The Experts below are selected from a list of 306 Experts worldwide ranked by ideXlab platform
Ce Wang - One of the best experts on this subject based on the ideXlab platform.
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lymphatic targeted cationic liposomes a robust vaccine adjuvant for promoting long term Immunological Memory
Journal of Controlled Release, 2015Co-Authors: Ce Wang, Yan Zhuang, Ping Li, Boling JiangAbstract:Although retaining antigens at the injection site (the so-called “depot effect”) is an important strategy for vaccine development, increasing evidence showed that lymphatic-targeted vaccine delivery with liposomes could be a promising approach for improving vaccine efficacy. However, it remains unclear whether antigen depot or lymphatic targeting would benefit long-term Immunological Memory, a major determinant of vaccine efficacy. In the present study, OVA antigen was encapsulated with DOTAP cationic liposomes (LP) or DOTAP-PEG-mannose liposomes (LP-Man) to generate depot or lymphatic-targeted liposome vaccines, respectively. The result of in vivo imaging showed that LP mostly accumulated near the injection site, whereas LP-Man not only effectively accumulated in draining lymph nodes (LNs) and the spleen, but also enhanced the uptake by resident antigen-presenting cells. Although LP vaccines with depot effect induced anti-OVA IgG more potently than LP-Man vaccines did on day 40 after priming, they failed to mount an effective B-cell Memory response upon OVA re-challenge after three months. In contrast, lymphatic-targeted LP-Man vaccines elicited sustained antibody production and robust recall responses three months after priming, suggesting lymphatic targeting rather than antigen au to depot promoted the establishment of long-term Memory responses. The enhanced long-term Immunological Memory by LP-Man was attributed to vigorous germinal center responses as well as increased Tfh cells and central Memory CD4+ T cells in the secondary lymphoid organs. Hence, lymphatic-targeted vaccine delivery with LP-Man could be an effective strategy to promote long-lasting Immunological Memory. © 2014 Elsevier Ltd. All rights reserved.
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lymphatic targeted cationic liposomes a robust vaccine adjuvant for promoting long term Immunological Memory
Vaccine, 2014Co-Authors: Ce Wang, Yan Zhuang, Ping Li, Boling JiangAbstract:Abstract Although retaining antigens at the injection site (the so-called “depot effect”) is an important strategy for vaccine development, increasing evidence showed that lymphatic-targeted vaccine delivery with liposomes could be a promising approach for improving vaccine efficacy. However, it remains unclear whether antigen depot or lymphatic targeting would benefit long-term Immunological Memory, a major determinant of vaccine efficacy. In the present study, OVA antigen was encapsulated with DOTAP cationic liposomes (LP) or DOTAP-PEG-mannose liposomes (LP-Man) to generate depot or lymphatic-targeted liposome vaccines, respectively. The result of in vivo imaging showed that LP mostly accumulated near the injection site, whereas LP-Man not only effectively accumulated in draining lymph nodes (LNs) and the spleen, but also enhanced the uptake by resident antigen-presenting cells. Although LP vaccines with depot effect induced anti-OVA IgG more potently than LP-Man vaccines did on day 40 after priming, they failed to mount an effective B-cell Memory response upon OVA re-challenge after three months. In contrast, lymphatic-targeted LP-Man vaccines elicited sustained antibody production and robust recall responses three months after priming, suggesting lymphatic targeting rather than antigen depot promoted the establishment of long-term Memory responses. The enhanced long-term Immunological Memory by LP-Man was attributed to vigorous germinal center responses as well as increased Tfh cells and central Memory CD4 + T cells in the secondary lymphoid organs. Hence, lymphatic-targeted vaccine delivery with LP-Man could be an effective strategy to promote long-lasting Immunological Memory.
