scholarly journals Mosquito saliva sialokinin-dependent enhancement of arbovirus infection through endothelial barrier leakage

2021 ◽  
Author(s):  
Daniella A Lefteri ◽  
Steven R Bryden ◽  
Marieke Pingen ◽  
Sandra Terry ◽  
Emily F Beswick ◽  
...  
Keyword(s):  
Immune Responses ◽  
Vascular Function ◽  
Rational Design ◽  
Complex Mixture ◽  
Host Susceptibility ◽  
Endothelial Barrier ◽  
Rapid Reduction ◽  
Salivary Microbiota ◽  
Mosquito Saliva ◽  
Arbovirus Infection

SummaryViruses transmitted by Aedes mosquitoes constitute an increasingly important global health burden. Defining common determinants of host susceptibility to this large group of heterogenous pathogens are key for informing the rational design of new pan-viral medicines. Infection of the vertebrate host with these viruses is enhanced by the presence of mosquito saliva, a complex mixture of salivary gland-derived factors and microbiota. We show that enhancement of infection by saliva was dependent on vascular function and was independent of most anti-saliva immune responses, including to salivary microbiota. Instead, the Aedes gene product sialokinin mediated enhancement of virus infection through a rapid reduction in endothelial barrier integrity. Sialokinin is unique within the insect world as having vertebrate-like tachykinin sequence and is absent from non-vector competent Anopheles mosquitoes, whose saliva was not pro-viral and did not induce similar vascular permeability. Therapeutic strategies targeting sialokinin have potential to limit disease severity following infection with Aedes mosquito-borne viruses.

scholarly journals SUMOylation restrains ACE2 degradation through TOLLIP-mediated selective autophagy to facilitate the host susceptibility to SARS-CoV-2 infection

2021 ◽  
Author(s):  
Jun Cui ◽  
Shouheng Jin ◽  
Xing He ◽  
Ling Ma ◽  
Meng Lin ◽  
...  
Keyword(s):  
Immune Responses ◽  
Antiviral Therapy ◽  
Rational Design ◽  
Interaction Analysis ◽  
Host Susceptibility ◽  
Pharmacological Intervention ◽  
Selective Autophagy ◽  
Sumo Ligase ◽  
Autophagic Degradation ◽  
Entry Receptor

Abstract Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent of the ongoing coronavirus disease 2019 (COVID-19) pandemic. Alongside investigations into the virology of SARS-CoV-2, understanding the host–virus dependencies are vital for the identification and rational design of effective antiviral therapy. Here, we report the dominant SARS-CoV-2 entry receptor, ACE2, conjugates with small ubiquitin-like modifier 3 (SUMO3) through a proteome-wide protein interaction analysis. We further demonstrate that E3 SUMO ligase PIAS4 prompts the SUMOylation and stabilization of ACE2, whereas deSUMOylation enzyme SENP3 reverses this process. Conjugation of SUMO3 with ACE2 at lysine (K) 187 hampers the K48-linked ubiquitination of ACE2, thus suppressing its subsequent cargo receptor TOLLIP-dependent autophagic degradation. Pharmacological intervention of ACE2 SUMOylation blocks the entry of SARS-CoV-2 and viral infection-triggered immune responses. Collectively, our findings suggest selective autophagic degradation of ACE2 orchestrated by SUMOylation and ubiquitination can be targeted to future antiviral therapy of SARS-CoV-2.

scholarly journals Intestinal Microbiota as an Alternative Therapeutic Target for Epilepsy

2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Jiaying Wu ◽  
Yuyu Zhang ◽  
Hongyu Yang ◽  
Yuefeng Rao ◽  
Jing Miao ◽  
...  
Keyword(s):  
Immune Responses ◽  
Intestinal Microbiota ◽  
Neurological Disorders ◽  
Digestive System ◽  
Hygiene Hypothesis ◽  
Host Susceptibility ◽  
Immune Disorders ◽  
The Central Nervous System ◽  
Symbiotic Microbiota

