scholarly journals Innate Immune Responses to Wildtype and Attenuated Sheeppox Virus Mediated Through RIG-1 Sensing in PBMC In-Vitro

2021 ◽  
Vol 12 ◽  
Author(s):  
Tesfaye Rufael Chibssa ◽  
Richard Thiga Kangethe ◽  
Francisco J. Berguido ◽  
Tirumala Bharani K. Settypalli ◽  
Yang Liu ◽  
...  
Keyword(s):  
Immune Responses ◽  
Small Ruminants ◽  
Significant Negative Correlation ◽  
Individual Variability ◽  
Innate Immune ◽  
Economic Losses ◽  
Viral Dsrna ◽  
Sheeppox Virus

Sheeppox (SPP) is a highly contagious disease of small ruminants caused by sheeppox virus (SPPV) and predominantly occurs in Asia and Africa with significant economic losses. SPPV is genetically and immunologically closely related to goatpox virus (GTPV) and lumpy skin disease virus (LSDV), which infect goats and cattle respectively. SPPV live attenuated vaccines (LAVs) are used for vaccination against SPP and goatpox (GTP). Mechanisms related to innate immunity elicited by SPPV are unknown. Although adaptive immunity is responsible for long-term immunity, it is the innate responses that prevent viral invasion and replication before LAVs generate specific long-term protection. We analyzed the relative expression of thirteen selected genes that included pattern recognition receptors (PRRs), Nuclear factor-κβ p65 (NF-κβ), and cytokines to understand better the interaction between SPPV and its host. The transcripts of targeted genes in sheep PBMC incubated with either wild type (WT) or LAV SPPV were analyzed using quantitative PCR. Among PRRs, we observed a significantly higher expression of RIG-1 in PBMC incubated with both WT and LAV, with the former producing the highest expression level. However, there was high inter-individual variability in cytokine transcripts levels among different donors, with the expression of TNFα, IL-15, and IL-10 all significantly higher in both PBMC infected with either WT or LAV compared to control PBMC. Correlation studies revealed a strong significant correlation between RIG-1 and IL-10, between TLR4, TNFα, and NF-κβ, between IL-18 and IL-15, and between NF-κβ and IL-10. There was also a significant negative correlation between RIG-1 and IFNγ, between TLR3 and IL-1 β, and between TLR4 and IL-15 (P< 0.05). This study identified RIG-1 as an important PRR in the signaling pathway of innate immune activation during SPPV infection, possibly through intermediate viral dsRNA. The role of immunomodulatory molecules produced by SPPV capable of inhibiting downstream signaling activation following RIG-1 upregulation is discussed. These findings advance our knowledge of the induction of immune responses by SPPV and will help develop safer and more potent vaccines against SPP and GTP.

scholarly journals Posttranslational Regulation of IL-23 Production Distinguishes the Innate Immune Responses to Live Toxigenic versus Heat-Inactivated Vibrio cholerae

mSphere ◽  
2019 ◽  
Vol 4 (4) ◽  
Author(s):  
Ana A. Weil ◽  
Crystal N. Ellis ◽  
Meti D. Debela ◽  
Taufiqur R. Bhuiyan ◽  
Rasheduzzaman Rashu ◽  
...  
Keyword(s):  
Immune Responses ◽  
Cholera Toxin ◽  
Vibrio Cholerae ◽  
Protective Immunity ◽  
Innate Immune ◽  
Posttranslational Regulation ◽  
Content Type ◽  
In Cells ◽  
Cholera Vaccines

