Defense Amplification and Priming, Is a Critical Regulator of Inducible Plant Immunity[W  

PubMed Central

Metabolic signals orchestrate plant defenses against microbial pathogen invasion. Here, we report the identification of the non-protein amino acid pipecolic acid (Pip), a common Lys catabolite in plants and animals, as a critical regulator of inducible plant immunity. Following pathogen recognition, Pip accumulates in inoculated Arabidopsis thaliana leaves, in leaves distal from the site of inoculation, and, most specifically, in petiole exudates from inoculated leaves. Defects of mutants in AGD2-LIKE DEFENSE RESPONSE PROTEIN1 (ALD1) in systemic acquired resistance (SAR) and in basal, specific, and ?-aminobutyric acid–induced resistance to bacterial infection are associated with a lack of Pip production. Exogenous Pip complements these resistance defects and increases pathogen resistance of wild-type plants. We conclude that Pip accumulation is critical for SAR and local resistance to bacterial pathogens. Our data indicate that biologically induced SAR conditions plants to more effectively synthesize the phytoalexin camalexin, Pip, and salicylic acid and primes plants for early defense gene expression. Biological priming is absent in the pipecolate-deficient ald1 mutants. Exogenous pipecolate induces SAR-related defense priming and partly restores priming responses in ald1. We conclude that Pip orchestrates defense amplification, positive regulation of salicylic acid biosynthesis, and priming to guarantee effective local resistance induction and the establishment of SAR. PMID:23221596

Návarová, Hana; Bernsdorff, Friederike; Döring, Anne-Christin; Zeier, Jürgen

2012-01-01

107

Stress, depression and immunity: the role of defense and coping styles  

Microsoft Academic Search

It is by now widely recognized that acute and chronic stress have an impact on the immune system. Acute stress may have a stimulating effect on the immune system, while in the case of chronic stress — and in particular in depression — the immune system may be down-regulated. However, there is considerable individual variability in the immune response to

Miranda Olff

1999-01-01

108

Toll-like receptors are part of the innate immune defense system of sponges (demospongiae: Porifera).  

PubMed

During evolution and with the emergence of multicellular animals, the need arose to ward off foreign organisms that threaten the integrity of the animal body. Among many different receptors that participate in the recognition of microbial invaders, toll-like receptors (TLRs) play an essential role in mediating the innate immune response. After binding distinct microbial components, TLRs activate intracellular signaling cascades that result in an induced expression of diverse antimicrobial molecules. Because sponges (phylum Porifera) are filter feeders, they are abundantly exposed to microorganisms that represent a potential threat. Here, we describe the identification, cloning, and deduced protein sequence from 3 major elements of the poriferan innate response (to bacterial lipopeptides): the TLR, the IL-1 receptor-associated kinase-4-like protein (IRAK-4l), and a novel effector caspase from the demosponge Suberites domuncula. Each molecule shares significant sequence similarity with its homologues in higher Metazoa. Sequence homologies were found in particular within the family-specific domains toll/interleukin-1 receptor/resistance (TLR family), Ser/Thr/Tyr kinase domain (IRAK family), and CASc (caspase family). In addition, in situ hybridization and immunohistological analyses revealed an abundance of SDTLR (TLR) transcripts in epithelial layers of the sponge surface (exopinacoderm and endopinacoderm). Furthermore, it is shown that both SDTLR and SDIRAK-4 like (IRAK) are expressed constitutively, regardless of treatment with synthetic triacyl lipopeptide Pam(3)Cys-Ser-(Lys)(4). In contrast, SDCASL (caspase) expression is highly Pam(3)Cys-Ser-(Lys)(4) inducible. However, blocking of the lipopeptide with recombinant TLR prior to its application completely prevented the induced expression of this poriferan caspase. These results underscore that the phylogenetically oldest extant metazoan phylum is provided already with the signaling pathways of the antimicrobial host-defense system of Metazoa. PMID:17190971

Wiens, Matthias; Korzhev, Michael; Perovic-Ottstadt, Sanja; Luthringer, Bérengère; Brandt, David; Klein, Stefanie; Müller, Werner E G

2007-03-01

109

The Nuclear Immune Receptor RPS4 Is Required for RRS1SLH1-Dependent Constitutive Defense Activation in Arabidopsis thaliana  

PubMed Central

Plant nucleotide-binding leucine-rich repeat (NB-LRR) disease resistance (R) proteins recognize specific “avirulent” pathogen effectors and activate immune responses. NB-LRR proteins structurally and functionally resemble mammalian Nod-like receptors (NLRs). How NB-LRR and NLR proteins activate defense is poorly understood. The divergently transcribed Arabidopsis R genes, RPS4 (resistance to Pseudomonas syringae 4) and RRS1 (resistance to Ralstonia solanacearum 1), function together to confer recognition of Pseudomonas AvrRps4 and Ralstonia PopP2. RRS1 is the only known recessive NB-LRR R gene and encodes a WRKY DNA binding domain, prompting suggestions that it acts downstream of RPS4 for transcriptional activation of defense genes. We define here the early RRS1-dependent transcriptional changes upon delivery of PopP2 via Pseudomonas type III secretion. The Arabidopsis slh1 (sensitive to low humidity 1) mutant encodes an RRS1 allele (RRS1SLH1) with a single amino acid (leucine) insertion in the WRKY DNA-binding domain. Its poor growth due to constitutive defense activation is rescued at higher temperature. Transcription profiling data indicate that RRS1SLH1-mediated defense activation overlaps substantially with AvrRps4- and PopP2-regulated responses. To better understand the genetic basis of RPS4/RRS1-dependent immunity, we performed a genetic screen to identify suppressor of slh1 immunity (sushi) mutants. We show that many sushi mutants carry mutations in RPS4, suggesting that RPS4 acts downstream or in a complex with RRS1. Interestingly, several mutations were identified in a domain C-terminal to the RPS4 LRR domain. Using an Agrobacterium-mediated transient assay system, we demonstrate that the P-loop motif of RPS4 but not of RRS1SLH1 is required for RRS1SLH1 function. We also recapitulate the dominant suppression of RRS1SLH1 defense activation by wild type RRS1 and show this suppression requires an intact RRS1 P-loop. These analyses of RRS1SLH1 shed new light on mechanisms by which NB-LRR protein pairs activate defense signaling, or are held inactive in the absence of a pathogen effector. PMID:25340333

Sarris, Panagiotis F.; Woo, Joo Yong; Williams, Simon J.; Newman, Toby E.; Paek, Kyung Hee; Kobe, Bostjan; Jones, Jonathan D. G.

2014-01-01

110

The nuclear immune receptor RPS4 is required for RRS1SLH1-dependent constitutive defense activation in Arabidopsis thaliana.  

PubMed

Plant nucleotide-binding leucine-rich repeat (NB-LRR) disease resistance (R) proteins recognize specific "avirulent" pathogen effectors and activate immune responses. NB-LRR proteins structurally and functionally resemble mammalian Nod-like receptors (NLRs). How NB-LRR and NLR proteins activate defense is poorly understood. The divergently transcribed Arabidopsis R genes, RPS4 (resistance to Pseudomonas syringae 4) and RRS1 (resistance to Ralstonia solanacearum 1), function together to confer recognition of Pseudomonas AvrRps4 and Ralstonia PopP2. RRS1 is the only known recessive NB-LRR R gene and encodes a WRKY DNA binding domain, prompting suggestions that it acts downstream of RPS4 for transcriptional activation of defense genes. We define here the early RRS1-dependent transcriptional changes upon delivery of PopP2 via Pseudomonas type III secretion. The Arabidopsis slh1 (sensitive to low humidity 1) mutant encodes an RRS1 allele (RRS1SLH1) with a single amino acid (leucine) insertion in the WRKY DNA-binding domain. Its poor growth due to constitutive defense activation is rescued at higher temperature. Transcription profiling data indicate that RRS1SLH1-mediated defense activation overlaps substantially with AvrRps4- and PopP2-regulated responses. To better understand the genetic basis of RPS4/RRS1-dependent immunity, we performed a genetic screen to identify suppressor of slh1 immunity (sushi) mutants. We show that many sushi mutants carry mutations in RPS4, suggesting that RPS4 acts downstream or in a complex with RRS1. Interestingly, several mutations were identified in a domain C-terminal to the RPS4 LRR domain. Using an Agrobacterium-mediated transient assay system, we demonstrate that the P-loop motif of RPS4 but not of RRS1SLH1 is required for RRS1SLH1 function. We also recapitulate the dominant suppression of RRS1SLH1 defense activation by wild type RRS1 and show this suppression requires an intact RRS1 P-loop. These analyses of RRS1SLH1 shed new light on mechanisms by which NB-LRR protein pairs activate defense signaling, or are held inactive in the absence of a pathogen effector. PMID:25340333

Sohn, Kee Hoon; Segonzac, Cécile; Rallapalli, Ghanasyam; Sarris, Panagiotis F; Woo, Joo Yong; Williams, Simon J; Newman, Toby E; Paek, Kyung Hee; Kobe, Bostjan; Jones, Jonathan D G

2014-10-01

111

Arabidopsis BRCA2 and RAD51 proteins are specifically involved in defense gene transcription during plant immune responses  

PubMed Central

Systemic acquired resistance (SAR) is a plant immune response associated with both transcriptional reprogramming and increased homologous DNA recombination (HR). SNI1 is a negative regulator of SAR and HR, as indicated by the increased basal expression of defense genes and HR in sni1. We found that the sni1 phenotypes are rescued by mutations in BREAST CANCER 2 (BRCA2). In humans, BRCA2 is a mediator of RAD51 in pairing of homologous DNA. Mutations in BRCA2 cause predisposition to breast/ovarian cancers; however, the role of the BRCA2–RAD51 complex in transcriptional regulation remains unclear. In Arabidopsis, both brca2 and rad51 were found to be hypersusceptible not only to genotoxic substances, but also to pathogen infections. A whole-genome microarray analysis showed that downstream of NPR1, BRCA2A is a major regulator of defense-related gene transcription. ChIP demonstrated that RAD51 is specifically recruited to the promoters of defense genes during SAR. This recruitment is dependent on the SAR signal salicylic acid (SA) and on the function of BRCA2. This study provides the molecular evidence showing that the BRCA2–RAD51 complex, known for its function in HR, also plays a direct and specific role in transcription regulation during plant immune responses. PMID:21149701

Wang, Shui; Durrant, Wendy E.; Song, Junqi; Spivey, Natalie W.; Dong, Xinnian

2010-01-01

112

An Efficient Immunization Strategy for Community Kai Gong1,2  

E-print Network

An Efficient Immunization Strategy for Community Networks Kai Gong1,2 , Ming Tang1,2,3 *, Pak Ming properly identify the targets to immunize or quarantine for preventing an epidemic in a population without with a larger number of weak ties, as immunizing targets based on the idea of referencing to an expanding

Lai, Ying-Cheng

113

Phage Anti-Immune Complex Assay: General Strategy for Noncompetitive Immunodetection of  

E-print Network

Phage Anti-Immune Complex Assay: General Strategy for Noncompetitive Immunodetection of Small. This has prompted the development of anti-immune complex antibodies, but these are difficult to produce that anti-immune complex antibodies can be substituted by phage particles isolated from phage display

Hammock, Bruce D.

114

Stimulation of Host Immune Defenses by a Small Molecule Protects C. elegans from Bacterial Infection  

PubMed Central

The nematode Caenorhabditis elegans offers currently untapped potential for carrying out high-throughput, live-animal screens of low molecular weight compound libraries to identify molecules that target a variety of cellular processes. We previously used a bacterial infection assay in C. elegans to identify 119 compounds that affect host-microbe interactions among 37,214 tested. Here we show that one of these small molecules, RPW-24, protects C. elegans from bacterial infection by stimulating the host immune response of the nematode. Using transcriptome profiling, epistasis pathway analyses with C. elegans mutants, and an RNAi screen, we show that RPW-24 promotes resistance to Pseudomonas aeruginosa infection by inducing the transcription of a remarkably small number of C. elegans genes (?1.3% of all genes) in a manner that partially depends on the evolutionarily-conserved p38 MAP kinase pathway and the transcription factor ATF-7. These data show that the immunostimulatory activity of RPW-24 is required for its efficacy and define a novel C. elegans–based strategy to identify compounds with activity against antibiotic-resistant bacterial pathogens. PMID:22719261

Pukkila-Worley, Read; Feinbaum, Rhonda; Kirienko, Natalia V.; Larkins-Ford, Jonah; Conery, Annie L.; Ausubel, Frederick M.

2012-01-01

115

Innate immune memory: towards a better understanding of host defense mechanisms.  

PubMed

Innate immunity is classically defined as unable to build up immunological memory. Recently however, the assumption of the lack of immunological memory within innate immune responses has been reconsidered. Plants and invertebrates lacking adaptive immune system can be protected against secondary infections. It has been shown that mammals can build cross-protection to secondary infections independently of T-lymphocytes and B-lymphocytes. Moreover, recent studies have demonstrated that innate immune cells such as NK cells and monocytes can display adaptive characteristics, a novel concept for which the term trained immunity has been proposed. Several mechanisms are involved in mediating innate immune memory, among which epigenetic histone modifications and modulation of recognition receptors on the surface of innate immune cells are likely to play a central role. PMID:24637148

Quintin, Jessica; Cheng, Shih-Chin; van der Meer, Jos W M; Netea, Mihai G

2014-08-01

116

Tolerance of fungal infection in European water frogs exposed to Batrachochytrium dendrobatidis after experimental reduction of innate immune defenses  

PubMed Central

Background While emerging diseases are affecting many populations of amphibians, some populations are resistant. Determining the relative contributions of factors influencing disease resistance is critical for effective conservation management. Innate immune defenses in amphibian skin are vital host factors against a number of emerging pathogens such as ranaviruses and the amphibian chytrid fungus Batrachochytrium dendrobatidis (Bd). Adult water frogs from Switzerland (Pelophylax esculentus and P. lessonae) collected in the field with their natural microbiota intact were exposed to Bd after experimental reduction of microbiota, skin peptides, both, or neither to determine the relative contributions of these defenses. Results Naturally-acquired Bd infections were detected in 10/51 P. lessonae and 4/19 P. esculentus, but no disease outbreaks or population declines have been detected at this site. Thus, this population was immunologically primed, and disease resistant. No mortality occurred during the 64 day experiment. Forty percent of initially uninfected frogs became sub-clinically infected upon experimental exposure to Bd. Reduction of both skin peptide and microbiota immune defenses caused frogs to gain less mass when exposed to Bd than frogs in other treatments. Microbiota-reduced frogs increased peptide production upon Bd infection. Ranavirus was undetectable in all but two frogs that appeared healthy in the field, but died within a week under laboratory conditions. Virus was detectable in both toe-clips and internal organs. Conclusion Intact skin microbiota reduced immune activation and can minimize subclinical costs of infection. Tolerance of Bd or ranavirus infection may differ with ecological conditions. PMID:23088169

2012-01-01

117

Final Report for Bio-Inspired Approaches to Moving-Target Defense Strategies  

SciTech Connect

This report records the work and contributions of the NITRD-funded Bio-Inspired Approaches to Moving-Target Defense Strategies project performed by Pacific Northwest National Laboratory under the technical guidance of the National Security Agency’s R6 division. The project has incorporated a number of bio-inspired cyber defensive technologies within an elastic framework provided by the Digital Ants. This project has created the first scalable, real-world prototype of the Digital Ants Framework (DAF)[11] and integrated five technologies into this flexible, decentralized framework: (1) Ant-Based Cyber Defense (ABCD), (2) Behavioral Indicators, (3) Bioinformatic Clas- sification, (4) Moving-Target Reconfiguration, and (5) Ambient Collaboration. The DAF can be used operationally to decentralize many such data intensive applications that normally rely on collection of large amounts of data in a central repository. In this work, we have shown how these component applications may be decentralized and may perform analysis at the edge. Operationally, this will enable analytics to scale far beyond current limitations while not suffering from the bandwidth or computational limitations of centralized analysis. This effort has advanced the R6 Cyber Security research program to secure digital infrastructures by developing a dynamic means to adaptively defend complex cyber systems. We hope that this work will benefit both our client’s efforts in system behavior modeling and cyber security to the overall benefit of the nation.

Fink, Glenn A.; Oehmen, Christopher S.

2012-09-01

118

Garland Science 2009 The concept of an immune system-the defense of  

E-print Network

) © Garland Science 2009 Agnathans (jawless fish) Hagfish lamprey Agnathans possess an adaptive by different species - Evolution of the innate immune system - Evolution of the adaptive immune, b) insects and c) mammals are structurally related and the progenitor gene may have been present

Utrecht, Universiteit

119

A Recessive Mutation, Immune Deficiency (imd), Defines Two Distinct Control Pathways in the Drosophila Host Defense  

Microsoft Academic Search

In this paper we report a recessive mutation, immune deficiency (imd), that impairs the inducibility of all genes encoding antibacterial peptides during the immune response of Drosophila. When challenged with bacteria, flies carrying this mutation show a lower survival rate than wild-type flies. We also report that, in contrast to the anti-bacterial peptides, the antifungal peptide drosomycin remains inducible in

Bruno Lemaitre; Elisabeth Kromer-Metzger; Lydia Michaut; Emmanuelle Nicolas; Marie Meister; Philippe Georgel; Jean-Marc Reichhart; Jules A. Hoffmann

1995-01-01

120

Immunity and emotions: Lipopolysaccharide increases defensive behaviours and potentiates despair in mice  

Microsoft Academic Search

Many studies have pointed out the relationships between immunity and depression, supporting a neuroimmune hypothesis of depressive disorders. However, despite the growing interest for such a hypothesis and the amount of clinical and experimental data available, the precise nature of this relationship between immunity and depression remains unclear. The present study aimed to investigate further the link between depression and

Julien Renault; Arnaud Aubert

2006-01-01

121

Passive Antibody Administration (Immediate Immunity) as a Specific Defense against Biological Weapons  

Microsoft Academic Search

The potential threat of biological warfare with a specific agent is proportional to the susceptibility of the population to that agent. Preventing disease after exposure to a biological agent is partially a function of the immunity of the exposed individual. The only available countermeasure that can provide immediate immunity against a biological agent is passive antibody. Unlike vaccines, which require

Arturo Casadevall

122

A Multipopulation Coevolutionary Strategy for Multiobjective Immune Algorithm  

PubMed Central

How to maintain the population diversity is an important issue in designing a multiobjective evolutionary algorithm. This paper presents an enhanced nondominated neighbor-based immune algorithm in which a multipopulation coevolutionary strategy is introduced for improving the population diversity. In the proposed algorithm, subpopulations evolve independently; thus the unique characteristics of each subpopulation can be effectively maintained, and the diversity of the entire population is effectively increased. Besides, the dynamic information of multiple subpopulations is obtained with the help of the designed cooperation operator which reflects a mutually beneficial relationship among subpopulations. Subpopulations gain the opportunity to exchange information, thereby expanding the search range of the entire population. Subpopulations make use of the reference experience from each other, thereby improving the efficiency of evolutionary search. Compared with several state-of-the-art multiobjective evolutionary algorithms on well-known and frequently used multiobjective and many-objective problems, the proposed algorithm achieves comparable results in terms of convergence, diversity metrics, and running time on most test problems. PMID:24672330

Shi, Jiao; Gong, Maoguo; Ma, Wenping; Jiao, Licheng

2014-01-01

123

Ecient Immunization Strategies for Computer Networks and Populations Reuven Cohen , 1 Shlomo Havlin, 1 and Daniel ben-Avraham 2  

E-print Network

EÃ?cient Immunization Strategies for Computer Networks and Populations Reuven Cohen #3; , 1 Shlomo;ective immunization strategy for computer networks and populations with broad and, in particular, scale-free degree distributions. The proposed strategy, acquaintance immuniza- tion, calls for the immunization

Cohen, Reuven

124

The Anopheles innate immune system in the defense against malaria infection  

PubMed Central

The multifaceted innate immune system of insects is capable of fighting infection by a variety of pathogens including those causing human malaria. Malaria transmission by the Anopheles mosquito depends on the Plasmodium parasite’s successful completion of its lifecycle in the insect vector, a process that involves interactions with several tissues and cell types as well as with the mosquito’s innate immune system. This review will discuss our current understanding of the Anopheles mosquito’s innate immune responses against the malaria parasite Plasmodium and the influence of the insect’s intestinal microbiota on parasite infection. PMID:23988482

Clayton, April M.; Dong, Yuemei; Dimopoulos, George

2014-01-01

125

Epithelial cells, the "switchboard" of respiratory immune defense responses: effects of air pollutants.  

PubMed

"Epimmunome", a term introduced recently by Swamy and colleagues, describes all molecules and pathways used by epithelial cells (ECs) to instruct immune cells. Today, we know that ECs are among the first sites within the human body to be exposed to pathogens (such as influenza viruses) and that the release of chemokine and cytokines by ECs is influenced by inhaled agents. The role of the ECs as a switchboard to initiate and regulate immune responses is altered through air pollutant exposure, such as ozone, tobacco smoke and diesel exhaust emissions. The details of the interplay between ECs and immune cells are not yet fully understood and need to be investigated further. Co-culture models, cell specific genetically-modified mice and the analysis of human biopsies provide great tools to gain knowledge about potential mechanisms. Increasing our understanding about the role of ECs in respiratory immunity may yield novel therapeutic targets to modulate downstream diseases. PMID:22851042

Müller, Loretta; Jaspers, Ilona

2012-01-01

126

Poplar extrafloral nectaries: two types, two strategies of indirect defenses against herbivores.  

PubMed

Many plant species grow extrafloral nectaries and produce nectar to attract carnivore arthropods as defenders against herbivores. Two nectary types that evolved with Populus trichocarpa (Ptr) and Populus tremula × Populus tremuloides (Ptt) were studied from their ecology down to the genes and molecules. Both nectary types strongly differ in morphology, nectar composition and mode of secretion, and defense strategy. In Ptt, nectaries represent constitutive organs with continuous merocrine nectar flow, nectary appearance, nectar production, and flow. In contrast, Ptr nectaries were found to be holocrine and inducible. Neither mechanical wounding nor the application of jasmonic acid, but infestation by sucking insects, induced Ptr nectar secretion. Thus, nectaries of Ptr and Ptt seem to answer the same threat by the use of different mechanisms. PMID:22573802

Escalante-Pérez, María; Jaborsky, Mario; Lautner, Silke; Fromm, Jörg; Müller, Tobias; Dittrich, Marcus; Kunert, Maritta; Boland, Wilhelm; Hedrich, Rainer; Ache, Peter

2012-07-01

127

Poplar Extrafloral Nectaries: Two Types, Two Strategies of Indirect Defenses against Herbivores1[C][W  

PubMed Central

Many plant species grow extrafloral nectaries and produce nectar to attract carnivore arthropods as defenders against herbivores. Two nectary types that evolved with Populus trichocarpa (Ptr) and Populus tremula × Populus tremuloides (Ptt) were studied from their ecology down to the genes and molecules. Both nectary types strongly differ in morphology, nectar composition and mode of secretion, and defense strategy. In Ptt, nectaries represent constitutive organs with continuous merocrine nectar flow, nectary appearance, nectar production, and flow. In contrast, Ptr nectaries were found to be holocrine and inducible. Neither mechanical wounding nor the application of jasmonic acid, but infestation by sucking insects, induced Ptr nectar secretion. Thus, nectaries of Ptr and Ptt seem to answer the same threat by the use of different mechanisms. PMID:22573802

Escalante-Pérez, María; Jaborsky, Mario; Lautner, Silke; Fromm, Jörg; Müller, Tobias; Dittrich, Marcus; Kunert, Maritta; Boland, Wilhelm; Hedrich, Rainer; Ache, Peter

2012-01-01

128

Novel vaccine development strategies for inducing mucosal immunity  

PubMed Central

To develop protective immune responses against mucosal pathogens, the delivery route and adjuvants for vaccination are important. The host, however, strives to maintain mucosal homeostasis by responding to mucosal antigens with tolerance, instead of immune activation. Thus, induction of mucosal immunity through vaccination is a rather difficult task, and potent mucosal adjuvants, vectors or other special delivery systems are often used, especially in the elderly. By taking advantage of the common mucosal immune system, the targeting of mucosal dendritic cells and microfold epithelial cells may facilitate the induction of effective mucosal immunity. Thus, novel routes of immunization and antigen delivery systems also show great potential for the development of effective and safe mucosal vaccines against various pathogens. The purpose of this review is to introduce several recent approaches to induce mucosal immunity to vaccines, with an emphasis on mucosal tissue targeting, new immunization routes and delivery systems. Defining the mechanisms of mucosal vaccines is as important as their efficacy and safety, and in this article, examples of recent approaches, which will likely accelerate progress in mucosal vaccine development, are discussed. PMID:22380827

Fujkuyama, Yoshiko; Tokuhara, Daisuke; Kataoka, Kosuke; Gilbert, Rebekah S; McGhee, Jerry R; Yuki, Yoshikazu; Kiyono, Hiroshi; Fujihashi, Kohtaro

2012-01-01

129

Origins of immunity: Relish, a compound Rel-like gene in the antibacterial defense of Drosophila.  

PubMed Central

NF-kappa B/Rel transcription factors are central regulators of mammalian immunity and are also implicated in the induction of cecropins and other antibacterial peptides in insects. We identified the gene for Relish, a compound Drosophila protein that, like mammalian p105 and p100, contains both a Rel homology domain and an I kappa B-like domain. Relish is strongly induced in infected flies, and it can activate transcription from the Cecropin A1 promoter. A Relish transcript is also detected in early embryos, suggesting that it acts in both immunity and embryogenesis. The presence of a compound Rel protein in Drosophila indicates that similar proteins were likely present in primordial immune systems and may serve unique signaling functions. Images Fig. 2 Fig. 3 Fig. 4 PMID:8816802

Dushay, M S; Asling, B; Hultmark, D

1996-01-01

130

Chemokines in innate and adaptive host defense: basic chemokinese grammar for immune cells.  

PubMed

Chemokines compose a sophisticated communication system used by all our cell types, including immune cells. Chemokine messages are decoded by specific receptors that initiate signal transduction events leading to a multitude of cellular responses, leukocyte chemotaxis and adhesion in particular. Critical determinants of the in vivo activities of chemokines in the immune system include their presentation by endothelial cells and extracellular matrix molecules, as well as their cellular uptake via "silent" chemokine receptors (interceptors) leading either to their transcytosis or to degradation. These regulatory mechanisms of chemokine histotopography, as well as the promiscuous and overlapping receptor specificities of inflammation-induced chemokines, shape innate responses to infections and tissue damage. Conversely, the specific patterns of homeostatic chemokines, where each chemokine is perceived by a single receptor, are charting lymphocyte navigation routes for immune surveillance. This review presents our current understanding of the mechanisms that regulate the cellular perception and pathophysiologic meaning of chemokines. PMID:15032599

Rot, Antal; von Andrian, Ulrich H

2004-01-01

131

Supporting information for Evolution of suicide as a defense strategy against pathogens in a spatially structured environment  

E-print Network

Supporting information for Evolution of suicide as a defense strategy against pathogens ( ), the evolution of altruistic suicide is given by: (A2) This equation shows that, in a well-mixed environment, altruistic suicide is never selected for. At best, when there is no cost of altruistic suicide, the evolution

132

Comparative analysis of the effectiveness of three immunization strategies in controlling disease outbreaks in realistic social networks.  

PubMed

The high incidence of emerging infectious diseases has highlighted the importance of effective immunization strategies, especially the stochastic algorithms based on local available network information. Present stochastic strategies are mainly evaluated based on classical network models, such as scale-free networks and small-world networks, and thus are insufficient. Three frequently referred stochastic immunization strategies-acquaintance immunization, community-bridge immunization, and ring vaccination-were analyzed in this work. The optimal immunization ratios for acquaintance immunization and community-bridge immunization strategies were investigated, and the effectiveness of these three strategies in controlling the spreading of epidemics were analyzed based on realistic social contact networks. The results show all the strategies have decreased the coverage of the epidemics compared to baseline scenario (no control measures). However the effectiveness of acquaintance immunization and community-bridge immunization are very limited, with acquaintance immunization slightly outperforming community-bridge immunization. Ring vaccination significantly outperforms acquaintance immunization and community-bridge immunization, and the sensitivity analysis shows it could be applied to controlling the epidemics with a wide infectivity spectrum. The effectiveness of several classical stochastic immunization strategies was evaluated based on realistic contact networks for the first time in this study. These results could have important significance for epidemic control research and practice. PMID:24787718

Xu, Zhijing; Zu, Zhenghu; Zheng, Tao; Zhang, Wendou; Xu, Qing; Liu, Jinjie

2014-01-01

133

The natural cytotoxicity receptor NKp46 is dispensable for IL-22-mediated innate intestinal immune defense against Citrobacter rodentium.  

PubMed

Natural cytotoxicity receptors (including NKp30, NKp44, and NKp46 in humans and NKp46 in mice) are type I transmembrane proteins that signal NK cell activation via ITAM-containing adapter proteins in response to stress- and pathogen-induced ligands. Although murine NKp46 expression (encoded by Ncr1) was thought to be predominantly restricted to NK cells, the identification of distinct intestinal NKp46(+) cell subsets that express the transcription factor Rorc and produce IL-22 suggests a broader function for NKp46 that could involve intestinal homeostasis and immune defense. Using mice carrying a GFP-modified Ncr1 allele, we found normal numbers of gut CD3(-)GFP(+) cells with a similar cell surface phenotype and subset distribution in the absence of Ncr1. Splenic and intestinal CD3(-)NKp46(+) cell subsets showed distinct patterns of cytokine secretion (IFN-gamma, IL-22) following activation via NK1.1, NKp46, IL-12 plus IL-18, or IL-23. However, IL-22 production was sharply restricted to intestinal CD3(-)GFP(+) cells with the CD127(+)NK1.1(-) phenotype and could be induced in an Ncr1-independent fashion. Because NKp46 ligands can trigger immune activation in the context of infectious pathogens, we assessed the response of wild-type and Ncr-1-deficient Rag2(-/-) mice to the enteric pathogen Citrobacter rodentium. No differences in the survival or clinical score were observed in C. rodentium-infected Rag2(-/-) mice lacking Ncr1, indicating that NKp46 plays a redundant role in the differentiation of intestinal IL-22(+) cells that mediate innate defense against this pathogen. Our results provide further evidence for functional heterogeneity in intestinal NKp46(+) cells that contrast with splenic NK cells. PMID:19846871

Satoh-Takayama, Naoko; Dumoutier, Laure; Lesjean-Pottier, Sarah; Ribeiro, Vera S G; Mandelboim, Ofer; Renauld, Jean-Christophe; Vosshenrich, Christian A J; Di Santo, James P

2009-11-15

134

Ironing Out the Wrinkles in Host Defense: Interactions between Iron Homeostasis and Innate Immunity  

Microsoft Academic Search

Iron is an essential micronutrient for both microbial pathogens and their mammalian hosts. Changes in iron availability and distribution have significant effects on pathogen virulence and on the immune response to infection. Recent advances in our understanding of the molecular regulation of iron metabolism have shed new light on how alterations in iron homeostasis both contribute to and influence innate

Lijian Wang; Bobby J. Cherayil

2009-01-01

135

Transgenerational effects of heavy metal pollution on immune defense of the blow fly Protophormia terraenovae.  

PubMed

Recently environmental conditions during early parental development have been found to have transgenerational effects on immunity and other condition-dependent traits. However, potential transgenerational effects of heavy metal pollution have not previously been studied. Here we show that direct exposure to heavy metal (copper) upregulates the immune system of the blow fly, Protophormia terraenovae, reared in copper contaminated food. In the second experiment, to test transgenerational effects of heavy metal, the parental generation of the P. terraenovae was reared in food supplemented with copper, and the immunocompetence of their offspring, reared on uncontaminated food, was measured. Copper concentration used in this study was, in the preliminary test, found to have no effect on mortality of the flies. Immunity was tested on the imago stage by measuring encapsulation response against an artificial antigen, nylon monofilament. We found that exposure to copper during the parental development stages through the larval diet resulted in immune responses that were still apparent in the next generation that was not exposed to the heavy metal. We found that individuals reared on copper-contaminated food developed more slowly compared with those reared on uncontaminated food. The treatment groups did not differ in their dry body mass. However, parental exposure to copper did not have an effect on the development time or body mass of their offspring. Our study suggests that heavy metal pollution has positive feedback effect on encapsulation response through generations which multiplies the harmful effects of heavy metal pollution in following generations. PMID:22719959

Pölkki, Mari; Kangassalo, Katariina; Rantala, Markus J

2012-01-01

136

Transgenerational Effects of Heavy Metal Pollution on Immune Defense of the Blow Fly Protophormia terraenovae  

PubMed Central

Recently environmental conditions during early parental development have been found to have transgenerational effects on immunity and other condition-dependent traits. However, potential transgenerational effects of heavy metal pollution have not previously been studied. Here we show that direct exposure to heavy metal (copper) upregulates the immune system of the blow fly, Protophormia terraenovae, reared in copper contaminated food. In the second experiment, to test transgenerational effects of heavy metal, the parental generation of the P. terraenovae was reared in food supplemented with copper, and the immunocompetence of their offspring, reared on uncontaminated food, was measured. Copper concentration used in this study was, in the preliminary test, found to have no effect on mortality of the flies. Immunity was tested on the imago stage by measuring encapsulation response against an artificial antigen, nylon monofilament. We found that exposure to copper during the parental development stages through the larval diet resulted in immune responses that were still apparent in the next generation that was not exposed to the heavy metal. We found that individuals reared on copper-contaminated food developed more slowly compared with those reared on uncontaminated food. The treatment groups did not differ in their dry body mass. However, parental exposure to copper did not have an effect on the development time or body mass of their offspring. Our study suggests that heavy metal pollution has positive feedback effect on encapsulation response through generations which multiplies the harmful effects of heavy metal pollution in following generations. PMID:22719959

Pölkki, Mari; Kangassalo, Katariina; Rantala, Markus J.

2012-01-01

137

Strategies for defending a dribbler: categorisation of three defensive patterns in 1-on-1 basketball.  

PubMed

To clarify the defending-dribbler mechanism, the interaction between the dribbler and defender should be investigated. The purposes of this study were to identify variables that explain the outcome (i.e. 'penetrating' and 'guarding') and to understand how defenders stop dribblers by categorising defensive patterns. Ten basketball players participated as 24 dribbler-defender pairs, who played a real-time, 1-on-1 sub-phase of the basketball. The trials were categorised into penetrating trials, where a dribbler invaded the defended area behind the defender, and guarding trials, where the defender stopped the dribbler's advance. Our results demonstrated that defenders in guarding trials initiated their movements earlier and moved quicker than the defenders in penetrating trials. Moreover, linear discriminant analysis revealed that the differences in initiation time and medio-lateral peak velocity between the defenders and dribblers were critical parameters for explaining the difference between penetrating and guarding trials. Lastly, guarding trials were further categorised into three process patterns during 1-on-1 basketball (i.e. 'early initiation' trials, 'quick movement' trials, and 'dribbler's stop' trials). The results suggest that there are three defending strategies and that one strategy would be insufficient to explain the defending-dribbler mechanism, because both players' anticipation and reactive movement must be considered. PMID:25203390

Fujii, Keisuke; Yamashita, Daichi; Yoshioka, Shinsuke; Isaka, Tadao; Kouzaki, Motoki

2014-09-01

138

Leukotriene B4 enhances innate immune defense against the puerperal sepsis agent Streptococcus pyogenes  

PubMed Central

Puerperal sepsis is a leading cause of maternal mortality worldwide. Streptococcus pyogenes (Group A Streptococcus; GAS) is a major etiologic agent of severe postpartum sepsis yet little is known regarding the pathogenesis of these infections. Tissue macrophages provide innate defense against GAS and their actions are highly regulated. The intracellular second messenger cAMP can negatively regulate macrophage actions against GAS. Because leukotriene (LT) B4 has been shown to suppress intracellular cAMP in macrophages, we hypothesized that it could enhance innate defenses against GAS. We assessed the capacity of LTB4 to modulate anti-streptococcal actions of human macrophages, including placental and decidual macrophages and used a novel intrauterine infection model of GAS in mice lacking the 5-lipoxygenase (5LO) enzyme to determine the role of endogenous LTs in host defense against this pathogen. Animals lacking 5LO were significantly more vulnerable to intrauterine GAS infection than wild-type mice and showed enhanced dissemination of bacteria out of the uterus and a more robust inflammatory response compared to wild-type mice. Additionally, LTB4 reduced intracellular cAMP levels via the BLT1 receptor and was a potent stimulant of macrophage phagocytosis and NADPH oxidase-dependent intracellular killing of GAS. Importantly, interference was observed between the macrophage immunomodulatory actions of LTB4 and the cAMP-inducing lipid prostaglandin E2, suggesting that interplay between pro- and anti-inflammatory compounds may be important in vivo. This work underscores the potential for pharmacological targeting of lipid mediator signaling cascades in the treatment of invasive GAS infections. PMID:23325886

Soares, Elyara M.; Mason, Katie L.; Rogers, Lisa M.; Serezani, Carlos H.; Faccioli, Lucia H.; Aronoff, David M.

2012-01-01

139

The evolution of immune mechanisms.  

PubMed

From early on in evolution, organisms have had to protect themselves from pathogens. Mechanisms for discriminating "self" from "non-self" evolved to accomplish this task, launching a long history of host-pathogen co-evolution. Evolution of mechanisms of immune defense has resulted in a variety of strategies. Even unicellular organisms have rich arsenals of mechanisms for protection, such as restriction endonucleases, antimicrobial peptides, and RNA interference. In multicellular organisms, specialized immune cells have evolved, capable of recognition, phagocytosis, and killing of foreign cells as well as removing their own cells changed by damage, senescence, infection, or cancer. Additional humoral factors, such as the complement cascade, have developed that co-operate with cellular immunity in fighting infection and maintaining homeostasis. Defensive mechanisms based on germline-encoded receptors constitute a system known as innate immunity. In jaw vertebrates, this system is supplemented with a second system, adaptive immunity, which in contrast to innate immunity is based on diversification of immune receptors and on immunological memory in each individual.Usually, each newly evolved defense mechanism did not replace the previous one, but supplemented it, resulting in a layered structure of the immune system. The immune system is not one system but rather a sophisticated network of various defensive mechanisms operating on different levels, ranging from mechanisms common for every cell in the body to specialized immune cells and responses at the level of the whole organism. Adaptive changes in pathogens have shaped the evolution of the immune system at all levels. PMID:16619242

Danilova, Nadia

2006-11-15

140

Inherent specificities in natural antibodies: a key to immune defense against pathogen invasion  

Microsoft Academic Search

Natural antibodies are produced at tightly regulated levels in the complete absence of external antigenic stimulation. They provide immediate, early and broad protection against pathogens, making them a crucial non-redundant component of the humoral immune system. These antibodies are produced mainly, if not exclusively, by a subset of long-lived, self-replenishing B cells termed B-1 cells. We argue here that the

Nicole Baumgarth; James W. Tung; Leonore A. Herzenberg

2005-01-01

141

Immune defence strategies of generalist and specialist insect herbivores.  

PubMed

Ecological immunology examines the adaptive responses of animals to pathogens in relation to other environmental factors and explores the consequences of trade-offs between investment in immune function and other life-history traits. Among species of herbivorous insects, diet breadth may vary greatly, with generalists consuming a wide variety of plant families and specialists restricted to a few species. Generalists may thus be exposed to a wider range of pathogens exerting stronger selection on the innate immune system. To examine whether this produces an increase in the robustness of the immune response, we compared larvae of the generalist herbivore Heliothis virescens and the specialist Heliothis subflexa challenged by entomopathogenic and non-pathogenic bacteria. Heliothis virescens larvae showed lower mortality, a lower number of recoverable bacteria, lower proliferation of haemocytes and higher phagocytic activity. These results indicate a higher tolerance to entomopathogenic bacteria by the generalist, which is associated with a more efficient cell-mediated immune response by mechanisms that differ between these closely related species. Our findings provide novel insights into the consequences of diet breadth and related environmental factors, which may be significant in further studies to understand the ecological forces and investment trade-offs that shape the evolution of innate immunity. PMID:24943370

Barthel, Andrea; Kopka, Isabell; Vogel, Heiko; Zipfel, Peter; Heckel, David G; Groot, Astrid T

2014-08-01

142

Temperature effect on the immune defense functions of Arctic charr Salvelinus alpinus.  