Epilepsy is one of the most widespread serious neurological disorders, and an aetiological explanation has not been fully identified. In recent decades, a growing body of evidence has highlighted the influential role of autoimmune mechanisms in the progression of epilepsy. The hygiene hypothesis draws people’s attention to the association between gut microbes and the onset of multiple immune disorders. It is also believed that, in addition to influencing digestive system function, symbiotic microbiota can bidirectionally and reversibly impact the programming of extraintestinal pathogenic immune responses during autoimmunity. Herein, we investigate the concept that the diversity of parasitifer sensitivity to commensal microbes and the specific constitution of the intestinal microbiota might impact host susceptibility to epilepsy through promotion of Th17 cell populations in the central nervous system (CNS).

scholarly journals Modulation of arbovirus infection by mosquito saliva

2019 ◽  
Vol 1 (10) ◽  
Author(s):  
Daniella A Lefteri ◽  
Emilie Pondeville ◽  
Steven R Bryden ◽  
Marieke Pingen ◽  
Clive S McKimmie
Keyword(s):  
Mosquito Saliva ◽  
Arbovirus Infection

scholarly journals Prior exposure to long-day photoperiods alters immune responses and increases susceptibility to parasitic infection in stickleback

2020 ◽  
Vol 287 (1930) ◽  
pp. 20201017
Author(s):  
James R. Whiting ◽  
Muayad A. Mahmud ◽  
Janette E. Bradley ◽  
Andrew D. C. MacColl
Keyword(s):  
Immune Responses ◽  
Parasitic Infection ◽  
Population Variation ◽  
Host Susceptibility ◽  
Day Length ◽  
Previous Exposure ◽  
Parasite Abundance ◽  
Susceptibility To Infection ◽  
Long Day ◽  
Host Parasite

Seasonal disease and parasitic infection are common across organisms, including humans, and there is increasing evidence for intrinsic seasonal variation in immune systems. Changes are orchestrated through organisms' physiological clocks using cues such as day length. Ample research in diverse taxa has demonstrated multiple immune responses are modulated by photoperiod, but to date, there have been few experimental demonstrations that photoperiod cues alter susceptibility to infection. We investigated the interactions among photoperiod history, immunity and susceptibility in laboratory-bred three-spined stickleback (a long-day breeding fish) and its external, directly reproducing monogenean parasite Gyrodactylus gasterostei . We demonstrate that previous exposure to long-day photoperiods (PLD) increases susceptibility to infection relative to previous exposure to short days (PSD), and modifies the response to infection for the mucin gene muc2 and Treg cytokine foxp3a in skin tissues in an intermediate 12 L : 12 D photoperiod experimental trial. Expression of skin muc2 is reduced in PLD fish, and negatively associated with parasite abundance. We also observe inflammatory gene expression variation associated with natural inter-population variation in resistance, but find that photoperiod modulation of susceptibility is consistent across host populations. Thus, photoperiod modulation of the response to infection is important for host susceptibility, highlighting new mechanisms affecting seasonality of host–parasite interactions.

scholarly journals Rational design of antisense oligonucleotides modulating the activity of TLR7/8 agonists

2020 ◽  
Author(s):  
Arwaf S Alharbi ◽  
Aurélie J Garcin ◽  
Kim A Lennox ◽  
Solène Pradeloux ◽  
Christophe Wong ◽  
...  
Keyword(s):  
Immune Responses ◽  
Gene Targeting ◽  
Immune Suppression ◽  
Immune Cells ◽  
Antisense Oligonucleotides ◽  
Rational Design ◽  
Locked Nucleic Acid ◽  
Dependent Manner ◽  
Therapeutic Development ◽  
Proof Of Principle