ABSTRACT Vibrio cholerae infection provides long-lasting protective immunity, while oral, inactivated cholera vaccines (OCV) result in more-limited protection. To identify characteristics of the innate immune response that may distinguish natural V. cholerae infection from OCV, we stimulated differentiated, macrophage-like THP-1 cells with live versus heat-inactivated V. cholerae with and without endogenous or exogenous cholera holotoxin (CT). Interleukin 23A gene (IL23A) expression was higher in cells exposed to live V. cholerae than in cells exposed to inactivated organisms (mean change, 38-fold; 95% confidence interval [95% CI], 4.0 to 42; P < 0.01). IL-23 secretion was also higher in cells exposed to live V. cholerae than in cells exposed to inactivated V. cholerae (mean change, 5.6-fold; 95% CI, 4.4 to 11; P < 0.001). This increase in IL-23 secretion was more marked than for other key innate immune cytokines (e.g., IL-1β and IL-6) and dependent on exposure to the combination of both live V. cholerae and CT. While IL-23 secretion was reduced following stimulation with either heat-inactivated wild-type V. cholerae or a live isogenic ctxAB mutant of V. cholerae, the addition of exogenous CT restored IL-23 secretion in combination with the live isogenic ctxAB mutant V. cholerae, but not when it was paired with stimulation by heat-inactivated V. cholerae. The posttranslational regulation of IL-23 under these conditions was dependent on the activity of the cysteine protease cathepsin B. In humans, IL-23 promotes the differentiation of Th17 cells to T follicular helper cells, which maintain and support long-term memory B cell generation after infection. Based on these findings, the stimulation of IL-23 production may be a determinant of protective immunity following V. cholerae infection. IMPORTANCE An episode of cholera provides better protection against reinfection than oral cholera vaccines, and the reasons for this are still under study. To better understand this, we compared the immune responses of human cells exposed to live Vibrio cholerae with those of cells exposed to heat-killed V. cholerae (similar to the contents of oral cholera vaccines). We also compared the effects of active cholera toxin and the inactive cholera toxin B subunit (which is included in some cholera vaccines). One key immune signaling molecule, IL-23, was uniquely produced in response to the combination of live bacteria and active cholera holotoxin. Stimulation with V. cholerae that did not produce the active toxin or was killed did not produce an IL-23 response. The stimulation of IL-23 production by cholera toxin-producing V. cholerae may be important in conferring long-term immunity after cholera.

scholarly journals An In Vitro Assessment of Immunostimulatory Responses to Ten Model Innate Immune Response Modulating Impurities (IIRMIs) and Peptide Drug Product, Teriparatide

Molecules ◽  
2021 ◽  
Vol 26 (24) ◽  
pp. 7461
Author(s):  
Claire K. Holley ◽  
Edward Cedrone ◽  
Duncan Donohue ◽  
Barry W. Neun ◽  
Daniela Verthelyi ◽  
...  
Keyword(s):  
Immune Response ◽  
Immune Responses ◽  
Innate Immune Response ◽  
Innate Immune ◽  
Cytokine Secretion ◽  
Poly I:C ◽  
In Vitro Assays ◽  
Innate Immune Responses ◽  
Vitro Assay

Understanding, predicting, and minimizing the immunogenicity of peptide-based therapeutics are of paramount importance for ensuring the safety and efficacy of these products. The so-called anti-drug antibodies (ADA) may have various clinical consequences, including but not limited to the alteration in the product’s distribution, biological activity, and clearance profiles. The immunogenicity of biotherapeutics can be influenced by immunostimulation triggered by the presence of innate immune response modulating impurities (IIRMIs) inadvertently introduced during the manufacturing process. Herein, we evaluate the applicability of several in vitro assays (i.e., complement activation, leukocyte proliferation, and cytokine secretion) for the screening of innate immune responses induced by ten common IIRMIs (Bacillus subtilis flagellin, FSL-1, zymosan, ODN2006, poly(I:C) HMW, poly(I:C) LMW, CLO75, MDP, ODN2216, and Escherichia coli O111:B4 LPS), and a model biotherapeutic Forteo™ (teriparatide). Our study identifies cytokine secretion from healthy human donor peripheral blood mononuclear cells (PBMC) as a sensitive method for the in vitro monitoring of innate immune responses to individual IIRMIs and teriparatide (TP). We identify signature cytokines, evaluate both broad and narrow multiplex cytokine panels, and discuss how the assay logistics influence the performance of this in vitro assay.

scholarly journals In vitro and in vivo anthelmintic activity of extracts from Artemisia parviflora and A. sieversiana