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lymphatic targeted liposome vaccines promote long term Immunological Memory vac10p 963
Journal of Immunology, 2014Co-Authors: Ce WangAbstract:Lymphatic-targeted vaccine delivery with liposome formulations has been reported to enhance the immunogenicity of vaccines. However, its effect on long-term Immunological Memory remains unclear. In the present study, OVA vaccines were formulated by cationic liposomes with different surface modification: DOTAP liposomes (LP), PEGylated DOTAP (LP-PEG) liposomes, and mannosylated DOTAP (LP-Man) liposomes. The in vivo imaging showed that LP mostly accumulated near the injection site, indicating its depot effect. In contrast, LP-PEG and LP-Man liposomes effectively accumulated in draining lymph nodes and the spleen, indicating their lymphatic targeting. More importantly, different liposomes differentially regulate antibody response and B-cell Memory. Although LP vaccine led to the highest level of anti-OVA IgG among three liposome formulations on day 40 post priming, they failed to establish an effective Memory response. In contrast, lymphatic-targeted LP-PEG and LP-Man vaccines elicited sustained antibody response and robust recall responses 3 months after priming. The enhanced long-term Immunological Memory by lymphatic-targeted liposome vaccines could be attributed to vigorous and persistent germinal center response, as well as increased Tfh cells and central Memory CD4+ T cells in the spleen and lymph nodes. Hence, lymphatic-targeted vaccine delivery with surface modified cationic liposomes could be an effective strategy to promote long-lasting Immunological Memory.
Boling Jiang - One of the best experts on this subject based on the ideXlab platform.
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lymphatic targeted cationic liposomes a robust vaccine adjuvant for promoting long term Immunological Memory
Journal of Controlled Release, 2015Co-Authors: Ce Wang, Yan Zhuang, Ping Li, Boling JiangAbstract:Although retaining antigens at the injection site (the so-called “depot effect”) is an important strategy for vaccine development, increasing evidence showed that lymphatic-targeted vaccine delivery with liposomes could be a promising approach for improving vaccine efficacy. However, it remains unclear whether antigen depot or lymphatic targeting would benefit long-term Immunological Memory, a major determinant of vaccine efficacy. In the present study, OVA antigen was encapsulated with DOTAP cationic liposomes (LP) or DOTAP-PEG-mannose liposomes (LP-Man) to generate depot or lymphatic-targeted liposome vaccines, respectively. The result of in vivo imaging showed that LP mostly accumulated near the injection site, whereas LP-Man not only effectively accumulated in draining lymph nodes (LNs) and the spleen, but also enhanced the uptake by resident antigen-presenting cells. Although LP vaccines with depot effect induced anti-OVA IgG more potently than LP-Man vaccines did on day 40 after priming, they failed to mount an effective B-cell Memory response upon OVA re-challenge after three months. In contrast, lymphatic-targeted LP-Man vaccines elicited sustained antibody production and robust recall responses three months after priming, suggesting lymphatic targeting rather than antigen au to depot promoted the establishment of long-term Memory responses. The enhanced long-term Immunological Memory by LP-Man was attributed to vigorous germinal center responses as well as increased Tfh cells and central Memory CD4+ T cells in the secondary lymphoid organs. Hence, lymphatic-targeted vaccine delivery with LP-Man could be an effective strategy to promote long-lasting Immunological Memory. © 2014 Elsevier Ltd. All rights reserved.
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lymphatic targeted cationic liposomes a robust vaccine adjuvant for promoting long term Immunological Memory
Vaccine, 2014Co-Authors: Ce Wang, Yan Zhuang, Ping Li, Boling JiangAbstract:Abstract Although retaining antigens at the injection site (the so-called “depot effect”) is an important strategy for vaccine development, increasing evidence showed that lymphatic-targeted vaccine delivery with liposomes could be a promising approach for improving vaccine efficacy. However, it remains unclear whether antigen depot or lymphatic targeting would benefit long-term Immunological Memory, a major determinant of vaccine efficacy. In the present study, OVA antigen was encapsulated with DOTAP cationic liposomes (LP) or DOTAP-PEG-mannose liposomes (LP-Man) to generate depot or lymphatic-targeted liposome vaccines, respectively. The result of in vivo imaging showed that LP mostly accumulated near the injection site, whereas LP-Man not only effectively accumulated in draining lymph nodes (LNs) and the spleen, but also enhanced the uptake by resident antigen-presenting cells. Although LP vaccines with depot effect induced anti-OVA IgG more potently than LP-Man vaccines did on day 40 after priming, they failed to mount an effective B-cell Memory response upon OVA re-challenge after three months. In contrast, lymphatic-targeted LP-Man vaccines elicited sustained antibody production and robust recall responses three months after priming, suggesting lymphatic targeting rather than antigen depot promoted the establishment of long-term Memory responses. The enhanced long-term Immunological Memory by LP-Man was attributed to vigorous germinal center responses as well as increased Tfh cells and central Memory CD4 + T cells in the secondary lymphoid organs. Hence, lymphatic-targeted vaccine delivery with LP-Man could be an effective strategy to promote long-lasting Immunological Memory.