Abstract Oligonucleotide-based therapeutics have become a reality, and are set to transform management of many diseases. Nevertheless, the modulatory activities of these molecules on immune responses remain incompletely defined. Here, we show that gene targeting 2′-O-methyl (2′OMe) gapmer antisense oligonucleotides (ASOs) can have opposing activities on Toll-Like Receptors 7 and 8 (TLR7/8), leading to divergent suppression of TLR7 and activation of TLR8, in a sequence-dependent manner. Surprisingly, TLR8 potentiation by the gapmer ASOs was blunted by locked nucleic acid (LNA) and 2′-methoxyethyl (2′MOE) modifications. Through a screen of 192 2′OMe ASOs and sequence mutants, we characterized the structural and sequence determinants of these activities. Importantly, we identified core motifs preventing the immunosuppressive activities of 2′OMe ASOs on TLR7. Based on these observations, we designed oligonucleotides strongly potentiating TLR8 sensing of Resiquimod, which preserve TLR7 function, and promote strong activation of phagocytes and immune cells. We also provide proof-of-principle data that gene-targeting ASOs can be selected to synergize with TLR8 agonists currently under investigation as immunotherapies, and show that rational ASO selection can be used to prevent unintended immune suppression of TLR7. Taken together, our work characterizes the immumodulatory effects of ASOs to advance their therapeutic development.

scholarly journals Induction of Protective Antiplague Immune Responses by Self-Adjuvanting Bionanoparticles Derived from Engineered Yersinia pestis

2020 ◽  
Vol 88 (5) ◽  
Author(s):  
Xiuran Wang ◽  
Amit K. Singh ◽  
Xiangmin Zhang ◽  
Wei Sun
Keyword(s):  
Immune Responses ◽  
Yersinia Pestis ◽  
Rational Design ◽  
Lipid A ◽  
Vaccine Development ◽  
Lethal Dose ◽  
Outer Membrane Vesicles ◽  
Vector System ◽  
Content Type ◽  
Monophosphoryl Lipid A

ABSTRACT A Yersinia pestis mutant synthesizing an adjuvant form of lipid A (monophosphoryl lipid A, MPLA) displayed increased biogenesis of bacterial outer membrane vesicles (OMVs). To enhance the immunogenicity of the OMVs, we constructed an Asd-based balanced-lethal host-vector system that oversynthesized the LcrV antigen of Y. pestis, raised the amounts of LcrV enclosed in OMVs by the type II secretion system, and eliminated harmful factors like plasminogen activator (Pla) and murine toxin from the OMVs. Vaccination with OMVs containing MPLA and increased amounts of LcrV with diminished toxicity afforded complete protection in mice against subcutaneous challenge with 8 × 105 CFU (80,000 50% lethal dose [LD50]) and intranasal challenge with 5 × 103 CFU (50 LD50) of virulent Y. pestis. This protection was significantly superior to that resulting from vaccination with LcrV/alhydrogel or rF1-V/alhydrogel. At week 4 postimmunization, the OMV-immunized mice showed more robust titers of antibodies against LcrV, Y. pestis whole-cell lysate (YPL), and F1 antigen and more balanced IgG1:IgG2a/IgG2b-derived Th1 and Th2 responses than LcrV-immunized mice. Moreover, potent adaptive and innate immune responses were stimulated in the OMV-immunized mice. Our findings demonstrate that self-adjuvanting Y. pestis OMVs provide a novel plague vaccine candidate and that the rational design of OMVs could serve as a robust approach for vaccine development.

scholarly journals Active vitamin D (1,25-dihydroxyvitamin D3) increases host susceptibility toCitrobacter rodentiumby suppressing mucosal Th17 responses

2012 ◽  
Vol 303 (12) ◽  
pp. G1299-G1311 ◽  
Author(s):  
Natasha R. Ryz ◽  
Scott J. Patterson ◽  
Yiqun Zhang ◽  
Caixia Ma ◽  
Tina Huang ◽  
...  
Keyword(s):  
Vitamin D ◽  
Immune Responses ◽  
Bacterial Pathogen ◽  
Enteric Bacteria ◽  
Host Susceptibility ◽  
Active Vitamin ◽  
Active Vitamin D ◽  
Increased Risk ◽  
The Impact

