scholarly journals Mucosal Immunization with High-Mobility Group Box 1 in Chitosan Enhances DNA Vaccine-Induced Protection against Coxsackievirus B3-Induced Myocarditis

2013 ◽  
Vol 20 (11) ◽  
pp. 1743-1751 ◽  
Author(s):  
Maowei Wang ◽  
Yan Yue ◽  
Chunsheng Dong ◽  
Xiaoyun Li ◽  
Wei Xu ◽  
...  

ABSTRACTCoxsackievirus B3 (CVB3), a small single-stranded RNA virus, belongs to thePicornaviridaefamily. Its infection is the most common cause of myocarditis, with no vaccine available. Gastrointestinal mucosa is the major entry port for CVB3; therefore, the induction of local immunity in mucosal tissues may help control initial viral infections and alleviate subsequent myocardial injury. Here we evaluated the ability of high-mobility group box 1 (HMGB1) encapsulated in chitosan particles to enhance the mucosal immune responses induced by the CVB3-specific mucosal DNA vaccine chitosan-pVP1. Mice were intranasally coimmunized with 4 doses of chitosan-pHMGB1 and chitosan-pVP1 plasmids, at 2-week intervals, and were challenged with CVB3 4 weeks after the last immunization. Compared with chitosan-pVP1 immunization alone, coimmunization with chitosan-pHMGB1 significantly (P< 0.05) enhanced CVB3-specific fecal secretory IgA levels and promoted mucosal T cell immune responses. In accordance, reduced severity of myocarditis was observed in coimmunized mice, as evidenced by significantly (P< 0.05) reduced viral loads, decreased myocardial injury, and increased survival rates. Flow cytometric analysis indicated that HMGB1 enhanced dendritic cell (DC) recruitment to mesenteric lymph nodes and promoted DC maturation, which might partly account for its mucosal adjuvant effect. This strategy may represent a promising approach to candidate vaccines against CVB3-induced myocarditis.

2019 ◽  
Vol 393 (8) ◽  
pp. 1527-1539 ◽  
Author(s):  
Hanqing Liu ◽  
Wei Liu ◽  
Huiliang Qiu ◽  
Dezhi Zou ◽  
Huayang Cai ◽  
...  

AbstractSalvianolic acid B (Sal B) has a significant protective effect on myocardial ischaemia-reperfusion (I/R) injury. Therefore, the aims of this study were to determine the effects of Sal B on myocardial ischaemic-reperfusion (I/R) injury in rats and to explore whether its underlying mechanism of cardioprotection occurs through activating the expression of the phosphoinositide 3-kinase/protein, kinase B (PI3K/Akt) and inhibiting the expression of high mobility group protein 1 (HMGB1). Ninety Sprague-Dawley rats were randomized into five groups: group 1 (sham-operated), group 2 (myocardial I/R), group 3 (low dose of Sal B+I/R), group 4 (high dose of Sal B+I/R), and group 5 (high dose of Sal B+I/R+LY294002, which is a specific PI3k inhibitor). All I/R rats received 30 min myocardial ischaemia followed by 24-h reperfusion. Cardiac function, infarct size, myocardial injury marker levels, inflammatory response and cardiomyocyte apoptosis as well as Bcl-2, Bax, P-Akt, HMGB1 and TLR4 expression were measured. In the current study, Sal B significantly ameliorated myocardial I/R injury in a dose-dependent manner, ameliorated cardiac function, reduced myocardial infarction size, decreased myocardial injury marker expression, decreased inflammatory responses, reduced apoptosis, activated PI3K/Akt expression and inhibited HMGB1 expression. However, all effects of Sal B were significantly reversed by LY294002. Overall, the present study indicated that Sal B attenuated myocardial I/R injury by activating PI3K/Akt and inhibiting the release of HMGB1 in rats.


2019 ◽  
Author(s):  
Annika Volmari ◽  
Katharina Foelsch ◽  
Karsten Yan ◽  
Minyue Qi ◽  
Karlotta Bartels ◽  
...  

