Transgenic Expression of Human C-Type Lectin Protein CLEC18A Reduces Dengue Virus Type 2 Infectivity in Aedes aegypti

The C-type lectins, one family of lectins featuring carbohydrate binding domains which participate in a variety of bioprocesses in both humans and mosquitoes, including immune response, are known to target DENV. A human C-type lectin protein CLEC18A in particular shows extensive glycan binding abilities and correlates with type-I interferon expression, making CLEC18A a potential player in innate immune responses to DENV infection; this potential may provide additional regulatory point in improving mosquito immunity. Here, we established for the first time a transgenic Aedes aegypti line that expresses human CLEC18A. This expression enhanced the Toll immune pathway responses to DENV infection. Furthermore, viral genome and virus titers were reduced by 70% in the midgut of transgenic mosquitoes. We found significant changes in the composition of the midgut microbiome in CLEC18A expressing mosquitoes, which may result from the Toll pathway enhancement and contribute to DENV inhibition. Transgenic mosquito lines offer a compelling option for studying DENV pathogenesis, and our analyses indicate that modifying the mosquito immune system via expression of a human immune gene can significantly reduce DENV infection.

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Immunotranscriptomic profiling the acute and clearance phases of a human challenge dengue virus serotype 2 infection model

Nature Communications ◽

10.1038/s41467-021-22930-6 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

John P. Hanley ◽

Huy A. Tu ◽

Julie A. Dragon ◽

Dorothy M. Dickson ◽

Roxana del Rio-Guerra ◽

...

Keyword(s):

Gene Expression ◽

Dengue Virus ◽

Natural Infection ◽

Denv Infection ◽

Severe Dengue ◽

Infection Model ◽

Type I ◽

Immune Gene ◽

Challenge Virus ◽

Virus Serotype

AbstractAbout 20–25% of dengue virus (DENV) infections become symptomatic ranging from self-limiting fever to shock. Immune gene expression changes during progression to severe dengue have been documented in hospitalized patients; however, baseline or kinetic information is difficult to standardize in natural infection. Here we profile the host immunotranscriptome response in humans before, during, and after infection with a partially attenuated rDEN2Δ30 challenge virus (ClinicalTrials.gov NCT02021968). Inflammatory genes including type I interferon and viral restriction pathways are induced during DENV2 viremia and return to baseline after viral clearance, while others including myeloid, migratory, humoral, and growth factor immune regulation factors pathways are found at non-baseline levels post-viremia. Furthermore, pre-infection baseline gene expression is useful to predict rDEN2Δ30-induced immune responses and the development of rash. Our results suggest a distinct immunological profile for mild rDEN2Δ30 infection and offer new potential biomarkers for characterizing primary DENV infection.

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LRRK2 maintains mitochondrial homeostasis and regulates innate immune responses to Mycobacterium tuberculosis

eLife ◽

10.7554/elife.51071 ◽

2020 ◽

Vol 9 ◽

Cited By ~ 6

Author(s):

Chi G Weindel ◽

Samantha L Bell ◽

Krystal J Vail ◽

Kelsi O West ◽

Kristin L Patrick ◽

...

Keyword(s):

Mycobacterium Tuberculosis ◽

Mycobacterial Infection ◽

Innate Immune ◽

Type I ◽

Immune Gene ◽

Innate Immune Responses ◽

Interferon Stimulated Genes ◽

Mitochondrial Homeostasis ◽

Mitochondrial Defects ◽

Interferon Responses

The Parkinson’s disease (PD)-associated gene leucine-rich repeat kinase 2 (LRRK2) has been studied extensively in the brain. However, several studies have established that mutations in LRRK2 confer susceptibility to mycobacterial infection, suggesting LRRK2 also controls immunity. We demonstrate that loss of LRRK2 in macrophages induces elevated basal levels of type I interferon (IFN) and interferon stimulated genes (ISGs) and causes blunted interferon responses to mycobacterial pathogens and cytosolic nucleic acid agonists. Altered innate immune gene expression in Lrrk2 knockout (KO) macrophages is driven by a combination of mitochondrial stresses, including oxidative stress from low levels of purine metabolites and DRP1-dependent mitochondrial fragmentation. Together, these defects promote mtDNA leakage into the cytosol and chronic cGAS engagement. While Lrrk2 KO mice can control Mycobacterium tuberculosis (Mtb) replication, they have exacerbated inflammation and lower ISG expression in the lungs. These results demonstrate previously unappreciated consequences of LRRK2-dependent mitochondrial defects in controlling innate immune outcomes.