Rolf M Zinkernagel - One of the best experts on this subject based on the ideXlab platform.
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Immunological Memory lessons from the past and a look to the future
Nature Reviews Immunology, 2016Co-Authors: Donna L Farber, Andreas Radbruch, Mihai G Netea, Klaus Rajewsky, Rolf M ZinkernagelAbstract:Immunological Memory is considered to be one of the cardinal features of the adaptive immune system. Despite being a recognized phenomenon since the time of the ancient Greeks, immunologists are yet to fully appreciate the mechanisms that control Memory responses in the immune system. Furthermore, our definition of Immunological Memory itself continues to evolve, with recent suggestions that innate immune cells also show Memory-like behaviour. In this Viewpoint article, Nature Reviews Immunology invites five leading immunologists to share their thoughts on our current understanding of the nature of Immunological Memory. Our experts highlight some of the seminal studies that have shaped the immune Memory field and offer contrasting views on the key questions that remain to be addressed.
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Immunological Memory protective immunity
Cellular and Molecular Life Sciences, 2012Co-Authors: Rolf M ZinkernagelAbstract:So-called ‘Immunological Memory’ is, in my view, a typical example where a field of enquiry, i.e. to understand long-term protection to survive reexposure to infection, has been overtaken by ‘l’art pour l’art’ of ‘basic immunology’. The aim of this critical review is to point out some key differences between academic text book-defined Immunological Memory and protective immunity as viewed from a co-evolutionary point of view, both from the host and the infectious agents. A key conclusion is that ‘Immunological Memory’ of course exists, but only in particular experimental laboratory models measuring ‘quicker and better’ responses after an earlier immunization. These often do correlate with, but are not the key mechanisms of, protection. Protection depends on pre-existing neutralizing antibodies or pre-activated T cells at the time of infection—as documented by the importance of maternal antibodies around birth for survival of the offspring. Importantly, both high levels of antibodies and of activated T cells are antigen driven. This conclusion has serious implications for our thinking about vaccines and maintaining a level of protection in the population to deal with old and new infectious diseases.
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Immunological Memory ≠ protective immunity
Cellular and Molecular Life Sciences, 2012Co-Authors: Rolf M ZinkernagelAbstract:So-called ‘Immunological Memory’ is, in my view, a typical example where a field of enquiry, i.e. to understand long-term protection to survive reexposure to infection, has been overtaken by ‘l’art pour l’art’ of ‘basic immunology’. The aim of this critical review is to point out some key differences between academic text book-defined Immunological Memory and protective immunity as viewed from a co-evolutionary point of view, both from the host and the infectious agents. A key conclusion is that ‘Immunological Memory’ of course exists, but only in particular experimental laboratory models measuring ‘quicker and better’ responses after an earlier immunization. These often do correlate with, but are not the key mechanisms of, protection. Protection depends on pre-existing neutralizing antibodies or pre-activated T cells at the time of infection—as documented by the importance of maternal antibodies around birth for survival of the offspring. Importantly, both high levels of antibodies and of activated T cells are antigen driven. This conclusion has serious implications for our thinking about vaccines and maintaining a level of protection in the population to deal with old and new infectious diseases.