Vitamin D deficiency affects more that 1 billion people worldwide and is associated with an increased risk of developing a number of inflammatory/autoimmune diseases, including inflammatory bowel disease (IBD). At present, the basis for the impact of vitamin D on IBD and mucosal immune responses is unclear; however, IBD is known to reflect exaggerated immune responses to luminal bacteria, and vitamin D has been shown to play a role in regulating bacteria-host interactions. Therefore, to test the effect of active vitamin D on host responses to enteric bacteria, we gave 1,25(OH)2D3to mice infected with the bacterial pathogen Citrobacter rodentium, an extracellular microbe that causes acute colitis characterized by a strong Th1/Th17 immune response. 1,25(OH)2D3treatment of infected mice led to increased pathogen burdens and exaggerated tissue pathology. In association with their increased susceptibility, 1,25(OH)2D3-treated mice showed substantially reduced numbers of Th17 T cells within their infected colons, whereas only modest differences were noted in Th1 and Treg numbers. In accordance with the impaired Th17 responses, 1,25(OH)2D3-treated mice showed defects in their production of the antimicrobial peptide REG3γ. Taken together, these studies show that 1,25(OH)2D3suppresses Th17 T-cell responses in vivo and impairs mucosal host defense against an enteric bacterial pathogen.

scholarly journals The multifunctional NS1 protein of influenza A viruses

2008 ◽  
Vol 89 (10) ◽  
pp. 2359-2376 ◽  
Author(s):  
Benjamin G. Hale ◽  
Richard E. Randall ◽  
Juan Ortín ◽  
David Jackson
Keyword(s):  
Immune Responses ◽  
Viral Protein ◽  
Influenza A ◽  
Rational Design ◽  
Intracellular Localization ◽  
Cell Physiology ◽  
Ns1 Protein ◽  
Oligoadenylate Synthetase ◽  
Influenza A Viruses ◽  
Viral Protein Synthesis

The non-structural (NS1) protein of influenza A viruses is a non-essential virulence factor that has multiple accessory functions during viral infection. In recent years, the major role ascribed to NS1 has been its inhibition of host immune responses, especially the limitation of both interferon (IFN) production and the antiviral effects of IFN-induced proteins, such as dsRNA-dependent protein kinase R (PKR) and 2'5'-oligoadenylate synthetase (OAS)/RNase L. However, it is clear that NS1 also acts directly to modulate other important aspects of the virus replication cycle, including viral RNA replication, viral protein synthesis, and general host-cell physiology. Here, we review the current literature on this remarkably multifunctional viral protein. In the first part of this article, we summarize the basic biochemistry of NS1, in particular its synthesis, structure, and intracellular localization. We then discuss the various roles NS1 has in regulating viral replication mechanisms, host innate/adaptive immune responses, and cellular signalling pathways. We focus on the NS1–RNA and NS1–protein interactions that are fundamental to these processes, and highlight apparent strain-specific ways in which different NS1 proteins may act. In this regard, the contributions of certain NS1 functions to the pathogenicity of human and animal influenza A viruses are also discussed. Finally, we outline practical applications that future studies on NS1 may lead to, including the rational design and manufacture of influenza vaccines, the development of novel antiviral drugs, and the use of oncolytic influenza A viruses as potential anti-cancer agents.

scholarly journals The critical role of endothelial function in fine particulate matter-induced atherosclerosis

2020 ◽  
Vol 17 (1) ◽  
Author(s):  
Shuang Liang ◽  
Jingyi Zhang ◽  
Ruihong Ning ◽  
Zhou Du ◽  
Jiangyan Liu ◽  
...  
Keyword(s):  
Air Pollution ◽  
Particulate Matter ◽  
Vascular Function ◽  
Fine Particulate Matter ◽  
Critical Role ◽  
Complex Mixture ◽  
Endothelial Injury ◽  
Vascular Endothelial ◽  
Vasomotor Function ◽  
Fine Particulate