AbstractHigh-mobility group box 1 (HMGB1) is a damage-associated molecular pattern with key proinflammatory functions following tissue injury. Moreover, HMGB1 neutralization was shown to alleviate LPS-induced shock, suggesting a role for the protein as a master therapeutic target for inflammatory and infectious diseases. Here, we report that HMGB1 neutralization impedes immune responses to Listeria monocytogenes, a wide-spread bacterium with pathogenic relevance for humans and rodents. Using genetic deletion strategies and neutralizing antibodies, we demonstrate that hepatocyte HMGB1, a major driver of post-necrotic inflammation in the liver, is dispensable for pathogen defense during moderately severe infection with listeria. In contrast, antibody-mediated HMGB1 neutralization and HMGB1 deficiency in myeloid cells effectuate rapid and uncontrolled bacterial dissemination in mice despite preserved basic leukocyte functionality and autophagy induction. During overwhelming infection, hepatocyte injury may contribute to increased HMGB1 serum levels and excessive inflammation in the liver, supporting context-dependent roles for HMGB1 from different cellular compartments during infection. We provide mechanistic evidence that HMGB1 from circulating immune cells contributes to the timely induction of hepatic immune regulatory gene networks, early inflammatory monocyte recruitment to the liver and promotion of neutrophil survival, which are mandatory for pathogen control. In summary, our data establish HMGB1 as a critical co-factor in the immunological clearance of listeria, and argue against HMGB1 neutralization as a universal therapeutic strategy for sepsis.Author summaryHigh-mobility group box 1 (HMGB1) is an abundantly expressed nucleoprotein with signaling properties following secretion or release into the extracellular space. Given its central immune-regulatory roles during tissue injury and LPS-induced septic shock, interventions aimed at HMGB1 signaling have been advocated as therapeutic options for various disease conditions. Here, we show that antibody-mediated HMGB1 neutralization interferes with immunological defense against Listeria monocytogenes, a gram-positive bacterium with high pathogenic relevance for rodents and humans, effectuating uncontrolled bacterial growth and inflammation. Using conditional knockout animals, we demonstrate that while leukocyte functionality is preserved in HMGB1-deficient myeloid cells, HMGB1 released in response to Listeria triggers hepatic inflammatory monocyte recruitment and activation of transcriptional immune networks required for the early control of bacterial dissemination. Hepatocyte HMGB1, a key driver of post-necrotic inflammation in the liver, is dispensable for the immune response during moderately severe infection, but likely contributes to excessive hepatitis when infection is uncontrolled and cellular injury is high. We demonstrate a critical and non-redundant role for HMGB1 in the immune-mediated clearance of listeriosis and argue against HMGB1 neutralization as a universal therapeutic option in the context of infection.


IUBMB Life ◽  
2020 ◽  
Vol 72 (5) ◽  
pp. 931-941 ◽  
Author(s):  
Xueyun Yan ◽  
Peier Xu ◽  
Le Zhou ◽  
Jinyue Lu ◽  
Haihua Tang ◽  
...  

2011 ◽  
Vol 209 (1) ◽  
pp. 157-171 ◽  
Author(s):  
De Yang ◽  
Yuri V. Postnikov ◽  
Yana Li ◽  
Poonam Tewary ◽  
Gonzalo de la Rosa ◽  
...  

Alarmins are endogenous mediators capable of promoting the recruitment and activation of antigen-presenting cells (APCs), including dendritic cells (DCs), that can potentially alert host defense against danger signals. However, the relevance of alarmins to the induction of adaptive immune responses remains to be demonstrated. In this study, we report the identification of HMGN1 (high-mobility group nucleosome-binding protein 1) as a novel alarmin and demonstrate that it contributes to the induction of antigen-specific immune responses. HMGN1 induced DC maturation via TLR4 (Toll-like receptor 4), recruitment of APCs at sites of injection, and activation of NF-κB and multiple mitogen-activated protein kinases in DCs. HMGN1 promoted antigen-specific immune response upon co-administration with antigens, and Hmgn1−/− mice developed greatly reduced antigen-specific antibody and T cell responses when immunized with antigens in the presence of lipopolysaccharide (LPS). The impaired ability of Hmgn1−/− mice to mount antigen-specific immune responses was accompanied by both deficient DC recruitment at sites of immunization and reduced production of inflammatory cytokines. Bone marrow chimera experiments revealed that HMGN1 derived from nonleukocytes was critical for the induction of antigen-specific antibody and T cell responses. Thus, extracellular HMGN1 acts as a novel alarmin critical for LPS-induced development of innate and adaptive immune responses.


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