During blood-feeding, mosquito saliva is injected into the skin to facilitate blood meal acquisition. D7 proteins are among the most abundant components of the mosquito saliva. Here we report the ...ligand binding specificity and physiological relevance of two D7 long proteins from Culex quinquefasciatus mosquito, the vector of filaria parasites or West Nile viruses. CxD7L2 binds biogenic amines and eicosanoids. CxD7L1 exhibits high affinity for ADP and ATP, a binding capacity not reported in any D7. We solve the crystal structure of CxD7L1 in complex with ADP to 1.97 Å resolution. The binding pocket lies between the two protein domains, whereas all known D7s bind ligands either within the N- or the C-terminal domains. We demonstrate that these proteins inhibit hemostasis in ex vivo and in vivo experiments. Our results suggest that the ADP-binding function acquired by CxD7L1 evolved to enhance blood-feeding in mammals, where ADP plays a key role in platelet aggregation.
Studies are needed to determine the mechanisms of mucosal dysregulation in patients with inflammatory bowel diseases (IBDs) and differences in inflammatory responses of patients with ulcerative ...colitis (UC) vs Crohn’s disease (CD). We used mass cytometry (CyTOF) to characterize and compare immune cell populations in the mucosa and blood from patients with IBD and without IBD (controls) at single-cell resolution.
We performed CyTOF analysis of colonic mucosa samples (n = 87) and peripheral blood mononuclear cells (n = 85) from patients with active or inactive UC or CD and controls. We also performed single-cell RNA sequencing, flow cytometry, and RNA in situ hybridization analyses to validate key findings. We used random forest modeling to identify differences in signatures across subject groups.
Compared with controls, colonic mucosa samples from patients with IBD had increased abundances of HLA-DR+CD38+ T cells, including T-regulatory cells that produce inflammatory cytokines; CXCR3+ plasmablasts; and IL1B+ macrophages and monocytes. Colonic mucosa samples from patients with UC were characterized by expansion of IL17A+ CD161+ effector memory T cells and IL17A+ T-regulatory cells; expansion of HLA-DR+CD56+ granulocytes; and reductions in type 3 innate lymphoid cells. Mucosal samples from patients with active CD were characterized by IL1B+HLA-DR+CD38+ T cells, IL1B+TNF+IFNG+ naïve B cells, IL1B+ dendritic cells (DCs), and IL1B+ plasmacytoid DCs. Peripheral blood mononuclear cells from patients with active CD differed from those of active UC in that the peripheral blood mononuclear cells from patients with CD had increased IL1B+ T-regulatory cells, IL1B+ DCs and IL1B+ plasmacytoid DCs, IL1B+ monocytes, and fewer group 1 innate lymphoid cells. Random forest modeling differentiated active UC from active CD in colonic mucosa and blood samples; top discriminating features included many of the cellular populations identified above.
We used single-cell technologies to identify immune cell populations specific to mucosa and blood samples from patients with active or inactive CD and UC and controls. This information might be used to develop therapies that target specific cell populations in patients with different types of IBD.
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Vector sand fly colonies are a critical component of studies aimed at improving the understanding of the neglected tropical disease leishmaniasis and alleviating its global impact. However, among ...laboratory-colonized arthropod vectors of infectious diseases, the labor-intensive nature of sand fly rearing coupled with the low number of colonies worldwide has generally discouraged the widespread use of sand flies in laboratory settings. Among the different factors associated with the low productivity of sand fly colonies, mite infestations are a significant factor. Sand fly colonies are prone to infestation by mites, and the physical interactions between sand flies and mites and metabolites have a negative impact on sand fly larval development.
Mites were collected from sand fly larval rearing pots and morphologically identified using taxonomic keys. Upon identification, they were photographed with a scanning electron microscope. Several mite control measures were adopted in two different laboratories, one at the Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases-National Institutes of Health (Rockville, MD, USA), and the other at the University of Calgary (Calgary, AB, Canada).
The mite species associated with sand fly colonies in the two laboratories were morphologically identified as Tyrophagus sp. and Stratiolaelaps scimitus. While complete eradication of mites in sand fly colonies is considered unrealistic, drastically reducing their population has been associated with higher sand fly productivity.