PubMed

The Arctic charr Salvelinus alpinus is an endangered fish species in Finland, and thus farming is carried out mainly for stocking purposes. Farmed charr are susceptible to infection with atypical Aeromonas salmonicida (aAS). Losses of valuable brood stock will severely reduce the genetic diversity of stocked charr. No commercial vaccines are available to prevent aAS infection, and vaccines against furunculosis (caused by typical A. salmonicida, tAS) do not protect the charr against aAS infection. The effects of a metabolizable oil-adjuvanted, bivalent vaccine (containing killed aAS and A. salmonicida salmonicida bacteria) on the immune system of 1 yr old hatchery-reared charr originating from Lake Inari in Northern Finland were examined. Fish vaccination in Finland generally takes place either from October to November or from February to April, when the water temperature is low (1 to 3degrees C). The water temperature starts to increase in mid-May. Therefore, we also investigated whether post-vaccination (p.v.) temperature had an influence on the immune system of this cold-water fish species. The fish were immunized intraperitoneally at 2.9 degrees C at the end of April. After 52 d, during which the water temperature increased from 2.9 to 10.0 degrees C, the charr were exposed to 1 of 3 test temperatures: 10.3, 14.1 or 18.1 degrees C. Prior to vaccination, and 49, 75 and 103 d p.v., several immune parameters were measured in both unvaccinated and vaccinated charr. Vaccination induced a significant anti-aAS-specific antibody response, and increased plasma lysozyme activity at all p.v. temperatures. The haemolytic activity of the complement system was unaffected either by vaccination or p.v. temperatures. There was a slight positive correlation between p.v. temperature and lysozyme activity of the charr. The significant increase in lysozyme activity took place in vaccinated charr in the first 49 d p.v. as water temperatures increased from 2.9 to 10 degrees C. Furthermore, the highest activity of lysozyme in the plasma was observed 49 d p.v. Our results indicate that a rise in water temperature above 10 degrees C does not significantly enhance the vaccination response of charr. This could be one reason why farmed Arctic charr, which are well adapted to a cold climate, are highly susceptible to aAS infection in the summer. PMID:12517005

Pylkkö, P; Lyytikäinen, T; Ritola, O; Pelkonen, S; Valtonen, E T

2002-11-01

143

Symbiotes and defensive Mutualism: Moving Target Defense  

E-print Network

Chapter 5 Symbiotes and defensive Mutualism: Moving Target Defense Ang Cui and Salvatore J. Stolfo on perpetual mutation and diversity, driven by symbiotic defensive mutualism can fundamentally change the `cat propose this new `clean slate design' principle and conjecture that this defensive strategy can also

Yang, Junfeng

144

Biomphalysin, a new ? pore-forming toxin involved in Biomphalaria glabrata immune defense against Schistosoma mansoni.  

PubMed

Aerolysins are virulence factors belonging to the ? pore-forming toxin (?-PFT) superfamily that are abundantly distributed in bacteria. More rarely, ?-PFTs have been described in eukaryotic organisms. Recently, we identified a putative cytolytic protein in the snail, Biomphalaria glabrata, whose primary structural features suggest that it could belong to this ?-PFT superfamily. In the present paper, we report the molecular cloning and functional characterization of this protein, which we call Biomphalysin, and demonstrate that it is indeed a new eukaryotic ?-PFT. We show that, despite weak sequence similarities with aerolysins, Biomphalysin shares a common architecture with proteins belonging to this superfamily. A phylogenetic approach revealed that the gene encoding Biomphalysin could have resulted from horizontal transfer. Its expression is restricted to immune-competent cells and is not induced by parasite challenge. Recombinant Biomphalysin showed hemolytic activity that was greatly enhanced by the plasma compartment of B. glabrata. We further demonstrated that Biomphalysin with plasma is highly toxic toward Schistosoma mansoni sporocysts. Using in vitro binding assays in conjunction with Western blot and immunocytochemistry analyses, we also showed that Biomphalysin binds to parasite membranes. Finally, we showed that, in contrast to what has been reported for most other members of the family, lytic activity of Biomphalysin is not dependent on proteolytic processing. These results provide the first functional description of a mollusk immune effector protein involved in killing S. mansoni. PMID:23555242

Galinier, Richard; Portela, Julien; Moné, Yves; Allienne, Jean François; Henri, Hélène; Delbecq, Stéphane; Mitta, Guillaume; Gourbal, Benjamin; Duval, David

2013-03-01

145

Biomphalysin, a New ? Pore-forming Toxin Involved in Biomphalaria glabrata Immune Defense against Schistosoma mansoni  

PubMed Central

Aerolysins are virulence factors belonging to the ? pore-forming toxin (?-PFT) superfamily that are abundantly distributed in bacteria. More rarely, ?-PFTs have been described in eukaryotic organisms. Recently, we identified a putative cytolytic protein in the snail, Biomphalaria glabrata, whose primary structural features suggest that it could belong to this ?-PFT superfamily. In the present paper, we report the molecular cloning and functional characterization of this protein, which we call Biomphalysin, and demonstrate that it is indeed a new eukaryotic ?-PFT. We show that, despite weak sequence similarities with aerolysins, Biomphalysin shares a common architecture with proteins belonging to this superfamily. A phylogenetic approach revealed that the gene encoding Biomphalysin could have resulted from horizontal transfer. Its expression is restricted to immune-competent cells and is not induced by parasite challenge. Recombinant Biomphalysin showed hemolytic activity that was greatly enhanced by the plasma compartment of B. glabrata. We further demonstrated that Biomphalysin with plasma is highly toxic toward Schistosoma mansoni sporocysts. Using in vitro binding assays in conjunction with Western blot and immunocytochemistry analyses, we also showed that Biomphalysin binds to parasite membranes. Finally, we showed that, in contrast to what has been reported for most other members of the family, lytic activity of Biomphalysin is not dependent on proteolytic processing. These results provide the first functional description of a mollusk immune effector protein involved in killing S. mansoni. PMID:23555242

Moné, Yves; Allienne, Jean François; Henri, Hélène; Delbecq, Stéphane; Mitta, Guillaume; Gourbal, Benjamin; Duval, David

2013-01-01

146

Selective Metabolism of Hypothiocyanous Acid by Mammalian Thioredoxin Reductase Promotes Lung Innate Immunity and Antioxidant Defense*  

PubMed Central

The endogenously produced oxidant hypothiocyanous acid (HOSCN) inhibits and kills pathogens but paradoxically is well tolerated by mammalian host tissue. Mammalian high molecular weight thioredoxin reductase (H-TrxR) is evolutionarily divergent from bacterial low molecular weight thioredoxin reductase (L-TrxR). Notably, mammalian H-TrxR contains a selenocysteine (Sec) and has wider substrate reactivity than L-TrxR. Recombinant rat cytosolic H-TrxR1, mouse mitochondrial H-TrxR2, and a purified mixture of both from rat selectively turned over HOSCN (kcat = 357 ± 16 min?1; Km = 31.9 ± 10.3 ?m) but were inactive against the related oxidant hypochlorous acid. Replacing Sec with Cys or deleting the final eight C-terminal peptides decreased affinity and turnover of HOSCN by H-TrxR. Similarly, glutathione reductase (an H-TrxR homologue lacking Sec) was less effective at HOSCN turnover. In contrast to H-TrxR and glutathione reductase, recombinant Escherichia coli L-TrxR was potently inhibited by HOSCN (IC50 = 2.75 ?m). Similarly, human bronchial epithelial cell (16HBE) lysates metabolized HOSCN, but E. coli and Pseudomonas aeruginosa lysates had little or no activity. HOSCN selectively produced toxicity in bacteria, whereas hypochlorous acid was nonselectively toxic to both bacteria and 16HBE. Treatment with the H-TrxR inhibitor auranofin inhibited HOSCN metabolism in 16HBE lysates and significantly increased HOSCN-mediated cytotoxicity. These findings demonstrate both the metabolism of HOSCN by mammalian H-TrxR resulting in resistance to HOSCN in mammalian cells and the potent inhibition of bacterial L-TrxR resulting in cytotoxicity in bacteria. These data support a novel selective mechanism of host defense in mammals wherein HOSCN formation simultaneously inhibits pathogens while sparing host tissue. PMID:23629660

Chandler, Joshua D.; Nichols, David P.; Nick, Jerry A.; Hondal, Robert J.; Day, Brian J.

2013-01-01

147

Sympathetic Modulation of Immunity: Relevance to Disease  

PubMed Central

Optimal host defense against pathogens requires cross-talk between the nervous and immune systems. This paper reviews sympathetic-immune interaction, one major communication pathway, and its importance for health and disease. Sympathetic innervation of primary and secondary immune organs is described, as well as evidence for neurotransmission with cells of the immune system as targets. Most research thus far as focused on neural-immune modulation in secondary lymphoid organs, and have revealed complex sympathetic modulation resulting in both potentiation and inhibition of immune functions. SNS-immune interaction may enhance immune readiness during disease- or injury-induced ‘fight’ responses. Research also indicate that dysregulation of the SNS can significantly affect the progression of immune-mediated diseases. However, a better understanding of neural-immune interactions is needed to develop strategies for treatment of immune-mediated diseases that are designed to return homeostasis and restore normal functioning neural-immune networks. PMID:18308299

Bellinger, Denise L.; Millar, Brooke A.; Perez, Sam; Carter, Jeff; Wood, Carlo; ThyagaRajan, Srinivasan; Molinaro, Christine; Lubahn, Cheri; Lorton, Dianne

2008-01-01

148

Nanovectorized radiotherapy: a new strategy to induce anti-tumor immunity  

PubMed Central

Recent experimental findings show that activation of the host immune system is required for the success of chemo- and radiotherapy. However, clinically apparent tumors have already developed multiple mechanisms to escape anti-tumor immunity. The fact that tumors are able to induce a state of tolerance and immunosuppression is a major obstacle in immunotherapy. Hence, there is an overwhelming need to develop new strategies that overcome this state of immune tolerance and induce an anti-tumor immune response both at primary and metastatic sites. Nanovectorized radiotherapy that combines ionizing radiation and nanodevices, is one strategy that could boost the quality and magnitude of an immune response in a predictable and designable fashion. The potential benefits of this emerging treatment may be based on the unique combination of immunostimulatory properties of nanoparticles with the ability of ionizing radiation to induce immunogenic tumor cell death. In this review, we will discuss available data and propose that the nanovectorized radiotherapy could be a powerful new strategy to induce anti-tumor immunity required for positive patient outcome. PMID:23087900

Vanpouille-Box, Claire; Hindré, François

2012-01-01

149

HDAC2 deregulation in tumorigenesis is causally connected to repression of immune modulation and defense escape.  

PubMed

Histone deacetylase 2 (HDAC2) is overexpressed or mutated in several disorders such as hematological cancers, and plays a critical role in transcriptional regulation, cell cycle progression and developmental processes. Here, we performed comparative transcriptome analyses in acute myeloid leukemia to investigate the biological implications of HDAC2 silencing versus its enzymatic inhibition using epigenetic-based drug(s). By gene expression analysis of HDAC2-silenced vs wild-type cells, we found that HDAC2 has a specific role in leukemogenesis. Gene expression profiling of U937 cell line with or without treatment of the well-known HDAC inhibitor vorinostat (SAHA) identifies and characterizes several gene clusters where inhibition of HDAC2 'mimics' its silencing, as well as those where HDAC2 is selectively and exclusively regulated by HDAC2 protein expression levels. These findings may represent an important tool for better understanding the mechanisms underpinning immune regulation, particularly in the study of major histocompatibility complex class II genes. PMID:25473896

Conte, Mariarosaria; Dell'Aversana, Carmela; Benedetti, Rosaria; Petraglia, Francesca; Carissimo, Annamaria; Petrizzi, Valeria Belsito; D'Arco, Alfonso Maria; Abbondanza, Ciro; Nebbioso, Angela; Altucci, Lucia

2014-11-25

150

New insights into innate immunity in Arabidopsis  

Microsoft Academic Search

Summary The term innate immunity has been described as '. . . the surveillance system that detects the presence and nature of the infection and provides the first line of host defense . . .' (Medzhitov, 2001; Nat Rev Immunol 1: 135-145). The strategy of innate immunity is based on the recognition of constitutive and conserved mol- ecules from pathogens

Clarence A. Ryan; Alisa Huffaker; Yube Yamaguchi

2007-01-01

151

Immune responses against virus and tumor in cervical carcinogenesis: treatment strategies for avoiding the HPV-induced immune escape.  

PubMed

Despite the availability of prophylactic vaccines against human papillomavirus (HPV), cervical cancer (CC) is still a major problem globally. It is the cancer with the second highest incidence and the third highest mortality in women worldwide, but, in less developed countries, it is an even greater problem being the second most common cause of cancer death. Although HPV infection is one of the most common sexually transmitted diseases, and high-risk HPV16 is the most frequent genotype involved, only a small number of HPV-infected women develop high-grade squamous intraepithelial lesions whereas, in the remainder of the women, the virus disappears spontaneously. There is a lot of evidence to support the view that host-dependent immunologic status and HPV-induced immune evasion are responsible for persistent HPV infection and subsequent development of cervical neoplasia. Therefore, the role of the immune system, not only in viral clearance but also in tumor antigen recognition, is particularly relevant in the case of cervical carcinogenesis. A better understanding of these processes would help in the development of therapeutic vaccines. This review aims to explain which immune cells and molecules are involved in the process of viral and tumor recognition, how their failure can lead to cervical carcinoma and what are the main therapeutic strategies so far tested in preclinical models and clinical trials to stimulate the immune system in cervical carcinoma. PMID:23994536

Conesa-Zamora, Pablo

2013-11-01

152

Strategies and challenges in eliciting immunity to melanoma  

PubMed Central

Summary The ability of CD8 T cells to recognize melanoma tumors has led to the development of immunotherapeutic approaches that use the antigens CD8 T cells recognize. However, clinical responses rates have been disappointing. Here we summarize our work to understand the mechanisms of self-tolerance that limit responses to currently utilized antigens, and our approach to identify new antigens directly tied to malignancy. We also explore several aspects of the anti-tumor immune response induced by peptide-pulsed dendritic cells. Dendritic cells differentially augment the low avidity of recall T cells specific for self-antigens, and overcome a process of aberrant CD8 T cell differentiation that occurs in tumor-draining lymph nodes. Dendritic cell migration is constrained by injection route, resulting in immune responses in localized lymphoid tissue, and differential control of tumors depending on their location in the body. We demonstrate that CD8 T cell differentiation in different lymphoid compartments alters the expression of homing receptor molecules and the presence of systemic central memory cells. Our studies highlight several issues that must be addressed to improve the efficacy of tumor immunotherapy. PMID:18363993

Ferguson, Andrew R.; Nichols, Lisa A.; Zarling, Angela L.; Thompson, Elizabeth D.; Brinkman, Colin C.; Hargadon, Kristian M.; Bullock, Timothy N.; Engelhard, Victor H.

2010-01-01

153

Dissemination strategy for immunizing scale-free networks  

NASA Astrophysics Data System (ADS)

We consider the problem of distributing a vaccine for immunizing a scale-free network against a given virus or worm. We introduce a method, based on vaccine dissemination, that seems to reflect more accurately what is expected to occur in real-world networks. Also, since the dissemination is performed using only local information, the method can be easily employed in practice. Using a random-graph framework, we analyze our method both mathematically and by means of simulations. We demonstrate its efficacy regarding the trade-off between the expected number of nodes that receive the vaccine and the network’s resulting vulnerability to develop an epidemic as the virus or worm attempts to infect one of its nodes. For some scenarios, the method is seen to render the network practically invulnerable to attacks while requiring only a small fraction of the nodes to receive the vaccine.

Stauffer, Alexandre O.; Barbosa, Valmir C.

2006-11-01

154

Clinical immune-monitoring strategies for predicting infection risk in solid organ transplantation  

PubMed Central

Infectious complications remain a leading cause of morbidity and mortality after solid organ transplantation (SOT), and largely depend on the net state of immunosuppression achieved with current regimens. Cytomegalovirus (CMV) is a major opportunistic viral pathogen in this setting. The application of strategies of immunological monitoring in SOT recipients would allow tailoring of immunosuppression and prophylaxis practices according to the individual's actual risk of infection. Immune monitoring may be pathogen-specific or nonspecific. Nonspecific immune monitoring may rely on either the quantification of peripheral blood biomarkers that reflect the status of a given arm of the immune response (serum immunoglobulins and complement factors, lymphocyte sub-populations, soluble form of CD30), or on the functional assessment of T-cell responsiveness (release of intracellular adenosine triphosphate following a mitogenic stimulus). In addition, various methods are currently available for monitoring pathogen-specific responses, such as CMV-specific T-cell-mediated immune response, based on interferon-? release assays, intracellular cytokine staining or main histocompatibility complex-tetramer technology. This review summarizes the clinical evidence to date supporting the use of these approaches to the post-transplant immune status, as well as their potential limitations. Intervention studies based on validated strategies for immune monitoring still need to be performed. PMID:25505960

Fernández-Ruiz, Mario; Kumar, Deepali; Humar, Atul

2014-01-01

155

PLANT DEFENSE SYNDROMES  

Microsoft Academic Search

Given that a plant's defensive strategy against herbivory is never likely to be a single trait, we develop the concept of plant defense syndromes, where association with specific ecological interactions can result in convergence on suites of covarying defensive traits. Defense syndromes can be studied within communities of diverse plant species as well as within clades of closely related species.

Anurag A. Agrawal; Mark Fishbein

2006-01-01

156

A Scallop Nitric Oxide Synthase (NOS) with Structure Similar to Neuronal NOS and Its Involvement in the Immune Defense  

PubMed Central

Background Nitric oxide synthase (NOS) is responsible for synthesizing nitric oxide (NO) from L-arginine, and involved in multiple physiological functions. However, its immunological role in mollusc was seldom reported. Methodology In the present study, an NOS (CfNOS) gene was identified from the scallop Chlamys farreri encoding a polypeptide of 1486 amino acids. Its amino acid sequence shared 50.0~54.7, 40.7~47.0 and 42.5~44.5% similarities with vertebrate neuronal (n), endothelial (e) and inducible (i) NOSs, respectively. CfNOS contained PDZ, oxygenase and reductase domains, which resembled those in nNOS. The CfNOS mRNA transcripts expressed in all embryos and larvae after the 2-cell embryo stage, and were detectable in all tested tissues with the highest level in the gonad, and with the immune tissues hepatopancreas and haemocytes included. Moreover, the immunoreactive area of CfNOS distributed over the haemocyte cytoplasm and cell membrane. After LPS, ?-glucan and PGN stimulation, the expression level of CfNOS mRNA in haemocytes increased significantly at 3 h (4.0-, 4.8- and 2.7-fold, respectively, P < 0.01), and reached the peak at 12 h (15.3- and 27.6-fold for LPS and ?-glucan respectively, P < 0.01) and 24 h (17.3-fold for PGN, P < 0.01). In addition, TNF-? also induced the expression of CfNOS, which started to increase at 1 h (5.2-fold, P < 0.05) and peaked at 6 h (19.9-fold, P < 0.01). The catalytic activity of the native CfNOS protein was 30.3 ± 0.3 U mgprot-1, and it decreased significantly after the addition of the selective inhibitors of nNOS and iNOS (26.9 ± 0.4 and 29.3 ± 0.1 U mgprot-1, respectively, P < 0.01). Conclusions These results suggested that CfNOS, with identical structure with nNOS and similar enzymatic characteristics to nNOS and iNOS, played the immunological role of iNOS to be involved in the scallop immune defense against PAMPs and TNF-?. PMID:23922688

Jiang, Qiufen; Zhou, Zhi; Wang, Leilei; Wang, Lingling; Yue, Feng; Wang, Jingjing; Song, Linsheng

2013-01-01

157

Addressing the Surveillance Goal in the National Strategy for Suicide Prevention: The Department of Defense Suicide Event Report  

PubMed Central

The US National Strategy for Suicide Prevention (National Strategy) described 11 goals across multiple areas, including suicide surveillance. Consistent with these goals, the Department of Defense (DoD) has engaged aggressively in the area of suicide surveillance. The DoD's population-based surveillance system, the DoD Suicide Event Report (DoDSER) collects information on suicides and suicide attempts for all branches of the military. Data collected includes suicide event details, treatment history, military and psychosocial history, and psychosocial stressors at the time of the event. Lessons learned from the DoDSER program are shared to assist other public health professionals working to address the National Strategy objectives. PMID:22390595

Reger, Mark A.; Kinn, Julie T.; Luxton, David D.; Skopp, Nancy A.; Bush, Nigel E.

2012-01-01

158

Caspase-8 mediates caspase-1 processing and innate immune defense in response to bacterial blockade of NF-?B and MAPK signaling.  

PubMed

Toll-like receptor signaling and subsequent activation of NF-?B- and MAPK-dependent genes during infection play an important role in antimicrobial host defense. The YopJ protein of pathogenic Yersinia species inhibits NF-?B and MAPK signaling, resulting in blockade of NF-?B-dependent cytokine production and target cell death. Nevertheless, Yersinia infection induces inflammatory responses in vivo. Moreover, increasing the extent of YopJ-dependent cytotoxicity induced by Yersinia pestis and Yersinia pseudotuberculosis paradoxically leads to decreased virulence in vivo, suggesting that cell death promotes anti-Yersinia host defense. However, the specific pathways responsible for YopJ-induced cell death and how this cell death mediates immune defense against Yersinia remain poorly defined. YopJ activity induces processing of multiple caspases, including caspase-1, independently of inflammasome components or the adaptor protein ASC. Unexpectedly, caspase-1 activation in response to the activity of YopJ required caspase-8, receptor-interacting serine/threonine kinase 1 (RIPK1), and Fas-associated death domain (FADD), but not RIPK3. Furthermore, whereas RIPK3 deficiency did not affect YopJ-induced cell death or caspase-1 activation, deficiency of both RIPK3 and caspase-8 or FADD completely abrogated Yersinia-induced cell death and caspase-1 activation. Mice lacking RIPK3 and caspase-8 in their hematopoietic compartment showed extreme susceptibility to Yersinia and were deficient in monocyte and neutrophil-derived production of proinflammatory cytokines. Our data demonstrate for the first time to our knowledge that RIPK1, FADD, and caspase-8 are required for YopJ-induced cell death and caspase-1 activation and suggest that caspase-8-mediated cell death overrides blockade of immune signaling by YopJ to promote anti-Yersinia immune defense. PMID:24799700

Philip, Naomi H; Dillon, Christopher P; Snyder, Annelise G; Fitzgerald, Patrick; Wynosky-Dolfi, Meghan A; Zwack, Erin E; Hu, Baofeng; Fitzgerald, Louise; Mauldin, Elizabeth A; Copenhaver, Alan M; Shin, Sunny; Wei, Lei; Parker, Matthew; Zhang, Jinghui; Oberst, Andrew; Green, Douglas R; Brodsky, Igor E

2014-05-20

159

Immune System (For Parents)  

MedlinePLUS

... can lead to illness and infection. About the Immune System The immune system is the body's defense against ... that cause colds. Back Continue Problems of the Immune System Disorders of the immune system fall into four ...

160

Strategies for Improving Influenza Immunization Rates among Hard-to-Reach Populations  

PubMed Central

Whereas considerable attention has been devoted to achieving high levels of influenza immunization, the importance of this issue is magnified by concern over pandemic influenza. Most recommendations for vaccine administration address high risk groups such as the elderly and those with chronic diseases, but coverage for hard-to-reach (HTR) populations has had less attention. HTR populations include minorities but also include other primarily urban groups such as undocumented immigrants, substance users, the homeless, and homebound elderly. Obstacles to the provision of immunization to HTR populations are present at the patient, provider, and structural levels. Strategies at the individual level for increasing immunization coverage include community-based educational campaigns to improve attitudes and increase motivation for receiving vaccine; at the provider level, education of providers to encourage immunizations, improving patient–provider interactions, broadening the provider base to include additional nurses and pharmacists, and adoption of standing orders for immunization administration; and at the structural level, promoting wider availability of and access to vaccine. The planning process for an influenza pandemic should include community engagement and extension of strategies beyond traditional providers to involve community-based organizations addressing HTR populations. PMID:17562184

Coady, Micaela H.; Ompad, Danielle C.; Galea, Sandro

2007-01-01

161

HDT701, a Histone H4 Deacetylase, Negatively Regulates Plant Innate Immunity by Modulating Histone H4 Acetylation of Defense-Related Genes in Rice[W][OA  

PubMed Central

Histone acetylation and deacetylation play an important role in the modification of chromatin structure and regulation of gene expression in eukaryotes. Chromatin acetylation status is modulated antagonistically by histone acetyltransferases and histone deacetylases (HDACs). In this study, we characterized the function of histone deacetylase701 (HDT701), a member of the plant-specific HD2 subfamily of HDACs, in rice (Oryza sativa) innate immunity. Transcription of HDT701 is increased in the compatible reaction and decreased in the incompatible reaction after infection by the fungal pathogen Magnaporthe oryzae. Overexpression of HDT701 in transgenic rice leads to decreased levels of histone H4 acetylation and enhanced susceptibility to the rice pathogens M. oryzae and Xanthomonas oryzae pv oryzae (Xoo). By contrast, silencing of HDT701 in transgenic rice causes elevated levels of histone H4 acetylation and elevated transcription of pattern recognition receptor (PRR) and defense-related genes, increased generation of reactive oxygen species after pathogen-associated molecular pattern elicitor treatment, as well as enhanced resistance to both M. oryzae and Xoo. We also found that HDT701 can bind to defense-related genes to regulate their expression. Taken together, these results demonstrate that HDT701 negatively regulates innate immunity by modulating the levels of histone H4 acetylation of PRR and defense-related genes in rice. PMID:22968716

Ding, Bo; Bellizzi, Maria del Rosario; Ning, Yuese; Meyers, Blake C.; Wang, Guo-Liang

2012-01-01

162

HDT701, a histone H4 deacetylase, negatively regulates plant innate immunity by modulating histone H4 acetylation of defense-related genes in rice.  

PubMed

Histone acetylation and deacetylation play an important role in the modification of chromatin structure and regulation of gene expression in eukaryotes. Chromatin acetylation status is modulated antagonistically by histone acetyltransferases and histone deacetylases (HDACs). In this study, we characterized the function of histone deacetylase701 (HDT701), a member of the plant-specific HD2 subfamily of HDACs, in rice (Oryza sativa) innate immunity. Transcription of HDT701 is increased in the compatible reaction and decreased in the incompatible reaction after infection by the fungal pathogen Magnaporthe oryzae. Overexpression of HDT701 in transgenic rice leads to decreased levels of histone H4 acetylation and enhanced susceptibility to the rice pathogens M. oryzae and Xanthomonas oryzae pv oryzae (Xoo). By contrast, silencing of HDT701 in transgenic rice causes elevated levels of histone H4 acetylation and elevated transcription of pattern recognition receptor (PRR) and defense-related genes, increased generation of reactive oxygen species after pathogen-associated molecular pattern elicitor treatment, as well as enhanced resistance to both M. oryzae and Xoo. We also found that HDT701 can bind to defense-related genes to regulate their expression. Taken together, these results demonstrate that HDT701 negatively regulates innate immunity by modulating the levels of histone H4 acetylation of PRR and defense-related genes in rice. PMID:22968716

Ding, Bo; Bellizzi, Maria del Rosario; Ning, Yuese; Meyers, Blake C; Wang, Guo-Liang

2012-09-01

163

Global Immunization Vision and Strategy (GIVS): a mid-term analysis of progress in 50 countries.  

PubMed

Within the overall framework set out in the Global Immunization Vision and Strategy (GIVS) for the period 2006-2015, over 70 countries had developed comprehensive Multi-Year Plans (cMYPs) by 2008, outlining their plans for implementing the GIVS strategies and for attaining the GIVS Goals at the midpoint in 2010 or earlier. These goals are to: (1) reach ?90% and ?80% vaccination coverage at national and district level, respectively; and (2) reduce measles-related mortality by 90% compared with the 2000 level. Fifty cMYPs were analysed along the four strategic areas of the GIVS: (1) protecting more people in a changing world; (2) introducing new vaccines and technologies; (3) integrating immunization, other health interventions and surveillance in the health system context; and (4) immunizing in the context of global interdependence. By 2010, all 50 countries planned to have introduced hepatitis B (HepB) vaccine, 48 the Haemophilus influenzae type B (Hib) vaccine and only a few countries had firm plans to introduce pneumococcal or rotavirus vaccines. Countries seem to be inadequately prepared in terms of cold-chain requirements to deal with the expected increases in storage that will be required for vaccines, and in making provisions to establish a corresponding surveillance system for planned new vaccine introductions. Immunization contacts are used to deliver other health interventions, especially in the countries in the World Health Organization (WHO) Africa Region. The cost for the planned immunization activities will double to U$27 per infant, of which U$5 per infant is the expected shortfall. Global Alliance for Vaccines and Immunization (GAVI) funding is becoming the largest contributor to immunization programmes. PMID:22411879

Kamara, Lidija; Lydon, Patrick; Bilous, Julian; Vandelaer, Jos; Eggers, Rudi; Gacic-Dobo, Marta; Meaney, William; Okwo-Bele, Jean-Marie

2013-01-01

164

Psychosocial Trauma, Defense Strategies and Treatment Considerations in Cancer Patients and Their Families.  

ERIC Educational Resources Information Center

Discusses the psychosocial impact of cancer on patients and families. Notes that group treatment is especially effective because of curative factors intrinsic to group experience, e.g., installation of hope, universality, and cohesiveness, that allow group members to lower their defensiveness and deal more adaptively with emotional and…

Singer, Barton A.

1983-01-01

165

75 FR 8272 - Defense Federal Acquisition Regulation Supplement; Acquisition Strategies To Ensure Competition...  

Federal Register 2010, 2011, 2012, 2013

...Competition Throughout the Life Cycle of Major Defense Acquisition...the MDAP throughout its life cycle as a means to improve contractor...invites comments from small business concerns and other interested...throughout the program life cycle as a means to improve...

2010-02-24

166

75 FR 54524 - Defense Federal Acquisition Regulation Supplement; Acquisition Strategies To Ensure Competition...  

Federal Register 2010, 2011, 2012, 2013

...Ensure Competition Throughout the Life Cycle of Major Defense Acquisition Programs...level of the MDAP throughout its life cycle as a means to improve contractor performance...imposes no changes on contractors doing business with DoD. C. Paperwork Reduction...

2010-09-08

167

Targeting IL-6 by both passive or active immunization strategies prevents bleomycin-induced skin fibrosis  

PubMed Central

Introduction Interleukin-6 (IL-6) is a pleiotropic cytokine for which preliminary data have suggested that it might contribute to systemic sclerosis (SSc). Our aims were to investigate, firstly, IL-6 expression in patients with SSc and, secondly, the efficacy of both passive and active immunization against IL-6 to reduce skin fibrosis in complementary mouse models of SSc. Methods Human serum levels and skin expression of IL-6 were determined by enzyme-linked immunosorbent assay and immunohistochemistry, respectively. We first evaluated the antifibrotic properties of the monoclonal anti-IL-6R antibody, MR16-1, in the bleomycin-induced dermal fibrosis mouse model, reflecting early and inflammatory stages of SSc. Then, we assessed the efficacy of MR16-1 in tight skin-1 (Tsk-1) mice, an inflammation-independent model of skin fibrosis. Additionally, we have developed an innovative strategy using an anti-IL-6 peptide-based active immunization. Infiltrating leukocytes, T cells, and B cells were quantified, and IL-6 levels were measured in the serum and lesional skin of mice after passive or active immunization. Results Serum and skin levels of IL-6 were significantly increased in patients with early SSc. Treatment with MR16-1 led in the bleomycin mouse model to a 25% (P = 0.02) and 30% (P = 0.007) reduction of dermal thickness and hydroxyproline content, respectively. MR16-1 demonstrated no efficacy in Tsk-1 mice. Thereafter, mice were immunized against a small peptide derived from murine IL-6 and this strategy led in the bleomycin model to a 20% (P = 0.02) and 25% (P = 0.005) decrease of dermal thickness and hydroxyproline content, respectively. Passive and active immunization led to decreased T-cell infiltration in the lesional skin of mice challenged with bleomycin. Upon bleomycin injections, serum and skin IL-6 levels were increased after treatment with MR16-1 and were significantly reduced after anti-IL-6 active immunization. Conclusions Our results support the relevance of targeting IL-6 in patients with early SSc since IL-6 is overexpressed in early stages of the disease. Targeting IL-6 by both passive and active immunization strategies prevented the development of bleomycin-induced dermal fibrosis in mice. Our results highlight the therapeutic potential of active immunization against IL-6, which is a seductive alternative to passive immunization. PMID:25059342

2014-01-01

168

A 'natural' way to provide innate mucosal immunity.  

PubMed

The mucosal barrier comprises a layered defense system including physio-chemical and immunological strategies to contain commensal microflora while protecting the host against potential pathogens. In contrast to the clearly established and well-characterized role for the adaptive immune system in intestinal defense, our knowledge on innate immune mechanisms that operate in the gut is much less defined. The recent identification of novel innate lymphoid cells (ILC), including 'NK-like' cells that naturally produce IL-22 and appear to play a role in intestinal defense, demonstrates an unexpected and increasing complexity in mucosal innate immunity. PMID:20573491

Di Santo, James P; Vosshenrich, Christian A J; Satoh-Takayama, Naoko

2010-08-01

169

Annual Defense Report 2000  

NSDL National Science Digital Library

Forwarded to the President and Congress annually, the Secretary of Defense's Annual Defense Report serves as "a basic reference document for those interested in national defense issues and programs." The 350-page 2000 edition is available in HTML and .pdf formats. It covers topics such as defense strategy, the current state of the armed forces, plans for transforming the armed forces and the Department of Defense, statutory reports from the individual secretaries, and a number of appendices.

170

Vaccination Strategies to Enhance Local Immunity and Protection Against Mycobacterium tuberculosis  

PubMed Central

To determine the immunogenicity and protective efficacy of the Mycobacterium tuberculosis 10 kD culture filtrate protein (CFP10), and to evaluate strategies that enhance local immunity, we used C57Bl/6 DR4 mice that were transgenic for human HLA DRB1*0401, because CFP10 contains epitopes for DRB1*0401 but not for C57Bl/6 mice. Intramuscular immunization with a DNA vaccine encoding CFP10 elicited production of IFN-? by systemic CD4+ T cells, and one intravenous dose of the CFP10-based DNA vaccine coated with polyethylenimine (PEI) stimulated IFN-? production by lung CD4+ cells and reduced the pulmonary bacillary burden. We conclude that CFP10 is a potential vaccine candidate and that coating vaccines with PEI enhances local protective immunity to tuberculosis. PMID:19402204

Klucar, Peter; Barnes, Peter F.; Kong, Ying; Howard, Susan T.; Pang, Xiuhua; Huang, Fang-Fang; Tvinnereim, Amy R.; Samten, Buka; Shams, Homayoun

2009-01-01

171

Immunization  

MedlinePLUS

... a lot worse. Some are even life-threatening. Immunization shots, or vaccinations, are essential. They protect against things like measles, ... B, polio, diphtheria, tetanus, and pertussis (whooping cough). Immunizations are important for adults as well as children. ...

172

Constraints on tree breeding: Growth tradeoffs, growth strategies, and defensive investments  

SciTech Connect

Analysis of basic growth processes and between-species trait correlations suggests that because of growth tradeoffs, breeding for growth rate (volume increment) may adversely affect defensive and other properties of trees. This can lead to negative impacts on sawtimber quality and tree life span. Selection for yield and for pathogen resistance may conflict, separate breeding programs may be needed for pulp and sawtimber purposes, and older ages may be more appropriate for selection of plus trees. In order for breeders to consider consequences of selection on tree performance, a means is required of assessing potential adult pathogen resistance and life span. Four methods are proposed for accomplishing this using properties of young trees. The properties of young trees that may correlate with adult performance are (1) wood properties related to defense, (2) wound healing ability, (3) the allometric growth coefficient, and (4) age of sexual maturity.

Loehle, C.; Namkoong, G.

1987-12-01

173

How reproductive, vegetative and defensive strategies of Mediterranean grassland species respond to a grazing intensity gradient  

Microsoft Academic Search

We analysed the morpho-functional response of grassland species to a grazing intensity gradient (1–3.5 sheep ha?1) in the Mediterranean-type climate region of Chile. A total of nine morpho-functional traits (with a total of 24 attributes)\\u000a were determined for 79 herbaceous plant species. Valuation of the traits enabled calculation of the reproductive, vegetative\\u000a and defensive potentials for each species. A classification analysis for

J. M. De Miguel; M. A. Casado; A. Del Pozo; C. Ovalle; P. Moreno-Casasola; A. C. Travieso-Bello; M. Barrera; N. Ricardo; P. A. Tecco; B. Acosta

2010-01-01

174

Transcriptional analysis of antioxidant and immune defense genes in disk abalone (Haliotis discus discus) during thermal, low-salinity and hypoxic stress.  

PubMed

This study describes the transcriptional analysis of antioxidant and immune defense genes in gills tissue of disk abalone exposed to thermal, salinity and hypoxia-related stress, using quantitative real-time PCR. Results showed that manganese superoxide dismutase (MnSOD), copper zinc superoxide dismutase (CuZnSOD), catalase (CAT), thioredoxin peroxidase (TPx), selenium dependant glutathione peroxidase (SeGPx), and thioredoxin-2 (TRx-2) transcripts were expressed differently in gills, and that they respond collectively as a classical enzymatic antioxidant defense system in abalone. Comparative analysis of expression profiles indicated that CAT, TPx and SeGPx transcripts were significantly up-regulated (p<0.05) by all three physical stress conditions - thermal (28 degrees C), salinity (25 per thousand) and hypoxia - relative to levels in respective controls. In contrast, CuZnSOD and TRx-2 transcription were down-regulated in response to thermal stress. Interestingly, all the antioxidant transcripts exhibited significant up-regulation in response to salinity-related stress. Meanwhile, hypoxia caused up-regulation of the MnSOD, CAT, TPx and SeGPx, but not the CuZnSOD and TRx-2 transcripts. One of the most significant outcomes was the more than 10-fold induction of SeGPx, suggesting that SeGPx is a potential biomarker gene among antioxidant enzymes, under conditions of physical stress. The effects of physical stress on the transcriptional responses of immune functional genes namely suppressor of cytokine signaling-2 (SOCS-2) and myxovirus resistance (Mx) were investigated. We observed that salinity and hypoxia increase both the SOCS-2 and Mx transcripts, while thermal stress at 28 degrees C exerts less of an effect, producing mixed transcriptional responses (both up and down regulation). Based upon these results, we postulate that abalones utilize antioxidant and immune defense mechanisms together to overcome physical stresses. PMID:19699310

De Zoysa, Mahanama; Whang, Ilson; Lee, Youngdeuk; Lee, Sukkyoung; Lee, Jae-Seong; Lee, Jehee

2009-12-01

175

Shigella's ways of manipulating the host intestinal innate and adaptive immune system: a tool box  

E-print Network

REVIEW Shigella's ways of manipulating the host intestinal innate and adaptive immune system response, and more generally defense responses of the intestinal mucosa. This review focuses killing, thus ensuring establishment of its infectious process. The escape strategies, the possible direct

Cai, Long

176

A novel "priming-boosting" strategy for immune interventions in cervical cancer.  

PubMed

Despite the encouraging development of a preventive vaccine for human papillomavirus (HPV), it cannot improve ongoing infections. Therefore, a new vaccine is urgently needed that can prevent and treat cervical cancer, and cure pre-cancerous lesions. In this study, we constructed two peptide-based vaccines. The first was a short-term, long-peptide (ST-LP) vaccine that simultaneously targeted three key carcinogenic epitopes (E5-E6-E7) on HPV16. We tested this vaccine in murine TC-1 cells infected with a recombinant adeno-associated virus (rAAV) fused with HPV16E5 DNA (rTC-1 cells), which served as a cell model; we also tested it in immune-competent mice loaded with rTC-1 cells, which served as an ectopic tumor model. The ST-LP injections resulted in strong, cell-mediated immunity, capable of attacking and eliminating abnormal antigen-bearing cells. Furthermore, to prolong immunogenic capability, we designed a unique rAAV that encoded the three predicted epitopes for a second, long-term, long-peptide (LT-LP) vaccine. Moreover, we used a new immune strategy of continuous re-injections, where three ST-LP injections were performed at one-week intervals (days 0, 7, 14), then one LT-LP injection was performed on day 120. Our in vitro and in vivo studies revealed that this strategy could boost the immune response to produce longer and stronger protection against target cells, and mice were thoroughly protected from tumor growth. Our results showed that priming the immune system with the ST-LP vaccine, followed by boosting the immune system with the LT-LP vaccine could generate a rapid, robust, durable cytotoxic T-lymphocyte response to HPV16-positive tumors. PMID:25575128

Liao, Shujie; Zhang, Weina; Hu, Xiaoji; Wang, Wei; Deng, Dongrui; Wang, Hui; Wang, Changyu; Zhou, Jianfeng; Wang, Shixuan; Zhang, Hanwang; Ma, Ding

2015-04-01

177

Selective rejection of H-2-deficient lymphoma variants suggests alternative immune defence strategy  

Microsoft Academic Search

Metazoan organisms may discriminate between self and non-self not only by the presence of foreign antigens but also by the absence of normal self markers1. Mammalian adaptive immune responses use the first strategy, with the additional requirement that foreign antigens are recognized in the context of self-major histocompatibility complex (MHC) products at the cell surface2. Aberrant cells which fail to

Klas Kärre; Hans Gustaf Ljunggren; Gerald Piontek; Rolf Kiessling

1986-01-01

178

Innate Immune Defenses Induced by CpG do not Promote Vaccine-Induced Protection Against Foot-and-Mouth Disease in Pigs  

Technology Transfer Automated Retrieval System (TEKTRAN)

Emergency vaccination as part of the control strategies against Foot-and-Mouth Disease (FMD) epidemics has the potential not only to limit the spread of the virus but also to reduce large-scale culling of affected herds. With the aim to reduce the time between vaccination and the onset of immunity, ...

