scholarly journals Immune responses of a CV-A16 live attenuated candidate strain and its protective effects in rhesus monkeys

2020 ◽  
Vol 9 (1) ◽  
pp. 2136-2146
Author(s):  
Ting Yang ◽  
Tianhong Xie ◽  
Hua Li ◽  
Xia Song ◽  
Lei Yue ◽  
...  
Author(s):  
Xiaowei Yang ◽  
Yifang Yang ◽  
Yong Wang ◽  
Qi Wei ◽  
Hui Ding ◽  
...  

2021 ◽  
Vol 12 ◽  
Author(s):  
Hyeogsun Kwon ◽  
David R. Hall ◽  
Ryan C. Smith

Lipid-derived signaling molecules known as eicosanoids have integral roles in mediating immune and inflammatory processes across metazoans. This includes the function of prostaglandins and their cognate G protein-coupled receptors (GPCRs) to employ their immunological actions. In insects, prostaglandins have been implicated in the regulation of both cellular and humoral immune responses, yet in arthropods of medical importance, studies have been limited. Here, we describe a prostaglandin E2 receptor (AgPGE2R) in the mosquito Anopheles gambiae and demonstrate that its expression is most abundant in oenocytoid immune cell populations. Through the administration of prostaglandin E2 (PGE2) and AgPGE2R-silencing, we demonstrate that prostaglandin E2 signaling regulates a subset of prophenoloxidases (PPOs) and antimicrobial peptides (AMPs) that are strongly expressed in populations of oenocytoids. We demonstrate that PGE2 signaling via the AgPGE2R significantly limits both bacterial replication and Plasmodium oocyst survival. Additional experiments establish that PGE2 treatment increases phenoloxidase (PO) activity through the increased expression of PPO1 and PPO3, genes essential to anti-Plasmodium immune responses that promote oocyst killing. We also provide evidence that the mechanisms of PGE2 signaling are concentration-dependent, where high concentrations of PGE2 promote oenocytoid lysis, negating the protective effects of lower concentrations of PGE2 on anti-Plasmodium immunity. Taken together, our results provide new insights into the role of PGE2 signaling on immune cell function and its contributions to mosquito innate immunity that promote pathogen killing.


Viruses ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 762 ◽  
Author(s):  
Maria K. Smatti ◽  
Farhan S. Cyprian ◽  
Gheyath K. Nasrallah ◽  
Asmaa A. Al Thani ◽  
Ruba O. Almishal ◽  
...  

For a long time, viruses have been shown to modify the clinical picture of several autoimmune diseases, including type 1 diabetes (T1D), systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), Sjögren’s syndrome (SS), herpetic stromal keratitis (HSK), celiac disease (CD), and multiple sclerosis (MS). Best examples of viral infections that have been proposed to modulate the induction and development of autoimmune diseases are the infections with enteric viruses such as Coxsackie B virus (CVB) and rotavirus, as well as influenza A viruses (IAV), and herpesviruses. Other viruses that have been studied in this context include, measles, mumps, and rubella. Epidemiological studies in humans and experimental studies in animal have shown that viral infections can induce or protect from autoimmunopathologies depending on several factors including genetic background, host-elicited immune responses, type of virus strain, viral load, and the onset time of infection. Still, data delineating the clear mechanistic interaction between the virus and the immune system to induce autoreactivity are scarce. Available data indicate that viral-induced autoimmunity can be activated through multiple mechanisms including molecular mimicry, epitope spreading, bystander activation, and immortalization of infected B cells. Contrarily, the protective effects can be achieved via regulatory immune responses which lead to the suppression of autoimmune phenomena. Therefore, a better understanding of the immune-related molecular processes in virus-induced autoimmunity is warranted. Here we provide an overview of the current understanding of viral-induced autoimmunity and the mechanisms that are associated with this phenomenon.


2016 ◽  
Vol 125 (1) ◽  
pp. 237-249 ◽  
Author(s):  
Harmke D. Kiers ◽  
Gert-Jan Scheffer ◽  
Johannes G. van der Hoeven ◽  
Holger K. Eltzschig ◽  
Peter Pickkers ◽  
...  

Abstract Hypoxia and immunity are highly intertwined at clinical, cellular, and molecular levels. The prevention of tissue hypoxia and modulation of systemic inflammation are cornerstones of daily practice in the intensive care unit. Potentially, immunologic effects of hypoxia may contribute to outcome and represent possible therapeutic targets. Hypoxia and activation of downstream signaling pathways result in enhanced innate immune responses, aimed to augment pathogen clearance. On the other hand, hypoxia also exerts antiinflammatory and tissue-protective effects in lymphocytes and other tissues. Although human data on the net immunologic effects of hypoxia and pharmacologic modulation of downstream pathways are limited, preclinical data support the concept of tailoring the immune response through modulation of the oxygen status or pharmacologic modulation of hypoxia-signaling pathways in critically ill patients.


2019 ◽  
Vol 10 (2) ◽  
pp. 1132-1145 ◽  
Author(s):  
Meiling Liu ◽  
Xiuxia Zhang ◽  
Yunpeng Hao ◽  
Jinhua Ding ◽  
Jing Shen ◽  
...  

Multiple articles have confirmed that an imbalance of the intestinal microbiota is closely related to aberrant immune responses of the intestines and to the pathogenesis of inflammatory bowel diseases (IBDs).


Author(s):  
Quan-Zhen Lv ◽  
De-Dong Li ◽  
Hua Han ◽  
Yi-Heng Yang ◽  
Jie-Lin Duan ◽  
...  

Abstract The morphological switch between yeast and hyphae of Candida albicans is essential for its interaction with the host defense system. However, the lack of understanding of host–pathogen interactions during C. albicans infection greatly hampers the development of effective immunotherapies. Here, we found that priming with the C. albicans FLO8-deficient (flo8) mutant, locked in yeast form, protected mice from subsequent lethal C. albicans infection. Deficiency of Dectin-2, a fungus-derived α-mannan recognition receptor, completely blocked flo8 mutant-induced protection. Mechanistically, the flo8 mutant-induced Dectin-2/CARD9-mediated IL-10 production in DCs and macrophages to block thymus atrophy by inhibiting the C. albicans-induced apoptosis of thymic T cells, which facilitated the continuous output of naive T cells from the thymus to the spleen. Continuous recruitment of naive T cells to the spleen enhanced Th1-biased antifungal immune responses. Consequently, depletion of CD4+ T cells or blockade of IL-10 receptor function using specific antibodies in mice completely blocked the protective effects of flo8 mutant priming against C. albicans infection. Moreover, mannans exposed on the surface of the flo8 mutant were responsible for eliciting protective immunity by inhibiting the C. albicans-induced apoptosis of thymic T cells to sustain the number of naive T cells in the spleen. Importantly, priming with the flo8 mutant extensively protected mice from polymicrobial infection caused by cecal ligation and puncture (CLP) by enhancing Th1-biased immune responses. Together, our findings imply that targeting FLO8 in C. albicans elicits protective immune responses against polymicrobial infections and that mannans extracted from the flo8 mutant are potential immunotherapeutic candidate(s) for controlling infectious diseases.


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