Stimulation of innate immune responses by malarial glycosylphosphatidylinositol via pattern recognition receptors

Parasitology ◽  
2005 ◽  
Vol 130 (S1) ◽  
pp. S45-S62 ◽  
Author(s):  
T. NEBL ◽  
M. J. DE VEER ◽  
L. SCHOFIELD

The glycosylphosphatidylinositol (GPI) anchor ofPlasmodium falciparumis thought to function as a critical toxin that contributes to severe malarial pathogenesis by eliciting the production of proinflammatory responses by the innate immune system of mammalian hosts. Analysis of the fine structure ofP. falciparumGPI suggests a requirement for the presence of both core glycan and lipid moieties in the recognition and signalling of parasite glycolipids by host immune cells. It has been demonstrated that GPI anchors of various parasitic protozoa can mediate cellular immune responses via members of the Toll-like family of pattern recognition receptors (TLRs). Recent studies indicate that GPI anchors ofP. falciparumand other protozoa are preferentially recognized by TLR-2, involving the MyD88-dependent activation of specific signalling pathways that mediate the production of proinflammatory cytokines and nitric oxide from host macrophagesin vitro. However, the contribution of malaria GPI toxin to severe disease syndromes and the role of specific TLRs or other pattern recognition receptors in innate immunityin vivois only just beginning to be characterized. A better understanding of the molecular mechanisms underlying severe malarial pathogenesis may yet lead to substantial new insights with important implications for the development of novel therapeutics for malaria treatment.

2020 ◽  
Author(s):  
naorem nihesh ◽  
Saikat Manna ◽  
Bradley Studnitzer ◽  
Jingjing Shen ◽  
Aaron Esser-Kahn

We developed a small-molecule trimeric PRR agonist-based adjuvant inspired by the stimulation pattern of a pathogen. This molecule generated by covalently linking TLR2/6 agonist, NOD2 agonist, and NLRP3 inflammasome activator, stimulates multiple subfamilies of PRRs in a spatially defined manner resulting in an amplified innate immune response <i>in vitro.</i> Moreover, it elicits both stronger humoral and cellular immune responses <i>in vivo</i>.


2020 ◽  
Author(s):  
naorem nihesh ◽  
Saikat Manna ◽  
Bradley Studnitzer ◽  
Jingjing Shen ◽  
Aaron Esser-Kahn

We developed a small-molecule trimeric PRR agonist-based adjuvant inspired by the stimulation pattern of a pathogen. This molecule generated by covalently linking TLR2/6 agonist, NOD2 agonist, and NLRP3 inflammasome activator, stimulates multiple subfamilies of PRRs in a spatially defined manner resulting in an amplified innate immune response <i>in vitro.</i> Moreover, it elicits both stronger humoral and cellular immune responses <i>in vivo</i>.


2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Cheng-Kang Tang ◽  
Chih-Hsuan Tsai ◽  
Carol-P. Wu ◽  
Yu-Hsien Lin ◽  
Sung-Chan Wei ◽  
...  

AbstractTo avoid inducing immune and physiological responses in insect hosts, parasitoid wasps have developed several mechanisms to inhibit them during parasitism, including the production of venom, specialized wasp cells, and symbioses with polydnaviruses (PDVs). These mechanisms alter the host physiology to give the wasp offspring a greater chance of survival. However, the molecular mechanisms for most of these alterations remain unclear. In the present study, we applied next-generation sequencing analysis and identified several miRNAs that were encoded in the genome of Snellenius manilae bracovirus (SmBV), and expressed in the host larvae, Spodoptera litura, during parasitism. Among these miRNAs, SmBV-miR-199b-5p and SmBV-miR-2989 were found to target domeless and toll-7 in the host, which are involved in the host innate immune responses. Microinjecting the inhibitors of these two miRNAs into parasitized S. litura larvae not only severely decreased the pupation rate of Snellenius manilae, but also restored the phagocytosis and encapsulation activity of the hemocytes. The results demonstrate that these two SmBV-encoded miRNAs play an important role in suppressing the immune responses of parasitized hosts. Overall, our study uncovers the functions of two SmBV-encoded miRNAs in regulating the host innate immune responses upon wasp parasitism.


Vaccines ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 1408
Author(s):  
Qiao Li ◽  
Zhihua Liu ◽  
Yi Liu ◽  
Chen Liang ◽  
Jiayi Shu ◽  
...  