179

Immune networks: multi-tasking capabilities at medium load E Agliari1,2  

E-print Network

of multiple patterns (i.e. of multiple defense strategies). Moreover, the architectures of neural and immune important in immunology, where stored patterns represent strategies to fight pathogens and nodes represent Hebbian synaptic couplings. In (adaptive) immune systems, effector branches (B- clones) and coordinator

Coolen, ACC "Ton"

180

Multilevel Coalition Formation Strategy for Suppression of Enemy Air Defenses Missions  

E-print Network

the bioinspired strategy. First, in the context of multi-agent systems, a mathematical model is produced to form coalitions in teams of heterogeneous vehicles. In particular, a coordination strategy is designed would benefit from a heterogeneous network of unmanned vehicles to search and destroy threats

Egerstedt, Magnus

181

Effects of temperature on hard clam (Mercenaria mercenaria) immunity and QPX (Quahog Parasite Unknown) disease development: II. Defense parameters  

E-print Network

Effects of temperature on hard clam (Mercenaria mercenaria) immunity and QPX (Quahog Parasite Keywords: Hard clam Mercenaria mercenaria QPX Thraustochytrid Parasite Immune response Temperature Environment a b s t r a c t Quahog Parasite Unknown (QPX) is a protistan parasite affecting hard clams

Allam, Bassem

182

Three beetles—three concepts. Different defensive strategies of congeneric myrmecophilous beetles  

Microsoft Academic Search

Myrmecophiles, i.e., organisms associated with ants live in a variety of ecological niches in the vicinity or inside ant colonies\\u000a and employ different strategies to survive ant encounters. Because different niches are characterized by different encounter\\u000a rates with host ants, strategies used to avoid ant aggressions should depend on these niches. This hypothesis was studied\\u000a with three rove beetle species

Michael Stoeffler; Till Tolasch; Johannes L. M. Steidle

2011-01-01

183

A cognitive and economic decision theory for examining cyber defense strategies.  

SciTech Connect

Cyber attacks pose a major threat to modern organizations. Little is known about the social aspects of decision making among organizations that face cyber threats, nor do we have empirically-grounded models of the dynamics of cooperative behavior among vulnerable organizations. The effectiveness of cyber defense can likely be enhanced if information and resources are shared among organizations that face similar threats. Three models were created to begin to understand the cognitive and social aspects of cyber cooperation. The first simulated a cooperative cyber security program between two organizations. The second focused on a cyber security training program in which participants interact (and potentially cooperate) to solve problems. The third built upon the first two models and simulates cooperation between organizations in an information-sharing program.

Bier, Asmeret Brooke

2014-01-01

184

An optimal defense strategy for phenolic glycoside production in Populus trichocarpa--isotope labeling demonstrates secondary metabolite production in growing leaves.  

PubMed

Large amounts of carbon are required for plant growth, but young, growing tissues often also have high concentrations of defensive secondary metabolites. Plants' capacity to allocate resources to growth and defense is addressed by the growth-differentiation balance hypothesis and the optimal defense hypothesis, which make contrasting predictions. Isotope labeling can demonstrate whether defense compounds are synthesized from stored or newly fixed carbon, allowing a detailed examination of these hypotheses. Populus trichocarpa saplings were pulse-labeled with 13CO2 at the beginning and end of a growing season, and the 13C signatures of phenolic glycosides (salicinoids), sugars, bulk tissue, and respired CO2 were traced over time. Half of the saplings were also subjected to mechanical damage. Populus trichocarpa followed an optimal defense strategy, investing 13C in salicinoids in expanding leaves directly after labeling. Salicinoids turned over quickly, and their production continued throughout the season. Salicin was induced by early-season damage, further demonstrating optimal defense. Salicinoids appear to be of great value to P. trichocarpa, as they command new C both early and late in the growing season, but their fitness benefits require further study. Export of salicinoids between tissues and biochemical pathways enabling induction also needs research. Nonetheless, the investigation of defense production afforded by isotope labeling lends new insights into plants' ability to grow and defend simultaneously. PMID:24739022

Massad, Tara Joy; Trumbore, Susan E; Ganbat, Gantsetseg; Reichelt, Michael; Unsicker, Sybille; Boeckler, Andreas; Gleixner, Gerd; Gershenzon, Jonathan; Ruehlow, Steffen

2014-07-01

185

Host–pathogen interactions and immune evasion strategies in Francisella tularensis pathogenicity  

PubMed Central

Francisella tularensis is an intracellular Gram-negative bacterium that causes life-threatening tularemia. Although the prevalence of natural infection is low, F. tularensis remains a tier I priority pathogen due to its extreme virulence and ease of aerosol dissemination. F. tularensis can infect a host through multiple routes, including the intradermal and respiratory routes. Respiratory infection can result from a very small inoculum (ten organisms or fewer) and is the most lethal form of infection. Following infection, F. tularensis employs strategies for immune evasion that delay the immune response, permitting systemic distribution and induction of sepsis. In this review we summarize the current knowledge of F. tularensis in an immunological context, with emphasis on the host response and bacterial evasion of that response. PMID:25258544

Steiner, Don J; Furuya, Yoichi; Metzger, Dennis W

2014-01-01

186

The role of mammalian antimicrobial peptides and proteins in awakening of innate host defenses and adaptive immunity  

Microsoft Academic Search

Since we live in a dirty environment, we have developed many host defenses to contend with microor- ganisms. The epithelial lining of our skin, gastrointestinal tract and bronchial tree produces a number of antibacte- rial peptides, and our phagocytic neutrophils rapidly in- gest and enzymatically degrade invading organisms, as well as produce peptides and enzymes with antimicrobial activities. Some of

D. Yang; O. Chertov; J. J. Oppenheim

2001-01-01

187

BMD Agents: An Agent-Based Framework to Model Ballistic Missile Defense Strategies  

Microsoft Academic Search

We introduce a model-based methodology for comparative eval- uation of the effectiveness of alternative ballistic missle de- fense strategies. The major new feature is that BMD is mod- elled as a distributed system of interacting agents in which some agents are physical (such as sensors and launch systems) and some are rule-based (such as decision makers and threat- evaluators). In

Duminda Wijesekera; James Bret Michael; Anil Nerode

188

Maternal Antibodies: Clinical Significance, Mechanism of Interference with Immune Responses, and Possible Vaccination Strategies  

PubMed Central

Neonates have an immature immune system, which cannot adequately protect against infectious diseases. Early in life, immune protection is accomplished by maternal antibodies transferred from mother to offspring. However, decaying maternal antibodies inhibit vaccination as is exemplified by the inhibition of seroconversion after measles vaccination. This phenomenon has been described in both human and veterinary medicine and is independent of the type of vaccine being used. This review will discuss the use of animal models for vaccine research. I will review clinical solutions for inhibition of vaccination by maternal antibodies, and the testing and development of potentially effective vaccines. These are based on new mechanistic insight about the inhibitory mechanism of maternal antibodies. Maternal antibodies inhibit the generation of antibodies whereas the T cell response is usually unaffected. B cell inhibition is mediated through a cross-link between B cell receptor (BCR) with the Fc?-receptor IIB by a vaccine–antibody complex. In animal experiments, this inhibition can be partially overcome by injection of a vaccine-specific monoclonal IgM antibody. IgM stimulates the B cell directly through cross-linking the BCR via complement protein C3d and antigen to the complement receptor 2 (CR2) signaling complex. In addition, it was shown that interferon alpha binds to the CD21 chain of CR2 as well as the interferon receptor and that this dual receptor usage drives B cell responses in the presence of maternal antibodies. In lieu of immunizing the infant, the concept of maternal immunization as a strategy to protect neonates has been proposed. This approach would still not solve the question of how to immunize in the presence of maternal antibodies but would defer the time of infection to an age where infection might not have such a detrimental outcome as in neonates. I will review successful examples and potential challenges of implementing this concept. PMID:25278941

Niewiesk, Stefan

2014-01-01

189

Innate immune recognition of microbial cell wall components and microbial strategies to evade such recognitions.  

PubMed

The innate immune system constitutes the first line of defence against invading microbes. The basis of this defence resides in the recognition of defined structural motifs of the microbes called "Microbial associated molecular patterns" that are absent in the host. Cell wall, the outer layer of both bacterial and fungal cells, a unique structure that is absent in the host and is recognized by the germ line encoded host receptors. Nucleotide oligomerization domain proteins, peptidoglycan recognition proteins and C-type lectins are host receptors that are involved in the recognition of bacterial cell wall (usually called peptidoglycan), whereas fungal cell wall components (N- and O-linked mannans, ?-glucans etc.) are recognized by host receptors like C-type lectins (Dectin-1, Dectin-2, mannose receptor, DC-SIGN), Toll like receptors-2 and -4 (TLR-2 and TLR-4). These recognitions lead to activation of a variety of host signaling cascades and ultimate production of anti-microbial compounds including phospholipase A2, antimicrobial peptides, lysozyme, reactive oxygen and nitrogen species. These molecules act in cohort against the invading microbes to eradicate infections. Additionally pathogen recognition leads to the production of cytokines, which further activate the adaptive immune system. Both pathogenic and commensal bacteria and fungus use numerous strategies to subvert the host defence. These strategies include bacterial peptidoglycan glycan backbone modifications by O-acetylation, N-deacetylation, N-glycolylation and stem peptide modifications by amidation of meso-Diaminopimelic acid; fungal cell wall modifications by shielding the ?-glucan layer with mannoproteins and ?-1,3 glucan. This review focuses on the recent advances in understanding the role of bacterial and fungal cell wall in their innate immune recognition and evasion strategies. PMID:23578963

Sukhithasri, V; Nisha, N; Biswas, Lalitha; Anil Kumar, V; Biswas, Raja

2013-08-25

190

Sexual self-defense versus the liaison dangereuse: a strategy for AIDS prevention in the '90s.  

PubMed

The present public health strategy to encourage the adoption of "safe sex" practices to contain the AIDS epidemic in America is incomplete. Current policy is responsive to and appropriate for control of homosexual, but not heterosexual transmission. Powerful societal forces restrict a woman's perception of risk. Consequently, the adoption of safe sex (condom use/insistence on use) by women at risk has not matched safe sex practice by homosexual men. Predictably, pattern two (heterosexual, maternal-fetal) HIV transmission is now rapidly increasing in the United States, particularly among minority women. In anticipation of an intensified pattern two subepidemic, AIDS containment policy should be reoriented to develop the role of women in AIDS prevention. An initiative, termed "sexual self-defense" (SSD), combines the technology of double-barrier (female irrespective of male) protection with a "universal precautions" approach to long-term sexual risk management. The initiative addresses both per-contact infectiousness and new partner acquisition, the principal determinants of HIV spread. As a female-targeted strategy, SSD is a timely supplement to existing programs, consistent with the direction of contemporary women's movements in the United States. A "street smart" approach, SSD bridges ethnic and socioeconomic individual differences. As a unifying philosophy of risk management in health promotion, SSD may avert the threatened fragmentation of AIDS control from existing programs of sexually transmitted disease control and teenage pregnancy prevention. PMID:1931142

Nelson, E W

1991-01-01

191

Toll-like receptors and the host defense against microbial pathogens: bringing specificity to the innate-immune system  

Microsoft Academic Search

Toll-like receptors (TLRs) have been identified as a major class of pattern-recognition receptors. Recognition of pathogen-associated mo- lecular patterns (PAMPs) by TLRs, alone or in heterodimerization with other TLR or non-TLR receptors, induces signals responsible for the acti- vation of genes important for an effective host defense, especially proinflammatory cytokines. Al- though a certain degree of redundancy exists be- tween

Mihai G. Netea; Chantal van der Graaf; Bart Jan Kullberg

2003-01-01

192

Co-immunization with DNA and protein mixture: A safe and efficacious immunotherapeutic strategy for Alzheimer's disease in PDAPP mice.  

PubMed

Active immunotherapy targeting ?-amyloid (A?) is the most promising strategy to prevent or treat Alzheimer's disease (AD). Based on pre-clinical studies and clinical trials, a safe and effective AD vaccine requires a delicate balance between providing therapeutically adequate anti-A? antibodies and eliminating or suppressing unwanted adverse T cell-mediated inflammatory reactions. We describe here the immunological characterization and protective efficacy of co-immunization with a 6A?15-T DNA and protein mixture without adjuvant as an AD immunotherapeutic strategy. Impressively, this co-immunization induced robust Th2-polarized A?-specific antibodies while simultaneously suppressed unwanted inflammatory T cell reactions and avoiding A?42-specific T cell-mediated autoimmune responses in immunized mice. Co-immunization with the DNA + protein vaccine could overcome A?42-associated hypo-responsiveness and elicit long-term A?-specific antibody responses, which helped to maintain antibody-mediated clearance of amyloid and accordingly alleviated AD symptoms in co-immunized PDAPP mice. Our DNA and protein combined vaccine, which could induce an anti-inflammatory Th2 immune response with high level A?-specific antibodies and low level IFN-? production, also demonstrated the capacity to inhibit amyloid accumulation and prevent cognitive dysfunction. Hence, co-immunization with antigen-matched DNA and protein may represent a novel and efficacious strategy for AD immunotherapy to eliminate T cell inflammatory reactions while retaining high level antibody responses. PMID:25586780

Liu, Si; Shi, DanYang; Wang, Hai-Chao; Yu, Yun-Zhou; Xu, Qing; Sun, Zhi-Wei

2015-01-01

193

Co-immunization with DNA and protein mixture: A safe and efficacious immunotherapeutic strategy for Alzheimer's disease in PDAPP mice  

PubMed Central

Active immunotherapy targeting ?-amyloid (A?) is the most promising strategy to prevent or treat Alzheimer's disease (AD). Based on pre-clinical studies and clinical trials, a safe and effective AD vaccine requires a delicate balance between providing therapeutically adequate anti-A? antibodies and eliminating or suppressing unwanted adverse T cell-mediated inflammatory reactions. We describe here the immunological characterization and protective efficacy of co-immunization with a 6A?15-T DNA and protein mixture without adjuvant as an AD immunotherapeutic strategy. Impressively, this co-immunization induced robust Th2-polarized A?-specific antibodies while simultaneously suppressed unwanted inflammatory T cell reactions and avoiding A?42-specific T cell-mediated autoimmune responses in immunized mice. Co-immunization with the DNA + protein vaccine could overcome A?42-associated hypo-responsiveness and elicit long-term A?-specific antibody responses, which helped to maintain antibody-mediated clearance of amyloid and accordingly alleviated AD symptoms in co-immunized PDAPP mice. Our DNA and protein combined vaccine, which could induce an anti-inflammatory Th2 immune response with high level A?-specific antibodies and low level IFN-? production, also demonstrated the capacity to inhibit amyloid accumulation and prevent cognitive dysfunction. Hence, co-immunization with antigen-matched DNA and protein may represent a novel and efficacious strategy for AD immunotherapy to eliminate T cell inflammatory reactions while retaining high level antibody responses. PMID:25586780

Liu, Si; Shi, DanYang; Wang, Hai-Chao; Yu, Yun-Zhou; Xu, Qing; Sun, Zhi-Wei

2015-01-01

194

The Nod1, Nod2, and Rip2 Axis Contributes to Host Immune Defense against Intracellular Acinetobacter baumannii Infection  

PubMed Central

Acinetobacter baumannii is a major extensively drug-resistant lethal human nosocomial bacterium. However, the host innate immune mechanisms controlling A. baumannii are not well understood. Although viewed as an extracellular pathogen, A. baumannii can also invade and survive intracellularly. However, whether host innate immune pathways sensing intracellular bacteria contribute to immunity against A. baumannii is not known. Here, we provide evidence for the first time that intracellular antibacterial innate immune receptors Nod1 and Nod2, and their adaptor Rip2, play critical roles in the sensing and clearance of A. baumannii by human airway epithelial cells in vitro. A. baumannii infection upregulated Rip2 expression. Silencing of Nod1, Nod2, and Rip2 expression profoundly increased intracellular invasion and prolonged the multiplication and survival of A. baumannii in lung epithelial cells. Notably, the Nod1/2-Rip2 axis did not contribute to the control of A. baumannii infection of human macrophages, indicating that they play cell type-specific roles. The Nod1/2-Rip2 axis was needed for A. baumannii infection-induced activation of NF-?B but not mitogen-activated protein kinases. Moreover, the Nod1/2-Rip2 axis was critical to induce optimal cytokine and chemokine responses to A. baumannii infection. Mechanistic studies showed that the Nod1/2 pathway contributed to the innate control of A. baumannii infection through the production of ?-defensin 2 by airway epithelial cells. This study revealed new insights into the immune control of A. baumannii and may contribute to the development of effective immune therapeutics and vaccines against A. baumannii. PMID:24366254

Bist, Pradeep; Dikshit, Neha; Koh, Tse Hsien; Mortellaro, Alessandra; Tan, Thuan Tong

2014-01-01

195

Different defense strategies of Dendrolimus pini, Galleria mellonella, and Calliphora vicina against fungal infection.  

PubMed

The resistance of Galleria mellonella, Dendrolimus pini, and Calliphora vicina larvae against infection by the enthomopathogen Conidiobolus coronatus was shown to vary among the studied species. Exposure of both G. mellonella and D. pini larvae to the fungus resulted in rapid insect death, while all the C. vicina larvae remained unharmed. Microscopic studies revealed diverse responses of the three species to the fungal pathogen: (1) the body cavities of D. pini larvae were completely overgrown by fungal hyphae, with no signs of hemocyte response, (2) infected G. mellonella larvae formed melanotic capsules surrounding the fungal pathogen, and (3) the conidia of C. coronatus did not germinate on the cuticle of C. vicina larvae. The in vitro study on the degradation of the insect cuticle by proteases secreted by C. coronatus revealed that the G. mellonella cuticle degraded at the highest rate. The antiproteolytic capacities of insect hemolymph against fungal proteases correlated well with the insects' susceptibility to fungal infection. The antiproteolytic capacities of insect hemolymph against fungal proteases correlated well with the insects' susceptibility to fungal infection. Of all the tested species, only plasmatocytes exhibited phagocytic potential. Exposure to the fungal pathogen resulted in elevated phagocytic activity, found to be the highest in the infected G. mellonella. The incubation of insect hemolymph with fungal conidia and hyphae revealed diverse reactions of hemocytes of the studied insect species. The encapsulation potential of D. pini hemocytes was low. Hemocytes of G. mellonella showed a high ability to attach and encapsulate fungal structures. Incubation of C. vicina hemolymph with C. coronatus did not result in any hemocytic response. Phenoloxidase (PO) activity was found to be highest in D. pini hemolymph, moderate in G. mellonella, and lowest in the hemolymph of C. vicina. Fungal infection resulted in a significant decrease of PO activity in G. mellonela larvae, while that in the larvae of D. pini remained unchanged. PO activity in C. vicina exposed to fungus slightly increased. The lysozyme-like activity increased in the plasma of all three insect species after contact with the fungal pathogen. Anti E. coli activity was detected neither in control nor in infected D. pini larvae. No detectable anti E. coli activity was found in the control larvae of G. mellonella; however, its exposure to C. coronatus resulted in an increase in the activity to detectable level. In the case of C. vicina exposure to the fungus, the anti E. coli activity was significantly higher than in control larvae. The defense mechanisms of D. pini (species of economic importance in Europe) are presented for the first time. PMID:17512001

Bogu?, M I; Kedra, E; Bania, J; Szczepanik, M; Czygier, M; Jab?o?ski, P; Pasztaleniec, A; Samborski, J; Mazgajska, J; Polanowski, A

2007-09-01

196

The Arabidopsis Mediator complex subunits MED14/SWP and MED16/SFR6/IEN1 differentially regulate defense gene expression in plant immune responses.  

PubMed

Pathogen infection in plants triggers large-scale transcriptional changes, both locally and systemically. Emerging evidence suggests that the Arabidopsis Mediator complex plays a crucial role in these transcriptional changes. Mediator is highly conserved in eukaryotes, and its core comprises more than 20 subunits organized into three modules named head, middle and tail. The head and middle modules interact with general transcription factors and RNA polymerase II, whereas the tail module associates with activators, and signals through the head and middle modules to the basal transcription machinery. In Arabidopsis, three tail module subunits, MED14, MED15 and MED16, have been identified. Both MED15 and MED16 have been implicated in plant immunity, but the role of MED14 has not been established. Here, we report the characterization of an Arabidopsis T-DNA insertion mutant of the MED14 gene. Similarly to the med15 and/or med16 mutations, the med14 mutation significantly suppresses salicylic acid-induced defense responses, alters transcriptional changes induced by the avirulent bacterial pathogen Pseudomonas syringae pv. tomato (Pst) DC3000/avrRpt2, and renders plants susceptible to both Pst DC3000/avrRpt2 and Pst DC3000. The med14 mutation also completely compromises biological induction of systemic acquired resistance (SAR), indicating that the tail module as a whole is essential for SAR. Interestingly, unlike the med16 mutation, which differentially affects expression of several SAR positive and negative regulators, med14 inhibits induction of a large group of defense genes, including both SAR positive and negative regulators, suggesting that individual subunits of the Mediator tail module employ distinct mechanisms to regulate plant immune responses. PMID:23607369

Zhang, Xudong; Yao, Jin; Zhang, Yanping; Sun, Yijun; Mou, Zhonglin

2013-08-01

197

Regulation of plant immunity to necrotrophic fungi  

Microsoft Academic Search

We examined Arabidopsis resistance mechanisms to Botrytis cinerea and Alternaria brassicicola, two necrotrophic fungal pathogens with overlapping pathogenesis strategies. B. cinerea is the causal agent of gray mold whereas A. brassicicola causes the black spot disease in cruciferous plants.^ In an effort to isolate regulators of plant defense, we used functional genomics approaches to identify genes involved in immune responses

Kristin A Laluk

2010-01-01

198

Estimating teh costs of achieving the WHO-UNICEF Global Immunization Vision and Strategy, 2006-2015  

Microsoft Academic Search

Objective To estimate the cost of scaling up childhood immunization services required to reach the WHO-UNICEF Global Immunization Vision and Strategy (GIVS) goal of reducing mortality due to vaccine-preventable diseases by two-thirds by 2015. Methods A model was developed to estimate the total cost of reaching GIVS goals by 2015 in 117 low- and lower-middle- income countries. Current spending was

Lara J Wolfson; François Gasse; Shook-Pui Lee-Martin; Patrick Lydon; Ahmed Magan; Abdelmajid Tibouti; Benjamin Johns; Raymond Hutubessy; Peter Salama; Jean-Marie Okwo-Bele

2008-01-01

199

Immunization.  

ERIC Educational Resources Information Center

These pamphlets present facts, background information and guides on the immunization of children against preventable diseases. Individual pamphlets are provided for mass media specialists, health personnel in the field, health policy makers and program administrators, as well as university personnel. Contents include a specification of the role of…

International Children's Centre, Paris (France).

200

Immunization.  

ERIC Educational Resources Information Center

Contents of this double journal issue concern immunization and primary health care of children. The issue decribes vaccine storage and sterilization techniques, giving particular emphasis to the role of the cold chain, i.e., the maintenance of a specific temperature range to assure potency of vaccines as they are moved from a national storage…

Guerin, Nicole; And Others

1986-01-01

201

An Active Immune Defense with a Minimal CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats) RNA and without the Cas6 Protein.  

PubMed

The prokaryotic immune system CRISPR-Cas (clustered regularly interspaced short palindromic repeats-CRISPR-associated) is a defense system that protects prokaryotes against foreign DNA. The short CRISPR RNAs (crRNAs) are central components of this immune system. In CRISPR-Cas systems type I and III, crRNAs are generated by the endonuclease Cas6. We developed a Cas6b-independent crRNA maturation pathway for the Haloferax type I-B system in vivo that expresses a functional crRNA, which we termed independently generated crRNA (icrRNA). The icrRNA is effective in triggering degradation of an invader plasmid carrying the matching protospacer sequence. The Cas6b-independent maturation of the icrRNA allowed mutation of the repeat sequence without interfering with signals important for Cas6b processing. We generated 23 variants of the icrRNA and analyzed them for activity in the interference reaction. icrRNAs with deletions or mutations of the 3' handle are still active in triggering an interference reaction. The complete 3' handle could be removed without loss of activity. However, manipulations of the 5' handle mostly led to loss of interference activity. Furthermore, we could show that in the presence of an icrRNA a strain without Cas6b (?cas6b) is still active in interference. PMID:25512373

Maier, Lisa-Katharina; Stachler, Aris-Edda; Saunders, Sita J; Backofen, Rolf; Marchfelder, Anita

2015-02-13

202

A Metabolic Profiling Strategy for the Dissection of Plant Defense against Fungal Pathogens  

PubMed Central

Here we present a metabolic profiling strategy employing direct infusion Orbitrap mass spectrometry (MS) and gas chromatography-mass spectrometry (GC/MS) for the monitoring of soybean's (Glycine max L.) global metabolism regulation in response to Rhizoctonia solani infection in a time-course. Key elements in the approach are the construction of a comprehensive metabolite library for soybean, which accelerates the steps of metabolite identification and biological interpretation of results, and bioinformatics tools for the visualization and analysis of its metabolome. The study of metabolic networks revealed that infection results in the mobilization of carbohydrates, disturbance of the amino acid pool, and activation of isoflavonoid, ?-linolenate, and phenylpropanoid biosynthetic pathways of the plant. Components of these pathways include phytoalexins, coumarins, flavonoids, signaling molecules, and hormones, many of which exhibit antioxidant properties and bioactivity helping the plant to counterattack the pathogen's invasion. Unraveling the biochemical mechanism operating during soybean-Rhizoctonia interaction, in addition to its significance towards the understanding of the plant's metabolism regulation under biotic stress, provides valuable insights with potential for applications in biotechnology, crop breeding, and agrochemical and food industries. PMID:25369450

Aliferis, Konstantinos A.; Faubert, Denis; Jabaji, Suha

2014-01-01

203

Species-specific defense strategies of vegetative versus reproductive blades of the Pacific kelps Lessonia nigrescens and Macrocystis integrifolia  

Microsoft Academic Search

Chemical defense is assumed to be costly and therefore algae should allocate defense investments in a way to reduce costs\\u000a and optimize their overall fitness. Thus, lifetime expectation of particular tissues and their contribution to the fitness\\u000a of the alga may affect defense allocation. Two brown algae common to the SE Pacific coasts, Lessonia nigrescens Bory and Macrocystis integrifolia Bory,

Christian Pansch; Ivan Gómez; Eva Rothäusler; Karina Veliz; Martin Thiel

2008-01-01

204

Message framing strategies to increase influenza immunization uptake among pregnant African American women.  

PubMed

We explored the attitudes, opinions, and concerns of African American women regarding influenza vaccination during pregnancy. As influenza immunization coverage rates remain suboptimal in the United States among this population, we elicited message framing strategies for multicomponent interventions aimed at decreasing future incident cases of maternal and neonatal influenza. Semi-structured in-depth interviews (N = 21) were conducted with pregnant African American women at urban OB/GYN clinics who had not received an influenza vaccine. Interviews were transcribed, subjected to intercoder reliability assessment, and content analyzed to identify common thematic factors related to acceptance of the influenza vaccine and health communication message preferences. Four major themes were identified. These were communication approaches, normal vaccine behavior, pregnancy vaccination, and positive versus negative framing. Two strong themes emerged: positively-framed messages were preferred over negatively-framed messages and those emphasizing the health of the infant. Additionally, previous immunization, message source, and vaccine misperceptions also played important roles in decision-making. The majority of women indicated that positively framed messages focusing on the infant's health would encourage them to receive an influenza vaccine. Messages emphasizing immunization benefits such as protection against preterm birth and low birth weight outcomes have potential to overcome widespread negative community perceptions and cultural beliefs. Additionally, messages transmitted via interpersonal networks and social media strongly influence motivation to obtain vaccination during pregnancy. The findings of this study will assist in developing tailored messages that change pregnant African American women's influenza vaccination decision-making to achieve improved coverage. PMID:24337776

Marsh, Heather A; Malik, Fauzia; Shapiro, Eve; Omer, Saad B; Frew, Paula M

2014-09-01

205

Repeated vaccinations do not improve specific immune defenses against Hepatitis B in non-responder health care workers.  

PubMed

Hepatitis B is a major infectious occupational hazard for health care workers and can be prevented with a safe and effective vaccine. The serum titer of anti-HBsAg antibodies is the most commonly used correlate of protection and post-vaccination anti-HBsAg concentrations of ?10mIU/ml are considered protective. Subjects with post-vaccination anti-HBsAg titers of <10mIU/ml 1-6 months post-vaccination, who tested negative for HBsAg and anti-HBc, are defined as non-responders. The question of whether non-responders should be repeatedly vaccinated is still open. The aim of the study was to (i) evaluate the distribution of lymphocyte subpopulations and the percentage of HBsAg-specific memory B cells in responders and non-responders (ii) assess whether non-responders can be induced to produce antibodies after administration of a booster dose of vaccine (iii) determine whether booster vaccination increases the number of specific memory B cells in non-responders. Combining flow-cytometry, ELISPOT and serology we tested the integrity and function of the immune system in 24 health care workers, confirmed to be non-responders after at least three vaccine injections. We compared the results with those obtained in 21 responders working in the same institution. We found that the great majority of the non-responders had a functional immune system and a preserved ability to respond to other conventional antigens. Our most important findings are that the frequency of HBsAg-specific memory B cells is comparable in non-responders and controls and that booster immunization does not lead either to antibody production or memory B cell increase in non-responders. PMID:25444815

Zaffina, Salvatore; Marcellini, Valentina; Santoro, Anna Paola; Scarsella, Marco; Camisa, Vincenzo; Vinci, Maria Rosaria; Musolino, Anna Maria; Nicolosi, Luciana; Rosado, M Manuela; Carsetti, Rita

2014-11-01

206

Local, regional and large scale integrated networks: Volume 1. Large networks for defense communications: Strategies, performance measures and cost trends  

Microsoft Academic Search

Investigations into local, regional, and large scale packet switched network cost and performance for Defense Department communications are summarized. The issues examined include: (1) alternative large network architectures; (2) performance evaluation criteria; (3) formulation of the large network design problem; (4) defense communication requirements; (5) local access network tradeoffs; (6) backbone and total network performance and cost characteristics; and (7)

H. Frank; I. Gitman; R. Vanslyke

1976-01-01

207

Spray-dried plasma promotes growth, modulates the activity of antioxidant defenses, and enhances the immune status of gilthead sea bream (Sparus aurata) fingerlings.  

PubMed

Terrestrial animal byproduct meals, including nonruminant blood meal and blood products, represent the largest and largely untapped safe source of animal protein available within the international market for the aquafeed industry. Spray-dried blood and spray-dried plasma (SDP) proteins have long been recognized as high-quality feed ingredients for farmed animals. In this study, we evaluated the inclusion of SDP from porcine blood (SDPP) in growing diets for gilthead sea bream. Three isonitrogenous (CP = 51.2%) and isolipidic (fat = 12.4%) diets manufactured by cold extrusion (0.8 to 1.5 mm pellet size) were prepared by substituting high-quality fish meal with 0, 3, and 6% SDPP. The diets were tested for a period of 60 d at 22°C with 4 replicates each (400-L cylindroconical tanks, 150 fish per tank, and initial density = 0.5 kg/m(3)). The SDPP inclusion in diets for gilthead sea bream fingerlings were evaluated in terms of growth performance, feed utilization, histological organization of the intestinal mucosa, activity of oxidative stress enzymes (catalase, glutathione S-transferase, glutathione peroxidase, and glutathione reductase) in the intestine, and nonspecific serum immune parameters (lysozyme and bactericidal activity). Results from this study indicated that dietary SDPP promoted fish growth in terms of BW and length; fish fed 3% SDPP were 10.5% heavier (P < 0.05) than those fed the control diet. Spray-dried plasma from porcine blood modulated the activity of the antioxidative defenses in the intestine (P < 0.05) and increased the density of goblet cells in the intestine (P < 0.05) and benefited the host by providing an effective immune barrier against gut pathogenic microbiota. The nonspecific serum immune response in fish fed diets with SDPP was greater (P < 0.05) than in fish fed the control diet. These results indicated that the inclusion of SDPP in gilthead sea bream feed could be beneficial for the fish by enhancing intestinal and serum innate immune function and the activity of antioxidative stress enzymes of the intestine and promoting growth performance. PMID:25568376

Gisbert, E; Skalli, A; Campbell, J; Solovyev, M M; Rodríguez, C; Dias, J; Polo, J

2015-01-01

208

Salmonella enterica serovar enteritidis antimicrobial peptide resistance genes aid in defense against chicken innate immunity, fecal shedding, and egg deposition.  

PubMed

Salmonella enterica serovar Enteritidis (S. Enteritidis) is a major etiologic agent of nontyphoid salmonellosis in the United States. S. Enteritidis persistently and silently colonizes the intestinal and reproductive tract of laying hens, resulting in contaminated poultry products. The consumption of contaminated poultry products has been identified as a significant risk factor for human salmonellosis. To understand the mechanisms S. Enteritidis utilizes to colonize and persist in laying hens, we used selective capture of transcribed sequences to identify genes overexpressed in the HD11 chicken macrophage cell line and in primary chicken oviduct epithelial cells. From the 15 genes found to be overexpressed in both cell types, we characterized the antimicrobial peptide resistance (AMPR) genes, virK and ybjX, in vitro and in vivo. In vitro, AMPR genes were required for natural morphology, motility, secretion, defense against detergents such as EDTA and bile salts, and resistance to antimicrobial peptides polymyxin B and avian ?-defensins. From this, we inferred the AMPR genes play a role in outer membrane stability and/or modulation. In the intestinal tract, AMPR genes were involved in early intestinal colonization and fecal shedding. In the reproductive tract, virK was required in early colonization whereas a deletion of ybjX caused prolonged ovary colonization and egg deposition. Data from the present study indicate that AMPR genes are differentially utilized in various host environments, which may ultimately assist S. Enteritidis in persistent and silent colonization of chickens. PMID:25267840

McKelvey, Jessica A; Yang, Ming; Jiang, Yanhua; Zhang, Shuping

2014-12-01

209

Evidence for two immune inhibitors from Bacillus thuringiensis interfering with the humoral defense system of saturniid pupae.  

PubMed Central

Mutants of Bacillus thuringiensis lacking either beta-exotoxin or gamma-endotoxin were compared for their virulence using pupae of a giant silk moth. Known doses of viable log-phase bacteria were injected, and the response was followed as the number of viable bacteria in the hemolymph. The results obtained imply that, in the system used, neither the beta-exotoxin nor the gamma-endotoxin and the sporeforming ability are of importance for virulence. Results with sterile culture filtrate from B. thuringiensis have given evidence for the production of two inhibitors, A and B, which interfere with the humoral defense system in pupae of Hyalophora cecropia. Inhibitor A, which blocked the lysis of Escherichia coli,was precipitated by trichloroacetic acid and sensitive to heating. Inhibitor B, which blocked the killing of Bacillus cereus, was soluble in trichloroacetic acid and resistant to 90 degrees C for 5 min. Both inhibitors are believed to contribute to the insecticidal nature of B. thuringiensis. PMID:992874

Edlund, T; Sidén, I; Boman, H G

1976-01-01

210

APS/123-QED Retrieving Infinite Numbers of Patterns in a Spin-Glass Model of Immune Networks  

E-print Network

networks, to recall and execute a large number of memorized defense strategies in parallel. The explanation that both multiple antigen defense and homeostasis can be accomplished. PACS numbers: 07.05.Mh,87.19.L-,05 that are dedicated to the coordination of the adaptive immune response, i.e. helper and regulator T-cells. B

Coolen, ACC "Ton"

211

Coping Strategies of Patients with Haemophilia as a Risk Group for AIDS (Acquired Immune Deficiency Syndrome). Brief Research Report.  

ERIC Educational Resources Information Center

Plans are described for a 2-year project whose major focus is the identification of ways in which patients with hemophilia and their families assimilate, interpret, and act on information about Acquired Immune Deficiency Syndrome (AIDS). Findings will be related to perceived risk, anxiety levels, and the development of coping strategies.…

Naji, Simon; And Others

1986-01-01

212

Newly diagnosed immune thrombocytopenic purpura in childhood: successful implementation of a limited intervention strategy in the setting of pediatric emergency care.  

PubMed

Immune thrombocytopenic purpura is a bleeding disorder for which management remains mainly guided by platelet counts. Pediatric hematologists and emergency physicians collaborated to set up a limited intervention strategy, focusing on clinical bleeding severity irrespective of platelet counts, starting in the emergency room. We report how this strategy was safely applied for 106 consecutive children admitted for newly diagnosed immune thrombocytopenic purpura. PMID:25454932

Rohmer, Barbara; Valla, Frédéric V; Baleydier, Frédéric; Launay, Valérie; Dommange-Romero, Florence; Pondarré, Corinne

2015-02-01

213

Modulation of Immune System by Kaposi’s Sarcoma-Associated Herpesvirus: Lessons from Viral Evasion Strategies  

PubMed Central

Kaposi’s sarcoma-associated herpesvirus (KSHV), a member of the herpesvirus family, has evolved to establish a long-term, latent infection of cells such that while they carry the viral genome gene expression is highly restricted. Latency is a state of cryptic viral infection associated with genomic persistence in their host and this hallmark of KSHV infection leads to several clinical–epidemiological diseases such as KS, a plasmablastic variant of multicentric Castleman’s disease, and primary effusion lymphoma upon immune suppression of infected hosts. In order to sustain efficient life-long persistency as well as their life cycle, KSHV dedicates a large portion of its genome to encode immunomodulatory proteins that antagonize its host’s immune system. In this review, we will describe our current knowledge of the immune evasion strategies employed by KSHV at distinct stages of its viral life cycle to control the host’s immune system. PMID:22403573

Lee, Hye-Ra; Brulois, Kevin; Wong, LaiYee; Jung, Jae U.

2012-01-01

214

RabGAP22 Is Required for Defense to the Vascular Pathogen Verticillium longisporum and Contributes to Stomata Immunity  

PubMed Central

Verticillium longisporum is a soil-borne pathogen with a preference for plants within the family Brassicaceae. Following invasion of the roots, the fungus proliferates in the plant vascular system leading to stunted plant growth, chlorosis and premature senescence. RabGTPases have been demonstrated to play a crucial role in regulating multiple responses in plants. Here, we report on the identification and characterization of the Rab GTPase-activating protein RabGAP22 gene from Arabidopsis, as an activator of multiple components in the immune responses to V. longisporum. RabGAP22Pro:GUS transgenic lines showed GUS expression predominantly in root meristems, vascular tissues and stomata, whereas the RabGAP22 protein localized in the nucleus. Reduced RabGAP22 transcript levels in mutants of the brassinolide (BL) signaling gene BRI1-ASSOCIATED RECEPTOR KINASE 1, together with a reduction of fungal proliferation following BL pretreatment, suggested RabGAP22 to be involved in BL-mediated responses. Pull-down assays revealed SERINE:GLYOXYLATE AMINOTRANSFERASE (AGT1) as an interacting partner during V. longisporum infection and bimolecular fluorescence complementation (BiFC) showed the RabGAP22-AGT1 protein complex to be localized in the peroxisomes. Further, fungal-induced RabGAP22 expression was found to be associated with elevated endogenous levels of the plant hormones jasmonic acid (JA) and abscisic acid (ABA). An inadequate ABA response in rabgap22-1 mutants, coupled with a stomata-localized expression of RabGAP22 and impairment of guard cell closure in response to V. longisporum and Pseudomonas syringae, suggest that RabGAP22 has multiple roles in innate immunity. PMID:24505423

Roos, Jonas; Bejai, Sarosh; Oide, Shinichi; Dixelius, Christina

2014-01-01

215

A multifunctional peptide based on the neutrophil immune defense molecule, CAP37, has antibacterial and wound-healing properties.  