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REL1, a Homologue ofDrosophilaDorsal, Regulates Toll Antifungal Immune Pathway in the Female MosquitoAedes aegypti

Journal of Biological Chemistry ◽

10.1074/jbc.m500711200 ◽

2005 ◽

Vol 280 (16) ◽

pp. 16499-16507 ◽

Cited By ~ 80

Author(s):

Sang Woon Shin ◽

Vladimir Kokoza ◽

Guowu Bian ◽

Hyang-Mi Cheon ◽

Yu Jung Kim ◽

...

Keyword(s):

Immune Response ◽

Gene Activation ◽

Ectopic Expression ◽

Innate Immune ◽

Immune Gene ◽

Gene Promoters ◽

Innate Immune Responses ◽

Immune Factor ◽

Toll Receptor ◽

Immune Pathway

Signaling byDrosophilaToll pathway activates two Rel/NF-κB transcription factors, Dorsal (Dl) and Dorsal-related immune factor (Dif). Dl plays a central role in the establishment of dorsoventral polarity during early embryogenesis, whereas Dif mediates the Toll receptor-dependent antifungal immune response in adultDrosophila. The absence of a Dif ortholog in mosquito genomes suggests that Dl may play its functional role in the mosquito Toll-mediated innate immune responses. We have cloned and molecularly characterized the gene homologous toDrosophila Dland toAnopheles gambiae REL1(Gambif1) from the yellow fever mosquitoAedes aegypti, namedAaREL1.AaREL1alternative transcripts encode two isoforms,AaREL1-AandAaREL1-B. Both transcripts are enriched during embryogenesis and are inducible by septic injury in larval and female mosquitoes. AaREL1 and AaREL2 (AedesRelish) selectively bind to different κB motifs from insect immune gene promoters. Ectopic expression of AaREL1-A in bothDrosophilambn-2 cells and transgenic flies specifically activates Drosomycin and results in increased resistance against the fungusBeauveria bassiana. AaREL1-B acted cooperatively with AaREL1-A to enhance the immune gene activation in Aag-2 cells. The RNA interference knock-outs revealed that AaREL1 affected the expression ofAedeshomologue ofDrosophila Serpin-27Aand mediated specific antifungal immune response againstB. bassiana. These results indicate that the homologue of Dl, but not that of Dif, is a key regulator of the Toll antifungal immune pathway inA. aegyptifemale mosquitoes.

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Genomic analysis of C-type lectins

Biochemical Society Symposium ◽

10.1042/bss0690059 ◽

2002 ◽

Vol 69 ◽

pp. 59-72 ◽

Cited By ~ 85

Author(s):

Kurt Drickamer ◽

Andrew J. Fadden

Keyword(s):

Biological Effects ◽

Cell Signalling ◽

Genomic Analysis ◽

Binding Activity ◽

Immunoglobulin Superfamily ◽

Carbohydrate Binding ◽

Carbohydrate Recognition ◽

Calcium Dependent ◽

Binding Domains ◽

Carbohydrate Recognition Domains

Many biological effects of complex carbohydrates are mediated by lectins that contain discrete carbohydrate-recognition domains. At least seven structurally distinct families of carbohydrate-recognition domains are found in lectins that are involved in intracellular trafficking, cell adhesion, cell–cell signalling, glycoprotein turnover and innate immunity. Genome-wide analysis of potential carbohydrate-binding domains is now possible. Two classes of intracellular lectins involved in glycoprotein trafficking are present in yeast, model invertebrates and vertebrates, and two other classes are present in vertebrates only. At the cell surface, calcium-dependent (C-type) lectins and galectins are found in model invertebrates and vertebrates, but not in yeast; immunoglobulin superfamily (I-type) lectins are only found in vertebrates. The evolutionary appearance of different classes of sugar-binding protein modules parallels a development towards more complex oligosaccharides that provide increased opportunities for specific recognition phenomena. An overall picture of the lectins present in humans can now be proposed. Based on our knowledge of the structures of several of the C-type carbohydrate-recognition domains, it is possible to suggest ligand-binding activity that may be associated with novel C-type lectin-like domains identified in a systematic screen of the human genome. Further analysis of the sequences of proteins containing these domains can be used as a basis for proposing potential biological functions.