We report a case of detrimental interaction between sand flies and Tyrophagus sp. and S. scimitus in a closed laboratory sand fly colony, discuss their impact on sand fly production and provide guidelines for limiting the mite population size in a closed laboratory colony leading to improved sand fly yields.
An 11-year-old girl presented with a papulovesicular rash and severe respiratory distress 5 weeks after receiving varicella vaccine. Restriction fragment length–polymorphism analysis of virus ...isolated from an endotracheal-tube aspirate and from bronchoalveolar lavage revealed that this patient’s illness was due to the Oka vaccine strain of varicella. An extensive immunologic analysis failed to identify a known diagnostic entity to explain her susceptibility to this attenuated vaccine strain. Analysis of her lymphocytes on separate occasions, months after recovery from her illness, revealed a profound deficiency of natural killer T (NKT) cells and of NKT-cell activity, suggesting that NKT cells contribute to host defense against varicella virus
Mosquito vectors of medical importance both blood and sugar feed, and their saliva contains bioactive molecules that aid in both processes. Although it has been shown that the salivary glands of ...several mosquito species exhibit α-glucosidase activities, the specific enzymes responsible for sugar digestion remain understudied. We therefore expressed and purified three recombinant salivary α-glucosidases from the mosquito vectors Aedes aegypti, Anopheles gambiae, and Culex quinquefasciatus and compared their functions and structures. We found that all three enzymes were expressed in the salivary glands of their respective vectors and were secreted into the saliva. The proteins, as well as mosquito salivary gland extracts, exhibited α-glucosidase activity, and the recombinant enzymes displayed preference for sucrose compared to p-nitrophenyl-α-D-glucopyranoside. Finally, we solved the crystal structure of the Ae. aegypti α-glucosidase bound to two calcium ions at a 2.3 Ångstrom resolution. Molecular docking suggested that the Ae. aegypti α-glucosidase preferred di- or polysaccharides compared to monosaccharides, consistent with enzymatic activity assays. Comparing structural models between the three species revealed a high degree of similarity, suggesting similar functional properties. We conclude that the α-glucosidases studied herein are important enzymes for sugar digestion in three mosquito species.
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•Mosquitoes blood and sugar feed.•Mosquito species of medical importance exhibit α-glucosidase activities.•Sugar digestion by mosquito saliva remains understudied.•Structural studies are instrumental in the understanding of biology of salivary glucosidases.
Case Description—2 horses were examined for chronic nasal discharge secondary to unilateral guttural pouch mycosis. Clinical Findings—Initial endoscopic examination of both horses confirmed the ...presence of a fungal plaque on the dorsomedial aspect of the medial compartment of the guttural pouch (auditory tube diverticulum) involving the internal carotid artery (ICA). No signs of hemorrhage or neurologic deficits were present at admission. Treatment and Outcome—Transarterial stainless steel coil embolization of the affected ICA was performed under general anesthesia, with fluoroscopic guidance. During treatment, an aberrant branch of the ICA, or a proposed bifid ICA, that anastomosed with the caudal cerebellar artery was identified. Occlusion of the distal (noncardiac) side of the aberrant branch was performed in both horses because of potential mycotic involvement at that level. Following treatment, resolution of the mycotic infection was observed in both horses; however, 1 horse developed neurologic signs compatible with unilateral caudal cerebellar artery ischemia on recovery from anesthesia; these signs resolved over the following 2 months. Clinical Relevance—Findings highlighted variability of the anatomy of the ICA in 2 horses that was identified during treatment for guttural pouch mycosis and identified caudal cerebellar artery infarction as a potential complication of treatment. Because of the size and pathway of both arterial branches, we suggest that the term bifurcation of the ICA is more appropriate than aberrant branching, as has been previously described in the literature. The information in this report may be of value to clinicians performing procedures involving the vasculature of the head and neck in horses.