PubMed

CAP37, a protein constitutively expressed in human neutrophils and induced in response to infection in corneal epithelial cells, plays a significant role in host defense against infection. Initially identified through its potent bactericidal activity for Gram-negative bacteria, it is now known that CAP37 regulates numerous host cell functions, including corneal epithelial cell chemotaxis. Our long-term goal is to delineate the domains of CAP37 that define these functions and synthesize bioactive peptides for therapeutic use. We report the novel finding of a multifunctional domain between aa 120 and 146. Peptide analogs 120-146 QR, 120-146 QH, 120-146 WR, and 120-146 WH were synthesized and screened for induction of corneal epithelial cell migration by use of the modified Boyden chamber assay, antibacterial activity, and LPS-binding activity. In vivo activity was demonstrated by use of mouse models of sterile and infected corneal wounds. The identity of the amino acid at position 132 (H vs. R) was important for cell migration and in vivo corneal wound healing. All analogs demonstrated antimicrobial activity. However, analogs containing a W at position 131 showed significantly greater antibacterial activity against the Gram-negative pathogen Pseudomonas aeruginosa. All analogs bound P. aeruginosa LPS. Topical administration of analog 120-146 WH, in addition to accelerating corneal wound healing, effectively cleared a corneal infection as a result of P. aeruginosa. In conclusion, we have identified a multifunctional bioactive peptide, based on CAP37, that induces cell migration, possesses antibacterial and LPS-binding activity, and is effective at healing infected and noninfected corneal wounds in vivo. PMID:25412625

Kasus-Jacobi, Anne; Noor-Mohammadi, Samaneh; Griffith, Gina L; Hinsley, Heather; Mathias, Lauren; Pereira, H Anne

2015-02-01

216

Defensive COBOL strategies  

Microsoft Academic Search

This paper will focus on an approach to teaching a stylistic subset of COBOL in such a manner that students are equipped with the “safe” way to program from the outset, even if this means “hiding” some of the more “dangerous” features of the language from them until they can better cope with them. This approach places the highest priority

James Landon Linderman

1982-01-01

217

House dust exposure mediates gut microbiome Lactobacillus enrichment and airway immune defense against allergens and virus infection  

PubMed Central

Exposure to dogs in early infancy has been shown to reduce the risk of childhood allergic disease development, and dog ownership is associated with a distinct house dust microbial exposure. Here, we demonstrate, using murine models, that exposure of mice to dog-associated house dust protects against ovalbumin or cockroach allergen-mediated airway pathology. Protected animals exhibited significant reduction in the total number of airway T cells, down-regulation of Th2-related airway responses, as well as mucin secretion. Following dog-associated dust exposure, the cecal microbiome of protected animals was extensively restructured with significant enrichment of, amongst others, Lactobacillus johnsonii. Supplementation of wild-type animals with L. johnsonii protected them against both airway allergen challenge or infection with respiratory syncytial virus. L. johnsonii-mediated protection was associated with significant reductions in the total number and proportion of activated CD11c+/CD11b+ and CD11c+/CD8+ cells, as well as significantly reduced airway Th2 cytokine expression. Our results reveal that exposure to dog-associated household dust results in protection against airway allergen challenge and a distinct gastrointestinal microbiome composition. Moreover, the study identifies L. johnsonii as a pivotal species within the gastrointestinal tract capable of influencing adaptive immunity at remote mucosal surfaces in a manner that is protective against a variety of respiratory insults. PMID:24344318

Fujimura, Kei E.; Demoor, Tine; Rauch, Marcus; Faruqi, Ali A.; Jang, Sihyug; Johnson, Christine C.; Boushey, Homer A.; Zoratti, Edward; Ownby, Dennis; Lukacs, Nicholas W.; Lynch, Susan V.

2014-01-01

218

78 FR 79469 - Strategies To Address Hemolytic Complications of Immune Globulin Infusions; Public Workshop  

Federal Register 2010, 2011, 2012, 2013

...Hemolytic Complications of Immune Globulin Infusions; Public Workshop AGENCY: Food and Drug...Hemolytic Complications of Immune Globulin Infusions.'' The purpose of the public workshop...Globulin Intravenous (IGIV) (Human) infusion. Complications of hemolysis...

2013-12-30

219

Prime-Boost Strategies in Mucosal Immunization Affect Local IgA Production and the Type of Th Response  

PubMed Central

Combinations of different delivery routes for priming and boosting represent vaccination strategies that can modulate magnitude, quality, and localization of the immune response. A murine model was used to study T cell clonal expansion following intranasal (IN) or subcutaneous (SC) priming, and secondary immune responses after boosting by either homologous or heterologous routes. T cell primary activation was studied by using the adoptive transfer model of ovalbumin-specific transgenic CD4+ T cells. Both IN and SC immunization efficiently elicited, in the respective draining lymph nodes, primary clonal expansion of antigen-specific CD4+ T cells that disseminated toward distal lymph nodes (mesenteric and iliac) and the spleen. After boosting, a significant serum IgG response was induced in all groups independent of the combination of immunization routes used, while significant levels of local IgA were detected only in mice boosted by the IN route. Mucosal priming drove a stronger Th1 polarization than the systemic route, as shown by serum IgG subclass analysis. IFN-gamma production was observed in splenocytes of all groups, while prime-boost vaccine combinations that included the mucosal route, yielded higher levels of IL-17. Memory lymphocytes were identified in both spleen and draining lymph nodes in all immunized mice, with the highest number of IL-2 producing cells detected in mice primed and boosted by the nasal route. This work shows the critical role of immunization routes in modulating quality and localization of immune responses in prime-boost vaccine strategies. PMID:23755051

Fiorino, Fabio; Pettini, Elena; Pozzi, Gianni; Medaglini, Donata; Ciabattini, Annalisa

2013-01-01

220

Integrated Immune  

NASA Technical Reports Server (NTRS)

This slide presentation reviews the program to replace several recent studies about astronaut immune systems with one comprehensive study that will include in-flight sampling. The study will address lack of in-flight data to determine the inflight status of immune systems, physiological stress, viral immunity, to determine the clinical risk related to immune dysregulation for exploration class spaceflight, and to determine the appropriate monitoring strategy for spaceflight-associated immune dysfunction, that could be used for the evaluation of countermeasures.

Crucian, Brian; Mehta, Satish; Stowe, Raymond; Uchakin, Peter; Quiriarte, Heather; Pierson, Duane; Sams, Clarnece

2010-01-01

221

A novel approach for the generation of Salmonella Gallinarum ghosts and evaluation of their vaccine potential using a prime-booster immunization strategy.  

PubMed

A novel, regulatory E-lysis cassette was used in this study to avoid the untimely expression of lysis gene E and to achieve stable and improved production of Salmonella Gallinarum (SG) ghosts. A prime-booster immunization strategy using these ghosts was subsequently utilized with the aim of inducing a robust immune response for the prevention of acute fowl typhoid infection. In the first animal experiment, a total of 54 chickens were equally divided into three groups (n=18): group A (non-immunized control), group B (prime-boost immunized), and group C (singly immunized). Chickens from both immunized groups demonstrated significant increases in plasma IgG, intestinal secretory IgA, and antigen-specific lymphocyte proliferative responses. After virulent SG challenge, group B chickens immunized with the prime-boost regimen showed optimized protection. In the second animal experiment, total 20 chickens were equally divided into two groups (n=10): group A (non-immunized control), group B (prime-boost immunized) and the immunogenicity of the ghosts was further evaluated after a booster dose of the immunization. In the second animal experiment, the population of CD3+CD4+ positive T cells in the immunized chickens was significantly higher after booster immunization. In addition, increased gene expression levels of Th1 cytokines, IFN-?, and IL-2 were observed in SG-specific antigen stimulated peripheral blood mononuclear cells of prime-boost immunized chickens compared to non-immunized chickens. In summary, the current study describes a novel approach for stable production of a safety-enhanced SG ghost preparation, and demonstrates that utilization of a prime-boost immunization strategy has an advantage over single immunization because it induces a robust immune response for optimum protection against fowl typhoid. PMID:25454861

Jawale, Chetan V; Lee, John Hwa

2014-11-28

222

Quadrennial Defense Review February 2010  

E-print Network

#12;Quadrennial Defense Review Report February 2010 #12;#12;CONTENTS PREFACE i EXECUTIVE SUMMARY iii INTRODUCTION 1 DEFENSE STRATEGY 5 A Complex Environment 5 America's Interests and the Roles of Military Power 9 U.S. Defense Objectives 11 REBALANCING THE FORCE 17 Defend the United States

223

Macroevolution of plant defense Anurag A. Agrawal  

E-print Network

to the evolution of plant defense strategies. First, as in most studies of adaptation, tradeoffs are assumedMacroevolution of plant defense strategies Anurag A. Agrawal Department of Ecology and Evolutionary strategies and plant­ herbivore coevolutionary interactions. I focus particularly on multivariate defense

Agrawal, Anurag

224

West European and East Asian perspectives on defense, deterrence, and strategy. Volume 5. Chinese perspectives on defense, deterrence, and strategy. Technical report, 1 December 1982-15 May 1984  

Microsoft Academic Search

This study assesses Chinese defense and foreign policy perspectives, especially as they influence, and are influenced by, China's strategic approach to international issues. Special emphasis is placed on China's recent perspectives on the Soviet Union, Japan, and the United States, together with other major countries, as well as the Third World. China's views on international and regional security issues are

R. L. Pfaltzgraff; J. K. Davis; J. E. Dougherty; C. M. Perry

1984-01-01

225

Cancer-associated fibroblast-targeted strategy enhances antitumor immune responses in the dendritic cell-based vaccine.  

PubMed

Given the close interaction between tumor cells and stromal cells in the tumor microenvironment (TME), TME-targeted strategies would be promising upon developing the integrated cancer immunotherapy. Cancer-associated fibroblasts (CAFs) are the dominant stromal component, playing critical roles in generation of the pro-tumorigenic TME. We focused on the immunosuppressive trait of CAFs, and systematically explored the alteration of tumor-associated immune responses by CAFs-targeted therapy. C57BL/6 mice subcutaneously bearing syngeneic E.G7 lymphoma, LLC1 Lewis lung cancer, or B16F1 melanoma were administered an anti-fibrotic agent tranilast to inhibit CAFs function. The infiltration of immune suppressor cell types including regulatory T cells and myeloid-derived suppressor cells in the TME was effectively decreased via reduction of stromal cell-derived factor-1, prostaglandin E2 , and transforming growth factor-?. In tumor-draining lymph nodes, these immune suppressor cell types were significantly decreased, leading to activation of tumor-associated antigen-specific CD8(+) T cells. In addition, CAFs-targeted therapy synergistically enhanced multiple types of systemic antitumor immune responses such as cytotoxic CD8+ T cells response, natural killer activity, and antitumor humoral immunity in combination with dendritic cell-based vaccines; however the suppressive effect on tumor growth was not observed in tumor-bearing SCID mice. These data demonstrate that systemic antitumor immune responses by various immunologic cell types are required to bring out the efficacy of CAFs-targeted therapy, and these effects are enhanced when combined with the effector-stimulatory immunotherapy such as the DC-based vaccine. Our mouse model provides a novel rationale with TME-targeted strategy for the development of cells-based cancer immunotherapy. This article is protected by copyright. All rights reserved. PMID:25483888

Ohshio, Yasuhiko; Teramoto, Koji; Hanaoka, Jun; Tezuka, Noriaki; Itoh, Yasushi; Asai, Tohru; Daigo, Yataro; Ogasawara, Kazumasa

2014-12-01

226

Maternal immune transfer in mollusc.  

PubMed

Maternal immunity refers to the immunity transferred from mother to offspring via egg, playing an important role in protecting the offspring at early life stages and contributing a trans-generational effect on offspring's phenotype. Because fertilization is external in most of the molluscs, oocytes and early embryos are directly exposed to pathogens in the seawater, and thus maternal immunity could provide a better protection before full maturation of their immunological systems. Several innate immune factors including pattern recognition receptors (PRRs) like lectins, and immune effectors like lysozyme, lipopolysaccharide binding protein/bacterial permeability-increasing proteins (LBP/BPI) and antioxidant enzymes have been identified as maternally derived immune factors in mollusc eggs. Among these immune factors, some maternally derived lectins and antibacterial factors have been proved to endue mollusc eggs with effective defense ability against pathogen infection, while the roles of other factors still remain untested. The physiological condition of mollusc broodstock has a profound effect on their offspring fitness. Many other factors such as nutrients, pathogens, environment conditions and pollutants could exert considerable influence on the maternal transfer of immunity. The parent molluscs which have encountered an immune stimulation endow their offspring with a trans-generational immune capability to protect them against infections effectively. The knowledge on maternal transfer of immunity and the trans-generational immune effect could provide us with an ideal management strategy of mollusc broodstock to improve the immunity of offspring and to establish a disease-resistant family for a long-term improvement of cultured stocks. PMID:24858027

Wang, Lingling; Yue, Feng; Song, Xiaorui; Song, Linsheng

2015-02-01

227

Mosquito Immunity against Arboviruses  

PubMed Central

Arthropod-borne viruses (arboviruses) pose a significant threat to global health, causing human disease with increasing geographic range and severity. The recent availability of the genome sequences of medically important mosquito species has kick-started investigations into the molecular basis of how mosquito vectors control arbovirus infection. Here, we discuss recent findings concerning the role of the mosquito immune system in antiviral defense, interactions between arboviruses and fundamental cellular processes such as apoptosis and autophagy, and arboviral suppression of mosquito defense mechanisms. This knowledge provides insights into co-evolutionary processes between vector and virus and also lays the groundwork for the development of novel arbovirus control strategies that target the mosquito vector. PMID:25415198

Sim, Shuzhen; Jupatanakul, Natapong; Dimopoulos, George

2014-01-01

228

???T Lymphocytes as a First Line of Immune Defense: Old and New Ways of Antigen Recognition and Implications for Cancer Immunotherapy  

PubMed Central

Among ??T cells, the V?1 subset, resident in epithelial tissues, is implied in the defense against viruses, fungi, and certain hematological malignancies, while the circulating V?2 subpopulation mainly respond to mycobacteria and solid tumors. Both subsets can be activated by stress-induced molecules (MIC-A, MIC-B, ULBPs) to produce pro-inflammatory cytokines and lytic enzymes and destroy bacteria or damaged cells. ??T lymphocytes can also recognize lipids, as those associated to M. tuberculosis, presented by the CD1 molecule, or phosphoantigens (P-Ag), either autologous, which accumulates in virus-infected cells, or microbial produced by prokaryotes and parasites. In cancer cells, P-Ag accumulate due to alterations in the mevalonate pathway; recently, butyrophilin 3A1 has been shown to be the presenting molecule for P-Ag. Of interest, aminobisphosphonates indirectly activate V?2 T cells inducing the accumulation of P-Ag. Based on these data, ??T lymphocytes are attractive effectors for cancer immunotherapy. However, the results obtained in clinical trials so far have been disappointing: this review will focus on the possible reasons of this failure as well as on suggestions for implementation of the therapeutic strategies. PMID:25426121

Poggi, Alessandro; Zocchi, Maria Raffaella

2014-01-01

229

Strategies of ROS regulation and antioxidant defense during transition from C? to C? photosynthesis in the genus Flaveria under PEG-induced osmotic stress.  

PubMed

In the present study, we aimed to elucidate how strategies of reactive oxygen species (ROS) regulation and the antioxidant defense system changed during transition from C? to C? photosynthesis, by using the model genus Flaveria, which contains species belonging to different steps in C? evolution. For this reason, four Flaveria species that have different carboxylation mechanisms, Flaveria robusta (C?), Flaveria anomala (C?-C?), Flaveria brownii (C?-like) and Flaveria bidentis (C?), were used. Physiological (growth, relative water content (RWC), osmotic potential), and photosynthetical parameters (stomatal conductance (g(s)), assimilation rate (A), electron transport rate (ETR)), antioxidant defense enzymes (superoxide dismutase (SOD), catalase (CAT), peroxidase (POX), ascorbate peroxidase (APX), glutathione reductases(GR)) and their isoenzymes, non-enzymatic antioxidant contents (ascorbate, glutathione), NADPH oxidase (NOX) activity, hydrogen peroxide (H?O?) content and lipid peroxidation levels (TBARS) were measured comparatively under polyethylene glycol (PEG 6000) induced osmotic stress. Under non-stressed conditions, there was a correlation only between CAT (decreasing), APX and GR (both increasing) and the type of carboxylation pathways through C? to C? in Flaveria species. However, they responded differently to PEG-induced osmotic stress in regards to antioxidant defense. The greatest increase in H?O? and TBARS content was observed in C? F. robusta, while the least substantial increase was detected in C?-like F. brownii and C? F. bidentis, suggesting that oxidative stress is more effectively countered in C?-like and C? species. This was achieved by a better induced enzymatic defense in F. bidentis (increased SOD, CAT, POX, and APX activity) and non-enzymatic antioxidants in F. brownii. As a response to PEG-induced oxidative stress, changes in activities of isoenzymes and also isoenzymatic patterns were observed in all Flaveria species, which might be related to ROS produced in different compartments of cells. PMID:23920414

Uzilday, Baris; Turkan, Ismail; Ozgur, Rengin; Sekmen, Askim H

2014-01-01

230

Child Immunization Status among a Sample of Adolescent Mothers: Comparing the Validity of Measurement Strategies  

ERIC Educational Resources Information Center

This study of adolescent mothers sought to identify whether a single general question asked by phone or a detailed, vaccine-specific question asked in a self-report questionnaire best captured infant immunization status at 6 months postpartum, by comparing them with immunization record books. Responses to a global question about whether infants…

Phillips, Clarissa; Cota-Robles, Sonia; Knight, Margaret; Francis, Judith; Phillips, Elizabeth; Mazerbo, Laurie

2011-01-01

231

Harnessing local and systemic immunity for vaccines against tuberculosis.  

PubMed

The lung is the portal of entry for Mycobacterium tuberculosis (Mtb) and animal experimental evidence indicates that local immune defense mechanisms are crucial for protective immunity. Immunization via the lower respiratory tract efficiently induces a dividing, activated, antigen-dependent, lung-resident, memory T-cell population, which is partly recoverable by bronchoalveolar lavage. These cells can inhibit the growth of Mtb in the lungs immediately after infection. Delivery of appropriate signals to the lung innate immune system is critical for induction of effective local immunity. In contrast after parenteral immunization, antigen-specific cells may be found in lung tissue but few are recoverable by lavage and inhibition of mycobacterial growth is delayed. Harnessing both local and systemic immunity can provide highly effective protection in animal models and the evidence suggests that taken in aggregate, multiple animal models may predict the success of novel vaccine strategies in humans. PMID:24253104

Beverley, P C L; Sridhar, S; Lalvani, A; Tchilian, E Z

2014-01-01

232

Biomimetic strategies based on viruses and bacteria for the development of immune evasive biomaterials  

PubMed Central

The field of biomaterial design has begun to focus upon methods by which materials can modulate immune response. While certain approaches appear promising, they are limited to isolated facets of inflammation. It is well documented that both bacteria and viruses have highly developed methods for evading the immune system, providing impetus for a more biomimetic approach to material design. This review presents the immune evasive tactics employed by viruses and bacteria and offers suggestions for future directions in applying these principles to biomaterial design. PMID:19185345

Novak, Matthew T.; Bryers, James D.; Reichert, William M.

2009-01-01

233

Salmonella enterica induces and subverts the plant immune system.  

PubMed

Infections with Salmonella enterica belong to the most prominent causes of food poisoning and infected fruits and vegetables represent important vectors for salmonellosis. Although it was shown that plants raise defense responses against Salmonella, these bacteria persist and proliferate in various plant tissues. Recent reports shed light into the molecular interaction between plants and Salmonella, highlighting the defense pathways induced and the means used by the bacteria to escape the plant immune system and accomplish colonization. It was recently shown that plants detect Salmonella pathogen-associated molecular patterns (PAMPs), such as the flagellin peptide flg22, and activate hallmarks of the defense program known as PAMP-triggered immunity (PTI). Interestingly, certain Salmonella strains carry mutations in the flg22 domain triggering PTI, suggesting that a strategy of Salmonella is to escape plant detection by mutating PAMP motifs. Another strategy may rely on the type III secretion system (T3SS) as T3SS mutants were found to induce stronger plant defense responses than wild type bacteria. Although Salmonella effector delivery into plant cells has not been shown, expression of Salmonella effectors in plant tissues shows that these bacteria also possess powerful means to manipulate the plant immune system. Altogether, these data suggest that Salmonella triggers PTI in plants and evolved strategies to avoid or subvert plant immunity. PMID:24772109

García, Ana V; Hirt, Heribert

2014-01-01

234

Interceptor-to-target allocation strategies for Strategic Defense I: adaptive strategies based upon system and threat characteristics. Final report, January-September 1987  

Microsoft Academic Search

This paper examines the topic of interceptor-to-target assignment algorithms and compares the system performance of a strategic defense system (SDS) as a function of the algorithm used. The algorithms used in this study range from being similar to some of those being developed under the SDIO's advanced-algorithm programs to those used in some of the more-popular engagement models. It is

M. E. Smith; T. S. Paterson

1988-01-01

235

Quadrennial Defense Review, 2001  

NSDL National Science Digital Library

Every four years, the military issues the Quadrennial Defense Review (QDR) Report, a document that is key in setting military goals and priorities. This 79-page report, issued September 30, 2001, is divided into seven main sections (e.g., Defense Strategy, Revitalizing the DoD Establishment) and includes a statement by the Chairman of the Joint Chiefs of Staff. The report explains that, "Even before the attack of September 11, 2001, the senior leaders of the Defense Department set out to establish a new strategy for America's defense that would embrace uncertainty and contend with surprise, a strategy premised on the idea that to be effective abroad, America must be safe at home." In the service of that new strategy, the QDR outlines DoD's four main policy objectives: to assure allies and friends of the US' steadfastness and military capability, to dissuade adversaries from undertaking programs potentially threatening to the US, to deter threats by increasing "the capacity to swiftly defeat attacks and impose severe penalties for aggression," and when deterrence fails, to decisively defeat any adversary. A central objective of this review was to shift the basis of defense planning. The report explains that overall the strategy seeks to move the US military "from a 'threat-based' model that has dominated thinking in the past to a 'capabilities-based' model for the future."

2001-01-01

236

Nuclear factor 45 of tongue sole (Cynoglossus semilaevis): evidence for functional differentiation between two isoforms in immune defense against viral and bacterial pathogens.  

PubMed

Nuclear factor 45 (NF45) is known to play an important role in regulating interleukin-2 expression in mammals. The function of fish NF45 is largely unknown. In a previous study, we reported the identification of a NF45 (named CsNF45) from half smooth tongue sole (Cynoglossus semilaevis). In the present study, we identified an isoform of CsNF45 (named CsNF45i) from half smooth tongue sole and examined its biological properties in comparison with CsNF45. We found that CsNF45i is a truncated version of CsNF45 and lacks the N-terminal 38 residues of CsNF45. Genetic analysis showed that the CsNF45 gene consists of 14 exons and 13 introns, and that CsNF45 and CsNF45i are the products of alternative splicing. Constitutive expression of CsNF45 and CsNF45i occurred in multiple tissues but differed in patterns. Experimental infection with viral and bacterial pathogens upregulated the expression of both isoforms but to different degrees, with potent induction of CsNF45 being induced by bacterial pathogen, while dramatic induction of CsNF45i being induced by viral pathogen. Transient transfection analysis showed that both isoforms were localized in the nucleus and able to stimulate the activity of IL-2 promoter to comparable extents. To examine their in vivo effects, the two isoforms were overexpressed in tongue sole. Subsequent analysis showed that following viral and bacterial infection, the viral loads in CsNF45i-overexpressing fish were significantly lower than those in CsNF45-overexpressing fish, whereas the bacterial loads in CsNF45-overexpressing fish were significantly lower than those in CsNF45i-overexpressing fish. These results indicate that both CsNF45 and CsNF45i possess immunoregulatory properties, however, the two isoforms most likely participate in different aspects of host immune defense that target different pathogens. PMID:24060504

Chi, Heng; Hu, Yong-hua; Xiao, Zhi-zhong; Sun, Li

2014-02-01

237

Estimating the costs of achieving the WHO–UNICEF Global Immunization Vision and Strategy, 2006–2015  

PubMed Central

Abstract Objective To estimate the cost of scaling up childhood immunization services required to reach the WHO–UNICEF Global Immunization Vision and Strategy (GIVS) goal of reducing mortality due to vaccine-preventable diseases by two-thirds by 2015. Methods A model was developed to estimate the total cost of reaching GIVS goals by 2015 in 117 low- and lower-middle-income countries. Current spending was estimated by analysing data from country planning documents, and scale-up costs were estimated using a bottom-up, ingredients-based approach. Financial costs were estimated by country and year for reaching 90% coverage with all existing vaccines; introducing a discrete set of new vaccines (rotavirus, conjugate pneumococcal, conjugate meningococcal A and Japanese encephalitis); and conducting immunization campaigns to protect at-risk populations against polio, tetanus, measles, yellow fever and meningococcal meningitis. Findings The 72 poorest countries of the world spent US$ 2.5 (range: US$ 1.8–4.2) billion on immunization in 2005, an increase from US$ 1.1 (range: US$ 0.9–1.6) billion in 2000. By 2015 annual immunization costs will on average increase to about US$ 4.0 (range US$ 2.9–6.7) billion. Total immunization costs for 2006–2015 are estimated at US$ 35 (range US$ 13–40) billion; of this, US$ 16.2 billion are incremental costs, comprised of US$ 5.6 billion for system scale-up and US$ 8.7 billion for vaccines; US$ 19.3 billion is required to maintain immunization programmes at 2005 levels. In all 117 low- and lower-middle-income countries, total costs for 2006–2015 are estimated at US$ 76 (range: US$ 23–110) billion, with US$ 49 billion for maintaining current systems and $27 billion for scaling-up. Conclusion In the 72 poorest countries, US$ 11–15 billion (30%–40%) of the overall resource needs are unmet if the GIVS goals are to be reached. The methods developed in this paper are approximate estimates with limitations, but provide a roadmap of financing gaps that need to be filled to scale up immunization by 2015. PMID:18235887

Gasse, François; Lee-Martin, Shook-Pui; Lydon, Patrick; Magan, Ahmed; Tibouti, Abdelmajid; Johns, Benjamin; Hutubessy, Raymond; Salama, Peter; Okwo-Bele, Jean-Marie

2008-01-01

238

Iron in Infection and Immunity  

PubMed Central

Iron is an essential nutrient for both humans and pathogenic microbes. Because of its ability to exist in one of two oxidation states, iron is an ideal redox catalyst for diverse cellular processes including respiration and DNA replication. However, the redox potential of iron also contributes to its toxicity, thus iron concentration and distribution must be carefully controlled. Given the absolute requirement for iron by virtually all human pathogens, an important facet of the innate immune system is to limit iron availability to invading microbes in a process termed nutritional immunity. Successful human pathogens must therefore possess mechanisms to circumvent nutritional immunity in order to cause disease. In this review, we discuss regulation of iron metabolism in the setting of infection and delineate strategies used by human pathogens to overcome iron-withholding defenses. PMID:23684303

Cassat, James E.; Skaar, Eric P.

2013-01-01

239

Antibody-mediated immunity against tuberculosis: implications for vaccine development.  

PubMed

There is an urgent need for new and better vaccines against tuberculosis (TB). Current vaccine design strategies are generally focused on the enhancement of cell-mediated immunity. Antibody-based approaches are not being considered, mostly due to the paradigm that humoral immunity plays little role in the protection against intracellular pathogens. Here, we reappraise and update the increasing evidence for antibody-mediated immunity against Mycobacterium tuberculosis, discuss the complexity of antibody responses to mycobacteria, and address mechanism of protection. Based on these findings and discussions, we challenge the common belief that immunity against M. tuberculosis relies solely on cellular defense mechanisms, and posit that induction of antibody-mediated immunity should be included in TB vaccine development strategies. PMID:23498951

Achkar, Jacqueline M; Casadevall, Arturo

2013-03-13

240

Antibody-Mediated Immunity against Tuberculosis: Implications for Vaccine Development  

PubMed Central

There is an urgent need for new and better vaccines against tuberculosis (TB). Current vaccine design strategies are generally focused on the enhancement of cell-mediated immunity. Antibody-based approaches are not being considered, mostly due to the paradigm that humoral immunity plays little role in the protection against intracellular pathogens. Here, we reappraise and update the increasing evidence for antibody-mediated immunity against Mycobacterium tuberculosis, discuss the complexity of antibody responses to mycobacteria, and address mechanism of protection. Based on these findings and discussions, we challenge the common belief that immunity against M. tuberculosis relies solely on cellular defense mechanisms, and posit that induction of antibody-mediated immunity should be included in TB vaccine development strategies. PMID:23498951

Achkar, Jacqueline M.; Casadevall, Arturo

2013-01-01

241

Defensive strategies in Geranium sylvaticum. Part 1: organ-specific distribution of water-soluble tannins, flavonoids and phenolic acids.  

PubMed

A combination of high-resolution mass spectrometry and modern HPLC column technology, assisted by diode array detection, was used for accurate characterization of water-soluble polyphenolic compounds in the pistils, stamens, petals, sepals, stems, leaves, roots and seeds of Geranium sylvaticum. The organs contained a large variety of polyphenols, five types of tannins (ellagitannins, proanthocyanidins, gallotannins, galloyl glucoses and galloyl quinic acids) as well as flavonoids and simple phenolic acids. In all, 59 compounds were identified. Geraniin and other ellagitannins dominated in all the green photosynthetic organs. The other organs seem to produce distinctive polyphenol groups: pistils accumulated gallotannins; petals acetylglucose derivatives of galloylglucoses; stamens kaempferol glycosides, and seeds and roots accumulated proanthocyanidins. The intra-plant distribution of the different polyphenol groups may reflect the different functions and importance of various types of tannins as the defensive chemicals against herbivory. PMID:23790750

Tuominen, Anu; Toivonen, Eija; Mutikainen, Pia; Salminen, Juha-Pekka

2013-11-01

242

Gamma Interferon, Tumor Necrosis Factor Alpha, and Nitric Oxide Synthase 2, Key Elements of Cellular Immunity, Perform Critical Protective Functions during Humoral Defense against Lethal Pulmonary Yersinia pestis Infection  

PubMed Central

Pulmonary infection by Yersinia pestis causes pneumonic plague, a rapidly progressing and often fatal disease. To aid the development of safe and effective pneumonic plague vaccines, we are deciphering mechanisms used by the immune system to protect against lethal pulmonary Y. pestis infection. In murine pneumonic plague models, passive transfer of convalescent-phase sera confers protection, as does active vaccination with live Y. pestis. Here, we demonstrate that protection by either protocol relies upon both gamma interferon (IFN-?) and tumor necrosis factor alpha (TNF-?) cytokines classically associated with type 1 cellular immunity. In both protocols, abrogating IFN-? or TNF-? activity significantly decreases survival and increases the bacterial burden in pulmonary, splenic, and hepatic tissues. Neutralization of either cytokine also counteracts challenge-induced, vaccination-dependent upregulation of nitric oxide synthase 2 (NOS2). Moreover, genetic depletion of NOS2 suppresses protection conferred by serotherapy. We conclude that IFN-?, TNF-?, and NOS2, key elements of cellular immunity, perform critical protective functions during humoral defense against lethal pulmonary Y. pestis challenge. These observations strongly suggest that plague vaccines should strive to maximally prime both cellular and humoral immunity. PMID:16714568

Parent, Michelle A.; Wilhelm, Lindsey B.; Kummer, Lawrence W.; Szaba, Frank M.; Mullarky, Isis K.; Smiley, Stephen T.

2006-01-01

243

A novel strategy for evasion of NK cell immunity by tumours expressing core2 O-glycans  

PubMed Central

The O-glycan branching enzyme, core2 ?-1,6-N-acetylglucosaminyltransferase (C2GnT), forms O-glycans containing an N-acetylglucosamine branch connected to N-acetylgalactosamine (core2 O-glycans) on cell-surface glycoproteins. Here, we report that upregulation of C2GnT is closely correlated with progression of bladder tumours and that C2GnT-expressing bladder tumours use a novel strategy to increase their metastatic potential. Our results showed that C2GnT-expressing bladder tumour cells are highly metastatic due to their high ability to evade NK cell immunity and revealed the molecular mechanism of the immune evasion by C2GnT expression. Engagement of an NK-activating receptor, NKG2D, by its tumour-associated ligand, Major histocompatibility complex class I-related chain A (MICA), is critical to tumour rejection by NK cells. In C2GnT-expressing bladder tumour cells, poly-N-acetyllactosamine was present on core2 O-glycans on MICA, and galectin-3 bound the NKG2D-binding site of MICA through this poly-N-acetyllactosamine. Galectin-3 reduced the affinity of MICA for NKG2D, thereby severely impairing NK cell activation and silencing the NK cells. This new mode of NK cell silencing promotes immune evasion of C2GnT-expressing bladder tumour cells, resulting in tumour metastasis. PMID:21712812

Tsuboi, Shigeru; Sutoh, Mihoko; Hatakeyama, Shingo; Hiraoka, Nobuyoshi; Habuchi, Tomonori; Horikawa, Yohei; Hashimoto, Yasuhiro; Yoneyama, Takahiro; Mori, Kazuyuki; Koie, Takuya; Nakamura, Toshiya; Saitoh, Hisao; Yamaya, Kanemitsu; Funyu, Tomihisa; Fukuda, Minoru; Ohyama, Chikara

2011-01-01

244

Therapeutic Strategies for Hepatitis and Other Infection-Related Immune Thrombocytopenias  

Microsoft Academic Search

Secondary thrombocytopenia may result from autoimmune diseases, lymphoproliferative disorders, infections, myelodysplastic syndromes, common variable immunodeficiency, agammaglobuline- mia, hypogammaglobulinemia, immunoglobulin A deficiency, and drugs. The presence of throm- bocytopenia may result from chronic infections with hepatitis C virus (HCV), human immunode- ficiency virus (HIV), and Helicobacter pylori and should be considered in the differential diagnosis of immune thrombocytopenic purpura (ITP). Studies

Roberto Stasi

2009-01-01

245

Assessment of Different Strategies to Determine MAP-specific Cellular Immune Responses in Cattle  

Technology Transfer Automated Retrieval System (TEKTRAN)

Assessment of cellular immunity in cattle against Mycobacterium avium ssp. paratuberculosis (MAP) by established methods remains unsatisfactory for diagnostic purposes. Recent studies conclude that analysis of T-cell subset responsiveness may improve diagnostic outcome. Aim of this study was to iden...

246

Shortening the 'short-course' therapy- insights into host immunity may contribute to new treatment strategies for tuberculosis.  

PubMed

Achieving global control of tuberculosis (TB) is a great challenge considering the current increase in multidrug resistance and mortality rate. Considerable efforts are therefore being made to develop new effective vaccines, more effective and rapid diagnostic tools as well as new drugs. Shortening the duration of TB treatment with revised regimens and modes of delivery of existing drugs, as well as development of new antimicrobial agents and optimization of the host response with adjuvant immunotherapy could have a profound impact on TB cure rates. Recent data show that chronic worm infection and deficiencies in micronutrients such as vitamin D and arginine are potential areas of intervention to optimize host immunity. Nutritional supplementation to enhance nitric oxide production and vitamin D-mediated effector functions as well as the treatment of worm infection to reduce immunosuppressive effects of regulatory T (Treg) lymphocytes may be more suitable and accessible strategies for highly endemic areas than adjuvant cytokine therapy. In this review, we focus mainly on immune control of human TB, and discuss how current treatment strategies, including immunotherapy and nutritional supplementation, could be optimized to enhance the host response leading to more effective treatment. PMID:23331325

Schön, T; Lerm, M; Stendahl, O

2013-04-01

247

Canine zona pellucida glycoprotein-3: Up-scaled production, immunization strategy and its outcome on fertility.  

PubMed

Zona pellucida (ZP) glycoproteins based contraceptive vaccines have been proposed for the management of wildlife population. In the present study, a fusion protein encompassing promiscuous T cell epitope of tetanus toxoid [TT; amino acid (aa) residues 830-844] followed by a dilysine linker and an ectodomain of dog ZP3 (ZP3; aa residues 23-348) without any affinity tag (TT-KK-ZP3) has been expressed in Escherichia coli. The recombinant protein was successfully produced in fed-batch fermentor and purified. The average yield of purified refolded protein was 12.20±0.61mg/2g wet cell pellet. Female FvB/J mice immunized with the varying doses of recombinant TT-KK-ZP3 supplemented with alum/PetGel A as adjuvants following a three injection schedule, showed dose dependent increase in serum IgG titer. Antibodies against TT-KK-ZP3 recognized native mouse/dog ZP and significantly inhibited mouse in-vitro fertilization (p=0.012). Immunized mice showed significant reduction in fertility (p<0.05). Higher antibody titers were associated with a decrease in the number of pups born to the immunized female mice. To reduce the number of injections, two injection schedule using various dose combinations of TT-KK-ZP3 supplemented with alum revealed lower immunogenicity and contraceptive efficacy as compared to the three injection schedule. To overcome this, CpG motif was included in addition to alum and both intraperitoneal and intranasal route of immunization following the two injection schedule was investigated. Inclusion of CpG significantly enhanced the antibody titer and improved contraceptive efficacy. In the mice immunized following intraperitoneal route, serum/vaginal IgG and in the mice immunized through intranasal route, vaginal IgA seemed to be important for curtailment in fertility. To conclude, the recombinant protein described herein may be a good candidate for developing contraceptive vaccine for the wildlife population management, in particular street dogs. PMID:25448113

Shrestha, Abhinav; Srichandan, Sudeepa; Minhas, Vidisha; Panda, Amulya Kumar; Gupta, Satish Kumar

2015-01-01

248

Optimal Network Security Strengthening Using Attack-Defense Game Model  

Microsoft Academic Search

For assessing the security and optimal strengthening of large enterprise networks, this paper proposes a new approach uses configuration information on firewalls and vulnerability information on all network devices to build defense graphs that show the attack and defense strategy. Some models including a defense graph model, attack-defense taxonomy and cost quantitative model, and Attack-Defense Game (ADG) model. We regard

Wei Jiang; Bin-xing Fang; Hong-li Zhang; Zhi-hong Tian; Xin-fang Song

2009-01-01

249

Evasion of innate immunity by Mycobacterium tuberculosis: is death an exit strategy?  

PubMed Central

Virulent Mycobacterium tuberculosis inhibits apoptosis and triggers necrosis of host macrophages to evade innate immunity and delay the initiation of adaptive immunity. By contrast, attenuated M. tuberculosis induces macrophage apoptosis, an innate defence mechanism that reduces bacterial viability. In this Opinion article, we describe how virulent M. tuberculosis blocks production of the eicosanoid lipid mediator prostaglandin E2 (PGE2). PGE2 production by infected macrophages prevents mitochondrial damage and initiates plasma membrane repair, two processes that are crucial for preventing necrosis and inducing apoptosis. Thus, M. tuberculosis-mediated modulation of eicosanoid production determines the death modality of the infected macrophage, which in turn has a substantial impact on the outcome of infection. PMID:20676146

Behar, Samuel M.; Divangahi, Maziar; Remold, Heinz G.

2011-01-01

250

Exploitation of Herpesvirus Immune Evasion Strategies to Modify the Immunogenicity of Human Mesenchymal Stem Cell Transplants  

PubMed Central

Background Mesenchymal stem cells (MSCs) are multipotent cells residing in the connective tissue of many organs and holding great potential for tissue repair. In culture, human MSCs (hMSCs) are capable of extensive proliferation without showing chromosomal aberrations. Large numbers of hMSCs can thus be acquired from small samples of easily obtainable tissues like fat and bone marrow. MSCs can contribute to regeneration indirectly by secretion of cytokines or directly by differentiation into specialized cell types. The latter mechanism requires their long-term acceptance by the recipient. Although MSCs do not elicit immune responses in vitro, animal studies have revealed that allogeneic and xenogeneic MSCs are rejected. Methodology/Principal Findings We aim to overcome MSC immune rejection through permanent down-regulation of major histocompatibility complex (MHC) class I proteins on the surface of these MHC class II-negative cells through the use of viral immune evasion proteins. Transduction of hMSCs with a retroviral vector encoding the human cytomegalovirus US11 protein resulted in strong inhibition of MHC class I surface expression. When transplanted into immunocompetent mice, persistence of the US11-expressing and HLA-ABC-negative hMSCs at levels resembling those found in immunodeficient (i.e., NOD/SCID) mice could be attained provided that recipients' natural killer (NK) cells were depleted prior to cell transplantation. Conclusions/Significance Our findings demonstrate the potential utility of herpesviral immunoevasins to prevent rejection of xenogeneic MSCs. The observation that down-regulation of MHC class I surface expression renders hMSCs vulnerable to NK cell recognition and cytolysis implies that multiple viral immune evasion proteins are likely required to make hMSCs non-immunogenic and thereby universally transplantable. PMID:21253016

de la Garza-Rodea, Anabel S.; Verweij, Marieke C.; Boersma, Hester; van der Velde-van Dijke, Ietje; de Vries, Antoine A. F.; Hoeben, Rob C.; van Bekkum, Dirk W.; Wiertz, Emmanuel J. H. J.; Knaän-Shanzer, Shoshan

2011-01-01

251

Immune memory-boosting dose of rapamycin impairs macrophage vesicle acidification and curtails glycolysis in effector CD8 cells, impairing defense against acute infections.  