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Modulation of Chicken Intestinal Immune Gene Expression by Small Cationic Peptides as Feed Additives during the First Week Posthatch

Clinical and Vaccine Immunology ◽

10.1128/cvi.00322-13 ◽

2013 ◽

Vol 20 (9) ◽

pp. 1440-1448 ◽

Cited By ~ 17

Author(s):

Michael H. Kogut ◽

Kenneth J. Genovese ◽

Haiqi He ◽

Christina L. Swaggerty ◽

Yiwei Jiang

Keyword(s):

Gene Expression ◽

Proinflammatory Cytokines ◽

Proinflammatory Cytokine ◽

Feed Additives ◽

Feed Additive ◽

Cationic Peptides ◽

Type I ◽

Immune Gene ◽

Content Type ◽

Functional Efficiency

ABSTRACTWe have been investigating modulation strategies tailored around the selective stimulation of the host's immune system as an alternative to direct targeting of microbial pathogens by antibiotics. One such approach is the use of a group of small cationic peptides (BT) produced by a Gram-positive soil bacterium,Brevibacillus texasporus. These peptides have immune modulatory properties that enhance both leukocyte functional efficiency and leukocyte proinflammatory cytokine and chemokine mRNA transcription activitiesin vitro. In addition, when provided as a feed additive for just 4 days posthatch, BT peptides significantly induce a concentration-dependent protection against cecal and extraintestinal colonization bySalmonella entericaserovar Enteritidis. In the present studies, we assessed the effects of feeding BT peptides on transcriptional changes on proinflammatory cytokines, inflammatory chemokines, and Toll-like receptors (TLR) in the ceca of broiler chickens with and withoutS. Enteritidis infection. After feeding a BT peptide-supplemented diet for the first 4 days posthatch, chickens were then challenged withS. Enteritidis, and intestinal gene expression was measured at 1 or 7 days postinfection (p.i.) (5 or 11 days of age). Intestinal expression of innate immune mRNA transcripts was analyzed by quantitative real-time PCR (qRT-PCR). Analysis of relative mRNA expression showed that a BT peptide-supplemented diet did not directly induce the transcription of proinflammatory cytokine, inflammatory chemokine, type I/II interferon (IFN), or TLR mRNA in chicken cecum. However, feeding the BT peptide-supplemented diet primed cecal tissue for increased (P≤ 0.05) transcription of TLR4, TLR15, and TLR21 upon infection withS. Enteritidis on days 1 and 7 p.i. Likewise, feeding the BT peptides primed the cecal tissue for increased transcription of proinflammatory cytokines (interleukin 1β [IL-1β], IL-6, IL-18, type I and II IFNs) and inflammatory chemokine (CxCLi2) in response toS. Enteritidis infection 1 and 7 days p.i. compared to the chickens fed the basal diet. These small cationic peptides may prove useful as alternatives to antibiotics as local immune modulators in neonatal poultry by providing prophylactic protection againstSalmonellainfections.

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Essential role of IPS-1 in innate immune responses against RNA viruses

Journal of Experimental Medicine ◽

10.1084/jem.20060792 ◽

2006 ◽

Vol 203 (7) ◽

pp. 1795-1803 ◽

Cited By ~ 345

Author(s):

Himanshu Kumar ◽

Taro Kawai ◽

Hiroki Kato ◽

Shintaro Sato ◽

Ken Takahashi ◽

...