2017 ◽  
Vol 54 (3) ◽  
pp. 218-224 ◽  
Author(s):  
S. Irum ◽  
H. Ahmed ◽  
B. Mirza ◽  
K. Donskow-Łysoniewska ◽  
A. Muhammad ◽  
...  
Keyword(s):  
Adult Worm ◽  
Plant Extracts ◽  
Small Ruminants ◽  
Anthelmintic Activity ◽  
Gastrointestinal Nematodes ◽  
Economic Losses ◽  
Egg Hatching ◽  
Infective Larvae

SummaryIn the northern areas of Pakistan, the use of Artemisia based therapeutics is a common practice. Plants of genus Artemisia are known to possess anthelmintic and therapeutic effect. Infections caused by gastrointestinal nematodes are major threat to livestock industry across the world resulting in loss of production and indirect economic losses due to high cost of anthelmintic drugs. Present study was carried out to evaluate in vitro and in vivo effect of Artemisia sieversiana and Artemisia parviflora on Haemonchus contortus, a parasitic nematode of small ruminants. Methanolic plant extract was tested against three different developmental stages using an egg hatch assay, infective larvae and adult worm motility assay. Different concentrations were used for the bioassays and post exposure mortality was recorded after 8 hr for adult worms and infective larvae, while egg inhibition percentage was observed after 27 hr. A highly significant ability to inhibit the egg hatching (100 %) was recorded for both plant extracts while, the highest activity for adult worm assay and larvicidal assay was 90 % for A. sieversiana. The highest activity for adult motility and larvicidal assay for A. parviflora was 89 % and 86.6 % respectively. For in vivo trials maximum parentage reduction was 77.0 % for A. sieversiana and 73.6 % for A. parviflora. It is concluded that selected plant extracts were effective in reducing worm burden in animals.

An appraisal of survival strategies

Parasitology ◽  
1984 ◽  
Vol 88 (4) ◽  
pp. 575-577 ◽  
Author(s):  
N. A. Mitchison
Keyword(s):  
Immune System ◽  
Immune Responses ◽  
Survival Strategies ◽  
Host Immune System ◽  
Cellular Immunology ◽  
Host Immune Responses ◽  
Host Defence System ◽  
Bio Engineering

Only a few years ago parasite immunology looked an unattractive subject better left to the dogged specialists. Parasites and hosts had been playing chess together for a million years, and there seemed little prospect of perturbing matters in favour of the host immune system. All that has changed, for three reasons. Firstly, we have learned how to grow at least some parasites in vitro, and prospects of doing so with others are encouraging. Secondly, progress in cellular immunology has revealed the sort of loopholes in the host defence system which parasites are likely to exploit: we are learning the questions which matter about parasites as antigens. Thirdly, and most importantly, molecular genetics is being brought to bear on parasites: we can now see a real, though long-term, prospect of manufacturing practicable vaccines through bio-engineering, and more immediately it gives us the tools needed to probe the host immune responses in the form of cloned antigens.

scholarly journals Long Non-coding RNAs RN7SK and GAS5 Regulate Macrophage Polarization and Innate Immune Responses

2020 ◽  
Vol 11 ◽  
Author(s):  
Imran Ahmad ◽  
Araceli Valverde ◽  
Raza Ali Naqvi ◽  
Afsar R. Naqvi
Keyword(s):  
Immune Responses ◽  
Epigenetic Regulation ◽  
Innate Immune ◽  
Differentially Expressed ◽  
Immune Functions ◽  
Innate Immune Responses ◽  
Antigen Uptake ◽  
Non Coding Rnas