TFPR1 is a novel adjuvant for protein and peptide antigens, which has been demonstrated in BALB/c mice in our previous studies; however, its adjuvanticity in mice with different genetic backgrounds remains unknown, and its adjuvanticity needs to be improved to fit the requirements for various vaccines. In this study, we first compared the adjuvanticity of TFPR1 in two commonly used inbred mouse strains, BALB/c and C57BL/6 mice, in vitro and in vivo, and demonstrated that TFPR1 activated TLR2 to exert its immune activity in vivo. Next, to prove the feasibility of TFPR1 acting as a major component of combined adjuvants, we prepared a combined adjuvant, TF–Al, by formulating TFPR1 and alum at a certain ratio and compared its adjuvanticity with that of TFPR1 and alum alone using OVA and recombinant HBsAg as model antigens in both BALB/c and C57BL/6 mice. Results showed that TFPR1 acts as an effective vaccine adjuvant in both BALB/c mice and C57BL/6 mice, and further demonstrated the role of TLR2 in the adjuvanticity of TFPR1 in vivo. In addition, we obtained a novel combined adjuvant, TF–Al, based on TFPR1, which can augment antibody and cellular immune responses in mice with different genetic backgrounds, suggesting its promise for vaccine development in the future.


2020 ◽  
Vol 11 ◽  
Author(s):  
Gaël Auray ◽  
Stephanie C. Talker ◽  
Irene Keller ◽  
Sylvie Python ◽  
Markus Gerber ◽  
...  

2010 ◽  
Vol 138 (5) ◽  
pp. S-36
Author(s):  
Yvonne Junker ◽  
Donatella Barisani ◽  
Daniel A. Leffler ◽  
Towia Libermann ◽  
Simon T. Dillon ◽  
...  

Blood ◽  
2010 ◽  
Vol 116 (10) ◽  
pp. 1669-1677 ◽  
Author(s):  
Sergey S. Seregin ◽  
Yasser A. Aldhamen ◽  
Daniel M. Appledorn ◽  
Zachary C. Hartman ◽  
Nathaniel J. Schuldt ◽  
...  

Abstract Adenovirus (Ad) vectors are widely used in human clinical trials. However, at higher dosages, Ad vector–triggered innate toxicities remain a major obstacle to many applications. Ad interactions with the complement system significantly contribute to innate immune responses in several models of Ad-mediated gene transfer. We constructed a novel class of Ad vectors, genetically engineered to “capsid-display” native and retro-oriented versions of the human complement inhibitor decay-accelerating factor (DAF), as a fusion protein from the C-terminus of the Ad capsid protein IX. In contrast to conventional Ad vectors, DAF-displaying Ads dramatically minimized complement activation in vitro and complement-dependent immune responses in vivo. DAF-displaying Ads did not trigger thrombocytopenia, minimized endothelial cell activation, and had diminished inductions of proinflammatory cytokine and chemokine responses. The retro-oriented display of DAF facilitated the greatest improvements in vivo, with diminished activation of innate immune cells, such as dendritic and natural killer cells. In conclusion, Ad vectors can capsid-display proteins in a manner that not only retains the functionality of the displayed proteins but also potentially can be harnessed to improve the efficacy of this important gene transfer platform for numerous gene transfer applications.


2010 ◽  
Vol 131 (2) ◽  
pp. 113-119 ◽  
Author(s):  
Whasun O. Chung ◽  
Jonathan Y. An ◽  
Lei Yin ◽  
Beth M. Hacker ◽  
Maryam G. Rohani ◽  
...  

2019 ◽  
Vol 116 (21) ◽  
pp. 10441-10446 ◽  
Author(s):  
Xiao Han ◽  
Mengning Wang ◽  
Songwei Duan ◽  
Paul J. Franco ◽  
Jennifer Hyoje-Ryu Kenty ◽  
...  

Polymorphic HLAs form the primary immune barrier to cell therapy. In addition, innate immune surveillance impacts cell engraftment, yet a strategy to control both, adaptive and innate immunity, is lacking. Here we employed multiplex genome editing to specifically ablate the expression of the highly polymorphic HLA-A/-B/-C and HLA class II in human pluripotent stem cells. Furthermore, to prevent innate immune rejection and further suppress adaptive immune responses, we expressed the immunomodulatory factors PD-L1, HLA-G, and the macrophage “don’t-eat me” signal CD47 from the AAVS1 safe harbor locus. Utilizing in vitro and in vivo immunoassays, we found that T cell responses were blunted. Moreover, NK cell killing and macrophage engulfment of our engineered cells were minimal. Our results describe an approach that effectively targets adaptive as well as innate immune responses and may therefore enable cell therapy on a broader scale.


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