Keyword(s):

Rna Viruses ◽

Rna Virus ◽

Critical Role ◽

Nuclear Factor Κb ◽

Type I ◽

Innate Immune Responses ◽

Antiviral Responses ◽

Deficient Mice

IFN-β promoter stimulator (IPS)-1 was recently identified as an adapter for retinoic acid–inducible gene I (RIG-I) and melanoma differentiation-associated gene 5 (Mda5), which recognize distinct RNA viruses. Here we show the critical role of IPS-1 in antiviral responses in vivo. IPS-1–deficient mice showed severe defects in both RIG-I– and Mda5-mediated induction of type I interferon and inflammatory cytokines and were susceptible to RNA virus infection. RNA virus–induced interferon regulatory factor-3 and nuclear factor κB activation was also impaired in IPS-1–deficient cells. IPS-1, however, was not essential for the responses to either DNA virus or double-stranded B-DNA. Thus, IPS-1 is the sole adapter in both RIG-I and Mda5 signaling that mediates effective responses against a variety of RNA viruses.

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Biochemical and structural characterization of the novel sialic acid-binding site of Escherichia coli heat-labile enterotoxin LT-IIb

Biochemical Journal ◽

10.1042/bcj20160575 ◽

2016 ◽

Vol 473 (21) ◽

pp. 3923-3936 ◽

Cited By ~ 3

Author(s):

Dani Zalem ◽

João P. Ribeiro ◽

Annabelle Varrot ◽

Michael Lebens ◽

Anne Imberty ◽

...

Keyword(s):

Escherichia Coli ◽

Binding Site ◽

Cholera Toxin ◽

Carbohydrate Binding ◽

Type I ◽

Type Ii ◽

E Coli ◽

B Subunit ◽

Heat Labile ◽

B Subunits

The structurally related AB5-type heat-labile enterotoxins of Escherichia coli and Vibrio cholerae are classified into two major types. The type I group includes cholera toxin (CT) and E. coli LT-I, whereas the type II subfamily comprises LT-IIa, LT-IIb and LT-IIc. The carbohydrate-binding specificities of LT-IIa, LT-IIb and LT-IIc are distinctive from those of cholera toxin and E. coli LT-I. Whereas CT and LT-I bind primarily to the GM1 ganglioside, LT-IIa binds to gangliosides GD1a, GD1b and GM1, LT-IIb binds to the GD1a and GT1b gangliosides, and LT-IIc binds to GM1, GM2, GM3 and GD1a. These previous studies of the binding properties of type II B-subunits have been focused on ganglio core chain gangliosides. To further define the carbohydrate binding specificity of LT-IIb B-subunits, we have investigated its binding to a collection of gangliosides and non-acid glycosphingolipids with different core chains. A high-affinity binding of LT-IIb B-subunits to gangliosides with a neolacto core chain, such as Neu5Gcα3- and Neu5Acα3-neolactohexaosylceramide, and Neu5Gcα3- and Neu5Acα3-neolactooctaosylceramide was detected. An LT-IIb-binding ganglioside was isolated from human small intestine and characterized as Neu5Acα3-neolactohexaosylceramide. The crystal structure of the B-subunit of LT-IIb with the pentasaccharide moiety of Neu5Acα3-neolactotetraosylceramide (Neu5Ac-nLT: Neu5Acα3Galβ4GlcNAcβ3Galβ4Glc) was determined providing the first information for a sialic-binding site in this subfamily, with clear differences from that of CT and LT-I.

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Aromatic interactions in Glycochemistry: from molecular recognition to catalysis

Current Medicinal Chemistry ◽

10.2174/0929867328666210709120216 ◽

2021 ◽

Vol 28 ◽

Author(s):

Andrés González Santana ◽

Laura Díaz-Casado ◽

Laura Montalvillo ◽

Ester Jiménez-Moreno ◽

Enrique Mann ◽

...

Keyword(s):

Molecular Recognition ◽

Transition States ◽

Carbohydrate Binding ◽

Potential Influence ◽

Chemical Structures ◽

Receptor Complexes ◽

Binding Domains ◽

Aromatic Interactions ◽

Aromatic Complexes ◽

Recognition Motifs

: Aromatic platforms are ubiquitous recognition motifs occurring in protein carbohydrate binding domains (CBDs), RNA receptors and enzymes. They stabilize the glycoside/receptor complexes by participating in stacking CH/ interactions with either the - or - face of the corresponding pyranose units. In addition, the role played by aromatic units in the stabilization of glycoside cationic transition states has started being recognized in recent years. Extensive studies carried out during the last decade have allowed to dissect the main contributing forces that stabilize the carbohydrate/aromatic complexes, while helping delineate not only the standing relationship between the glycoside/aromatic chemical structures and the strength of this interaction, but also their potential influence on glycoside reactivity.