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protective immunity by pre existent neutralizing antibody titers and preactivated t cells but not by so called Immunological Memory
Immunological Reviews, 2006Co-Authors: Rolf M Zinkernagel, Hans HengartnerAbstract:Summary: The idea of Immunological Memory originally arose from the observation that survivors of infections were subsequently resistant to disease caused by the same infection. While most immunologists accept a special ‘remembering’ Memory quality, we have argued previously and document here that increased resistance against re-infection, i.e. immunity, reflects low-level antigen-driven T- and B-cell responses, resulting in elevated serum or mucosal titers of protective antibodies or of activated T cells, respectively. Periodic antigen re-exposure is from within, by persisting infection (long-term) or by immune complexes (short-term), or from without, by low-level re-infections. This simple concept is supported by clinical evidence and model experiments but is often ignored, although this concept, but not so-called ‘Immunological Memory’, as defined in textbooks (i.e. earlier and better responses of a primed host), is compatible with evolutionary maternal antibody transfer of protection as well as immunity against existing infections. The concept of ‘immunity without Immunological remembering Memory’ explains why it is easy to generate vaccines against acute cytopathic infections, particularly those of early childhood, where neutralizing antibodies are the key to protection, because it has been validated by adoptive transfer of maternal antibodies. It also explains why we have not succeeded (yet?) to generate truly protective vaccines against persisting infections, because we cannot imitate ‘infection immunity’ that is long-lasting, generating protective T- and B-cell stimulation against variable infections without causing disease by either immunopathology or tolerance.
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on differences between immunity and Immunological Memory
Current Opinion in Immunology, 2002Co-Authors: Rolf M ZinkernagelAbstract:Abstract The evolutionary benefits of Immunological Memory are important: whereas antibodies can be transmitted to offspring by their mother and thereby benefit the species, T cell Memory may function to help the individual combat persistent infection in peripheral tissues. Although experimental Immunological Memory is largely maintained antigen-independently, protective immunity is antigen-dependent.
Jan Born - One of the best experts on this subject based on the ideXlab platform.
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system consolidation during sleep a common principle underlying psychological and Immunological Memory formation
Trends in Neurosciences, 2015Co-Authors: Jurgen Westermann, Tanja Lange, Johannes Textor, Jan BornAbstract:Sleep benefits the consolidation of psychological Memory, and there are hints that sleep likewise supports Immunological Memory formation. Comparing psychological and Immunological domains, we make the case for active system consolidation that is similarly established in both domains and partly conveyed by the same sleep-associated processes. In the psychological domain, neuronal reactivation of declarative Memory during slow-wave sleep (SWS) promotes the redistribution of representations initially stored in hippocampal circuitry to extra-hippocampal circuitry for long-term storage. In the Immunological domain, SWS seems to favor the redistribution of antigenic memories initially held by antigen-presenting cells, to persisting T cells serving as a long-term store. Because storage capacities are limited in both systems, system consolidation presumably reduces information by abstracting 'gist' for long-term storage.
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sleep after vaccination boosts Immunological Memory
Journal of Immunology, 2011Co-Authors: Tanja Lange, Stoyan Dimitrov, Thomas Bollinger, Susanne Diekelmann, Jan BornAbstract:Sleep regulates immune functions. We asked whether sleep can influence Immunological Memory formation. Twenty-seven healthy men were vaccinated against hepatitis A three times, at weeks 0, 8, and 16 with conditions of sleep versus wakefulness in the following night. Sleep was recorded polysomnographically, and hormone levels were assessed throughout the night. Vaccination-induced Th cell and Ab responses were repeatedly monitored for 1 y. Compared with the wake condition, sleep after vaccination doubled the frequency of Ag-specific Th cells and increased the fraction of Th1 cytokine-producing cells in this population. Moreover, sleep markedly increased Ag-specific IgG1. The effects were followed up for 1 y and were associated with high sleep slow-wave activity during the postvaccination night as well as with accompanying levels of immunoregulatory hormones (i.e., increased growth hormone and prolactin but decreased cortisol release). Our findings provide novel evidence that sleep promotes human Th1 immune responses, implicating a critical role for slow-wave sleep in this process. The proinflammatory milieu induced during this sleep stage apparently acts as adjuvant that facilitates the transfer of antigenic information from APCs to Ag-specific Th cells. Like the nervous system, the immune system takes advantage of the offline conditions during sleep to foster adaptive immune responses resulting in improved Immunological Memory.
Mihai G Netea - One of the best experts on this subject based on the ideXlab platform.