PubMed

Direct mammalian target of rapamycin (Rapa) complex 1 inhibition by short-term low-dose Rapa treatment has recently been shown to improve CD8 T cell immunological memory. Whereas these studies focused on memory development, the impact of low-dose Rapa on the primary immune response, particularly as it relates to functional effector immunity, is far less clear. In this study, we investigated the impact of acute Rapa treatment on immune effector cell function during the primary immune response to several acute infections. We found that functional CD8 T cell and macrophage responses to both viral and intracellular bacterial pathogens were depressed in mice in vivo and in humans to phorbol ester and calcium ionophore stimulation in vitro in the face of low-dose Rapa treatment. Mechanistically, the CD8 defect was linked to impaired glycolytic switch in stimulated naive cells and the reduced formation of short-lived effector cells. Therefore, more than one cell type required for a protective effector immune response is impaired by Rapa in both mice and humans, at the dose shown to improve immune memory and extend lifespan. This urges caution with regard to the relative therapeutic costs and benefits of Rapa treatment as means to improve immune memory. PMID:24913978

Goldberg, Emily L; Smithey, Megan J; Lutes, Lydia K; Uhrlaub, Jennifer L; Nikolich-Žugich, Janko

2014-07-15

252

Captive and free-living red knots Calidris canutus exhibit differences in non-induced immunity that suggest different immune strategies in different environments  

Microsoft Academic Search

Experiments on captive animals, in which conditions can be controlled, are useful for examining complex biological phenomena such as immune function. Such experiments have increased our understanding of immune responses in the context of trade-offs and pathogen pressure. However, few studies have examined how captivity itself affects immune function. We used microbial killing, leukocyte concentrations and complement-natural antibody assays to

Deborah M. Buehler; Theunis Piersma; B. Irene Tieleman

2008-01-01

253

Base Modification Strategies to Modulate Immune Stimulation by an siRNA.  

PubMed

Immune stimulation triggered by siRNAs is one of the major challenges in the development of safe RNAi-based therapeutics. Within an immunostimulatory siRNA sequence, this hurdle is commonly addressed by using ribose modifications (e.g., 2'-OMe or 2'-F), which results in decreased cytokine production. However, as immune stimulation by siRNAs is a sequence-dependent phenomenon, recognition of the nucleobases by the trigger receptor(s) is also likely. Here, we use the recently published crystal structures of Toll-like receptor 8 (TLR8) bound to small-molecule agonists to generate computational models for ribonucleotide binding by this immune receptor. Our modeling suggested that modification of either the Watson-Crick or Hoogsteen face of adenosine would disrupt nucleotide/TLR8 interactions. We employed chemical synthesis to alter either the Watson-Crick or Hoogsteen face of adenosine and evaluated the effect of these modifications in an siRNA guide strand by measuring the immunostimulatory and RNA interference properties. For the siRNA guide strand tested, we found that modifying the Watson-Crick face is generally more effective at blocking TNF? production in human peripheral blood mononuclear cells (PBMCs) than modification at the Hoogsteen edge. We also observed that modifications near the 5'-end were more effective at blocking cytokine production than those placed at the 3'-end. This work advances our understanding of how chemical modifications can be used to optimize siRNA performance. PMID:25487859

Valenzuela, Rachel Anne P; Suter, Scott R; Ball-Jones, Alexi A; Ibarra-Soza, José M; Zheng, Yuxuan; Beal, Peter A

2014-12-01

254

Pharmacy-based Immunization in Rural Communities Strategy (PhICS)  

PubMed Central

Background: Influenza is a major cause of morbidity and mortality in Canada, with up to 7000 influenza-related deaths occurring every year. The elderly and individuals with chronic diseases are at increased risk for influenza-related morbidity and mortality. Methods: We conducted a 2-year, community cluster-randomized trial targeting elderly people and at-risk groups to assess the effectiveness of pharmacy-based influenza vaccination clinics on influenza vaccination rates. Small rural communities in interior and northern British Columbia were randomly allocated to the intervention or control. In the intervention communities, pharmacy-based influenza vaccination clinics were held and were promoted to eligible patients using personalized invitations from the pharmacists, invitations distributed opportunistically by a pharmacist to eligible patients presenting to pharmacies during the flu season and community-wide promotion using posters and the local media. The main outcome measure was a difference in the mean influenza vaccination rates. The immunization rates were calculated using the number of immunizations given in each community divided by the population size estimated from the census data. Results: Baseline influenza immunization rates in the population ?65 years of age were the same in the control (n = 10, mean 85.6% [SD 16.6]) and intervention (n = 14, mean 83.8% [SD 16.3]) communities in 2009 (p = 0.79). In 2010, the mean influenza immunization rate was 56.9% (SD 28.0) in the control communities (n = 15) and 80.1% (SD 18.4) in the intervention communities (n = 14) (p = 0.01) for those ?65 years of age. However, in 2010, for those 2 to 64 years with chronic medical conditions, the immunization rates were lower in the intervention communities (mean 16.3% [SD 7.1]) compared with the control communities (mean 21.2% [SD 5.8]) (p = 0.04). Conclusion Clinics were feasible and well attended and they resulted in increased vaccination rates for elderly residents. In contrast, vaccination rates in the younger population with comorbidities remained low and unchanged. PMID:24494014

Kaczorowski, Janusz; Gastonguay, Louise; Marra, Carlo A.; Lynd, Larry D.; Kendall, Perry

2014-01-01

255

Species-speciWc defense strategies of vegetative versus reproductive blades of the PaciWc kelps Lessonia nigrescens and Macrocystis integrifolia  

Microsoft Academic Search

Chemical defense is assumed to be costly and therefore algae should allocate defense investments in a way to reduce costs and optimize their overall Wtness. Thus, lifetime expectation of particular tissues and their contribu- tion to the Wtness of the alga may aVect defense allocation. Two brown algae common to the SE PaciWc coasts, Lesso- nia nigrescens Bory and Macrocystis

Christian Pansch; Ivan Gómez; Eva Rothäusler; Karina Veliz; Martin Thiel

2008-01-01

256

HvWRKY10, HvWRKY19, and HvWRKY28 positively regulate Mla-triggered immunity and basal defense to barley powdery mildew  

Technology Transfer Automated Retrieval System (TEKTRAN)

WRKY proteins represent a large family of transcription factors (TFs), involved in plant development and defense responses. So far, fifty-five unique barley TFs have been annotated that contain the WRKY domain; twenty-six of these are present on the Barley1 GeneChip. We analyzed time-course expres...

257

Stability of Microbiota Facilitated by Host Immune Regulation: Informing Probiotic Strategies to Manage Amphibian Disease  

PubMed Central

Microbial communities can augment host immune responses and probiotic therapies are under development to prevent or treat diseases of humans, crops, livestock, and wildlife including an emerging fungal disease of amphibians, chytridiomycosis. However, little is known about the stability of host-associated microbiota, or how the microbiota is structured by innate immune factors including antimicrobial peptides (AMPs) abundant in the skin secretions of many amphibians. Thus, conservation medicine including therapies targeting the skin will benefit from investigations of amphibian microbial ecology that provide a model for vertebrate host-symbiont interactions on mucosal surfaces. Here, we tested whether the cutaneous microbiota of Panamanian rocket frogs, Colostethus panamansis, was resistant to colonization or altered by treatment. Under semi-natural outdoor mesocosm conditions in Panama, we exposed frogs to one of three treatments including: (1) probiotic - the potentially beneficial bacterium Lysinibacillus fusiformis, (2) transplant – skin washes from the chytridiomycosis-resistant glass frog Espadarana prosoblepon, and (3) control – sterile water. Microbial assemblages were analyzed by a culture-independent T-RFLP analysis. We found that skin microbiota of C. panamansis was resistant to colonization and did not differ among treatments, but shifted through time in the mesocosms. We describe regulation of host AMPs that may function to maintain microbial community stability. Colonization resistance was metabolically costly and microbe-treated frogs lost 7–12% of body mass. The discovery of strong colonization resistance of skin microbiota suggests a well-regulated, rather than dynamic, host-symbiont relationship, and suggests that probiotic therapies aiming to enhance host immunity may require an approach that circumvents host mechanisms maintaining equilibrium in microbial communities. PMID:24489847

Küng, Denise; Bigler, Laurent; Davis, Leyla R.; Gratwicke, Brian; Griffith, Edgardo; Woodhams, Douglas C.

2014-01-01

258

Strategies of Echinococcus species responses to immune attacks: implications for therapeutic tool development.  

PubMed

Echinococcus species have been studied as a model to investigate parasite-host interactions. Echinococcus spp. can actively communicate dynamically with a host to facilitate infection, growth and proliferation partially via secretion of molecules, especially in terms of harmonization of host immune attacks. This review systematically outlines our current knowledge of how the Echinococcus species have evolved to adapt to their host's microenvironment. This understanding of parasite-host interplay has implications in profound appreciation of parasite plasticity and is informative in designing novel and effective tools including vaccines and drugs for the treatment of echinococcosis and other diseases. PMID:23973651

Zheng, Yadong

2013-11-01

259

Evolution of decoration in majoid crabs: a comparative phylogenetic analysis of the role of body size and alternative defensive strategies.  

PubMed

Although experimental studies have demonstrated the antipredatory advantages of camouflage and its associated costs, few studies have examined the evolution of camouflage in a phylogenetic context. We use phylogenetic comparative methods to examine evolutionary trade-offs associated with camouflage in the crab superfamily Majoidea. The majoids, or spider crabs, are known for their decoration behavior in which they attach materials from their environment to hooked setae on their carapace. We found that coverage of hooked setae on a crab (morphology) strongly predicts decoration cover in the field (behavior). Half of the species examined exhibited decreases in the coverage of hooked setae with ontogeny, and we also found a strong negative correlation between the extent of hooked setae and adult body size among species using independent contrasts, suggesting that size may constrain the evolution of camouflage. Finally, using a well-resolved clade of epialtids (kelp crabs)--many of which decorate little but use color change as an alternative camouflage strategy--we found a negative correlation between utilization of decoration versus color camouflage strategies. Our findings suggest that the costs of hook production and decoration maintenance and/or the lowered adaptive value of camouflage for larger species may limit the evolutionary distribution of decoration camouflage among the majoids. PMID:19278336

Hultgren, K M; Stachowicz, J J

2009-05-01

260

On the Mechanism Determining the Th1/Th2 Phenotype of an Immune Response, and its Pertinence to Strategies for the Prevention, and Treatment, of Certain Infectious Diseases  

PubMed Central

It is well recognized that the physiological/pathological consequences of an immune response, against a foreign or a self-antigen, are often critically dependent on the class of immunity generated. Here we focus on how antigen interacts with the cells of the immune system to determine whether antigen predominantly generates Th1 or Th2 cells. We refer to this mechanism as the ‘decision criterion’ controlling the Th1/Th2 phenotype of the immune response. A plausible decision criterion should account for the variables of immunization known to affect the Th1/Th2 phenotype of the ensuing immune response. Documented variables include the nature of the antigen, in terms of its degree of foreignness, the dose of antigen and the time after immunization at which the Th1/Th2 phenotype of the immune response is assessed. These are quantitative variables made at the level of the system. In addition, the route of immunization is also critical. I describe a quantitative hypothesis as to the nature of the decision criterion, referred to as the Threshold Hypothesis. This hypothesis accounts for the quantitative variables of immunization known to affect the Th1/Th2 phenotype of the immune response generated. I suggest and illustrate how this is not true of competing, contemporary hypotheses. I outline studies testing predictions of the hypothesis and illustrate its potential utility in designing strategies to prevent or treat medical situations where a predominant Th1 response is required to contain an infection, such as those caused by HIV-1 and by Mycobacterium tuberculosis, or to contain cancers. PMID:24684592

Bretscher, P A

2014-01-01

261

Fighting a losing battle: vigorous immune response countered by pathogen suppression of host defenses in the chytridiomycosis-susceptible frog Atelopus zeteki.  

PubMed

The emergence of the disease chytridiomycosis caused by the chytrid fungus Batrachochytrium dendrobatidis (Bd) has been implicated in dramatic global amphibian declines. Although many species have undergone catastrophic declines and/or extinctions, others appear to be unaffected or persist at reduced frequencies after Bd outbreaks. The reasons behind this variance in disease outcomes are poorly understood: differences in host immune responses have been proposed, yet previous studies suggest a lack of robust immune responses to Bd in susceptible species. Here, we sequenced transcriptomes from clutch-mates of a highly susceptible amphibian, Atelopus zeteki, with different infection histories. We found significant changes in expression of numerous genes involved in innate and inflammatory responses in infected frogs despite high susceptibility to chytridiomycosis. We show evidence of acquired immune responses generated against Bd, including increased expression of immunoglobulins and major histocompatibility complex genes. In addition, fungal-killing genes had significantly greater expression in frogs previously exposed to Bd compared with Bd-naïve frogs, including chitinase and serine-type proteases. However, our results appear to confirm recent in vitro evidence of immune suppression by Bd, demonstrated by decreased expression of lymphocyte genes in the spleen of infected compared with control frogs. We propose susceptibility to chytridiomycosis is not due to lack of Bd-specific immune responses but instead is caused by failure of those responses to be effective. Ineffective immune pathway activation and timing of antibody production are discussed as potential mechanisms. However, in light of our findings, suppression of key immune responses by Bd is likely an important factor in the lethality of this fungus. PMID:24841130

Ellison, Amy R; Savage, Anna E; DiRenzo, Grace V; Langhammer, Penny; Lips, Karen R; Zamudio, Kelly R

2014-07-01

262

Enhancing Artificial Bee Colony Algorithm with Self-Adaptive Searching Strategy and Artificial Immune Network Operators for Global Optimization  

PubMed Central

Artificial bee colony (ABC) algorithm, inspired by the intelligent foraging behavior of honey bees, was proposed by Karaboga. It has been shown to be superior to some conventional intelligent algorithms such as genetic algorithm (GA), artificial colony optimization (ACO), and particle swarm optimization (PSO). However, the ABC still has some limitations. For example, ABC can easily get trapped in the local optimum when handing in functions that have a narrow curving valley, a high eccentric ellipse, or complex multimodal functions. As a result, we proposed an enhanced ABC algorithm called EABC by introducing self-adaptive searching strategy and artificial immune network operators to improve the exploitation and exploration. The simulation results tested on a suite of unimodal or multimodal benchmark functions illustrate that the EABC algorithm outperforms ACO, PSO, and the basic ABC in most of the experiments. PMID:24772023

Chen, Tinggui; Xiao, Renbin

2014-01-01

263

The Price of Defense Marios Mavronicolas  

E-print Network

The Price of Defense Marios Mavronicolas Loizos Michael Vicky Papadopoulou Anna Philippou Paul deviate from its randomized strategy. The Price of Defense is the worst-case ratio, over all Nash equilibrium. In this work, we provide a comprehensive collection of trade-offs between the Price of Defense

Mavronicolas, Marios

264

An improved ant colony algorithm with diversified solutions based on the immune strategy  

PubMed Central

Background Ant colony algorithm has emerged recently as a new meta-heuristic method, which is inspired from the behaviours of real ants for solving NP-hard problems. However, the classical ant colony algorithm also has its defects of stagnation and premature. This paper aims at remedying these problems. Results In this paper, we propose an adaptive ant colony algorithm that simulates the behaviour of biological immune system. The solutions of the problem are much more diversified than traditional ant colony algorithms. Conclusion The proposed method for improving the performance of traditional ant colony algorithm takes into account the polarization of the colonies, and adaptively adjusts the distribution of the solutions obtained by the ants. This makes the solutions more diverse so as to avoid the stagnation and premature phenomena. PMID:17217521

Qin, Ling; Pan, Yi; Chen, Ling; Chen, Yixin

2006-01-01

265

Insect Defenses  

NSDL National Science Digital Library

A page from Dr. John Meyer's General Entomology course at NC State University detailing how insects defend themselves. Topics covered include speed, playing-dead, urticating hairs, chemical defenses, protective coloration and more.

0000-00-00

266

Quantal and graded stimulation of B lymphocytes as alternative strategies for regulating adaptive immune responses  

PubMed Central

Lymphocytes undergo a typical response pattern following stimulation in vivo: they proliferate, differentiate to effector cells, cease dividing and predominantly die, leaving a small proportion of long-lived memory and effector cells. This pattern results from cell-intrinsic processes following activation and the influence of external regulation. Here we apply quantitative methods to study B-cell responses in vitro. Our results reveal that B cells stimulated through two Toll-like receptors (TLRs) require minimal external direction to undergo the basic pattern typical of immunity. Altering the stimulus strength regulates the outcome in a quantal manner by varying the number of cells that participate in the response. In contrast, the T-cell-dependent CD40 activation signal induces a response where division times and differentiation rates vary in relation to stimulus strength. These studies offer insight into how the adaptive antibody response may have evolved from simple autonomous response patterns to the highly regulable state that is now observed in mammals. PMID:24009041

Hawkins, E.D.; Turner, M.L.; Wellard, C.J.; Zhou, J.H.S.; Dowling, M.R.; Hodgkin, P.D.

2013-01-01

267

Ebolavirus VP35 uses a bimodal strategy to bind dsRNA for innate immune suppression  

SciTech Connect

Ebolavirus causes a severe hemorrhagic fever and is divided into five distinct species, of which Reston ebolavirus is uniquely nonpathogenic to humans. Disease caused by ebolavirus is marked by early immunosuppression of innate immune signaling events, involving silencing and sequestration of double-stranded RNA (dsRNA) by the viral protein VP35. Here we present unbound and dsRNA-bound crystal structures of the dsRNA-binding domain of Reston ebolavirus VP35. The structures show that VP35 forms an unusual, asymmetric dimer on dsRNA binding, with each of the monomers binding dsRNA in a different way: one binds the backbone whereas the other caps the terminus. Additional SAXS, DXMS, and dsRNA-binding experiments presented here support a model of cooperative dsRNA recognition in which binding of the first monomer assists binding of the next monomer of the oligomeric VP35 protein. This work illustrates how ebolavirus VP35 could mask key recognition sites of molecules such as RIG-I, MDA-5, and Dicer to silence viral dsRNA in infection.

Kimberlin, Christopher R.; Bornholdt, Zachary A.; Li, Sheng; Woods, Jr., Virgil L.; MacRae, Ian J.; Saphire, Erica Ollmann (Scripps); (UCSD)

2010-03-12

268

The genome of obligately intracellular Ehrlichia canis revealsthemes of complex membrane structure and immune evasion strategies  

SciTech Connect

Ehrlichia canis, a small obligately intracellular, tick-transmitted, gram-negative, a-proteobacterium is the primary etiologic agent of globally distributed canine monocytic ehrlichiosis. Complete genome sequencing revealed that the E. canis genome consists of a single circular chromosome of 1,315,030 bp predicted to encode 925 proteins, 40 stable RNA species, and 17 putative pseudogenes, and a substantial proportion of non-coding sequence (27 percent). Interesting genome features include a large set of proteins with transmembrane helices and/or signal sequences, and a unique serine-threonine bias associated with the potential for O-glycosylation that was prominent in proteins associated with pathogen-host interactions. Furthermore, two paralogous protein families associated with immune evasion were identified, one of which contains poly G:C tracts, suggesting that they may play a role in phase variation and facilitation of persistent infections. Proteins associated with pathogen-host interactions were identified including a small group of proteins (12) with tandem repeats and another with eukaryotic-like ankyrin domains (7).

Mavromatis, K.; Kuyler Doyle, C.; Lykidis, A.; Ivanova, N.; Francino, P.; Chain, P.; Shin, M.; Malfatti, S.; Larimer, F.; Copeland,A.; Detter, J.C.; Land, M.; Richardson, P.M.; Yu, X.J.; Walker, D.H.; McBride, J.W.; Kyrpides, N.C.

2005-09-01

269

Avian host defense peptides.  

PubMed

Host defense peptides (HDPs) are important effector molecules of the innate immune system of vertebrates. These antimicrobial peptides are also present in invertebrates, plants and fungi. HDPs display broad-spectrum antimicrobial activities and fulfill an important role in the first line of defense of many organisms. It is becoming increasingly clear that in the animal kingdom the functions of HDPs are not confined to direct antimicrobial actions. Research in mammals has indicated that HDPs have many immunomodulatory functions and are also involved in other physiological processes ranging from development to wound healing. During the past five years our knowledge about avian HDPs has increased considerably. This review addresses our current knowledge on the evolution, regulation and biological functions of HDPs of birds. PMID:23644014

Cuperus, Tryntsje; Coorens, Maarten; van Dijk, Albert; Haagsman, Henk P

2013-11-01

270

Immunity and Nutrition.  

ERIC Educational Resources Information Center

The three articles in this issue of a periodical focussed on various aspects of the life and health of children in the tropics concern: (1) immune defenses; (2) interactions between nutrition disorders and infection; and (3) immunity and vaccination. The science of immunology has progressed rapidly in recent years. A brief review of present…

Dupin, Henri; Guerin, Nicole

1990-01-01

271

Dietary supplementation with lacto-wolfberry enhances the immune response and reduces pathogenesis to influenza infection in mice  

Technology Transfer Automated Retrieval System (TEKTRAN)

Despite the availability of vaccines, influenza is a significant public health problem, emphasizing the need for development of additional strategies to enhance host defense against influenza. Wolfberry or Goji berry, long used as a medicinal food in China, has recently been shown to improve immune ...

272

Synthetic plant defense elicitors  

PubMed Central

To defend themselves against invading pathogens plants utilize a complex regulatory network that coordinates extensive transcriptional and metabolic reprogramming. Although many of the key players of this immunity-associated network are known, the details of its topology and dynamics are still poorly understood. As an alternative to forward and reverse genetic studies, chemical genetics-related approaches based on bioactive small molecules have gained substantial popularity in the analysis of biological pathways and networks. Use of such molecular probes can allow researchers to access biological space that was previously inaccessible to genetic analyses due to gene redundancy or lethality of mutations. Synthetic elicitors are small drug-like molecules that induce plant defense responses, but are distinct from known natural elicitors of plant immunity. While the discovery of some synthetic elicitors had already been reported in the 1970s, recent breakthroughs in combinatorial chemical synthesis now allow for inexpensive high-throughput screens for bioactive plant defense-inducing compounds. Along with powerful reverse genetics tools and resources available for model plants and crop systems, comprehensive collections of new synthetic elicitors will likely allow plant scientists to study the intricacies of plant defense signaling pathways and networks in an unparalleled fashion. As synthetic elicitors can protect crops from diseases, without the need to be directly toxic for pathogenic organisms, they may also serve as promising alternatives to conventional biocidal pesticides, which often are harmful for the environment, farmers and consumers. Here we are discussing various types of synthetic elicitors that have been used for studies on the plant immune system, their modes-of-action as well as their application in crop protection. PMID:25674095

Bektas, Yasemin; Eulgem, Thomas

2015-01-01

273

Extensive Central Nervous System Cryptococcal Disease Presenting as Immune Reconstitution Syndrome in a Patient with Advanced HIV: Report of a Case and Review of Management Dilemmas and Strategies  

PubMed Central

One of the complications of the use of antiretroviral therapy (ART), immune reconstitution inflammatory syndrome (IRIS), is particularly problematic in the management of cryptococcal meningitis. We present the case of a 35-year-old male with acquired immune deficiency syndrome diagnosed with extensive central nervous system (CNS) cryptococcal disease, including meningitis and multiple intracranial cysts, diagnosed eight weeks after the initiation of ART. The patient experienced a relapsing and remitting clinical course despite repeated courses of potent antifungal therapy and aggressive management of raised intracranial pressure. This review highlights therapeutic dilemmas and strategies in the management of CNS cryptococcosis complicated with IRIS and highlights gaps in available treatment guidelines. PMID:25568756

Ogbuagu, Onyema; Villanueva, Merceditas

2014-01-01

274

Immune and oxidative stress trade-offs in four classes of Ruffs (Philomachus pugnax) with different reproductive strategies  

E-print Network

ARTICLE Immune and oxidative stress trade-offs in four classes of Ruffs (Philomachus pugnax was evident for oxidative stress or resistance, and no relationship was detected between immunity and oxidative resistance or stress. Hence, during the breeding season immunity reflected the risk of injury

275

Immunity to Fungi  

PubMed Central

The global increase in fungal disease burden, the emergence of novel pathogenic fungi, and the lack of fungal vaccines have focused intense interest in elucidating immune defense mechanisms against fungi. Recent studies in animal models and in humans identify an integrated role for C-type lectin and Toll-like receptor signaling in activating innate and adaptive responses that control medically relevant fungi. Beyond the critical role of phagocytes in host defense, the generation and balance of specific T helper subsets contributes to sterilizing immunity. These advances form a basis for the development of fungal vaccines and immune-based therapeutic adjuncts. PMID:22613091

LeibundGut-Landmann, Salomé; Wüthrich, Marcel; Hohl, Tobias M.

2012-01-01

276

Humoral immune responses are maintained with age in a long-lived ectotherm, the red-eared slider turtle.  

PubMed

Aging is typically associated with a decrease in immune function. However, aging does not affect each branch of the immune system equally. Because of these varying effects of age on immune responses, aging could affect taxa differently based on how the particular taxon employs its resources towards different components of immune defense. An example of this is found in the humoral immune system. Specific responses tend to decrease with age while non-specific, natural antibody responses increase with age. Compared with mammals, reptiles of all ages have a slower and less robust humoral immune system. Therefore, they may invest more in non-specific responses and thus avoid the negative consequences of age on the immune system. We examined how the humoral immune system of reptiles is affected by aging and investigated the roles of non-specific, natural antibody responses and specific responses by examining several characteristics of antibodies against lipopolysaccharide (LPS) in the red-eared slider turtle. We found very little evidence of immunosenescence in the humoral immune system of the red-eared slider turtle, Trachemys scripta, which supports the idea that non-specific, natural antibody responses are an important line of defense in reptiles. Overall, this demonstrates that a taxon's immune strategy can influence how the immune system is affected by age. PMID:23077164

Zimmerman, Laura M; Clairardin, Sandrine G; Paitz, Ryan T; Hicke, Justin W; LaMagdeleine, Katie A; Vogel, Laura A; Bowden, Rachel M

2013-02-15

277

Harnessing the power of the immune system via blockade of PD-1 and PD-L1: a promising new anticancer strategy.  

PubMed

Cancer cells employ several mechanisms to evade the immune system of their host, thus escaping immune recognition and elimination. Of particular interest is a cancer cell's ability to co-opt the immune system's innate ligands and inhibitory receptors (also known as checkpoints), thus creating an immunosuppressive microenvironment that downregulates T-cell activation and cell signaling. The recent development of the checkpoint inhibitors anti-programmed death-1 and anti-programmed death ligand-1 has generated an enormous amount of interest as a potential new anticancer strategy in solid tumors, particularly in non-small-cell lung cancer, renal cell carcinoma and melanoma. Data suggest significant disease response rates using anti-programmed death-1 and anti-programmed death ligand-1 antibodies, even in heavily pretreated patients. Future directions include optimization of drug delivery sequence and combination of immunotherapy with other therapies including cytotoxic chemotherapy, radiation, antiangiogenic agents and small-molecule tyrosine kinase inhibitors. PMID:24815784

Reiss, Kim A; Forde, Patrick M; Brahmer, Julie R

2014-01-01

278

Missile Defenses and Mother Russia: Scarecrow or Showstopper?  

Microsoft Academic Search

Missile defenses will neither derail the post-Cold War political relationship between the US and Russia nor repeal the existence of mutual deterrence as between their respective nuclear arsenals. Because politics rules strategy and strategy must pay homage to the realities of physics, missile defenses will emerge into arsenals gradually, if at all. Whether missile defenses exacerbate political tensions, or can

Stephen J. Cimbala

2007-01-01

279

Inhibition of the TRAIL Death Receptor by CMV Reveals Its Importance in NK Cell-Mediated Antiviral Defense  

PubMed Central

TNF-related apoptosis inducing ligand (TRAIL) death receptors (DR) regulate apoptosis and inflammation, but their role in antiviral defense is poorly understood. Cytomegaloviruses (CMV) encode many immune-modulatory genes that shape host immunity, and they utilize multiple strategies to target the TNF-family cytokines. Here we show that the m166 open reading frame (orf) of mouse CMV (MCMV) is strictly required to inhibit expression of TRAIL-DR in infected cells. An MCMV mutant lacking m166 expression (m166stop) is severely compromised for replication in vivo, most notably in the liver, and depleting natural killer (NK) cells, or infecting TRAIL-DR?/? mice, restored MCMV-m166stop replication completely. These results highlight the critical importance for CMV to have evolved a strategy to inhibit TRAIL-DR signaling to thwart NK-mediated defenses. PMID:25122141

Wang, Qiao; McDonald, Bryan; Redwood, Alec; Benedict, Chris A.

2014-01-01

280

The Quadrennial Defense Review: May 1997  

NSDL National Science Digital Library

On May 19, 1997, as mandated by the National Defense Authorization Act of 1996, US Secretary of Defense William S. Cohen presented the Quadrennial Defense Review to Congress. This site contains the May 19 Defense Department news release and briefing (along with slides), the text of the report, and the legislation mandating it. The report is composed of ten sections ranging from "The Global Security Environment" to "Force Readiness" to "Achieving a 21st Century Defense Infrastructure." However, its thrust can be ascertained from a single statement by the Secretary: "The strategy devised through the QDR can be summed up in three words: shape, respond, and prepare."

Cohen, William S.

1998-01-01

281

Evolution of Adaptive Immune Recognition in Jawless Vertebrates  

PubMed Central

All extant vertebrates possess an adaptive immune system wherein diverse immune receptors are created and deployed in specialized blood cell lineages. Recent advances in DNA sequencing and developmental resources for basal vertebrates have facilitated numerous comparative analyses that have shed new light on the molecular and cellular bases of immune defense and the mechanisms of immune receptor diversification in the “jawless” vertebrates. With data from these key species in hand, it is becoming possible to infer some general aspects of the early evolution of vertebrate adaptive immunity. All jawed vertebrates assemble their antigen-receptor genes through combinatorial recombination of different “diversity” segments into immunoglobulin or T-cell receptor genes. However, the jawless vertebrates employ an analogous, but independently-derived set of immune receptors in order to recognize and bind antigens: the variable lymphocyte receptors (VLRs). The means by which this locus generates receptor diversity and achieves antigen specificity is of considerable interest because these mechanisms represent a completely independent strategy for building a large immune repertoire. Therefore, studies of the VLR system are providing insight into the fundamental principles and evolutionary potential of adaptive immune recognition systems. Here we review and synthesize the wealth of data that have been generated towards understanding the evolution of the adaptive immune system in the jawless vertebrates. PMID:20056434

Saha, Nil Ratan; Smith, Jeramiah; Amemiya, Chris T.

2009-01-01

282

Molecular profile and functional characterization of the ferritin H subunit from rock bream (Oplegnathus fasciatus), revealing its putative role in host antioxidant and immune defense.  

PubMed

Ferritins are iron binding proteins made out of 24 subunits, involved in iron homeostasis and metabolism in cellular environments. Here, we sought to identify and functionally characterize a one type of subunits of ferritin (ferritin H-like subunit) from rock bream (Oplegnathus fasciatus; RbFerH). The complete coding sequence of RbFerH was 531 bp in length, encoding a 177-amino acid protein with a predicted molecular mass of 20.8 kDa. The deduced protein structure possessed the domain architecture characteristic of known ferritin H subunits, including metal ligands for iron binding, a ferroxidase center, and two iron-binding region signatures. As expected, the 5' untranslated region of the RbFerH cDNA sequence contained a putative iron response element region, a characteristic regulatory element involved in its translation. The RbFerH gene comprised 5 exons and 4 introns spanning a 4195 bp region. Overexpressed recombinant RbFerH protein demonstrated prominent Fe(II) ion depriving activity, bacteriostatic properties, and protective effects against oxidative double-stranded DNA damage. Using quantitative polymerase chain reaction (qPCR), we found that RbFerH was expressed ubiquitously in the majority of physiologically important tissues in rock bream. A greater abundance of the mRNA transcripts were detected in blood and liver tissues. Upon administering different microbial pathogens and pathogen-derived mitogens, RbFerH transcription was markedly elevated in the blood of rock bream. Taken together, our findings suggest that RbFerH acts as a potent iron sequestrator in rock bream and may actively participate in antimicrobial as well as antioxidative defense. PMID:25020197

Elvitigala, Don Anushka Sandaruwan; Priyathilaka, Thanthrige Thiunuwan; Lim, Bong-Soo; Whang, Ilson; Yeo, Sang-Yeob; Choi, Cheol Young; Lee, Jehee

2014-11-01

283

Applying Convergent Immunity to Innovative Vaccines Targeting Staphylococcus aureus  

PubMed Central

Recent perspectives forecast a new paradigm for future “third generation” vaccines based on commonalities found in diverse pathogens or convergent immune defenses to such pathogens. For Staphylococcus aureus, recurring infections and a limited success of vaccines containing S. aureus antigens imply that native antigens induce immune responses insufficient for optimal efficacy. These perspectives exemplify the need to apply novel vaccine strategies to high-priority pathogens. One such approach can be termed convergent immunity, where antigens from non-target organisms that contain epitope homologs found in the target organism are applied in vaccines. This approach aims to evoke atypical immune defenses via synergistic processes that (1) afford protective efficacy; (2) target an epitope from one organism that contributes to protective immunity against another; (3) cross-protect against multiple pathogens occupying a common anatomic or immunological niche; and/or (4) overcome immune subversion or avoidance strategies of target pathogens. Thus, convergent immunity has a potential to promote protective efficacy not usually elicited by native antigens from a target pathogen. Variations of this concept have been mainstays in the history of viral and bacterial vaccine development. A more far-reaching example is the pre-clinical evidence that specific fungal antigens can induce cross-kingdom protection against bacterial pathogens. This trans-kingdom protection has been demonstrated in pre-clinical studies of the recombinant Candida albicans agglutinin-like sequence 3 protein (rAls3) where it was shown that a vaccine containing rAls3 provides homologous protection against C. albicans, heterologous protection against several other Candida species, and convergent protection against several strains of S. aureus. Convergent immunity reflects an intriguing new approach to designing and developing vaccine antigens and is considered here in the context of vaccines to target S. aureus. PMID:25309545

Yeaman, Michael R.; Filler, Scott G.; Schmidt, Clint S.; Ibrahim, Ashraf S.; Edwards, John E.; Hennessey, John P.

2014-01-01

284

Integrated Immune Experiment  

NASA Technical Reports Server (NTRS)

This viewgraph presentation reviews NASA's Integrated Immune Experiment. The objectives include: 1) Address significant lack of data regarding immune status during flight; 2) Replace several recent immune studies with one comprehensive study that will include in-flight sampling; 3) Determine the in-flight status of immunity, physiological stress, viral immunity/reactivation; 4) Determine the clinical risk related to immune dysregulation for exploration class spaceflight; and 5) Determine the appropriate monitoring strategy for spaceflight-associated immune dysfunction, that could be used for the evaluation of countermeasures.

Crucian, Brian

2009-01-01

285

Responses of innate immune cells to group A Streptococcus  

PubMed Central

Group A Streptococcus (GAS), also called Streptococcus pyogenes, is a Gram-positive beta-hemolytic human pathogen which causes a wide range of mostly self-limiting but also several life-threatening diseases. Innate immune responses are fundamental for defense against GAS, yet their activation by pattern recognition receptors (PRRs) and GAS-derived pathogen-associated molecular patterns (PAMPs) is incompletely understood. In recent years, the use of animal models together with the powerful tools of human molecular genetics began shedding light onto the molecular mechanisms of innate immune defense against GAS. The signaling adaptor MyD88 was found to play a key role in launching the immune response against GAS in both humans and mice, suggesting that PRRs of the Toll-like receptor (TLR) family are involved in sensing this pathogen. The specific TLRs and their ligands have yet to be identified. Following GAS recognition, induction of cytokines such as TNF and type I interferons (IFNs), leukocyte recruitment, phagocytosis, and the formation of neutrophil extracellular traps (NETs) have been recognized as key events in host defense. A comprehensive knowledge of these mechanisms is needed in order to understand their frequent failure against GAS immune evasion strategies. PMID:25325020

Fieber, Christina; Kovarik, Pavel

2014-01-01

286

Immunization with adenovirus at the large intestinal mucosa as an effective vaccination strategy against sexually transmitted viral infection  

Microsoft Academic Search

The large intestinal mucosa contains immunological structures that may potentially serve as a site for induction of mucosal immunity against infections. Adenovirus (Ad), which is effective in gene transfer to epithelia, may be an ideal antigen delivery system for vaccination at the large intestinal mucosa. To investigate this potential, we immunized mice with recombinant replication-deficient Ad through a single intracolorectal

Q Zhu; C W Thomson; K L Rosenthal; M R McDermott; S M Collins; J Gauldie

2008-01-01

287

Heteropentameric Cholera Toxin B Subunit Chimeric Molecules Genetically Fused to a Vaccine Antigen Induce Systemic and Mucosal Immune Responses: a Potential New Strategy To Target Recombinant Vaccine Antigens to Mucosal Immune Systems  

PubMed Central

Noninvasive mucosal vaccines are attractive alternatives to parenteral vaccines. Although the conjugation of vaccine antigens with the B subunit of cholera toxin (CTB) is one of the most promising strategies for vaccine delivery to mucosal immune systems, the molecule cannot tolerate large-protein fusion, as it severely impairs pentamerization and loses affinity for GM1-ganglioside. Here we report a new strategy, in which steric hindrance between CTB-antigen fusion subunits is significantly reduced through the integration of unfused CTB “molecular buffers” into the pentamer unit, making them more efficiently self-assemble into biologically active pentamers. In addition, the chimeric protein took a compact configuration, becoming small enough to be secreted, and one-step affinity-purified proteins, when administered through a mucosal route, induced specific immune responses in mice. Since our results are not dependent on the use of a particular expression system or vaccine antigen, this strategy could be broadly applicable to bacterial enterotoxin-based vaccine design. PMID:16113283

Harakuni, Tetsuya; Sugawa, Hideki; Komesu, Ai; Tadano, Masayuki; Arakawa, Takeshi

2005-01-01

288

A Rapid Immunization Strategy with a Live-Attenuated Tetravalent Dengue Vaccine Elicits Protective Neutralizing Antibody Responses in Non-Human Primates  

PubMed Central

Dengue viruses (DENVs) cause approximately 390 million cases of DENV infections annually and over 3 billion people worldwide are at risk of infection. No dengue vaccine is currently available nor is there an antiviral therapy for DENV infections. We have developed a tetravalent live-attenuated DENV vaccine tetravalent dengue vaccine (TDV) that consists of a molecularly characterized attenuated DENV-2 strain (TDV-2) and three chimeric viruses containing the pre-membrane and envelope genes of DENV-1, -3, and -4 expressed in the context of the TDV-2 genome. To impact dengue vaccine delivery in endemic areas and immunize travelers, a simple and rapid immunization strategy (RIS) is preferred. We investigated RIS consisting of two full vaccine doses being administered subcutaneously or intradermally on the initial vaccination visit (day 0) at two different anatomical locations with a needle-free disposable syringe jet injection delivery devices (PharmaJet) in non-human primates. This vaccination strategy resulted in efficient priming and induction of neutralizing antibody responses to all four DENV serotypes comparable to those elicited by the traditional prime and boost (2?months later) vaccination schedule. In addition, the vaccine induced CD4+ and CD8+ T cells producing IFN-?, IL-2, and TNF-?, and targeting the DENV-2 NS1, NS3, and NS5 proteins. Moreover, vaccine-specific T cells were cross-reactive with the non-structural NS3 and NS5 proteins of DENV-4. When animals were challenged with DENV-2 they were protected with no detectable viremia, and exhibited sterilizing immunity (no increase of neutralizing titers post-challenge). RIS could decrease vaccination visits and provide quick immune response to all four DENV serotypes. This strategy could increase vaccination compliance and would be especially advantageous for travelers into endemic areas. PMID:24926294

Ambuel, Yuping; Young, Ginger; Brewoo, Joseph N.; Paykel, Joanna; Weisgrau, Kim L.; Rakasz, Eva G.; Haller, Aurelia A.; Royals, Michael; Huang, Claire Y.-H.; Capuano, Saverio; Stinchcomb, Dan T.; Partidos, Charalambos D.; Osorio, Jorge E.