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Chloride channels in apical membrane patches of stellate cells of Malpighian tubules of Aedes aegypti

Journal of Experimental Biology ◽

10.1242/jeb.204.2.367 ◽

2001 ◽

Vol 204 (2) ◽

pp. 367-378 ◽

Cited By ~ 9

Author(s):

K.R. O'Connor ◽

K.W. Beyenbach

Keyword(s):

Aedes Aegypti ◽

Apical Membrane ◽

Stellate Cells ◽

Malpighian Tubules ◽

Type I ◽

Open Probability ◽

Cl Secretion ◽

Cl Channel ◽

Open Time ◽

Channel Type

Stellate cells of Aedes aegypti Malpighian tubules were investigated using patch-clamp methods to probe the route of transepithelial Cl(−) secretion. Two types of Cl(−) channel were identified in excised, inside-out apical membrane patches. The first Cl(−) channel, type I, had a conductance of 24 pS, an open probability of 0.816+/−0.067, an open time of 867+/−114 ms (mean +/− s.e.m., four patches) and the selectivity sequence I(−)>Cl(−)(much greater than) isethionate>gluconate. The I(−)/Cl(−)>>isethionate>gluconate. The I(−)Cl(−) permeability ratio was 1.48, corresponding to Eisenman sequence I. The type I Cl(−) channel was blocked by 2,2′-iminodibenzoic acid (DPC) and niflumic acid (2-[3-(trifluoromethyl)anilo]nicotinic acid). The removal of Ca(2+) from the Ringer's solution on the cytoplasmic side had no effect on channel activity. The second Cl(−) channel, type II, had a conductance of 8 pS, an open probability of 0.066+/−0.021 and an open time of 7.53+/−1.46 ms (mean +/− s.e.m., four patches). The high density and halide selectivity sequence of the type I Cl(−) channel is consistent with a role in transepithelial Cl(−) secretion under control conditions, but it remains to be determined whether these Cl(−) channels also mediate transepithelial Cl(−) secretion under diuretic conditions in the presence of leucokinin.

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Immunologic Pathways in Protective versus Maladaptive Host Responses to Attenuated and Pathogenic Strains ofMycoplasma gallisepticum

Infection and Immunity ◽

10.1128/iai.00613-18 ◽

2018 ◽

Vol 87 (3) ◽

Cited By ~ 2

Author(s):

Jessica Beaudet ◽

Edan R. Tulman ◽

Katherine Pflaum ◽

Jessica A. Canter ◽

Lawrence K. Silbart ◽

...

Keyword(s):

Innate Immune ◽

Host Responses ◽

Immune Gene ◽

Avian Host ◽

Innate Immune Responses ◽

Content Type ◽

Mucosal Tissues ◽

Rapid Clearance ◽

Pathogen Clearance ◽

Host Genes

ABSTRACTMycoplasmas are small bacterial commensals or pathogens that commonly colonize host mucosal tissues and avoid rapid clearance, in part by stimulating inflammatory, immunopathogenic responses. We previously characterized a wide array of transcriptomic perturbations in avian host tracheal mucosae infected with virulent, immunopathologicMycoplasma gallisepticum; however, mechanisms delineating these from protective responses, such as those induced upon vaccination, have not been thoroughly explored. In this study, host transcriptomic responses to two experimentalM. gallisepticumvaccines were assessed during the first 2 days of infection. Relative to virulent infection, host metabolic and immune gene responses to both vaccines were greatly decreased, including early innate immune responses critical to disease development and subsequent adaptive immunity. These data specify host genes and potential mechanisms contributing to maladaptive versus beneficial host responses—information critical for design of vaccines efficacious in both limiting inflammation and enabling pathogen clearance.

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