AbstractAmbient and indoor air pollution contributes annually to approximately seven million premature deaths. Air pollution is a complex mixture of gaseous and particulate materials. In particular, fine particulate matter (PM2.5) plays a major mortality risk factor particularly on cardiovascular diseases through mechanisms of atherosclerosis, thrombosis and inflammation. A review on the PM2.5-induced atherosclerosis is needed to better understand the involved mechanisms. In this review, we summarized epidemiology and animal studies of PM2.5-induced atherosclerosis. Vascular endothelial injury is a critical early predictor of atherosclerosis. The evidence of mechanisms of PM2.5-induced atherosclerosis supports effects on vascular function. Thus, we summarized the main mechanisms of PM2.5-triggered vascular endothelial injury, which mainly involved three aspects, including vascular endothelial permeability, vasomotor function and vascular reparative capacity. Then we reviewed the relationship between PM2.5-induced endothelial injury and atherosclerosis. PM2.5-induced endothelial injury associated with inflammation, pro-coagulation and lipid deposition. Although the evidence of PM2.5-induced atherosclerosis is undergoing continual refinement, the mechanisms of PM2.5-triggered atherosclerosis are still limited, especially indoor PM2.5. Subsequent efforts of researchers are needed to improve the understanding of PM2.5 and atherosclerosis. Preventing or avoiding PM2.5-induced endothelial damage may greatly reduce the occurrence and development of atherosclerosis.

scholarly journals Aging Dampens the Intestinal Innate Immune Response during Severe Clostridioides difficile Infection and Is Associated with Altered Cytokine Levels and Granulocyte Mobilization

2020 ◽  
Vol 88 (6) ◽  
Author(s):  
Lisa Abernathy-Close ◽  
Michael G. Dieterle ◽  
Kimberly C. Vendrov ◽  
Ingrid L. Bergin ◽  
Krishna Rao ◽  
...  
Keyword(s):  
Immune Responses ◽  
Disease Severity ◽  
Immune Cell ◽  
White Blood Cells ◽  
Host Susceptibility ◽  
Simultaneous Increase ◽  
Content Type ◽  
Aged Mice ◽  
Clostridioides Difficile ◽  
Age Related

ABSTRACT Clostridioides (formerly Clostridium) difficile is the most common cause of hospital-acquired infection, and advanced age is a risk factor for C. difficile infection. Disruption of the intestinal microbiota and immune responses contribute to host susceptibility and severity of C. difficile infection. However, the specific impact of aging on immune responses during C. difficile infection remains to be well described. This study explores the effect of age on cellular and cytokine immune responses during C. difficile infection. Young mice (2 to 3 months old) and aged mice (22 to 28 months old) were rendered susceptible to C. difficile infection with the antibiotic cefoperazone and then infected with C. difficile strains with varied disease-causing potentials. We observe that the host age and the infecting C. difficile strain influenced the severity of disease associated with infection. Tissue-specific CD45+ immune cell responses occurred at the time of peak disease severity in the ceca and colons of all mice infected with a high-virulence strain of C. difficile; however, significant deficits in intestinal neutrophils and eosinophils were detected in aged mice, with a corresponding decrease in circulating CXCL1, an important neutrophil recruiter and activator. Interestingly, this lack of intestinal granulocyte response in aged mice during severe C. difficile infection was accompanied by a simultaneous increase in circulating white blood cells, granulocytes, and interleukin 17A (IL-17A). These findings demonstrate that age-related alterations in neutrophils and eosinophils and systemic cytokine and chemokine responses are associated with severe C. difficile infection and support a key role for intestinal eosinophils in mitigating C. difficile-mediated disease severity.

Sign in / Sign up

Export Citation Format

Share Document