Macrophages (Mφ) are immune cells that exhibit remarkable functional plasticity. Identification of novel endogenous factors that can regulate plasticity and innate immune functions of Mφ will unravel new strategies to curb immune-related diseases. Long non-coding RNAs (lncRNAs) are a class of endogenous, non-protein coding, regulatory RNAs that are increasingly being associated with various cellular functions and diseases. Despite their ubiquity and abundance, lncRNA-mediated epigenetic regulation of Mφ polarization and innate immune functions is poorly studied. This study elucidates the regulatory role of lncRNAs in monocyte to Mφ differentiation, M1/M2 dichotomy and innate immune responses. Expression profiling of eighty-eight lncRNAs in monocytes and in vitro differentiated M2 Mφ identified seventeen differentially expressed lncRNAs. Based on fold-change and significance, we selected four differentially expressed lncRNAs viz., RN7SK, GAS5, IPW, and ZFAS1 to evaluate their functional impact. LncRNA knockdown was performed on day 3 M2 Mφ and the impact on polarization was assessed on day 7 by surface marker analysis. Knockdown of RN7SK and GAS5 showed downregulation of M2 surface markers (CD163, CD206, or Dectin) and concomitant increase in M1 markers (MHC II or CD23). RN7SK or GAS5 knockdown showed no significant impact on CD163, CD206, or CD23 transcripts. M1/M2 markers were not impacted by IPW or ZFAS1 knockdown. Functional regulation of antigen uptake/processing and phagocytosis, two central innate immune pathways, by candidate lncRNA was assessed in M1/M2 Mφ. Compared to scramble, enhanced antigen uptake and processing were observed in both M1/M2 Mφ transfected with siRNA targeting GAS5 and RN7SK but not IPW and ZFAS1. In addition, knockdown of RN7SK significantly augmented uptake of labelled E. coli in vitro by M1/M2 Mφ, while no significant difference was in GAS5 silencing cells. Together, our results highlight the instrumental role of lncRNA (RN7SK and GAS5)-mediated epigenetic regulation of macrophage differentiation, polarization, and innate immune functions.

scholarly journals Enhancing innate antiviral immune responses in rainbow trout by double stranded RNA delivered with cationic phytoglycogen nanoparticles

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Tamiru N. Alkie ◽  
Jondavid de Jong ◽  
Kristof Jenik ◽  
Karl M. Klinger ◽  
Stephanie J. DeWitte-Orr
Keyword(s):  
Rainbow Trout ◽  
Immune Responses ◽  
Cell Line ◽  
Culture Conditions ◽  
Type I Interferons ◽  
Poly I:C ◽  
Synthetic Analogue ◽  
Type I ◽  
Viral Dsrna

Abstract Innate immunity is induced when pathogen-associated molecular patterns (PAMPs) bind host pattern recognition receptors (PRRs). Polyinosinic:polycytidylic acid [poly(I:C)] is a synthetic analogue of viral dsRNA that acts as a PAMP, inducing type I interferons (IFNs) in vertebrates. In the present study, the immunostimulatory effects of high molecular weight (HMW) poly(I:C) in rainbow trout cells were measured when bound to a cationic phytoglycogen nanoparticle (Nano-HMW). The physical characteristics of the nanoparticle itself, when bound to different lengths of dsRNA and when cell associated was evaluated. Optimal concentration and timing for innate immune stimulation was measured using the RTG-P1 reporter cell line. The immunostimulatory effects of HMW poly (I:C) was compared to Nano-HMW in vitro using the RTgutGC cell line cultured in a conventional monolayer or a transwell culture system. The ability of an activated intestinal epithelium to transmit an antiviral signal to macrophages was evaluated using a co-culture of RTgutGC cells and RTSll (a monocyte/macrophage cell). In all culture conditions, Nano-HMW was a more effective inducer of IFN-related antiviral immune responses compared to HMW poly (I:C) alone. This study introduces the use of cationic phytoglycogen nanoparticles as a novel delivery system for immunomodulatory molecules to enhance immune responses in aquatic vertebrates.

scholarly journals The Absence of Hck, Fgr, and Lyn Tyrosine Kinases Augments Lung Innate Immune Responses to Pneumocystis murina

2009 ◽  
Vol 77 (5) ◽  
pp. 1790-1797 ◽  
Author(s):  
Michael P. Nelson ◽  
Allison E. Metz ◽  
Shaoguang Li ◽  
Clifford A. Lowell ◽  
Chad Steele
Keyword(s):  
Immune Responses ◽  
Alveolar Macrophages ◽  
Tyrosine Kinases ◽  
Innate Immune ◽  
Innate Immune Responses ◽  
Independent Manner ◽  
Intratracheal Administration ◽  
Monocyte Chemoattractant Protein 1 ◽  
Immunoglobulin Receptor