2014-01-01

289

THESIS DEFENSE REPORT FORM Defense Date  

E-print Network

THESIS DEFENSE REPORT FORM Defense Date: Student: Department: Dissertation Title: Please hand: (718) 430-8655 Committee Member Decision Signature P CP F (Chair) The decision of the Thesis Defense' on the scientific merit of the thesis defense and the dissertation, but with substantial reservation. The candidate

Jenny, Andreas

290

THESIS DEFENSE REPORT FORM Defense Date  

E-print Network

THESIS DEFENSE REPORT FORM Defense Date: Student: Department: Dissertation Title: Please hand: (718) 430-8655 Committee Member Decision Signature P CP F (Chair) The decision of the Thesis Defense' on the scientific merit of the Thesis Defense and the Dissertation, but with substantial revisions. If someone other

Yates, Andrew

291

SECRETARY OF DEFENSE 1000 DEFENSE PENTAGON  

E-print Network

ig SECRETARY OF DEFENSE 1000 DEFENSE PENTAGON WASHINGTON, DC 20301 -1000 AUG 6 2013 MEMORANDUM FOR SECRETARIES OF THE MILITARY DEPARTMENTS CHAIRMAN OF THE JOINT CHIEFS OF STAFF UNDER SECRETARIES OF DEFENSE DEPUTY CHIEF MANAGEMENT OFFICER COMMANDERS OF THE COMBATANT COMMANDS ASSISTANT SECRETARIES OF DEFENSE

US Army Corps of Engineers

292

ASSISTANT SECRETARY OF DEFENSE 4000 DEFENSE PENTAGON  

E-print Network

ASSISTANT SECRETARY OF DEFENSE 4000 DEFENSE PENTAGON WASHINGTON, D.C. 20301-4000 READINESS Force Management Reference: (a) Secretary ofDefense Memorandum, "Furloughs", dated 14 May 2013 The Secretary of Defense, per reference (a), directed civilian furloughs beginning July 8, 2013. Reference (a

US Army Corps of Engineers

293

DEPUTY SECRETARY OF DEFENSE 1010 DEFENSE PENTAGON  

E-print Network

DEPUTY SECRETARY OF DEFENSE 1010 DEFENSE PENTAGON WASHINGTON, DC 20301-1010 JAN 10 2013 MEMORANDUM FOR SECRETARIES OF THE MILITARY DEPARTMENTS CHAIRMAN OF THE JOINT CHIEFS OF STAFF UNDER SECRETARIES OF DEFENSE TEST AND EVALUATION GENERAL COUNSEL OF THE DEPARTMENT OF DEFENSE INSPECTOR GENERAL OF THE DEPARTMENT

US Army Corps of Engineers

294

Tsetse immune responses and trypanosome transmission: Implications for the development of tsetse-based strategies to reduce trypanosomiasis  

PubMed Central

Tsetse flies are the medically and agriculturally important vectors of African trypanosomes. Information on the molecular and biochemical nature of the tsetse/trypanosome interaction is lacking. Here we describe three antimicrobial peptide genes, attacin, defensin, and diptericin, from tsetse fat body tissue obtained by subtractive cloning after immune stimulation with Escherichia coli and trypanosomes. Differential regulation of these genes shows the tsetse immune system can discriminate not only between molecular signals specific for bacteria and trypanosome infections but also between different life stages of trypanosomes. The presence of trypanosomes either in the hemolymph or in the gut early in the infection process does not induce transcription of attacin and defensin significantly. After parasite establishment in the gut, however, both antimicrobial genes are expressed at high levels in the fat body, apparently not affecting the viability of parasites in the midgut. Unlike other insect immune systems, the antimicrobial peptide gene diptericin is constitutively expressed in both fat body and gut tissue of normal and immune stimulated flies, possibly reflecting tsetse immune responses to the multiple Gram-negative symbionts it naturally harbors. When flies were immune stimulated with bacteria before receiving a trypanosome containing bloodmeal, their ability to establish infections was severely blocked, indicating that up-regulation of some immune responsive genes early in infection can act to block parasite transmission. The results are discussed in relation to transgenic approaches proposed for modulating vector competence in tsetse. PMID:11592981

Hao, Zhengrong; Kasumba, Irene; Lehane, Michael J.; Gibson, Wendy C.; Kwon, Johnny; Aksoy, Serap

2001-01-01

295

Mathematical model approach to describe tumour response in mice after vaccine administration and its applicability to immune-stimulatory cytokine-based strategies.  

PubMed

Immunotherapy is a growing therapeutic strategy in oncology based on the stimulation of innate and adaptive immune systems to induce the death of tumour cells. In this paper, we have developed a population semi-mechanistic model able to characterize the mechanisms implied in tumour growth dynamic after the administration of CyaA-E7, a vaccine able to target antigen to dendritic cells, thus triggering a potent immune response. The mathematical model developed presented the following main components: (1) tumour progression in the animals without treatment was described with a linear model, (2) vaccine effects were modelled assuming that vaccine triggers a non-instantaneous immune response inducing cell death. Delayed response was described with a series of two transit compartments, (3) a resistance effect decreasing vaccine efficiency was also incorporated through a regulator compartment dependent upon tumour size, and (4) a mixture model at the level of the elimination of the induced signal vaccine (k 2) to model tumour relapse after treatment, observed in a small percentage of animals (15.6%). The proposed model structure was successfully applied to describe antitumor effect of IL-12, suggesting its applicability to different immune-stimulatory therapies. In addition, a simulation exercise to evaluate in silico the impact on tumour size of possible combination therapies has been shown. This type of mathematical approaches may be helpful to maximize the information obtained from experiments in mice, reducing the number of animals and the cost of developing new antitumor immunotherapies. PMID:23605806

Parra-Guillen, Zinnia P; Berraondo, Pedro; Grenier, Emmanuel; Ribba, Benjamin; Troconiz, Iñaki F

2013-07-01

296

Small RNAs in plant defense responses during viral and bacterial interactions: similarities and differences  

PubMed Central

Small non-coding RNAs constitute an important class of gene expression regulators that control different biological processes in most eukaryotes. In plants, several small RNA (sRNA) silencing pathways have evolved to produce a wide range of small RNAs with specialized functions. Evidence for the diverse mode of action of the small RNA pathways has been highlighted during plant–microbe interactions. Host sRNAs and small RNA silencing pathways have been recognized as essential components of plant immunity. One way plants respond and defend against pathogen infections is through the small RNA silencing immune system. To deal with plant defense responses, pathogens have evolved sophisticated mechanisms to avoid and counterattack this defense strategy. The relevance of the small RNA-mediated plant defense responses during viral infections has been well-established. Recent evidence points out its importance also during plant–bacteria interactions. Herein, this review discusses recent findings, similarities and differences about the small RNA-mediated arms race between plants and these two groups of microbes, including the small RNA silencing pathway components that contribute to plant immune responses, the pathogen-responsive endogenous sRNAs and the pathogen-delivered effector proteins. PMID:24046772

Peláez, Pablo; Sanchez, Federico

2013-01-01

297

PHD DISSERTATION DEFENSE MS. QIAN CHEN  

E-print Network

PHD DISSERTATION DEFENSE MS. QIAN CHEN Advisor: Dr. Virginia Ayres Department of Electrical Building (ECE Conference Room) "SCANNING PROBE RECOGNITION MICROSCOPY: RECOGNITION STRATEGIES" ABSTRACT fields. Adaptive learning and prediction are also implemented to make the object detection and tracking

Ayres, Virginia

298

Innate immune sensing and response to influenza.  

PubMed

Influenza viruses pose a substantial threat to human and animal health worldwide. Recent studies in mouse models have revealed an indispensable role for the innate immune system in defense against influenza virus. Recognition of the virus by innate immune receptors in a multitude of cell types activates intricate signaling networks, functioning to restrict viral replication. Downstream effector mechanisms include activation of innate immune cells and, induction and regulation of adaptive immunity. However, uncontrolled innate responses are associated with exaggerated disease, especially in pandemic influenza virus infection. Despite advances in the understanding of innate response to influenza in the mouse model, there is a large knowledge gap in humans, particularly in immunocompromised groups such as infants and the elderly. We propose here, the need for further studies in humans to decipher the role of innate immunity to influenza virus, particularly at the site of infection. These studies will complement the existing work in mice and facilitate the quest to design improved vaccines and therapeutic strategies against influenza. PMID:25078919

Pulendran, Bali; Maddur, Mohan S

2015-01-01

299

Immune System Defender  

NSDL National Science Digital Library

This interactive unit demonstrates the immune system's defense mechanisms. Users will defend the human body against an infection using a "team" of white blood cells called granulocytes. The white blood cells will be used to destroy the bacteria via a fun interactive game. In the "Information Terminal" section of the interactive unit, students can read more about the immune system and its cells as well as the Nobel Prize awarded for the discovery of the phagocyte cell.

2012-06-18

300

Pathogenicity of and plant immunity to soft rot pectobacteria  

PubMed Central

Soft rot pectobacteria are broad host range enterobacterial pathogens that cause disease on a variety of plant species including the major crop potato. Pectobacteria are aggressive necrotrophs that harbor a large arsenal of plant cell wall-degrading enzymes as their primary virulence determinants. These enzymes together with additional virulence factors are employed to macerate the host tissue and promote host cell death to provide nutrients for the pathogens. In contrast to (hemi)biotrophs such as Pseudomonas, type III secretion systems (T3SS) and T3 effectors do not appear central to pathogenesis of pectobacteria. Indeed, recent genomic analysis of several Pectobacterium species including the emerging pathogen Pectobacterium wasabiae has shown that many strains lack the entire T3SS as well as the T3 effectors. Instead, this analysis has indicated the presence of novel virulence determinants. Resistance to broad host range pectobacteria is complex and does not appear to involve single resistance genes. Instead, activation of plant innate immunity systems including both SA (salicylic acid) and JA (jasmonic acid)/ET (ethylene)-mediated defenses appears to play a central role in attenuation of Pectobacterium virulence. These defenses are triggered by detection of pathogen-associated molecular patterns (PAMPs) or recognition of modified-self such as damage-associated molecular patterns (DAMPs) and result in enhancement of basal immunity (PAMP/DAMP-triggered immunity or pattern-triggered immunity, PTI). In particular plant cell wall fragments released by the action of the degradative enzymes secreted by pectobacteria are major players in enhanced immunity toward these pathogens. Most notably bacterial pectin-degrading enzymes release oligogalacturonide (OG) fragments recognized as DAMPs activating innate immune responses. Recent progress in understanding OG recognition and signaling allows novel genetic screens for OG-insensitive mutants and will provide new insights into plant defense strategies against necrotrophs such as pectobacteria. PMID:23781227

Davidsson, Pär R.; Kariola, Tarja; Niemi, Outi; Palva, E. T.

2013-01-01

301

Pathogenicity of and plant immunity to soft rot pectobacteria.  

PubMed

Soft rot pectobacteria are broad host range enterobacterial pathogens that cause disease on a variety of plant species including the major crop potato. Pectobacteria are aggressive necrotrophs that harbor a large arsenal of plant cell wall-degrading enzymes as their primary virulence determinants. These enzymes together with additional virulence factors are employed to macerate the host tissue and promote host cell death to provide nutrients for the pathogens. In contrast to (hemi)biotrophs such as Pseudomonas, type III secretion systems (T3SS) and T3 effectors do not appear central to pathogenesis of pectobacteria. Indeed, recent genomic analysis of several Pectobacterium species including the emerging pathogen Pectobacterium wasabiae has shown that many strains lack the entire T3SS as well as the T3 effectors. Instead, this analysis has indicated the presence of novel virulence determinants. Resistance to broad host range pectobacteria is complex and does not appear to involve single resistance genes. Instead, activation of plant innate immunity systems including both SA (salicylic acid) and JA (jasmonic acid)/ET (ethylene)-mediated defenses appears to play a central role in attenuation of Pectobacterium virulence. These defenses are triggered by detection of pathogen-associated molecular patterns (PAMPs) or recognition of modified-self such as damage-associated molecular patterns (DAMPs) and result in enhancement of basal immunity (PAMP/DAMP-triggered immunity or pattern-triggered immunity, PTI). In particular plant cell wall fragments released by the action of the degradative enzymes secreted by pectobacteria are major players in enhanced immunity toward these pathogens. Most notably bacterial pectin-degrading enzymes release oligogalacturonide (OG) fragments recognized as DAMPs activating innate immune responses. Recent progress in understanding OG recognition and signaling allows novel genetic screens for OG-insensitive mutants and will provide new insights into plant defense strategies against necrotrophs such as pectobacteria. PMID:23781227

Davidsson, Pär R; Kariola, Tarja; Niemi, Outi; Palva, E T

2013-01-01

302

MAIT cells and pathogen defense.  

PubMed

Mucosa-associated invariant T (MAIT) cells are a unique population of innate T cells that are abundant in humans. These cells possess an evolutionarily conserved invariant T cell receptor ? chain restricted by the nonpolymorphic class Ib major histocompatibility (MHC) molecule, MHC class I-related protein (MR1). The recent discovery that MAIT cells are activated by MR1-bound riboflavin metabolite derivatives distinguishes MAIT cells from all other ?? T cells in the immune system. Since mammals lack the capacity to synthesize riboflavin, intermediates from the riboflavin biosynthetic pathway are distinct microbial molecular patterns that provide a unique signal to the immune system. Multiple lines of evidence suggest that MAIT cells, which produce important cytokines such as IFN-?, TNF, and IL-17A, have the potential to influence immune responses to a broad range of pathogens. Here we will discuss our current understanding of MAIT cell biology and their role in pathogen defense. PMID:25164578

Cowley, Siobhán C

2014-12-01

303

Priming Arabidopsis for defense : Molecular and ecological aspects  

Microsoft Academic Search

Plants are capable to enhance basal defense strategies against harmful organisms upon the perception of certain stimuli. This enhanced resistance is not necessarily accompanied by direct activation of defenses, but often depends on a sensitization of the plant tissue to express defenses faster and\\/or stronger when the plant is under attack. In analogy with a similar phenomenon in animals, this

M. H. A. van Hulten

2009-01-01

304

Applying Game Theory to Analyze Attacks and Defenses in Virtual Coordinate Systems  

E-print Network

define and use a game theory framework in order to identify the best attack and defense strategies and efficiency of these attack and defense strategies using a well-known virtual coordinate system and real and consider the effectiveness of the defense strategies under the restric- tive assumption that an attacker

Nita-Rotaru, Cristina

305

Brassinosteroids Antagonize Gibberellin- and Salicylate-Mediated Root Immunity in Rice1[C][W][OA  

PubMed Central

Brassinosteroids (BRs) are a unique class of plant steroid hormones that orchestrate myriad growth and developmental processes. Although BRs have long been known to protect plants from a suite of biotic and abiotic stresses, our understanding of the underlying molecular mechanisms is still rudimentary. Aiming to further decipher the molecular logic of BR-modulated immunity, we have examined the dynamics and impact of BRs during infection of rice (Oryza sativa) with the root oomycete Pythium graminicola. Challenging the prevailing view that BRs positively regulate plant innate immunity, we show that P. graminicola exploits BRs as virulence factors and hijacks the rice BR machinery to inflict disease. Moreover, we demonstrate that this immune-suppressive effect of BRs is due, at least in part, to negative cross talk with salicylic acid (SA) and gibberellic acid (GA) pathways. BR-mediated suppression of SA defenses occurred downstream of SA biosynthesis, but upstream of the master defense regulators NONEXPRESSOR OF PATHOGENESIS-RELATED GENES1 and OsWRKY45. In contrast, BR alleviated GA-directed immune responses by interfering at multiple levels with GA metabolism, resulting in indirect stabilization of the DELLA protein and central GA repressor SLENDER RICE1 (SLR1). Collectively, these data favor a model whereby P. graminicola coopts the plant BR pathway as a decoy to antagonize effectual SA- and GA-mediated defenses. Our results highlight the importance of BRs in modulating plant immunity and uncover pathogen-mediated manipulation of plant steroid homeostasis as a core virulence strategy. PMID:22353574

De Vleesschauwer, David; Van Buyten, Evelien; Satoh, Kouji; Balidion, Johny; Mauleon, Ramil; Choi, Il-Ryong; Vera-Cruz, Casiana; Kikuchi, Shoshi; Höfte, Monica

2012-01-01

306

The costs, effects and cost-effectiveness of strategies to increase coverage of routine immunizations in low- and middle-income countries: systematic review of the grey literature.  

PubMed Central

Evidence-based reviews of published literature can be subject to several biases. Grey literature, however, can be of poor quality and expensive to access. Effective search strategies also vary by topic and are rarely known in advance. This paper complements a systematic review of the published literature on the costs and effects of expanding immunization services in developing countries. The quality of data on the effectiveness and cost-effectiveness of strategies to increase immunization coverage is shown to be similar across literatures, but the quality of information on costing is much lower in the grey literature. After excluding poorer quality studies from this review we found the quantity of available evidence almost doubled, particularly for more complex health-system interventions and cost or cost-effectiveness analyses. Interventions in the grey literature are more up to date and cover a different geographical spread. Consequently the conclusions of the published and grey literatures differ, although the number of papers is still too low to account for differences across types of interventions. We recommend that in future researchers consider using non-English keywords in their searches. PMID:15628207

Batt, Katherine; Fox-Rushby, J. A.; Castillo-Riquelme, Marianela

2004-01-01

307

Innate and Adaptive Immune Responses in Wound Epithelialization.  

PubMed

Significance: Over the years, it has become clear that, in addition to performing their regular duties in immune defense, the innate and adaptive arms of the immune system are important regulators of the complex series of events that lead to wound healing. Immune cells modulate wound healing by promoting cellular cross-talk; they secrete signaling molecules, including cytokines, chemokines, and growth factors. In line with the major effort in wound healing research to find efficient therapeutic agents for the constantly increasing number of patients with chronic wounds, findings regarding the contributions of innate and adaptive immune responses to the re-epithelialization of damaged skin may bring novel therapeutics. Recent Advances: Increasing evidence suggests that induction of the adaptive immune response requires activation of innate immunity and that there is a dependent relationship between the two systems. Consequently, the bridge between the innate and the acquired immune systems has become an area of emerging exploration. It is clear that a better understanding of the epithelial cells (keratinocytes), immune cells, and mechanisms that contribute to an effective wound healing process is necessary so that new strategies for successful wounds treatment can be devised. Critical Issues: A greater understanding of the biology of skin innate and adaptive immune cells during wound epithelialization may have an impact on development of novel strategies for significant improvements in the quality of tissue repair. Future Directions: Future studies should clarify the importance of particular molecules and mechanisms utilized for development and functions of skin-resident ??T and Langerhans cells, as well as identify therapeutic targets for manipulation of these cells to combat epithelial diseases. PMID:25032069

Strbo, Natasa; Yin, Natalie; Stojadinovic, Olivera

2014-07-01

308

22 CFR 130.4 - Defense articles and defense services.  

...Relations 1 2014-04-01 2014-04-01 false Defense articles and defense services. 130.4 Section 130.4 Foreign...CONTRIBUTIONS, FEES AND COMMISSIONS § 130.4 Defense articles and defense services. Defense...

2014-04-01

309

22 CFR 130.4 - Defense articles and defense services.  

Code of Federal Regulations, 2010 CFR

...Relations 1 2010-04-01 2010-04-01 false Defense articles and defense services. 130.4 Section 130.4 Foreign...CONTRIBUTIONS, FEES AND COMMISSIONS § 130.4 Defense articles and defense services. Defense...

2010-04-01

310

22 CFR 130.4 - Defense articles and defense services.  

Code of Federal Regulations, 2013 CFR

...Relations 1 2013-04-01 2013-04-01 false Defense articles and defense services. 130.4 Section 130.4 Foreign...CONTRIBUTIONS, FEES AND COMMISSIONS § 130.4 Defense articles and defense services. Defense...

2013-04-01

311

22 CFR 130.4 - Defense articles and defense services.  

Code of Federal Regulations, 2011 CFR

...Relations 1 2011-04-01 2011-04-01 false Defense articles and defense services. 130.4 Section 130.4 Foreign...CONTRIBUTIONS, FEES AND COMMISSIONS § 130.4 Defense articles and defense services. Defense...

2011-04-01

312

22 CFR 130.4 - Defense articles and defense services.  

Code of Federal Regulations, 2012 CFR

...Relations 1 2012-04-01 2012-04-01 false Defense articles and defense services. 130.4 Section 130.4 Foreign...CONTRIBUTIONS, FEES AND COMMISSIONS § 130.4 Defense articles and defense services. Defense...

2012-04-01

313

Host defense peptides in skin secretions of Odorrana tiannanensis: Proof for other survival strategy of the frog than merely anti-microbial.  

PubMed

Genus Odorrana, among all amphibians studied, is generally reported to have the most abundant and diversified anti-microbial peptides even from a single individual frog. In our previous work, 46 cDNA sequences encoding precursors of 22 different anti-microbial peptides (AMPs) were characterized from the skin of frog, Odorrana tiannanensis. In this work, we reported the purification of three AMPs from skin secretions of O. tiannanensis. Their amino acid sequences matched well with the sequences deduced from cDNAs and they were designated as Odorranain-C7HSa, Brevinin-1-OT2 and Odorranain-G-OT, respectively. Furthermore, we selected to analyze the four most structurally diversified sequences among the 22 AMPs that are significantly different from all reported AMPs. By structural characterization, three of them were designated as pleurain-E-OT, odorranain-G-OT, odorranain-A-OT, belonging to AMP families already identified. The forth one with a unique 14-mer sequence of AILTTLANWARKFLa and C-terminal amidation represents the prototypes of a new class of amphibian AMP, and thereby named tiannanensin. Such broad diversity in sequences and structures are consistent with other species in Genus Odorrana. Multi-functions of the synthesized four special AMPs were screened, including anti-microbial, antioxidant, cytotoxic and hemolytic activities. The results suggest that these AMPs may employ sophisticated mechanisms of action in host defense in addition to anti-microbial, although their precise contribution to host defense still seems unclear. PMID:21963433

He, Weiyu; Feng, Feifei; Huang, Yong; Guo, Huanhuan; Zhang, Songyan; Li, Zheng; Liu, Jingze; Wang, Yipeng; Yu, Haining

2012-03-01

314

Comparative genomics of defense systems in archaea and bacteria  

PubMed Central

Our knowledge of prokaryotic defense systems has vastly expanded as the result of comparative genomic analysis, followed by experimental validation. This expansion is both quantitative, including the discovery of diverse new examples of known types of defense systems, such as restriction-modification or toxin-antitoxin systems, and qualitative, including the discovery of fundamentally new defense mechanisms, such as the CRISPR-Cas immunity system. Large-scale statistical analysis reveals that the distribution of different defense systems in bacterial and archaeal taxa is non-uniform, with four groups of organisms distinguishable with respect to the overall abundance and the balance between specific types of defense systems. The genes encoding defense system components in bacterial and archaea typically cluster in defense islands. In addition to genes encoding known defense systems, these islands contain numerous uncharacterized genes, which are candidates for new types of defense systems. The tight association of the genes encoding immunity systems and dormancy- or cell death-inducing defense systems in prokaryotic genomes suggests that these two major types of defense are functionally coupled, providing for effective protection at the population level. PMID:23470997

Makarova, Kira S.; Wolf, Yuri I.; Koonin, Eugene V.

2013-01-01

315

Effects of kefir fractions on innate immunity  

Microsoft Academic Search

Innate immunity that protects against pathogens in the tissues and circulation is the first line of defense in the immune reaction, where macrophages have a critical role in directing the fate of the infection. We recently demonstrated that kefir modulates the immune response in mice, increasing the number of IgA+ cells in the intestinal and bronchial mucosa and the phagocytic

Gabriel Vinderola; Gabriela Perdigon; Jairo Duarte; Deepa Thangavel; Edward Farnworth; Chantal Matar

2006-01-01

316

COMPETING HIV STRAINS AND IMMUNE SYSTEM RESPONSE  

E-print Network

COMPETING HIV STRAINS AND IMMUNE SYSTEM RESPONSE THIERRY GOBRON1 , MARIO SANTORO2 , AND LIVIO between an immune system with a specific and powerful response, and a virus with a broad toxicity and fast on the cells which are the keystone of the immune defense system. A number of theoretical papers have studied

Paris-Sud XI, Université de

317

Qualitative differences in the early immune response to live and killed Leishmania major: Implications for vaccination strategies against Leishmaniasis.  

PubMed

Recovery from natural or deliberate infection with Leishmania major leads to the development of lifelong immunity against rechallenge infections. In contrast, vaccination with killed parasites or defined leishmanial antigens generally induces only short-term protection. The reasons for this difference are currently not known but may be related to differences in the quality of the early immune responses to live and killed parasites. Here, we report that live and killed L. major parasites elicit comparable early inflammatory response as evidenced by influx and/or proliferation of cells in the draining lymph nodes (dLNs). In contrast, the early cytokine responses were qualitatively different. Cells from mice inoculated with killed parasites produced significantly more antigen-specific IL-4 and less IFN-gamma than those from mice injected with live parasites. Inclusion of CpG ODN into killed parasite preparations changed the early response to killed parasites from IL-4 to a predominantly IFN-gamma response, resulting in better protection following secondary high dose virulent L. major challenge. Interestingly, CpG-mediated enhancement of killed parasites-induced protection was short-lived and waned after 12 weeks. Taken together, these results suggest that the nature of primary immunity induced by killed and live parasites are qualitatively different and that these differences may account for the differential protection seen in mice following vaccination with live and killed parasites. They further suggest that modulating the early response with an appropriate adjuvant could enhance efficacy of killed parasite vaccines. PMID:19428861

Okwor, Ifeoma; Liu, Dong; Uzonna, Jude

2009-04-28

318

Department of Defense INSTRUCTION  

E-print Network

Department of Defense INSTRUCTION NUMBER 1400.25-V810 April 12, 2005 Administratively reissued regarding civilian personnel management within the Department of Defense. b. Volume. This Volume, the Office of the Inspector General of the Department of Defense, the Defense Agencies, the DoD Field

319

Department of Defense INSTRUCTION  

E-print Network

Department of Defense INSTRUCTION NUMBER 2040.02 July 10, 2008 USD(P) SUBJECT: International Secretary of Defense for Policy (USD(P)) in Deputy Secretary of Defense Memorandum (Reference (b)). b-use and defense-related technology, articles, and services, by implementing relevant portions of section 1701 et

320

Innate immunity and aging  

PubMed Central

Advanced age is associated with defects in all of the cells of the innate immune system, including numbers, function, their, and early stages of activation. In this review, the current state of the field on the impact of age on the innate immune system is presented. The analysis of the literature suggests that a dysfunctional innate immune system is a contributing factor to aberrant outcomes after injury or infection and to the development of many of the diseases observed in the elderly. Gaining an understanding of the nature of the defects in innate immune cells may allow the development of therapeutic strategies aimed at restoring innate immune function in aged individuals. PMID:18586079

Gomez, Christian R.; Nomellini, Vanessa; Faunce, Douglas E.; Kovacs, Elizabeth J.

2008-01-01

321

Common loon nest defense against an American mink  

USGS Publications Warehouse

We describe a successful nest defense strategy of an adult Gavia immer (Common Loon) during an attempted predation event by a Nevison vison (American Mink) at Umbagog National Wildlife Refuge, NH. It is suspected that mink occasionally depredate loon nests, but defense strategies have not been described previously.

McCarthy, K.P.; DeStefano, S.

2011-01-01

322

DEFENSE ACQUISITION GUIDEBOOK FOREWORD  

E-print Network

The Defense Acquisition System exists to manage the Nation's investments in technologies, programs, and product support necessary to achieve the National Security Strategy and support the United States Armed Forces. In that context, our continued objective is to rapidly acquire quality products that satisfy user needs with measurable improvements to mission capability at a fair and reasonable price. The fundamental principles and procedures that the Department follows in achieving those objectives are described in DoD Directive 5000.1 and DoD Instruction 5000.2. The Defense Acquisition Guidebook is designed to complement those policy documents by providing the acquisition workforce with discretionary best practice that should be tailored to the needs of each program. Acquisition professionals should use this Guidebook as a reference source supporting their management responsibilities. As an “on-line ” resource, the information is limited only by the user’s interest or need. Some chapters contain general content; they provide individual topic discussions and describe processes and considerations that will improve the effectiveness of program planning. Some chapters may provide a tutorial on the application of these topics to the acquisition framework. Depending on the subject matter, a chapter may contain general

unknown authors

323

Dendritic cell-based vaccine strategy against human immunodeficiency virus clade C: skewing the immune response toward a helper T cell type 2 profile.  

PubMed

Given the continued spread of human immunodeficiency virus (HIV)-1 worldwide, developing efficient vaccine strategies against HIV-1 is a key task. We tested the safety and immunogenicity of a multicomponent, cell-based vaccine that consisted of antigen-expressing apoptotic bodies with or without autologous dendritic cells (DCs). The vaccine strategy involved transfection of human 293T cells with codon-optimized DNA vectors expressing env of HIV1084i, a newly transmitted pediatric HIV-1 clade C strain; SHIV89.6P tat; and SIVmac239 gag-protease. Apoptotic bodies were generated by heat shock and ultraviolet irradiation and mixed either with mouse DCs (DC-cell vaccine) or given directly (cell-only vaccine) to BALB/c mice for initial priming; boosts consisted of apoptotic bodies only. The immunogens were well tolerated with or without DCs. Compared with the cell-only vaccine, the DC-cell vaccine induced higher antibody titers against all three antigens, whereas virus-specific cytotoxic T lymphocyte responses were equally strong in both groups. Iso-type analysis of viral antigen-specific antibodies revealed a skewing toward helper T type 2 responses induced by the DC-cell vaccine but not by the cell-only vaccine. In summary, both vaccine strategies were safe and induced cellular as well as humoral antiviral immunity; the DC-based approach had the advantage of significantly stronger antibody responses. PMID:17425430

Gruber, Andreas; Chalmers, Alistair S; Rasmussen, Robert A; Ong, Helena; Popov, Sergei; Andersen, Janet; Hu, Shiu-Lok; Ruprecht, Ruth M

2007-01-01

324

Subversion and Utilization of Host Innate Defense by Leishmania amazonensis.  

PubMed

Infection with Leishmania amazonensis and other members of the Leishmania mexicana complex can lead to diverse clinical manifestations, some of which are relatively difficult to control, even with standard chemotherapy. Diffuse cutaneous leishmaniasis (CL) is a rare but severe form, and its clinical hallmark is excessive parasitic growth in infected cells accompanied by profound impairments in host immune responses to the parasites. Since these parasites also cause non-healing CL in most inbred strains of mice, these animals are valuable models for dissecting the mechanisms of persistent infection and disease pathogenesis. In comparison to other Leishmania species, L. amazonensis infections are most remarkable for their ability to repress the activation and effector functions of macrophages, dendritic cells, and CD4(+) T cells, implying discrete mechanisms at work. In addition to this multilateral suppression of host innate and adaptive immunity, the activation of types I and II interferon-mediated responses and autophagic/lipid metabolic pathways actually promotes rather than restrains L. amazonensis infection. These seemingly contradictory findings reflect the remarkable adaptation of the parasites to the ancient defense machinery of the host, as well as the complex parasite-host interactions at different stages of infection, which collectively contribute to non-healing leishmaniasis in the New World. This review article highlights new evidence that reveals the strategies utilized by L. amazonensis parasites to subvert or modulate host innate defense machinery in neutrophils and macrophages, as well as the regulatory roles of host innate responses in promoting parasite survival and replication within the huge parasitophorous vacuoles. A better understanding of unique features in host responses to these parasites at early and late stages of infection is important for the rational design of control strategies for non-healing leishmaniasis. PMID:22566939

Soong, Lynn

2012-01-01

325

Distance-dependent defensive coloration.  

PubMed

Camouflage and warning coloration are usually viewed as alternative defensive strategies at opposite ends of the conspicuousness continuum. However, camouflage is compromised by factors such as habitat heterogeneity and motion [1], and aposematism bears the cost of ineffectiveness against ignorant, hasty or nutritionally stressed predators [2]. To reduce these costs, it has been suggested that camouflage and warning coloration can be combined by the use of patterns that are detectable at different distances [3]. This hypothesis finds support in experiments on humans searching for photographs of animals on computer screens [4-6]. Using spatial frequency blending, a technique developed in computer graphics [7], we show that such distance-dependent defences are effective under field conditions against natural, avian predators. We isolate the mechanism as concealment-at-a-distance and avoidance-close-up. This supports the argument that color patterns need not be optimised for one defensive strategy, and that signals may change with viewing conditions. PMID:25514004

Barnett, James B; Cuthill, Innes C

2014-12-15

326

Independently Evolved Virulence Effectors Converge onto Hubs in a Plant Immune System Network  

PubMed Central

Plants generate effective responses to infection by recognizing both conserved and variable pathogen-encoded molecules. Pathogens deploy virulence effector proteins into host cells, where they interact physically with host proteins to modulate defense. We generated a plant-pathogen immune system protein interaction network using effectors from two pathogens spanning the eukaryote-eubacteria divergence, three classes of Arabidopsis immune system proteins and ~8,000 other Arabidopsis proteins. We noted convergence of effectors onto highly interconnected host proteins, and indirect, rather than direct, connections between effectors and plant immune receptors. We demonstrated plant immune system functions for 15 of 17 tested host proteins that interact with effectors from both pathogens. Thus, pathogens from different kingdoms deploy independently evolved virulence proteins that interact with a limited set of highly connected cellular hubs to facilitate their diverse life cycle strategies. PMID:21798943

Mukhtar, M. Shahid; Carvunis, Anne-Ruxandra; Dreze, Matija; Epple, Petra; Steinbrenner, Jens; Moore, Jonathan; Tasan, Murat; Galli, Mary; Hao, Tong; Nishimura, Marc T.; Pevzner, Samuel J.; Donovan, Susan E.; Ghamsari, Lila; Santhanam, Balaji; Romero, Viviana; Poulin, Matthew M.; Gebreab, Fana; Gutierrez, Bryan J.; Tam, Stanley; Monachello, Dario; Boxem, Mike; Harbort, Christopher J.; McDonald, Nathan; Gai, Lantian; Chen, Huaming; He, Yijian; Vandenhaute, Jean; Roth, Frederick P.; Hill, David E.; Ecker, Joseph R.; Vidal, Marc; Beynon, Jim; Braun, Pascal; Dangl, Jeffery L.

2011-01-01

327

Does AIDS involve some collusion by the neuro-immune system because of positive learning of the disarmament strategy?  

PubMed

Korzybski's general semantics recommends considering living beings as organisms-as-a-whole in their environment. Our cognitive abilities, specific to the human species, have thus to be taken into account. In this framework we establish a semantic similarity between particular stressful events of the 20th century and AIDS in which the immune-deficiency-caused is semiotically seen as a biological state of disarmament of the organism. It then appears that: These observations suggest that AIDS could benefit from some collusion by the neuro-immune system because of positive learning of the semiotic concept of disarmament, thus making the terrain favorable to the germ in response to intense stress. The disease would then result from a conditioning process based on semiotics and involve some confusion at the level of the unconscious cognitive system between disarmament toward outside the body and disarmament toward inside the body. This hypothesis is discussed within a multidisciplinary perspective considering the specificities of our modern lifestyles, the cybernetic ability of signs to control metabolism and behavior, and the recent advances of epigenetics and cognition sciences. This hypothesis may explain the multiple cross-species transmissions of the immunodeficiency virus into humans during the 20th century. Further research is suggested for evaluating this hypothesis. PMID:23317541

Sandoz, Patrick

2013-04-01

328

A comparative approach to strategies for cloning, expression, and purification of Mycobacterium tuberculosis mycolyl transferase 85B and evaluation of immune responses in BALB/c mice.  

PubMed

Protein antigens have drawn a lot of attention from investigators working on tuberculosis vaccines. These proteins can be used to improve the immunogenicity of the new generation BCG vaccines or even replace them completely. Recombinant technology is used to insure the production of pure mycobacterial antigens in high quantities. Mycolyl transferase 85B (Ag85B) is a potent, mycobacterial antigen that significantly stimulates immune responses. Since Ag85B is an apolar protein, production of the water-soluble antigen is of interest. In this work, we report a systematic optimization strategy concerning cloning systems and purification methods, aiming at increasing the yield of recombinant Ag85B. Our optimized method resulted in a yield of 8 mg of recombinant Ag85B from 1 liter of induced culture (400 ?g/ml) by using pET32a(+), Escherichia coli Rosseta-gami™(DE3) pLysS and a Ni-NTA agarose-based procedure and on-column re-solubilization. The purified recombinant Ag85B showed strong immunostimulating properties by inducing high levels of TNF-?, IFN-?, IL-12, and IgG2a in immunized mice, therefore it can effectively be applied in TB vaccine researches. PMID:24619477

Aghababa, Haniyeh; Mohabati Mobarez, Ashraf; Khoramabadi, Nima; Behmanesh, Mehrdad; Mahdavi, Mehdi; Tebianian, Majid; Nejati, Mehdi

2014-06-01

329

Male and female strategies during intergroup encounters in guerezas ( Colobus guereza ): evidence for resource defense mediated through males and a comparison with other primates  

Microsoft Academic Search

Although socioecological theory predicts that differences in male and female parental investment will be reflected in their behavior during intergroup encounters, the strategies actually pursued by adults of each sex during intergroup encounters remain poorly known for most primate species. Over an 11-month period, I examined the functions of adult male and female participation in intergroup aggression in five groups

Peter J. Fashing

2001-01-01

330

EBV, the Human Host, and the 7TM Receptors: Defense or Offense?  

PubMed

Being present in around 90% of the worldwide population, Epstein-Barr virus (EBV) is an exceptionally prevalent virus. This highly successful virus establishes a latent infection in resting memory B cells and is maintained in a balance between viral homeostasis on one side and antiviral defense of the immune system on the other side. The life cycle of EBV is dependent on many viral proteins, but EBV also regulates a number of endogenous proteins. 7TM receptors and ligands of viral and host origin are examples of such proteins. 7TM receptors are highly druggable and they are among the most popular class of investigational drug targets. The 7TM receptor encoded by EBV-BILF1, is known to downregulate cell surface MHC class I expression as part of the immune evasion strategy of EBV. However, the functional impact of the relationship between EBV and the regulated endogenous 7TM receptors and ligands is still unclear. This is for instance the case for the most upregulated 7TM receptor EBI2 (EBV-induced gene 2 or GPR183). Whereas some regulated genes have been suggested to be involved in the EBV life cycle, others could also be important for the antiviral immune defense. As many of these 7TM receptors and ligands have been shown to be modulated in EBV-associated diseases, targeting these could provide an efficient and specific way to inhibit EBV-associated disease progression. Here, we will review current knowledge on EBV infection, the immune defense against EBV and 7TM receptors and ligands being either encoded or manipulated by EBV. PMID:25595811

Arfelt, Kristine Niss; Fares, Suzan; Rosenkilde, Mette M

2015-01-01

331

Relations between different coping strategies for social stress, tumor development and neuroendocrine and immune activity in male mice.  

PubMed

This study analyzes the effects of acute social stress and different coping strategies employed in response to it on the development of B16F10 melanoma pulmonary metastases, the activation of the HPA axis and the NKG2D receptor expression. To this end, male OF1 mice were subjected to 24h of social stress using the sensorial contact model. This model includes three 5-min sessions of direct social interaction with resident cagemates selected for consistent levels of aggression. Subjects' behavior was videotaped and assessed. Six days after the first social interaction (1st social stress), the animals were inoculated with tumor cells or vehicle, and six days later, both tumor-bearing and non tumor-bearing mice were subjected to a second 24h sensorial contact social stress session (2nd social stress). One hour after the 2nd social interaction, corticosterone levels and NKG2D receptor expression were determined. Lung metastatic foci numbers were determined 21 days after inoculation (15 days post-stress). Social stress increased the number of pulmonary metastases and the serum corticosterone level. A combination of cluster and discriminant analyses established the existence of two types of coping strategies: (1) a passive-reactive strategy characterized by subjects dedicating a greater percentage of time to submission, flee and avoidance behaviors; and (2) an active-proactive strategy, characterized by subjects dedicating a greater percentage of time to attack and non social exploration behaviors. Subjects belonging to the passive-reactive group were found to have a higher number of tumor foci, a higher level of corticosterone and a lower NKG2D receptor expression than subjects in the active-proactive group. These data indicate the relationship between different coping strategies for social stress and tumor development. PMID:18061400

Azpiroz, A; De Miguel, Z; Fano, E; Vegas, O

2008-07-01

332

Chemokines: Key Players in Innate and Adaptive Immunity  

Microsoft Academic Search

Healthy individuals initiate an immediate immune response to microbes by using a set of germline-encoded receptors that recognize common molecular patterns found on the surface of pathogens that are distinct from self-antigens. This innate immune response is the first line of defense against microorganisms in vertebrates, and constitutes the only immune response in plants and invertebrates. The innate immune system

Clemens Esche; Cristiana Stellato; Lisa A. Beck

2005-01-01

333

Survival for Immunity: The Price of Immune System Activation for Bumblebee Workers  

Microsoft Academic Search

Parasites do not always harm their hosts because the immune system keeps an infection at bay. Ironically, the cost of using immune defenses could itself reduce host fitness. This indirect cost of parasitism is often not visible because of compensatory resource intake. Here, workers of the bumblebee, Bombus terrestris, were challenged with lipopolysaccharides and micro-latex beads to induce their immune

Yannick Moret; Paul Schmid-Hempel

2000-01-01

334

Strategic defense initiative: Folly or future  

SciTech Connect

This collection of analyses is a guide through the maze of claims and criticisms about ''Star Wars,'' the controversial effort of the Reagan administration to reorient United States nuclear strategy to strategic defense. The text starts with an introduction by the editors followed by individual chapters outlining the strategic defense initiative as originally conceived and subsequently modified by the Reagan administration; the arguments for and against the plan's strategic and technical feasibility; and assessments of the harmful and constructive effects of strategic defense on U.S.-Soviet and U.S.-allied relations.

Haley, P.E.; Merritt, J.