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Immunological Memory lessons from the past and a look to the future
Nature Reviews Immunology, 2016Co-Authors: Donna L Farber, Andreas Radbruch, Mihai G Netea, Klaus Rajewsky, Rolf M ZinkernagelAbstract:Immunological Memory is considered to be one of the cardinal features of the adaptive immune system. Despite being a recognized phenomenon since the time of the ancient Greeks, immunologists are yet to fully appreciate the mechanisms that control Memory responses in the immune system. Furthermore, our definition of Immunological Memory itself continues to evolve, with recent suggestions that innate immune cells also show Memory-like behaviour. In this Viewpoint article, Nature Reviews Immunology invites five leading immunologists to share their thoughts on our current understanding of the nature of Immunological Memory. Our experts highlight some of the seminal studies that have shaped the immune Memory field and offer contrasting views on the key questions that remain to be addressed.
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Immunological Memory in innate immunity
Journal of Innate Immunity, 2014Co-Authors: Mihai G NeteaAbstract:‘trained immunity’. Trained immunity provides protection against reinfection in a T-/B-cell-independent manner, with nonspecific potentiation of inflammatory reactions and antimicrobial mechanisms playing a central role in these effects [4] . The current issue of the Journal of Innate Immunity presents a series of studies that shed additional light on important aspects of the adaptive properties of innate immunity. One of the most important groups of organisms in which innate immune Memory has been reported are insects. In a study in Anopheles gambiae mosquitoes, Ramirez et al. [5] describe the cellular and molecular pathways responsible for the priming of the hematocytes of the insect during infections with plasmodia. The role of innate immune cells for the capacity of innate host defense to adapt to stimuli has been previously stated both in insects and vertebrates [2] . An additional argument for adaptive effects in innate immune cells is provided by the study of Short et al. [6] , which demonstrates that innate immune stimulation with a microbial ligand, in this case lipopolysaccharide, decreases susceptibility to influenza. Nonspecific effects of lipopolysaccharides on antiviral type I interferons are involved in these effects. In addition to effects mediated through cellular mechanisms, generation of natural xenoantibodies also induces Traditionally, vertebrate immune responses have been divided into innate responses, which are rapid, nonspecific and incapable of building immune Memory, and adaptive responses, which develop more slowly, are highly specific, and build a long-term Immunological Memory. While the nonspecificity of innate immune responses has been challenged by the discovery of pattern recognition receptors, recent studies suggest that adaptive characteristics are also found in cells of the innate immune system [1] . This concept has been supported by studies in plants, invertebrates, and mammals, with a paradigm shift in our understanding of host defense, and mounting evidence for innate immune Memory, i.e. increased responses to secondary infections [2] . The adaptive characteristics of innate immune Memory are exerted at several levels. Earlier studies have shown that an enhanced state of innate immunity can be triggered by certain infections or vaccinations, which are mediated by prototypical innate immune cells such as natural killer cells and monocytes/macrophages. Changes at the level of membrane receptors on the cell surface of natural killer cells [3] or epigenetic reprogramming of monocytes and macrophages through histone modifications [4] are some of the mechanisms mediating innate immune Memory, and this process has been also termed Published online: December 5, 2013 Journal of Innate Immunity
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training innate immunity the changing concept of Immunological Memory in innate host defence
European Journal of Clinical Investigation, 2013Co-Authors: Mihai G NeteaAbstract:The inability of innate immunity to build an Immunological Memory is considered a main difference with adaptive immunity. This concept has been challenged by studies in plants, invertebrates and mammals. Recently, a paradigm shift in our understanding host defence has been triggered by the mounting evidence for innate immune Memory, leading to increased responses to secondary infections. Important differences between the cell populations and the molecular mechanisms exist between the adaptive traits of innate host defence on the one hand and Immunological Memory of adaptive immunity on the other hand. The lasting state of enhanced innate immunity termed ‘trained immunity’ is mediated by prototypical innate immune cells such as natural killer cells and monocytes/macrophages. It provides protection against reinfection in a T/B-cell-independent manner, with both specific mechanisms and nonspecific epigenetic reprogramming mediating these effects. This concept represents a paradigm change in immunity, and its putative role in resistance to reinfection may represent the next step in the design of future vaccines.