ABSTRACT Src family tyrosine kinases (SFKs) phosphorylate immunotyrosine activation motifs in the cytoplasmic tail of multiple immunoreceptors, leading to the initiation of cellular effector functions, such as phagocytosis, reactive oxygen species production, and cytokine production. SFKs also play important roles in regulating these responses through the activation of immunotyrosine inhibitory motif-containing inhibitory receptors. As myeloid cells preferentially express the SFKs Hck, Fgr, and Lyn, we questioned the role of these kinases in innate immune responses to Pneumocystis murina. Increased phosphorylation of Hck was readily detectable in alveolar macrophages after stimulation with P. murina. We further observed decreased phosphorylation of Lyn on its C-terminal inhibitory tyrosine in P. murina-stimulated alveolar macrophages, indicating that SFKs were activated in alveolar macrophages in response to P. murina. Mice deficient in Hck, Fgr, and Lyn exhibited augmented clearance 3 and 7 days after intratracheal administration of P. murina, which correlated with elevated levels of interleukin 1β (IL-1β), IL-6, CXCL1/KC, CCL2/monocyte chemoattractant protein 1, and granulocyte colony-stimulating factor in lung homogenates and a dramatic increase in macrophage and neutrophil recruitment. Augmented P. murina clearance was also observed in Lyn−/− mice 3 days postchallenge, although the level was less than that observed in Hck−/− Fgr−/− Lyn−/− mice. A correlate to augmented clearance of P. murina in Hck−/− Fgr−/− Lyn−/− mice was a greater ability of alveolar macrophages from these mice to kill P. murina in vitro, suggesting that SFKs regulate the alveolar macrophage effector function against P. murina. Mice deficient in paired immunoglobulin receptor B (PIR-B), an inhibitory receptor activated by SFKs, did not exhibit enhanced inflammatory responsiveness to or clearance of P. murina. Our results suggest that SFKs regulate innate lung responses to P. murina in a PIR-B-independent manner.

scholarly journals Evolutionary and structural analysis of SARS-CoV-2 specific evasion of host immunity

2020 ◽  
Vol 21 (6-8) ◽  
pp. 409-419
Author(s):  
Irfan Hussain ◽  
Nashaiman Pervaiz ◽  
Abbas Khan ◽  
Shoaib Saleem ◽  
Huma Shireen ◽  
...  
Keyword(s):  
Immune Responses ◽  
Nonstructural Protein ◽  
Critical Role ◽  
Clinical Manifestations ◽  
Host Immunity ◽  
Innate Immune ◽  
Host Immune System ◽  
Innate Immune Responses ◽  
In Vivo Models

AbstractThe outbreak of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is spreading fast worldwide. There is a pressing need to understand how the virus counteracts host innate immune responses. Deleterious clinical manifestations of coronaviruses have been associated with virus-induced direct dysregulation of innate immune responses occurring via viral macrodomains located within nonstructural protein-3 (Nsp3). However, no substantial information is available concerning the relationship of macrodomains to the unusually high pathogenicity of SARS-CoV-2. Here, we show that structural evolution of macrodomains may impart a critical role to the unique pathogenicity of SARS-CoV-2. Using sequence, structural, and phylogenetic analysis, we identify a specific set of historical substitutions that recapitulate the evolution of the macrodomains that counteract host immune response. These evolutionary substitutions may alter and reposition the secondary structural elements to create new intra-protein contacts and, thereby, may enhance the ability of SARS-CoV-2 to inhibit host immunity. Further, we find that the unusual virulence of this virus is potentially the consequence of Darwinian selection‐driven epistasis in protein evolution. Our findings warrant further characterization of macrodomain-specific evolutionary substitutions in in vitro and in vivo models to determine their inhibitory effects on the host immune system.

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