1986-01-01

335

Budgeting For Defense: Maintaining Today's Forces  

NSDL National Science Digital Library

This report from the Congressional Budget Office provides excellent background research for the current debate between the two major Presidential candidates over the American military's state of readiness. In keeping with its nonpartisan mandate, the report makes no recommendations, but it does summarize the current threats to US security, current military strategy, and the factors that drive Defense Department budgetary requests. In addition, the report offers estimates for budgetary requirements for sustaining defense capabilities at their current levels (as well as a discussion of the limitations to these estimates) and reviews alternative budget approaches, including reducing or raising defense funding.

336

Can plants use an entomopathogenic virus as a defense against herbivores?  

Microsoft Academic Search

It is by now well established that plants use various strategies to defend themselves against herbivores. Besides conventional weapons such as spines and stinging hairs and sophisticated chemical defenses, plants can also involve the enemies of the herbivores in their defense. It has been suggested that plants could even use entomopathogens as part of their defense strategies. In this paper,

Manuela van Munster; Arne Janssen; Alain Clérivet; Johannes van den Heuvel

2005-01-01

337

Dissertation Defense/Graduation  

E-print Network

Dissertation Semesters (Years 3+) Defense/Graduation Take 3 courses. T.A. for PHI 171, 172, 191, 197, or 251-writing 4) Defense Before defending, you must 1) submit a program of study and 2) request for examination

Kovalev, Leonid

338

Dissertation Defense/Graduation  

E-print Network

Dissertation Semesters (Years 3+) Defense/Graduation Fellows entering with an M.A. Take 3 or 4 courses. Take 3) Dissertation-writing 4) Defense Before defending, you must 1) submit a program of study and 2) request

Kovalev, Leonid

339

Immune Reactions Among Marine and Other Invertebrates  

ERIC Educational Resources Information Center

Discusses the defense mechanisms and immune reaction found in invertebrates, and examines the wealth of related biological problems that need study and many of the leads that have recently been developed. (JR)

Bang, Frederik B.

1973-01-01

340

Antiviral Immunity in Amphibians  

PubMed Central

Although a variety of virus species can infect amphibians, diseases caused by ranaviruses ([RVs]; Iridoviridae) have become prominent, and are a major concern for biodiversity, agriculture and international trade. The relatively recent and rapid increase in prevalence of RV infections, the wide range of host species infected by RVs, the variability in host resistance among population of the same species and among different developmental stages, all suggest an important involvement of the amphibian immune system. Nevertheless, the roles of the immune system in the etiology of viral diseases in amphibians are still poorly investigated. We review here the current knowledge of antiviral immunity in amphibians, focusing on model species such as the frog Xenopus and the salamander (Ambystoma tigrinum), and on recent progress in generating tools to better understand how host immune defenses control RV infections, pathogenicity, and transmission. PMID:22163335

Chen, Guangchun; Robert, Jacques

2011-01-01

341

Radiological Defense. Textbook.  

ERIC Educational Resources Information Center

This textbook has been prepared under the direction of the Defense Civil Preparedness Agency (DCPA) Staff College for use as a student reference manual in radiological defense (RADEF) courses. It provides much of the basic technical information necessary for a proper understanding of radiological defense and summarizes RADEF planning and expected…

Defense Civil Preparedness Agency (DOD), Washington, DC.

342

Department of Defense INSTRUCTION  

E-print Network

Department of Defense INSTRUCTION NUMBER 3210.7 May 14, 2004 USD(AT&L) SUBJECT: Research Integrity Regulations, Chapter 2, "Defense Federal Acquisition Regulation Supplement (DFARS)," current edition (e and standards for the Department of Defense for the prevention of research misconduct. This Instruction

Weston, Ken

343

Toll-like receptor control of the adaptive immune responses  

Microsoft Academic Search

Recognition of microbial infection and initiation of host defense responses is controlled by multiple mechanisms. Toll-like receptors (TLRs) have recently emerged as a key component of the innate immune system that detect microbial infection and trigger antimicrobial host defense responses. TLRs activate multiple steps in the inflammatory reactions that help to eliminate the invading pathogens and coordinate systemic defenses. In

Akiko Iwasaki; Ruslan Medzhitov

2004-01-01

344

Immune System  

MedlinePLUS

... could put us out of commission. What the Immune System Does The immune (pronounced: ih- myoon ) system, which ... Continue Things That Can Go Wrong With the Immune System Disorders of the immune system can be broken ...

345

Role of innate immunity in the pathogenesis of otitis media.  

PubMed

Otitis media (OM) is a public health problem in both developed and developing countries. It is the leading cause of hearing loss and represents a significant healthcare burden. In some cases, acute OM progresses to chronic suppurative OM (CSOM), characterized by effusion and discharge, despite antimicrobial therapy. The emergence of antibiotic resistance and potential ototoxicity of antibiotics has created an urgent need to design non-conventional therapeutic strategies against OM based on modern insights into its pathophysiology. In this article, we review the role of innate immunity as it pertains to OM and discuss recent advances in understanding the role of innate immune cells in protecting the middle ear. We also discuss the mechanisms utilized by pathogens to subvert innate immunity and thereby overcome defensive responses. A better knowledge about bacterial virulence and host resistance promises to reveal novel targets to design effective treatment strategies against OM. The identification and characterization of small natural compounds that can boost innate immunity may provide new avenues for the treatment of OM. There is also a need to design novel methods for targeted delivery of these compounds into the middle ear, allowing higher therapeutic doses and minimizing systemic side effects. PMID:25447732

Mittal, Rahul; Kodiyan, Joyson; Gerring, Robert; Mathee, Kalai; Li, Jian-Dong; Grati, M'hamed; Liu, Xue Zhong

2014-12-01

346

Alphacoronavirus Protein 7 Modulates Host Innate Immune Response  

PubMed Central

Innate immune response is the first line of antiviral defense resulting, in most cases, in pathogen clearance with minimal clinical consequences. Viruses have developed diverse strategies to subvert host defense mechanisms and increase their survival. In the transmissible gastroenteritis virus (TGEV) as a model, we previously reported that accessory gene 7 counteracts the host antiviral response by associating with the catalytic subunit of protein phosphatase 1 (PP1c). In the present work, the effect of the absence of gene 7 on the host cell, during infection, was further analyzed by transcriptomic analysis. The pattern of gene expression of cells infected with a recombinant mutant TGEV, lacking gene 7 expression (rTGEV-?7), was compared to that of cells infected with the parental virus (rTGEV-wt). Genes involved in the immune response, the interferon response, and inflammation were upregulated during TGEV infection in the absence of gene 7. An exacerbated innate immune response during infection with rTGEV-?7 virus was observed both in vitro and in vivo. An increase in macrophage recruitment and activation in lung tissues infected with rTGEV-?7 virus was observed compared to cells infected with the parental virus. In summary, the absence of protein 7 both in vitro and in vivo led to increased proinflammatory responses and acute tissue damage after infection. In a porcine animal model, which is immunologically similar to humans, we present a novel example of how viral proteins counteract host antiviral pathways to determine the infection outcome and pathogenesis. PMID:23824792

Cruz, Jazmina L. G.; Becares, Martina; Sola, Isabel; Oliveros, Juan Carlos; Zúñiga, Sonia

2013-01-01

347

Immune Effector Mechanisms Implicated in Atherosclerosis: From Mice to Humans  

PubMed Central

According to the traditional view, atherosclerosis results from a passive buildup of cholesterol in the artery wall. Yet, burgeoning evidence implicates inflammation and immune effector mechanisms in the pathogenesis of this disease. Both innate and adaptive immunity operate during atherogenesis and link many traditional risk factors to altered arterial functions. Inflammatory pathways have become targets in the quest for novel preventive and therapeutic strategies against cardiovascular disease, a growing contributor to morbidity and mortality worldwide. Here we review current experimental and clinical knowledge of the pathogenesis of atherosclerosis through an immunological lens and how host defense mechanisms essential for survival of the species actually contribute to this chronic disease but also present new opportunities for its mitigation. PMID:23809160

Libby, Peter; Lichtman, Andrew H.; Hansson, Göran K.

2013-01-01

348

Synergy of local, regional, and systemic non-specific stressors for host defense against pathogens.  

PubMed

The immune brinksmanship conceptual model postulates that many of the non-specific stressful components of the acute-phase response (e.g. fever, loss of appetite, iron and zinc sequestration) are host-derived systemic stressors used with the "hope" that pathogens will be harmed relatively more than the host. The concept proposes that pathogens, needing to grow and replicate in order to invade their host, should be relatively more vulnerable to non-specific systemic stress than the host and its cells. However, the conceptual model acknowledges the risk to the host in that the gamble to induce systemic self-harming stress to harm pathogens may not pay off in the end. We developed an agent-based model of a simplified host having a local infection to evaluate the utility of non-specific stress, harming host and pathogen alike, for host defense. With our model, we explore the benefits and risks of self-harming strategies and confirm the immune brinksmanship concept of the potential of systemic stressors to be an effective but costly host defense. Further, we extend the concept by including in our model the effects of local and regional non-specific stressors at sites of infection as additional defenses. These include the locally hostile inflammatory environment and the stress of reduced perfusion in the infected region due to coagulation and vascular leakage. In our model, we found that completely non-specific stressors at the local, regional, and systemic levels can act synergistically in host defense. PMID:25457230

Day, J D; LeGrand, E K

2015-02-21

349

The Immune System - Nobel Prize Educational Game  

NSDL National Science Digital Library

The Immune System Defender educational game, with three related readings, are based on the 1908 Nobel Prize in Physiology or Medicine, which was awarded for key discoveries about the immune defense system ÃÂ for identifying certain body cells that engulfe bacteria and for work on trying to explain how antibodies are formed in the body.

2009-01-01

350

Strategic Power Infrastructure Defense  

Microsoft Academic Search

This paper provides a comprehensive state-of-the-art overview on power infrastructure defense systems. A review of the literature on the subjects of critical infrastructures, threats to the power grids, defense system concepts, and the special protection systems is reported. The proposed Strategic Power Infrastructure Defense (SPID) system methodology is a real-time, wide-area, adaptive protection and control system involving the power, communication,

Hao Li; GARY W. ROSENWALD; JUHWAN JUNG; Chen-ching Liu

2005-01-01

351

Intracellular immunity: finding the enemy within—how cells recognize and respond to intracellular pathogens  

PubMed Central

Historically, once a cell became infected, it was considered to be beyond all help. By this stage, the invading pathogen had breached the innate defenses and was beyond the reach of the humoral arm of the adaptive immune response. The pathogen could still be removed by cell-mediated immunity (e.g., by NK cells or cytotoxic T lymphocytes), but these mechanisms necessitated the destruction of the infected cell. However, in recent years, it has become increasingly clear that many cells possess sensor and effector mechanisms for dealing with intracellular pathogens. Most of these mechanisms are not restricted to professional immune cells nor do they all necessitate the destruction of the host. In this review, we examine the strategies that cells use to detect and destroy pathogens once the cell membrane has been penetrated. PMID:24899588

Tam, Jerry C. H.; Jacques, David A.

2014-01-01

352

Intracellular immunity: finding the enemy within--how cells recognize and respond to intracellular pathogens.  

PubMed

Historically, once a cell became infected, it was considered to be beyond all help. By this stage, the invading pathogen had breached the innate defenses and was beyond the reach of the humoral arm of the adaptive immune response. The pathogen could still be removed by cell-mediated immunity (e.g., by NK cells or cytotoxic T lymphocytes), but these mechanisms necessitated the destruction of the infected cell. However, in recent years, it has become increasingly clear that many cells possess sensor and effector mechanisms for dealing with intracellular pathogens. Most of these mechanisms are not restricted to professional immune cells nor do they all necessitate the destruction of the host. In this review, we examine the strategies that cells use to detect and destroy pathogens once the cell membrane has been penetrated. PMID:24899588

Tam, Jerry C H; Jacques, David A

2014-08-01

353

Molecular mechanisms of epithelial host defense in the airways  

Microsoft Academic Search

Airway epithelial cells are indispensable for the host defense system in the lungs. Various strategies by which epithelial cells protect the lungs against inhaled pathogens have been described. In spite of that, the molecular mechanisms by which epithelial cells initiate and control the host defense response have not been explored systematically. In this thesis, the molecular mechanisms underlying the initiation

Joost Bastiaan Vos

2007-01-01

354

Hormone defense networking in rice: tales from a different world.  

PubMed

Recent advances in plant immunity research underpin the pivotal role of small-molecule hormones in regulating the plant defense signaling network. Although most of our understanding comes from studies of dicot plants such as Arabidopsis thaliana, new studies in monocots are providing additional insights into the defense-regulatory role of phytohormones. Here, we review the roles of both classical and more recently identified stress hormones in regulating immunity in the model monocot rice (Oryza sativa) and highlight the importance of hormone crosstalk in shaping the outcome of rice-pathogen interactions. We also propose a defense model for rice that does not support a dichotomy between the pathogen lifestyle and the effectiveness of the archetypal defense hormones salicylic acid (SA) and jasmonic acid (JA). PMID:23910453

De Vleesschauwer, David; Gheysen, Godelieve; Höfte, Monica

2013-10-01

355

BIOLOGICAL MEDIATORS OF INSECT IMMUNITY  

Microsoft Academic Search

Infection in insects stimulates a complex defensive response. Recognition of pathogens may be accomplished by plasma or hemocyte proteins that bind specif- ically to bacterial or fungal polysaccharides. Several morphologically distinct hemocyte cell types cooperate in the immune response. Hemocytes attach to invading organisms and then isolate them by phagocytosis, by trapping them in hemocyte aggregates called nodules, or by

Jeremy P. Gillespie; Michael R. Kanost; Tina Trenczek

1997-01-01

356

Xanthomonas campestris lipooligosaccharides trigger innate immunity and oxidative burst in Arabidopsis.  

PubMed

Plants lack the adaptive immunity mechanisms of jawed vertebrates, so they rely on innate immune responses to defense themselves from pathogens. The plant immune system perceives the presence of pathogens by recognition of molecules known as pathogen-associated molecular patterns (PAMPs). PAMPs have several common characteristics, including highly conserved structures, essential for the microorganism but absent in host organisms. Plants can specifically recognize PAMPs using a large set of receptors and can respond with appropriate defenses by activating a multicomponent and multilayered response. Lipopolysaccharides (LPSs) and lipooligosaccharides (LOSs) are major components of the cell surface of Gram-negative bacteria with diverse roles in bacterial pathogenesis of animals and plants that include elicitation of host defenses. Little is known on the mechanisms of perception of these molecules by plants and the associated signal transduction pathways that trigger plant immunity. Here we addressed the question whether the defense signaling pathway in Arabidopsis thaliana was triggered by LOS from Xanthomonas campestris pv. campestris (Xcc), using proteomic and transcriptomic approaches. By using affinity capture strategies with immobilized LOS and LC-MS/MS analyses, we identified 8 putative LOS protein ligands. Further investigation of these interactors led to the definition that LOS challenge is able to activate a signal transduction pathway that uses nodal regulators in common with salicylic acid-mediated pathway. Moreover, we proved evidence that Xcc LOS are responsible for oxidative burst in Arabidopsis either in infiltrated or systemic leaves. In addition, gene expression studies highlighted the presence of gene network involved in reactive oxygen species transduction pathway. PMID:25394800

Proietti, S; Giangrande, C; Amoresano, A; Pucci, P; Molinaro, A; Bertini, L; Caporale, C; Caruso, C

2014-10-22

357

Dynamics of Defense Responses and Cell Fate Change during Arabidopsis-Pseudomonas syringae Interactions  

PubMed Central

Plant-pathogen interactions involve sophisticated action and counteraction strategies from both parties. Plants can recognize pathogen derived molecules, such as conserved pathogen associated molecular patterns (PAMPs) and effector proteins, and subsequently activate PAMP-triggered immunity (PTI) and effector-triggered immunity (ETI), respectively. However, pathogens can evade such recognitions and suppress host immunity with effectors, causing effector-triggered susceptibility (ETS). The differences among PTI, ETS, and ETI have not been completely understood. Toward a better understanding of PTI, ETS, and ETI, we systematically examined various defense-related phenotypes of Arabidopsis infected with different Pseudomonas syringae pv. maculicola ES4326 strains, using the virulence strain DG3 to induce ETS, the avirulence strain DG34 that expresses avrRpm1 (recognized by the resistance protein RPM1) to induce ETI, and HrcC- that lacks the type three secretion system to activate PTI. We found that plants infected with different strains displayed dynamic differences in the accumulation of the defense signaling molecule salicylic acid, expression of the defense marker gene PR1, cell death formation, and accumulation/localization of the reactive oxygen species, H2O2. The differences between PTI, ETS, and ETI are dependent on the doses of the strains used. These data support the quantitative nature of PTI, ETS, and ETI and they also reveal qualitative differences between PTI, ETS, and ETI. Interestingly, we observed the induction of large cells in the infected leaves, most obviously with HrcC- at later infection stages. The enlarged cells have increased DNA content, suggesting a possible activation of endoreplication. Consistent with strong induction of abnormal cell growth by HrcC-, we found that the PTI elicitor flg22 also activates abnormal cell growth, depending on a functional flg22-receptor FLS2. Thus, our study has revealed a comprehensive picture of dynamic changes of defense phenotypes and cell fate determination during Arabidopsis-P. syringae interactions, contributing to a better understanding of plant defense mechanisms. PMID:24349466

Hamdoun, Safae; Liu, Zhe; Gill, Manroop; Yao, Nan; Lu, Hua

2013-01-01

358

Dynamics of defense responses and cell fate change during Arabidopsis-Pseudomonas syringae interactions.  

PubMed

Plant-pathogen interactions involve sophisticated action and counteraction strategies from both parties. Plants can recognize pathogen derived molecules, such as conserved pathogen associated molecular patterns (PAMPs) and effector proteins, and subsequently activate PAMP-triggered immunity (PTI) and effector-triggered immunity (ETI), respectively. However, pathogens can evade such recognitions and suppress host immunity with effectors, causing effector-triggered susceptibility (ETS). The differences among PTI, ETS, and ETI have not been completely understood. Toward a better understanding of PTI, ETS, and ETI, we systematically examined various defense-related phenotypes of Arabidopsis infected with different Pseudomonas syringae pv. maculicola ES4326 strains, using the virulence strain DG3 to induce ETS, the avirulence strain DG34 that expresses avrRpm1 (recognized by the resistance protein RPM1) to induce ETI, and HrcC(-) that lacks the type three secretion system to activate PTI. We found that plants infected with different strains displayed dynamic differences in the accumulation of the defense signaling molecule salicylic acid, expression of the defense marker gene PR1, cell death formation, and accumulation/localization of the reactive oxygen species, H2O2. The differences between PTI, ETS, and ETI are dependent on the doses of the strains used. These data support the quantitative nature of PTI, ETS, and ETI and they also reveal qualitative differences between PTI, ETS, and ETI. Interestingly, we observed the induction of large cells in the infected leaves, most obviously with HrcC(-) at later infection stages. The enlarged cells have increased DNA content, suggesting a possible activation of endoreplication. Consistent with strong induction of abnormal cell growth by HrcC(-), we found that the PTI elicitor flg22 also activates abnormal cell growth, depending on a functional flg22-receptor FLS2. Thus, our study has revealed a comprehensive picture of dynamic changes of defense phenotypes and cell fate determination during Arabidopsis-P. syringae interactions, contributing to a better understanding of plant defense mechanisms. PMID:24349466

Hamdoun, Safae; Liu, Zhe; Gill, Manroop; Yao, Nan; Lu, Hua

2013-01-01

359

The cell-mediated immunity of Drosophila melanogaster: hemocyte lineages, immune compartments, microanatomy and regulation.  

PubMed

In the animal kingdom, innate immunity is the first line of defense against invading pathogens. The dangers of microbial and parasitic attacks are countered by similar mechanisms, involving the prototypes of the cell-mediated immune responses, the phagocytosis and encapsulation. Work on Drosophila has played an important role in promoting an understanding of the basic mechanisms of phylogenetically conserved modules of innate immunity. The aim of this review is to survey the developments in the identification and functional definition of immune cell types and the immunological compartments of Drosophila melanogaster. We focus on the molecular and developmental aspects of the blood cell types and compartments, as well as the dynamics of blood cell development and the immune response. Further advances in the characterization of the innate immune mechanisms in Drosophila will provide basic clues to the understanding of the importance of the evolutionary conserved mechanisms of innate immune defenses in the animal kingdom. PMID:23800719

Honti, Viktor; Csordás, Gábor; Kurucz, Éva; Márkus, Róbert; Andó, István

2014-01-01

360

Abstract--The safe operation of electrical power systems is an ongoing problem. Despite the existing defense lines in the  

E-print Network

the existing defense lines in the different electrical systems, they are not immune to widespread incidents leading to tripping of most consumers. In the defense plans against these major incidents, selective load]. In this context, we can imagine a defense system based on an intelligent SLS. The objective of this study

Paris-Sud XI, Université de

361

The hnRNP-Q protein LIF2 participates in the plant immune response.  

PubMed

Eukaryotes have evolved complex defense pathways to combat invading pathogens. Here, we investigated the role of the Arabidopsis thaliana heterogeneous nuclear ribonucleoprotein (hnRNP-Q) LIF2 in the plant innate immune response. We show that LIF2 loss-of-function in A. thaliana leads to changes in the basal expression of the salicylic acid (SA)- and jasmonic acid (JA)- dependent defense marker genes PR1 and PDF1.2, respectively. Whereas the expression of genes involved in SA and JA biosynthesis and signaling was also affected in the lif2-1 mutant, no change in SA and JA hormonal contents was detected. In addition, the composition of glucosinolates, a class of defense-related secondary metabolites, was altered in the lif2-1 mutant in the absence of pathogen challenge. The lif2-1 mutant exhibited reduced susceptibility to the hemi-biotrophic pathogen Pseudomonas syringae and the necrotrophic ascomycete Botrytis cinerea. Furthermore, the lif2-1 sid2-2 double mutant was less susceptible than the wild type to P. syringae infection, suggesting that the lif2 response to pathogens was independent of SA accumulation. Together, our data suggest that lif2-1 exhibits a basal primed defense state, resulting from complex deregulation of gene expression, which leads to increased resistance to pathogens with various infection strategies. Therefore, LIF2 may function as a suppressor of cell-autonomous immunity. Similar to its human homolog, NSAP1/SYNCRIP, a trans-acting factor involved in both cellular processes and the viral life cycle, LIF2 may regulate the conflicting aspects of development and defense programs, suggesting that a conserved evolutionary trade-off between growth and defense pathways exists in eukaryotes. PMID:24914891

Le Roux, Clémentine; Del Prete, Stefania; Boutet-Mercey, Stéphanie; Perreau, François; Balagué, Claudine; Roby, Dominique; Fagard, Mathilde; Gaudin, Valérie

2014-01-01

362

Immune Restoration  

MedlinePLUS

... marrow cells immune to HIV infection. Letting the immune system repair itself: CD4 counts have increased for many ... have taken ART. Some scientists believe that the immune system might be able to heal and repair itself ...

363

Induction of antitumor immunity through xenoplacental immunization  

PubMed Central

Historically cancer vaccines have yielded suboptimal clinical results. We have developed a novel strategy for eliciting antitumor immunity based upon homology between neoplastic tissue and the developing placenta. Placenta formation shares several key processes with neoplasia, namely: angiogenesis, activation of matrix metalloproteases, and active suppression of immune function. Immune responses against xenoantigens are well known to break self-tolerance. Utilizing xenogeneic placental protein extracts as a vaccine, we have successfully induced anti-tumor immunity against B16 melanoma in C57/BL6 mice, whereas control xenogeneic extracts and B16 tumor extracts where ineffective, or actually promoted tumor growth, respectively. Furthermore, dendritic cells were able to prime tumor immunity when pulsed with the placental xenoantigens. While vaccination-induced tumor regression was abolished in mice depleted of CD4 T cells, both CD4 and CD8 cells were needed to adoptively transfer immunity to naïve mice. Supporting the role of CD8 cells in controlling tumor growth are findings that only freshly isolated CD8 cells from immunized mice were capable of inducing tumor cell caspases-3 activation ex vivo. These data suggest feasibility of using xenogeneic placental preparations as a multivalent vaccine potently targeting not just tumor antigens, but processes that are essential for tumor maintenance of malignant potential. PMID:16725035

Zhong, Zhaohui; Kusznieruk, Kornel P; Popov, Igor A; Riordan, Neil H; Izadi, Hamid; Yijian, Li; Sher, Salman; Szczurko, Orest M; Agadjanyan, Michael G; Tullis, Richard H; Harandi, Amir; Reznik, Boris N; Mamikonyan, Grigor V; Ichim, Thomas E

2006-01-01

364

Active and passive immunization strategies based on the SDPM1 peptide demonstrate pre-clinical efficacy in the APPswePSEN1dE9 mouse model for Alzheimer’s disease  

PubMed Central

Recent clinical and pre-clinical studies suggest that both active and passive immunization strategies targeting A? amyloid may have clinical benefit in Alzheimer’s disease. Here, we demonstrate that vaccination of APPswePSEN1dE9 mice with SDPM1, an engineered non-native A? amyloid-specific binding peptide, lowers brain A? amyloid plaque burden and brain A?1-40 and A?1-42 peptide levels, improves cognitive learning and memory in Morris Water maze tests and increases the expression of synaptic brain proteins. This was the case in young mice immunized prior to development of significant brain amyloid burden, and in older mice, where brain amyloid was already present. Active immunization was optimized using ALUM as an adjuvant to stimulate production of anti-SDPM1 and anti-A? amyloid antibodies. Intracerebral injection of P4D6, an SDPM1 peptide-mimotope antibody, also lowered brain amyloid plaque burden in APPswePSEN1dE9 mice. Additionally, P4D6 inhibited A? amyloid-mediated toxicity in cultured neuronal cells. The protein sequence of the variable domain within the P4D6 heavy chain was found to mimic a multimer of the SDPM1 peptide motif. These data demonstrate the efficacy of active and passive vaccine strategies to target specific A? amyloid oligomers using an engineered peptide-mimotope strategy. PMID:24021662

Camboni, Marybeth; Wang, Chiou-Miin; Miranda, Carlos; Yoon, Jung Hae; Xu, Rui; Zygmunt, Deborah; Kaspar, Brian K.; Martin, Paul T.

2013-01-01

365

Immunization of epidemics in multiplex networks.  

PubMed

Up to now, immunization of disease propagation has attracted great attention in both theoretical and experimental researches. However, vast majority of existing achievements are limited to the simple assumption of single layer networked population, which seems obviously inconsistent with recent development of complex network theory: each node could possess multiple roles in different topology connections. Inspired by this fact, we here propose the immunization strategies on multiplex networks, including multiplex node-based random (targeted) immunization and layer node-based random (targeted) immunization. With the theory of generating function, theoretical analysis is developed to calculate the immunization threshold, which is regarded as the most critical index for the effectiveness of addressed immunization strategies. Interestingly, both types of random immunization strategies show more efficiency in controlling disease spreading on multiplex Erdös-Rényi (ER) random networks; while targeted immunization strategies provide better protection on multiplex scale-free (SF) networks. PMID:25401755

Zhao, Dawei; Wang, Lianhai; Li, Shudong; Wang, Zhen; Wang, Lin; Gao, Bo

2014-01-01

366

Immunization of Epidemics in Multiplex Networks  

PubMed Central

Up to now, immunization of disease propagation has attracted great attention in both theoretical and experimental researches. However, vast majority of existing achievements are limited to the simple assumption of single layer networked population, which seems obviously inconsistent with recent development of complex network theory: each node could possess multiple roles in different topology connections. Inspired by this fact, we here propose the immunization strategies on multiplex networks, including multiplex node-based random (targeted) immunization and layer node-based random (targeted) immunization. With the theory of generating function, theoretical analysis is developed to calculate the immunization threshold, which is regarded as the most critical index for the effectiveness of addressed immunization strategies. Interestingly, both types of random immunization strategies show more efficiency in controlling disease spreading on multiplex Erdös-Rényi (ER) random networks; while targeted immunization strategies provide better protection on multiplex scale-free (SF) networks. PMID:25401755

Zhao, Dawei; Wang, Lianhai; Li, Shudong; Wang, Zhen; Wang, Lin; Gao, Bo

2014-01-01

367

14 CFR 297.23 - Waiver of sovereign immunity.  

Code of Federal Regulations, 2011 CFR

...2011-01-01 false Waiver of sovereign immunity. 297.23 Section 297.23 Aeronautics...Associations § 297.23 Waiver of sovereign immunity. By accepting an approval registration...possess to assert any defense of sovereign immunity from suit in any action or...

2011-01-01

368

14 CFR 380.67 - Waiver of sovereign immunity.  

Code of Federal Regulations, 2012 CFR

...2012-01-01 false Waiver of sovereign immunity. 380.67 Section 380.67 Aeronautics...Operators § 380.67 Waiver of sovereign immunity. By accepting an approved registration...have to assert any defense of sovereign immunity from suit in any proceeding against...

2012-01-01

369

14 CFR 297.23 - Waiver of sovereign immunity.  

Code of Federal Regulations, 2010 CFR

...2010-01-01 false Waiver of sovereign immunity. 297.23 Section 297.23 Aeronautics...Associations § 297.23 Waiver of sovereign immunity. By accepting an approval registration...possess to assert any defense of sovereign immunity from suit in any action or...

2010-01-01

370

14 CFR 297.23 - Waiver of sovereign immunity.  

...2014-01-01 false Waiver of sovereign immunity. 297.23 Section 297.23 Aeronautics...Associations § 297.23 Waiver of sovereign immunity. By accepting an approval registration...possess to assert any defense of sovereign immunity from suit in any action or...

2014-01-01

371

14 CFR 294.80 - Waiver of sovereign immunity.  

Code of Federal Regulations, 2012 CFR

...2012-01-01 false Waiver of sovereign immunity. 294.80 Section 294.80 Aeronautics...Part § 294.80 Waiver of sovereign immunity. By accepting an approved registration...possess to assert any defense of sovereign immunity in any action or proceeding...

2012-01-01

372

14 CFR 294.80 - Waiver of sovereign immunity.  

Code of Federal Regulations, 2010 CFR

...2010-01-01 false Waiver of sovereign immunity. 294.80 Section 294.80 Aeronautics...Part § 294.80 Waiver of sovereign immunity. By accepting an approved registration...possess to assert any defense of sovereign immunity in any action or proceeding...

2010-01-01

373

14 CFR 380.67 - Waiver of sovereign immunity.  

Code of Federal Regulations, 2011 CFR

...2011-01-01 false Waiver of sovereign immunity. 380.67 Section 380.67 Aeronautics...Operators § 380.67 Waiver of sovereign immunity. By accepting an approved registration...have to assert any defense of sovereign immunity from suit in any proceeding against...

2011-01-01

374

14 CFR 375.26 - Waiver of sovereign immunity.  

...2014-01-01 false Waiver of sovereign immunity. 375.26 Section 375.26 Aeronautics...Applicable § 375.26 Waiver of sovereign immunity. Owners and operators of aircraft...activities waive any defense of sovereign immunity from suit in any action or...

2014-01-01

375

14 CFR 375.26 - Waiver of sovereign immunity.  

Code of Federal Regulations, 2013 CFR

...2013-01-01 false Waiver of sovereign immunity. 375.26 Section 375.26 Aeronautics...Applicable § 375.26 Waiver of sovereign immunity. Owners and operators of aircraft...activities waive any defense of sovereign immunity from suit in any action or...

2013-01-01

376

14 CFR 294.80 - Waiver of sovereign immunity.  

Code of Federal Regulations, 2013 CFR

...2013-01-01 false Waiver of sovereign immunity. 294.80 Section 294.80 Aeronautics...Part § 294.80 Waiver of sovereign immunity. By accepting an approved registration...possess to assert any defense of sovereign immunity in any action or proceeding...

2013-01-01

377

14 CFR 294.80 - Waiver of sovereign immunity.  

...2014-01-01 false Waiver of sovereign immunity. 294.80 Section 294.80 Aeronautics...Part § 294.80 Waiver of sovereign immunity. By accepting an approved registration...possess to assert any defense of sovereign immunity in any action or proceeding...

2014-01-01

378

14 CFR 297.23 - Waiver of sovereign immunity.  

Code of Federal Regulations, 2013 CFR

...2013-01-01 false Waiver of sovereign immunity. 297.23 Section 297.23 Aeronautics...Associations § 297.23 Waiver of sovereign immunity. By accepting an approval registration...possess to assert any defense of sovereign immunity from suit in any action or...

2013-01-01

379

14 CFR 294.80 - Waiver of sovereign immunity.  

Code of Federal Regulations, 2011 CFR

...2011-01-01 false Waiver of sovereign immunity. 294.80 Section 294.80 Aeronautics...Part § 294.80 Waiver of sovereign immunity. By accepting an approved registration...possess to assert any defense of sovereign immunity in any action or proceeding...

2011-01-01

380

14 CFR 375.26 - Waiver of sovereign immunity.  

Code of Federal Regulations, 2012 CFR

...2012-01-01 false Waiver of sovereign immunity. 375.26 Section 375.26 Aeronautics...Applicable § 375.26 Waiver of sovereign immunity. Owners and operators of aircraft...activities waive any defense of sovereign immunity from suit in any action or...

2012-01-01

381

14 CFR 375.26 - Waiver of sovereign immunity.  

Code of Federal Regulations, 2011 CFR

...2011-01-01 false Waiver of sovereign immunity. 375.26 Section 375.26 Aeronautics...Applicable § 375.26 Waiver of sovereign immunity. Owners and operators of aircraft...activities waive any defense of sovereign immunity from suit in any action or...

2011-01-01

382

14 CFR 375.26 - Waiver of sovereign immunity.  

Code of Federal Regulations, 2010 CFR

...2010-01-01 false Waiver of sovereign immunity. 375.26 Section 375.26 Aeronautics...Applicable § 375.26 Waiver of sovereign immunity. Owners and operators of aircraft...activities waive any defense of sovereign immunity from suit in any action or...

2010-01-01

383

14 CFR 380.67 - Waiver of sovereign immunity.  

Code of Federal Regulations, 2013 CFR

...2013-01-01 false Waiver of sovereign immunity. 380.67 Section 380.67 Aeronautics...Operators § 380.67 Waiver of sovereign immunity. By accepting an approved registration...have to assert any defense of sovereign immunity from suit in any proceeding against...

2013-01-01

384

14 CFR 297.23 - Waiver of sovereign immunity.  

Code of Federal Regulations, 2012 CFR

...2012-01-01 false Waiver of sovereign immunity. 297.23 Section 297.23 Aeronautics...Associations § 297.23 Waiver of sovereign immunity. By accepting an approval registration...possess to assert any defense of sovereign immunity from suit in any action or...

2012-01-01

385

14 CFR 380.67 - Waiver of sovereign immunity.  

Code of Federal Regulations, 2010 CFR

...2010-01-01 false Waiver of sovereign immunity. 380.67 Section 380.67 Aeronautics...Operators § 380.67 Waiver of sovereign immunity. By accepting an approved registration...have to assert any defense of sovereign immunity from suit in any proceeding against...

2010-01-01

386

14 CFR 380.67 - Waiver of sovereign immunity.  

...2014-01-01 false Waiver of sovereign immunity. 380.67 Section 380.67 Aeronautics...Operators § 380.67 Waiver of sovereign immunity. By accepting an approved registration...have to assert any defense of sovereign immunity from suit in any proceeding against...

2014-01-01

387

Skunk Defensive Secretion  

NSDL National Science Digital Library

Skunk Defensive Secretion is a interesting site maintained by William F. Wood from the Department of Chemistry at Humboldt State University. He explains how to remove skunk odor, the chemistry of skunk spray, the history of skunk defensive secretion research, skunk pictures, and even how to happily coexist with skunks. This is a fun, informative, and potentially olfactory friendly site.

Wood, William F.

1999-01-01

388

Defense Mechanisms: A Bibliography.  

ERIC Educational Resources Information Center

This bibliography includes studies of defense mechanisms, in general, and studies of multiple mechanisms. Defense mechanisms, briefly and simply defined, are the unconscious ego defendants against unpleasure, threat, or anxiety. Sigmund Freud deserves the clinical credit for studying many mechanisms and introducing them in professional literature.…

Pedrini, D. T.; Pedrini, Bonnie C.

389

Forgiveness and Defense Style  

ERIC Educational Resources Information Center

Within the literature on the psychology of forgiveness, researchers have hypothesized that the 1st stage in the process of being able to forgive is the role of psychological defense. To examine such a hypothesis, the authors explored the relationship between forgiveness and defense style. The 304 respondents (151 men, 153 women) completed measures…

Maltby, John; Day, Liz

2004-01-01

390

The Economics of Defense  

Microsoft Academic Search

This compelling book provides an up-to-date survey of the field of defense economics, the study of defense and peace issues, with the application of economic analysis and methods. The subject embraces both microeconomics and macroeconomics, taking into account such features as growth theory, comparative statistics, game theory and econometrics. A wide range of topics are addressed, including all aspects of

Todd Sandler; Keith Hartley

1995-01-01

391

Glutamate Utilization Couples Oxidative Stress Defense and the Tricarboxylic Acid Cycle in Francisella Phagosomal Escape  

PubMed Central

Intracellular bacterial pathogens have developed a variety of strategies to avoid degradation by the host innate immune defense mechanisms triggered upon phagocytocis. Upon infection of mammalian host cells, the intracellular pathogen Francisella replicates exclusively in the cytosolic compartment. Hence, its ability to escape rapidly from the phagosomal compartment is critical for its pathogenicity. Here, we show for the first time that a glutamate transporter of Francisella (here designated GadC) is critical for oxidative stress defense in the phagosome, thus impairing intra-macrophage multiplication and virulence in the mouse model. The gadC mutant failed to efficiently neutralize the production of reactive oxygen species. Remarkably, virulence of the gadC mutant was partially restored in mice defective in NADPH oxidase activity. The data presented highlight links between glutamate uptake, oxidative stress defense, the tricarboxylic acid cycle and phagosomal escape. This is the first report establishing the role of an amino acid transporter in the early stage of the Francisella intracellular lifecycle. PMID:24453979

Ramond, Elodie; Gesbert, Gael; Rigard, Mélanie; Dairou, Julien; Dupuis, Marion; Dubail, Iharilalao; Meibom, Karin; Henry, Thomas; Barel, Monique; Charbit, Alain

2014-01-01

392

Seaweed resistance to microbial attack: A targeted chemical defense against marine fungi  

PubMed Central

Pathogenic microbes can devastate populations of marine plants and animals. Yet, many sessile organisms such as seaweeds and sponges suffer remarkably low levels of microbial infection, despite lacking cell-based immune systems. Antimicrobial defenses of marine organisms are largely uncharacterized, although from a small number of studies it appears that chemical defenses may improve host resistance. In this study, we asked whether the common seaweed Lobophora variegata is chemically defended against potentially deleterious microorganisms. Using bioassay-guided fractionation, we isolated and characterized a 22-membered cyclic lactone, lobophorolide (1), of presumed polyketide origin, with sub-?M activity against pathogenic and saprophytic marine fungi. Deterrent concentrations of 1 were found in 46 of 51 samples collected from 10 locations in the Bahamas over a 4-year period. Lobophorolide (1) is structurally unprecedented, yet parts of the molecule are related to tolytoxin, the scytophycins, and the swinholides, macrolides previously isolated from terrestrial cyanobacteria and from marine sponges and gastropods. Until now, compounds of this structural class have not been associated with marine macrophytes. Our findings suggest that seaweeds use targeted antimicrobial chemical defense strategies and that secondary metabolites important in the ecological interactions between marine macroorganisms and microorganisms could be a promising source of novel bioactive compounds. PMID:12756301

Kubanek, Julia; Jensen, Paul R.; Keifer, Paul A.; Sullards, M. Cameron; Collins, Dwight O.; Fenical, William

2003-01-01

393

Mechanisms of plant defense against insect herbivores  

PubMed Central

Plants respond to herbivory through various morphological, biochemicals, and molecular mechanisms to counter/offset the effects of herbivore attack. The biochemical mechanisms of defense against the herbivores are wide-ranging, highly dynamic, and are mediated both by direct and indirect defenses. The defensive compounds are either produced constitutively or in response to plant damage, and affect feeding, growth, and survival of herbivores. In addition, plants also release volatile organic compounds that attract the natural enemies of the herbivores. These strategies either act independently or in conjunction with each other. However, our understanding of these defensive mechanisms is still limited. Induced resistance could be exploited as an important tool for the pest management to minimize the amounts of insecticides used for pest control. Host plant resistance to insects, particularly, induced resistance, can also be manipulated with the use of chemical elicitors of secondary metabolites, which confer resistance to insects. By understanding the mechanisms of induced resistance, we can predict the herbivores that are likely to be affected by induced responses. The elicitors of induced responses can be sprayed on crop plants to build up the natural defense system against damage caused by herbivores. The induced responses can also be engineered genetically, so that the defensive compounds are constitutively produced in plants against are challenged by the herbivory. Induced resistance can be exploited for developing crop cultivars, which readily produce the inducible response upon mild infestation, and can act as one of components of integrated pest management for sustainable crop production. PMID:22895106

War, Abdul Rashid; Paulraj, Michael Gabriel; Ahmad, Tariq; Buhroo, Abdul Ahad; Hussain, Barkat; Ignacimuthu, Savarimuthu; Sharma, Hari Chand

2012-01-01

394

GRADUATE COLLEGE ORAL DEFENSE RESULTS  

E-print Network

GRADUATE COLLEGE ORAL DEFENSE RESULTS THESIS, DISSERTATION/MUSIC DOCUMENT, PROFESSIONAL: Phone: MEANS OF PUBLICIZING ORAL DEFENSE Department email Posted flyer UNLV Today Department website GPSA/GPSA Lounge Other (specify): Date: ORAL DEFENSE

Cho, Hokwon

395

Earthworm immune responses.  

PubMed

The knowledge of the immunity in annelids started with the use of earthworms as biomarkers indicating changes caused by environmental pollution. Defence strategies effectively protect earthworms against bacterial infections and parasitic invasion. A natural immunity formed by anatomical and chemical protective barriers prevents damage of the underlying tissues, body fluid losses, and microbial infections of the body cavity. The internal defence mechanisms of annelids involve phagocytosis, nodule formation and encapsulation, blood coagulation and wound repair, and antibacterial immune proteins. The antibacterial activity of coelomic fluid associated with lysozyme-like substances and inducible humoral molecules support haemocytic reactions in the annelid defence system. PMID:9557138

Jarosz, J; Gli?ski, Z

1997-01-01

396

Dynamic Imaging of the Effector Immune Response to Listeria Infection In Vivo  

E-print Network

Host defense against the intracellular pathogen Listeria monocytogenes (Lm) requires innate and adaptive immunity. Here, we directly imaged immune cell dynamics at Lm foci established by dendritic cells in the subcapsular ...

Waite, Janelle C.

397

Simultaneous targeting of toll- and nod-like receptors induces effective tumor-specific immune responses.  

PubMed

Toll-like receptor (TLR) ligands are increasingly being used as adjuvants in cancer vaccine trials to harness innate immunity and prime effective antitumor immune responses. Despite some success, enhancing tumor antigen presentation, promoting a protective antitumor response, and overcoming the immunosuppressive tumor microenvironment pose considerable challenges that necessitate further improvements in vaccine design. Here, we show that expression of the TLR ligand flagellin within tumor cells constitutes an effective antitumor vaccination strategy that relies on simultaneous engagement of TLR5 and the Nod-like receptors (NLRs) NLRC4/NAIP5 (neuronal apoptosis inhibitory protein 5) by flagellin along with associative recognition of tumor antigen for optimal antigen presentation to T cells. Although TLR5 signaling was critical for mediating rapid macrophage-dependent clearance of flagellin-expressing tumor cells in vivo, TLR5 and NLRC4/NAIP5 were equally important for priming antitumor CD4(+) and CD8(+) T cells and suppressing tumor growth. Vaccination with irradiated flagellin-expressing tumor cells prevented tumor development, and disrupting flagellin recognition by TLR5 or NLRC4/NAIP5 impaired protective immunization against an existing or subsequent tumor. Our findings delineate a new strategy to induce anticancer immune responses consisting of introducing microbial structures with dual TLR and NLR stimulatory activity into tumor cells. This ensures recognition of tumor-derived antigen within the inflammatory context of microbial recognition and additionally activates both the phagocytic and the cytosolic pathways of innate immune defense against the tumor. PMID:22323829

Garaude, Johan; Kent, Andrew; van Rooijen, Nico; Blander, J Magarian

2012-02-01

398

Nitroaspirin corrects immune dysfunction in tumor-bearing hosts and promotes tumor eradication by cancer vaccination  

NASA Astrophysics Data System (ADS)

Active suppression of tumor-specific T lymphocytes can limit the immune-mediated destruction of cancer cells. Of the various strategies used by tumors to counteract immune attacks, myeloid suppressors recruited by growing cancers are particularly efficient, often resulting in the induction of systemic T lymphocyte dysfunction. We have previously shown that the mechanism by which myeloid cells from tumor-bearing hosts block immune defense strategies involves two enzymes that metabolize L-arginine: arginase and nitric oxide (NO) synthase. NO-releasing aspirin is a classic aspirin molecule covalently linked to a NO donor group. NO aspirin does not possess direct antitumor activity. However, by interfering with the inhibitory enzymatic activities of myeloid cells, orally administered NO aspirin normalized the immune status of tumor-bearing hosts, increased the number and function of tumor-antigen-specific T lymphocytes, and enhanced the preventive and therapeutic effectiveness of the antitumor immunity elicited by cancer vaccination. Because cancer vaccines and NO aspirin are currently being investigated in independent phase I/II clinical trials, these findings offer a rationale to combine these treatments in subjects with advanced neoplastic diseases. arginase | immunosuppression | myeloid cells | nitric oxide | immunotherapy

de Santo, Carmela; Serafini, Paolo; Marigo, Ilaria; Dolcetti, Luigi; Bolla, Manlio; del Soldato, Piero; Melani, Cecilia; Guiducci, Cristiana; Colombo, Mario P.; Iezzi, Manuela; Musiani, Piero; Zanovello, Paola; Bronte, Vincenzo

2005-03-01

399

Geographic distribution of the anti-parasite trait "slave rebellion" and potential costs of the defense  

E-print Network

of parasite pressure, host species have developed a variety of defensive strategies that limit the impact of parasites. Such defensive adaptations on the host side can lead to counter-adaptations of parasites of the defense TOBIAS PAMMINGER*,, ANNETTE LEINGÃ?RTNER; ALEXANDRA ACHENBACH, PLEUNI S. PENNINGS# AND SUSANNE

400

Directed energy planetary defense  

NASA Astrophysics Data System (ADS)

Asteroids and comets that cross Earth's orbit pose a credible risk of impact, with potentially severe disturbances to Earth and society. Numerous risk mitigation strategies have been described, most involving dedicated missions to a threatening object. We propose an orbital planetary defense system capable of heating the surface of potentially hazardous objects to the vaporization point as a feasible approach to impact risk mitigation. We call the system DE-STAR for Directed Energy System for Targeting of Asteroids and exploRation. DE-STAR is a modular phased array of kilowatt class lasers powered by photovoltaic's. Modular design allows for incremental development, test, and initial deployment, lowering cost, minimizing risk, and allowing for technological co-development, leading eventually to an orbiting structure that would be developed in stages with both technological and target milestones. The main objective of DE-STAR is to use the focused directed energy to raise the surface spot temperature to ~3,000K, allowing direct vaporization of all known substances. In the process of heating the surface ejecting evaporated material a large reaction force would alter the asteroid's orbit. The baseline system is a DE-STAR 3 or 4 (1-10km array) depending on the degree of protection desired. A DE-STAR 4 allows for asteroid engagement starting beyond 1AU with a spot temperature sufficient to completely evaporate up to 500-m diameter asteroids in one year. Small asteroids and comets can be diverted/evaporated with a DESTAR 2 (100m) while space debris is vaporized with a DE-STAR 1 (10m).

Lubin, Philip; Hughes, Gary B.; Bible, Johanna; Bublitz, Jesse; Arriola, Josh; Motta, Caio; Suen, Jon; Johansson, Isabella; Riley, Jordan; Sarvian, Nilou; Clayton-Warwick, Deborah; Wu, Jane; Milich, Andrew; Oleson, Mitch; Pryor, Mark; Krogen, Peter; Kangas, Miikka

2013-09-01

401

Multiantibody Strategies for HIV  

PubMed Central

Vaccination strategies depend entirely on the appropriate responsiveness of our immune system against particular antigens. For this active immunization to be truly effective, neutralizing antibodies (nAbs) need to efficiently counter the infectivity or propagation of the pathogen. Some viruses, including HIV, are able to take advantage of this immune response in order to evade nAbs. This review focuses on viral immune evasion strategies that result directly from a robust immune response to infection or vaccination. A rationale for multi-Ab therapy to circumvent this phenomenon is discussed. Progress in the formulation, production, and regulatory approval of monoclonal antibodies (mAbs) is presented. PMID:23840243

Whaley, Kevin J.

2013-01-01

402

Lifespan-extending caloric restriction or mTOR inhibition impair adaptive immunity of old mice by distinct mechanisms.  

PubMed

Aging of the world population and a concomitant increase in age-related diseases and disabilities mandates the search for strategies to increase healthspan, the length of time an individual lives healthy and productively. Due to the age-related decline of the immune system, infectious diseases remain among the top 5-10 causes of mortality and morbidity in the elderly, and improving immune function during aging remains an important aspect of healthspan extension. Calorie restriction (CR) and more recently rapamycin (rapa) feeding have both been used to extend lifespan in mice. Preciously few studies have actually investigated the impact of each of these interventions upon in vivo immune defense against relevant microbial challenge in old organisms. We tested how rapa and CR each impacted the immune system in adult and old mice. We report that each intervention differentially altered T-cell development in the thymus, peripheral T-cell maintenance, T-cell function and host survival after West Nile virus infection, inducing distinct but deleterious consequences to the aging immune system. We conclude that neither rapa feeding nor CR, in the current form/administration regimen, may be optimal strategies for extending healthy immune function and, with it, lifespan. PMID:25424641

Goldberg, Emily L; Romero-Aleshire, Melissa J; Renkema, Kristin R; Ventevogel, Melissa S; Chew, Wade M; Uhrlaub, Jennifer L; Smithey, Megan J; Limesand, Kirsten H; Sempowski, Gregory D; Brooks, Heddwen L; Nikolich-Žugich, Janko

2015-02-01

403

Lifespan-extending caloric restriction or mTOR inhibition impair adaptive immunity of old mice by distinct mechanisms  

PubMed Central

Aging of the world population and a concomitant increase in age-related diseases and disabilities mandates the search for strategies to increase healthspan, the length of time an individual lives healthy and productively. Due to the age-related decline of the immune system, infectious diseases remain among the top 5–10 causes of mortality and morbidity in the elderly, and improving immune function during aging remains an important aspect of healthspan extension. Calorie restriction (CR) and more recently rapamycin (rapa) feeding have both been used to extend lifespan in mice. Preciously few studies have actually investigated the impact of each of these interventions upon in vivo immune defense against relevant microbial challenge in old organisms. We tested how rapa and CR each impacted the immune system in adult and old mice. We report that each intervention differentially altered T-cell development in the thymus, peripheral T-cell maintenance, T-cell function and host survival after West Nile virus infection, inducing distinct but deleterious consequences to the aging immune system. We conclude that neither rapa feeding nor CR, in the current form/administration regimen, may be optimal strategies for extending healthy immune function and, with it, lifespan. PMID:25424641

Goldberg, Emily L; Romero-Aleshire, Melissa J; Renkema, Kristin R; Ventevogel, Melissa S; Chew, Wade M; Uhrlaub, Jennifer L; Smithey, Megan J; Limesand, Kirsten H; Sempowski, Gregory D; Brooks, Heddwen L; Nikolich-Žugich, Janko

2015-01-01

404

Chemoimmunotherapy: reengineering tumor immunity  

PubMed Central

Cancer chemotherapy drugs have long been considered immune suppressive. However, more recent data indicate that some cytotoxic drugs effectively treat cancer in part by facilitating an immune response to the tumor when given at the standard dose and schedule. These drugs induce a form of tumor cell death that is immunologically active, thereby inducing an adaptive immune response specific for the tumor. In addition, cancer chemotherapy drugs can promote tumor immunity through ancillary and largely unappreciated immunologic effects on both the malignant and normal host cells present within the tumor microenvironment. These more subtle immunomodulatory effects are dependent on the drug itself, its dose, and its schedule in relation to an immune-based intervention. The recent approvals of two new immune-based therapies for prostate cancer and melanoma herald a new era in cancer treatment and have led to heightened interest in immunotherapy as a valid approach to cancer treatment. A detailed understanding of the cellular and molecular basis of interactions between chemotherapy drugs and the immune system is essential for devising the optimal strategy for integrating new immune-based therapies into the standard of care for various cancers, resulting in the greatest long-term clinical benefit for cancer patients. PMID:23389507

Chen, Gang

2013-01-01

405

Defense Health Program DEPARTMENT OF DEFENSE MULTIPLE SCLEROSIS RESEARCH PROGRAM  

E-print Network

Defense Health Program DEPARTMENT OF DEFENSE MULTIPLE SCLEROSIS RESEARCH PROGRAM FISCAL YEAR 2013) to the Department of Defense Multiple Sclerosis Research Program (MSRP). The Department of Defense Multiple to critical discoveries in understanding the causes and progression of multiple sclerosis (MS) and

von der Heydt, Rüdiger

406

THE UNDER SECRETARY OF DEFENSE 3010 DEFENSE PENTAGON  

E-print Network

SECRETARY OF THE AIR FORCE (CONTRACTING) DIRECTOR, DEFENSE ADVANCED RESEARCH PROJECTS AGENCY ASSISTANT or Defense Agency that may obligate or transfer for obligation Basic Research appropriations, to complyTHE UNDER SECRETARY OF DEFENSE 3010 DEFENSE PENTAGON WASHINGTON, DC 20301·3010 OCT 28 2008

Yang, Eui-Hyeok

407

THE UNDER SECRETARY OF DEFENSE 301 0 DEFENSE PENTAGON  

E-print Network

THE UNDER SECRETARY OF DEFENSE 301 0 DEFENSE PENTAGON WASHINGTON, DC 20301-3010 ACQUISITION. Dtr L 0 TECHNOLOGY AND LOGISTICS MEMORANDUM FOR: SEE DISTRIBUTION SUBJECT: FY 2012 Depaitment of Defense in its spending. Department of Defense (DoD) Components attain savings by using a simple, flexible

US Army Corps of Engineers

408

OFFICE OF THE ASSISTANT SECRETARY OF DEFENSE 4000 DEFENSE PENTAGON  

E-print Network

OFFICE OF THE ASSISTANT SECRETARY OF DEFENSE 4000 DEFENSE PENTAGON READINESS AND FORCE MANAGEMENT on Leave Without Pay Status for the Department of Defense Civilian Employees during an Administrative." This memorandum provides the Department ofDefense supplemental guidance on the treatment ofemployees who

US Army Corps of Engineers

409

Extracellular DNA: the tip of root defenses?  

PubMed

This review discusses how extracellular DNA (exDNA) might function in plant defense, and at what level(s) of innate immunity this process might operate. A new role for extracellular factors in mammalian defense has been described in a series of studies. These studies reveal that cells including neutrophils, eosinophils, and mast cells produce 'extracellular traps' (ETs) consisting of histone-linked exDNA. When pathogens are attracted to such ETs, they are trapped and killed. When the exDNA component of ETs is degraded, trapping is impaired and resistance against invasion is reduced. Conversely, mutation of microbial genes encoding exDNases that degrade exDNA results in loss of virulence. This discovery that exDNases are virulence factors opens new avenues for disease control. In plants, exDNA is required for defense of the root tip. Innate immunity-related proteins are among a group of >100 proteins secreted from the root cap and root border cell populations. Direct tests revealed that exDNA also is rapidly synthesized and exported from the root tip. When this exDNA is degraded by the endonuclease DNase 1, root tip resistance to fungal infection is lost; when the polymeric structure is degraded more slowly, by the exonuclease BAL31, loss of resistance to fungal infection is delayed accordingly. The results suggest that root border cells may function in a manner analogous to that which occurs in mammalian cells. PMID:21497709

Hawes, Martha C; Curlango-Rivera, Gilberto; Wen, Fushi; White, Gerard J; Vanetten, Hans D; Xiong, Zhongguo

2011-06-01

410

Exploring the Pharmacological Potential of Promiscuous Host-Defense Peptides: From Natural Screenings to Biotechnological Applications  

PubMed Central

In the last few years, the number of bacteria with enhanced resistance to conventional antibiotics has dramatically increased. Most of such bacteria belong to regular microbial flora, becoming a real challenge, especially for immune-depressed patients. Since the treatment is sometimes extremely expensive, and in some circumstances completely inefficient for the most severe cases, researchers are still determined to discover novel compounds. Among them, host-defense peptides (HDPs) have been found as the first natural barrier against microorganisms in nearly all living groups. This molecular class has been gaining attention every day for multiple reasons. For decades, it was believed that these defense peptides had been involved only with the permeation of the lipid bilayer in pathogen membranes, their main target. Currently, it is known that these peptides can bind to numerous targets, as well as lipids including proteins and carbohydrates, from the surface to deep within the cell. Moreover, by using in vivo models, it was shown that HDPs could act both in pathogens and cognate hosts, improving immunological functions as well as acting through multiple pathways to control infections. This review focuses on structural and functional properties of HDP peptides and the additional strategies used to select them. Furthermore, strategies to avoid problems in large-scale manufacture by using molecular and biochemical techniques will also be explored. In summary, this review intends to construct a bridge between academic research and pharmaceutical industry, providing novel insights into the utilization of HDPs against resistant bacterial strains that cause infections in humans. PMID:22125552

Silva, Osmar N.; Mulder, Kelly C. L.; Barbosa, Aulus E. A. D.; Otero-Gonzalez, Anselmo J.; Lopez-Abarrategui, Carlos; Rezende, Taia M. B.; Dias, Simoni C.; Franco, Octávio L.

2011-01-01

411

Jane's Internet Defense Glossary  

NSDL National Science Digital Library

Jane's Information Group, well-known publisher of defense and aerospace information, provides this handy, no-nonsense glossary of over 20,000 pertinent acronyms and abbreviations. The glossary is both browseable and searchable by acronym or definition.

412

Comparison of single, homologous prime-boost and heterologous prime-boost immunization strategies against H5N1 influenza virus in a mouse challenge model  

Microsoft Academic Search

Preparation for an H5N1 influenza pandemic in humans may involve priming the population with a vaccine produced from an existing, available H5N1 strain. We have used a mouse challenge model to compare the immunogenicity and efficacy of inactivated, Vero cell-derived, whole virus H5N1 vaccines in single immunization and homologous or heterologous prime-boost regimes. A single immunization was sufficient to protect

Nicolas Sabarth; M. Keith Howard; Helga Savidis-Dacho; André van Maurik; P. Noel Barrett; Otfried Kistner

2010-01-01

413

Immune tolerance induction by integrating innate and adaptive immune regulators  

PubMed Central

A diversity of immune tolerance mechanisms have evolved to protect normal tissues from immune damage. Immune regulatory cells are critical contributors to peripheral tolerance. These regulatory cells, exemplified by the CD4+Foxp3+ regulatory T (Treg) cells and a recently identified population named myeloid-derived suppressor cells (MDSCs), regulate immune responses and limiting immune-mediated pathology. In a chronic inflammatory setting, such as allograft-directed immunity, there may be a dynamic “crosstalk” between the innate and adaptive immunomodulatory mechanisms for an integrated control of immune damage. CTLA4-B7-based interaction between the two branches may function as a molecular “bridge” to facilitate such “crosstalk”. Understanding the interplays among Treg cells, innate suppressors and pathogenic effector T (Teff) cells will be critical in the future to assist in the development of therapeutic strategies to enhance and synergize physiological immunosuppressive elements in the innate and adaptive immune system. Successful development of localized strategies of regulatory cell therapies could circumvent the requirement for very high number of cells and decrease the risks associated with systemic immunosuppression. To realize the potential of innate and adaptive immune regulators for the still-elusive goal of immune tolerance induction, adoptive cell therapies may also need to be coupled with agents enhancing endogenous tolerance mechanisms. PMID:19919733

Suzuki, Jun; Ricordi, Camillo; Chen, Zhibin

2009-01-01

414

Mother-derived trans-generational immune priming in the red palm weevil, Rhynchophorus ferrugineus Olivier (Coleoptera, Dryophthoridae).  

PubMed

Rhynchophorus ferrugineus (Coleoptera, Curculionidae) is the most destructive pest of palm trees worldwide containing it invasive areas, such as the southern part of China. It is always emphasized to develop integrated pest management based on biological agents, but their success is not very exciting. Presently, the immune defenses of this pest against biological agents attract scarce attention. It is still unclear whether immune priming also generally occurs in insect pests and in response to different pathogens. Our results indicated that previous challenge of bacteria pathogen enhanced the magnitude of phenoloxidase activity and antibacterial activity in R. ferrugineus larvae against the secondary infection. Furthermore, trans-generational immune priming was also determined in this pest, and only challenged R. ferrugineus mothers transferred the immune protection to their offspring which suggested males and females of this pest might have evolved different strategies on the investment of delivering immune protection to their offspring. Importantly, our data provide the evidence to suggest that different kinds of biological control agents might be used alternatively or in combination to fight against R. ferrugineus because of the existence of immune priming with low species-specific level. On the other hand, for this invasive pest, the immune priming may also facilitate its adaptation and dispersal in the new regions. PMID:25208627

Shi, Z H; Lin, Y T; Hou, Y M

2014-12-01

415

Plant defense activators: applications and prospects in cereal crops  

Technology Transfer Automated Retrieval System (TEKTRAN)

This review addresses the current understanding of the plant immune response and the molecular mechanisms responsible for systemic acquired resistance as well as the phenomenon of "priming" in plant defense. A detailed discussion of the role of salicylic acid in activating the plant transcription c...

416

Combining Cytotoxic and Immune-Mediated Gene Therapy to Treat Brain Tumors  

PubMed Central

Glioblastoma (GBM) is a type of intracranial brain tumor, for which there is no cure. In spite of advances in surgery, chemotherapy and radiotherapy, patients die within a year of diagnosis. Therefore, there is a critical need to develop novel therapeutic approaches for this disease. Gene therapy, which is the use of genes or other nucleic acids as drugs, is a powerful new treatment strategy which can be developed to treat GBM. Several treatment modalities are amenable for gene therapy implementation, e.g. conditional cytotoxic approaches, targeted delivery of toxins into the tumor mass, immune stimulatory strategies, and these will all be the focus of this review. Both conditional cytotoxicity and targeted toxin mediated tumor death, are aimed at eliminating an established tumor mass and preventing further growth. Tumors employ several defensive strategies that suppress and inhibit anti-tumor immune responses. A better understanding of the mechanisms involved in eliciting anti-tumor immune responses has identified promising targets for immunotherapy. Immunotherapy is designed to aid the immune system to recognize and destroy tumor cells in order to eliminate the tumor burden. Also, immune-therapeutic strategies have the added advantage that an activated immune system has the capability of recognizing tumor cells at distant sites from the primary tumor, therefore targeting metastasis distant from the primary tumor locale. Pre-clinical models and clinical trials have demonstrated that in spite of their location within the central nervous system (CNS), a tissue described as ‘immune privileged’, brain tumors can be effectively targeted by the activated immune system following various immunotherapeutic strategies. This review will highlight recent advances in brain tumor immunotherapy, with particular emphasis on advances made using gene therapy strategies, as well as reviewing other novel therapies that can be used in combination with immunotherapy. Another important aspect of implementing gene therapy in the clinical arena is to be able to image the targeting of the therapeutics to the tumors, treatment effectiveness and progression of disease. We have therefore reviewed the most exciting non-invasive, in vivo imaging techniques which can be used in combination with gene therapy to monitor therapeutic efficacy over time. PMID:16248789

Curtin, James F.; King, Gwendalyn D.; Candolfi, Marianela; Greeno, Remy B.; Kroeger, Kurt M.; Lowenstein, Pedro R.; Castro, Maria G.

2006-01-01

417

Ly6G+ neutrophils are dispensable for defense against systemic Listeria monocytogenes infection  

PubMed Central

Listeria monocytogenes is a facultative intracellular bacterium that causes systemic infections in immunocompromised hosts. Early recruitment of myeloid cells, including inflammatory monocytes and neutrophils, to sites of L. monocytogenes infection is essential for the control of infection and host survival. Because previous experimental studies used depleting or blocking antibodies that affected both inflammatory monocytes and neutrophils, the relative contributions of these cell populations to defense against L. monocytogenes infection remain incompletely defined. Herein, we used highly selective depletion strategies to either deplete inflammatory monocytes or neutrophils from L. monocytogenes infected mice and demonstrate that neutrophils are dispensable for early and late control of infection. In contrast, inflammatory monocytes are essential for bacterial clearance during the innate and adaptive phases of the immune response to L. monocytogenes infection. PMID:21976773

Shi, Chao; Hohl, Tobias M.; Leiner, Ingrid; Equinda, Michele J.; Fan, Xiaozhou; Pamer, Eric G.

2011-01-01

418

Ly6G+ neutrophils are dispensable for defense against systemic Listeria monocytogenes infection.  

PubMed

Listeria monocytogenes is a facultative intracellular bacterium that causes systemic infections in immunocompromised hosts. Early recruitment of myeloid cells, including inflammatory monocytes and neutrophils, to sites of L. monocytogenes infection is essential for the control of infection and host survival. Because previous experimental studies used depleting or blocking Abs that affected both inflammatory monocytes and neutrophils, the relative contributions of these cell populations to defense against L. monocytogenes infection remain incompletely defined. In this article, we used highly selective depletion strategies to either deplete inflammatory monocytes or neutrophils from L. monocytogenes-infected mice and demonstrate that neutrophils are dispensable for early and late control of infection. In contrast, inflammatory monocytes are essential for bacterial clearance during the innate and adaptive phases of the immune response to L. monocytogenes infection. PMID:21976773

Shi, Chao; Hohl, Tobias M; Leiner, Ingrid; Equinda, Michele J; Fan, Xiaozhou; Pamer, Eric G

2011-11-15

419

HPV: immune response to infection and vaccination  

E-print Network

coat protein L1 is protective suggesting that this would be an effective prophylactic vaccine strategy. The current prophylactic HPV VLP vaccines are delivered i.m. circumventing the intra-epithelial immune evasion strategies. These vaccines generate...

Stanley, Margaret A

2010-10-20

420

Childhood Immunization  

MedlinePLUS

... lowest levels in history, thanks to years of immunization. Children must get at least some vaccines before ... child provide protection for many years, adults need immunizations too. Centers for Disease Control and Prevention

421

Immunization Coverage  

MedlinePLUS

... based on local priorities and needs. World Immunization Week The last week of April each year is marked by WHO and partners as World Immunization Week. It aims to raise public awareness of how ...

422

Study of Diseases and the Immune System of Bivalves Using Molecular Biology and Genomics  

Microsoft Academic Search

Environmental chemico-physical factors, pathogens, and biological interactions constantly affect organism physiology and behavior. Invertebrates, including bivalve mollusks do not possess acquired immunity. Their defense mechanisms rely on an innate, non-adaptive immune system employing circulating cells and a large variety of molecular effectors. The mechanisms underlying host defense depend on the presence of functional proteins in appropriate quantities, within a crucial

Camino Gestal; Philippe Roch; Tristan Renault; Alberto Pallavicini; Christine Paillard; Beatriz Novoa; Radouane Oubella; Paola Venier; Antonio Figueras

2008-01-01

423

INTERACTIVE IMMUNITY  

NSDL National Science Digital Library

The resource is an interactive on-line book based upon the book “Your Amazing Immune System” which brings students to an exploration on how our immune system protects our body from infectious diseases. In addition, it gives students background on autoimmune diseases, immune reactions, and how immunology can be used in fighting cancer.

European Federation Of Immunological Societies, Efis

2012-07-19

424

The Role of Nutrition in Enhancing Immunity in Aging  

PubMed Central

Aging is associated with declined immune function, particularly T cell-mediated activity, which contributes to increased morbidity and mortality from infectious disease and cancer in the elderly. Studies have shown that nutritional intervention may be a promising approach to reversing impaired immune function and diminished resistance to infection with aging. However, controversy exists concerning every nutritional regimen tested to date. In this article, we will review the progress of research in this field with a focus on nutrition factor information that is relatively abundant in the literature. While vitamin E deficiency is rare, intake above recommended levels can enhance T cell function in aged animals and humans. This effect is believed to contribute toward increased resistance to influenza infection in animals and reduced incidence of upper respiratory infection in the elderly. Zinc deficiency, common in the elderly, is linked to impaired immune function and increased risk for acquiring infection, which can be rectified by zinc supplementation. However, higher than recommended upper limits of zinc may adversely affect immune function. Probiotics are increasingly being recognized as an effective, immune-modulating nutritional factor. However, to be effective, they require an adequate supplementation period; additionally, their effects are strain-specific and among certain strains, a synergistic effect is observed. Increased intake of fish or n-3 PUFA may be beneficial to inflammatory and autoimmune disorders as well as to several age-related diseases. Conversely, the immunosuppressive effect of fish oils on T cell-mediated function has raised concerns regarding their impact on resistance to infection. Caloric restriction (CR) is shown to delay immunosenescence in animals, but this effect needs to be verified in humans. Timing for CR initiation may be important to determine whether CR is effective or even beneficial at all. Recent studies have suggested that CR, which is effective at improving the immune response of unchallenged animals, might compromise the host’s defense against pathogenic infection and result in higher morbidity and mortality. The studies published thus far describe a critical role for nutrition in maintaining the immune response of the aged, but they also indicate the need for a more in-depth, wholestic approach to determining the optimal nutritional strategies that would maintain a healthy immune system in the elderly and promote their resistance to infection and other immune-related diseases PMID:22500273

Pae, Munkyong; Meydani, Simin Nikbin; Wu, Dayong

2011-01-01

425

The role of nutrition in enhancing immunity in aging.  

PubMed

Aging is associated with declined immune function, particularly T cell-mediated activity, which contributes to increased morbidity and mortality from infectious disease and cancer in the elderly. Studies have shown that nutritional intervention may be a promising approach to reversing impaired immune function and diminished resistance to infection with aging. However, controversy exists concerning every nutritional regimen tested to date. In this article, we will review the progress of research in this field with a focus on nutrition factor information that is relatively abundant in the literature. While vitamin E deficiency is rare, intake above recommended levels can enhance T cell function in aged animals and humans. This effect is believed to contribute toward increased resistance to influenza infection in animals and reduced incidence of upper respiratory infection in the elderly. Zinc deficiency, common in the elderly, is linked to impaired immune function and increased risk for acquiring infection, which can be rectified by zinc supplementation. However, higher than recommended upper limits of zinc may adversely affect immune function. Probiotics are increasingly being recognized as an effective, immune-modulating nutritional factor. However, to be effective, they require an adequate supplementation period; additionally, their effects are strain-specific and among certain strains, a synergistic effect is observed. Increased intake of fish or n-3 PUFA may be beneficial to inflammatory and autoimmune disorders as well as to several age-related diseases. Conversely, the immunosuppressive effect of fish oils on T cell-mediated function has raised concerns regarding their impact on resistance to infection. Caloric restriction (CR) is shown to delay immunosenescence in animals, but this effect needs to be verified in humans. Timing for CR initiation may be important to determine whether CR is effective or even beneficial at all. Recent studies have suggested that CR, which is effective at improving the immune response of unchallenged animals, might compromise the host's defense against pathogenic infection and result in higher morbidity and mortality. The studies published thus far describe a critical role for nutrition in maintaining the immune response of the aged, but they also indicate the need for a more in-depth, wholestic approach to determining the optimal nutritional strategies that would maintain a healthy immune system in the elderly and promote their resistance to infection and other immune-related diseases. PMID:22500273

Pae, Munkyong; Meydani, Simin Nikbin; Wu, Dayong

2012-02-01

426

Plant immunity in plant–aphid interactions  

PubMed Central

Aphids are economically important pests that cause extensive feeding damage and transmit viruses. While some species have a broad host range and cause damage to a variety of crops, others are restricted to only closely related plant species. While probing and feeding aphids secrete saliva, containing effectors, into their hosts to manipulate host cell processes and promote infestation. Aphid effector discovery studies pointed out parallels between infection and infestation strategies of plant pathogens and aphids. Interestingly, resistance to some aphid species is known to involve plant resistance proteins with a typical NB-LRR domain structure. Whether these resistance proteins indeed recognize aphid effectors to trigger ETI remains to be elucidated. In addition, it was recently shown that unknown aphid derived elicitors can initiate reactive oxygen species (ROS) production and callose deposition and that these responses were dependent on BAK1 (BRASSINOSTERIOD INSENSITIVE 1-ASSOCIATED RECEPTOR KINASE 1) which is a key component of the plant immune system. In addition, BAK-1 contributes to non-host resistance to aphids pointing to another parallel between plant-pathogen and – aphid interactions. Understanding the role of plant immunity and non-host resistance to aphids is essential to generate durable and sustainable aphid control strategies. Although insect behavior plays a role in host selection and non-host resistance, an important observation is that aphids interact with non-host plants by probing the leaf surface, but are unable to feed or establish colonization. Therefore, we hypothesize that aphids interact with non-host plants at the molecular level, but are potentially not successful in suppressing plant defenses and/or releasing nutrients. PMID:25520727

Jaouannet, Maëlle; Rodriguez, Patricia A.; Lenoir, Camille J. G.; MacLeod, Ruari; Escudero-Martinez, Carmen; Bos, Jorunn I.B.

2014-01-01

427

Immune Camouflage: Relevance to Vaccine Design and Human Immunology.  

PubMed

High strain sequence variability, interference with innate immune mechanisms, and epitope deletion are all examples of strategies that pathogens have evolved to subvert host defenses. To this list we would add another strategy: immune camouflage. Pathogens whose epitope sequences are cross-conserved with multiple human proteins at the TCR-facing residues may be exploiting "ignorance and tolerance", which are mechanisms by which mature T cells avoid immune responses to self-antigens. By adopting amino acid configurations that may be recognized by autologous regulatory T cells, pathogens may be actively suppressing protective immunity. Using the new JanusMatrix TCR-homology-mapping tool, we have identified several such 'camouflaged' tolerizing epitopes that are present in the viral genomes of pathogens such as emerging H7N9 influenza. Thus in addition to the overall low number of T helper epitopes that is present in H7 hemaglutinin (as described previously, see http://dx.doi.org/10.4161/hv.24939), the presence of such tolerizing epitopes in H7N9 could explain why, in recent vaccine trials, whole H7N9-HA was poorly immunogenic and associated with low seroconversion rates (see http://dx.doi.org/10.4161/hv.28135). In this commentary, we provide an overview of the immunoinformatics process leading to the discovery of tolerizing epitopes in pathogen genomic sequences, provide a brief summary of laboratory data that validates the discovery, and point the way forward. Removal of viral, bacterial and parasite tolerizing epitopes may permit researchers to develop more effective vaccines and immunotherapeutics in the future. PMID:25483703

Moise, Leonard; Liu, Rui; Gutierrez, Andres; Tassone, Ryan; Bailey-Kellogg, Chris; Martin, Bill; De Groot, Anne

2014-11-01

428

Rationality Validation of a Layered Decision Model for Network Defense  

SciTech Connect

We propose a cost-effective network defense strategy built on three key: three decision layers: security policies, defense strategies, and real-time defense tactics for countering immediate threats. A layered decision model (LDM) can be used to capture this decision process. The LDM helps decision-makers gain insight into the hierarchical relationships among inter-connected entities and decision types, and supports the selection of cost-effective defense mechanisms to safeguard computer networks. To be effective as a business tool, it is first necessary to validate the rationality of model before applying it to real-world business cases. This paper describes our efforts in validating the LDM rationality through simulation.

Wei, Huaqiang; Alves-Foss, James; Zhang, Du; Frincke, Deb

2007-08-31

429

Modulation of immune responses of Rhynchophorus ferrugineus (Insecta: Coleoptera) induced by the entomopathogenic nematode Steinernema carpocapsae (Nematoda: Rhabditida).  

PubMed

Aim of this study was to investigate relationships between the red palm weevil (RPW) Rhynchophorus ferrugineus (Olivier) and the entomopathogenic nematode Steinernema carpocapsae (EPN); particularly, the work was focused on the immune response of the insect host in naive larvae and after infection with the EPN. Two main immunological processes have been addressed: the activity and modulation of host prophenoloxidase-phenoloxidase (proPO) system, involved in melanization of not-self and hemocytes recognition processes responsible for not-self encapsulation. Moreover, immune depressive and immune evasive strategies of the parasite have been investigated. Our results suggest that RPW possess an efficient immune system, however in the early phase of infection, S. carpocapsae induces a strong inhibition of the host proPO system. In addition, host cell-mediated mechanisms of encapsulation, are completely avoided by the parasite, the elusive strategies of S. carpocapsae seem to be related to the structure of its body-surface, since induced alterations of the parasite cuticle resulted in the loss of its mimetic properties. S. carpocapsae before the release of its symbiotic bacteria, depress and elude RPW immune defenses, with the aim to arrange a favorable environment for its bacteria responsible of the septicemic death of the insect target. PMID:24846780

Mastore, Maristella; Arizza, Vincenzo; Manachini, Barbara; Brivio, Maurizio F

2014-05-20

430

Augmentation of Innate Host Defense by Expression of a Cathelicidin Antimicrobial Peptide  

Microsoft Academic Search

Antimicrobial peptides, such as defensins or cathelicidins, are effector substances of the innate immune system and are thought to have antimicrobial properties that contribute to host defense. The evidence that vertebrate antimicrobial peptides contribute to innate immunity in vivo is based on their expression pattern and in vitro activity against microorganisms. The goal of this study was to investigate whether

ROBERT BALS; DANIEL J. WEINER; A. DAVID MOSCIONI; RUPALIE L. MEEGALLA; JAMES M. WILSON

1999-01-01

431

Immune response and immunotherapy in intraepithelial and invasive lesions of the uterine cervix.  

PubMed

Infection with the human papillomavirus virus (HPV) induces innate and acquired immune responses in the cervical stroma, which are a delicate, balanced and generally unpredictable immunological defense. Because of the immunological breaks that the HPV virus causes, eradication of infected cells does not occur, potentially leading to development of intraepithelial and invasive lesions. Advances in our understanding of the immune system and in the definition of antigens in tumor cells has led to many new treatment strategies. As a result, immunotherapy has the potential to be the most specific treatment for tumors, and one that requires elaboration. Recently, immunotherapy with interferon and dendritc cells has been used on intrapepithelial and invasive cervical lesions with promising results. PMID:22675951

Machado, F A; Janssens, J Ph; Michelin, M A; Murta, E F C

2012-01-01

432

Inflammatory monocytes orchestrate innate antifungal immunity in the lung.  

PubMed

Aspergillus fumigatus is an environmental fungus that causes invasive aspergillosis (IA) in immunocompromised patients. Although -CC-chemokine receptor-2 (CCR2) and Ly6C-expressing inflammatory monocytes (CCR2?Mo) and their derivatives initiate adaptive pulmonary immune responses, their role in coordinating innate immune responses in the lung remain poorly defined. Using conditional and antibody-mediated cell ablation strategies, we found that CCR2?Mo and monocyte-derived dendritic cells (Mo-DCs) are essential for innate defense against inhaled conidia. By harnessing fluorescent Aspergillus reporter (FLARE) conidia that report fungal cell association and viability in vivo, we identify two mechanisms by which CCR2?Mo and Mo-DCs exert innate antifungal activity. First, CCR2?Mo and Mo-DCs condition the lung inflammatory milieu to augment neutrophil conidiacidal activity. Second, conidial uptake by CCR2?Mo temporally coincided with their differentiation into Mo-DCs, a process that resulted in direct conidial killing. Our findings illustrate both indirect and direct functions for CCR2?Mo and their derivatives in innate antifungal immunity in the lung. PMID:24586155

Espinosa, Vanessa; Jhingran, Anupam; Dutta, Orchi; Kasahara, Shinji; Donnelly, Robert; Du, Peicheng; Rosenfeld, Jeffrey; Leiner, Ingrid; Chen, Chiann-Chyi; Ron, Yacov; Hohl, Tobias M; Rivera, Amariliz

2014-02-01

433

Inflammatory Monocytes Orchestrate Innate Antifungal Immunity in the Lung  

PubMed Central

Aspergillus fumigatus is an environmental fungus that causes invasive aspergillosis (IA) in immunocompromised patients. Although -CC-chemokine receptor-2 (CCR2) and Ly6C-expressing inflammatory monocytes (CCR2+Mo) and their derivatives initiate adaptive pulmonary immune responses, their role in coordinating innate immune responses in the lung remain poorly defined. Using conditional and antibody-mediated cell ablation strategies, we found that CCR2+Mo and monocyte-derived dendritic cells (Mo-DCs) are essential for innate defense against inhaled conidia. By harnessing fluorescent Aspergillus reporter (FLARE) conidia that report fungal cell association and viability in vivo, we identify two mechanisms by which CCR2+Mo and Mo-DCs exert innate antifungal activity. First, CCR2+Mo and Mo-DCs condition the lung inflammatory milieu to augment neutrophil conidiacidal activity. Second, conidial uptake by CCR2+Mo temporally coincided with their differentiation into Mo-DCs, a process that resulted in direct conidial killing. Our findings illustrate both indirect and direct functions for CCR2+Mo and their derivatives in innate antifungal immunity in the lung. PMID:24586155

Dutta, Orchi; Kasahara, Shinji; Donnelly, Robert; Du, Peicheng; Rosenfeld, Jeffrey; Leiner, Ingrid; Chen, Chiann-Chyi; Ron, Yacov; Hohl, Tobias M.; Rivera, Amariliz

2014-01-01