Patient-centered care requires that treatments respond to the problematic situation of each patient in a manner that makes intellectual, emotional, and practical sense, an achievement that requires ...shared decision making (SDM). To implement SDM in practice, tools-sometimes called conversation aids or decision aids-are prepared by collating, curating, and presenting high-quality, comprehensive, and up-to-date evidence. Yet, the literature offers limited guidance for how to make evidence support SDM. Herein, we describe our approach and the challenges encountered during the development of Anticoagulation Choice, a conversation aid to help patients with atrial fibrillation and their clinicians jointly consider the risk of thromboembolic stroke and decide whether and how to respond to this risk with anticoagulation.
Female mosquitoes require blood meals for egg development. The saliva of blood feeding arthropods contains biochemically active molecules, whose anti-hemostatic and anti-inflammatory properties ...facilitate blood feeding on vertebrate hosts. While transcriptomics has presented new opportunities to investigate the diversity of salivary proteins from hematophagous arthropods, many of these proteins remain functionally undescribed. Previous transcriptomic analysis of female salivary glands from Culex quinquefasciatus, an important vector of parasitic and viral infections, uncovered a 12-member family of putatively secreted proteins of unknown function, named the Cysteine and Tryptophan-Rich (CWRC) proteins. Here, we present advances in the characterization of two C. quinquefasciatus CWRC family members, CqDVP-2 and CqDVP-4, including their enrichment in female salivary glands, their specific localization within salivary gland tissues, evidence that these proteins are secreted into the saliva, and their native crystal structures, at 2.3 Å and 1.87 Å, respectively. The β-trefoil fold common to CqDVP-2 and CqDVP-4 is similar to carbohydrate-binding proteins, including the B subunit of the AB toxin, ricin, from the castor bean Ricinus communis. Further, we used a glycan array approach, which identifies carbohydrate ligands associated with inflammatory processes and signal transduction. Glycan array 300 testing identified 100 carbohydrate moieties with positive binding to CqDVP-2, and 77 glycans with positive binding to CqDVP-4. The glycan with the highest relative fluorescence intensities, which exhibited binding to both CqDVP-2 and CqDVP-4, was used for molecular docking experiments. We hypothesize that these proteins bind to carbohydrates on the surface of cells important to host immunology. Given that saliva is deposited into the skin during a mosquito bite, and acts as the vehicle for arbovirus inoculation, understanding the role of these proteins in pathogen transmission is of critical importance. This work presents the first solved crystal structures of C. quinquefasciatus salivary proteins with unknown function. These two molecules are the second and third structures reported from salivary proteins from C. quinquefasciatus, an important, yet understudied disease vector.
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•Saliva of blood feeding mosquitoes contains biochemically active molecules that facilitate blood feeding and pathogen transmission.•CqDVP-2 and CqDVP-4, two major proteins from Culex quinquefasciatus, are specific to adult female salivary glands and are secreted into the saliva.•Sex and tissue specificity of these proteins indicate their possible function(s) in blood feeding and pathogen transmission.•The native crystal structures of CqDVP-2 and CqDVP-4 have a ß-trefoil fold similar to carbohydrate-binding proteins.•CqDVP protein binding to carbohydrates is thought to play a role in inflammation and may be an evolutionary adaptation to blood feeding and help improve mosquito survival.
How patients with atrial fibrillation (AF) and their clinicians consider cost in forming care plans remains unknown.
To identify factors that inform conversations regarding costs of anticoagulants ...for treatment of AF between patients and clinicians and outcomes associated with these conversations.
This cohort study of recorded encounters and participant surveys at 5 US medical centers (including academic, community, and safety-net centers) from the SDM4AFib randomized trial compared standard AF care with and without use of a shared decision-making (SDM) tool. Included patients were considering anticoagulation treatment and were recruited by their clinicians between January 30, 2017, and June 27, 2019. Data were analyzed between August and November 2019.
The incidence of and factors associated with cost conversations, and the association of cost conversations with patients' consideration of treatment cost burden and their choice of anticoagulation.
A total of 830 encounters (out of 922 enrolled participants) were recorded. Patients' mean (SD) age was 71.0 (10.4) years; 511 patients (61.6%) were men, 704 (86.0%) were White, 303 (40.9%) earned between $40 000 and $99 999 in annual income, and 657 (79.2%) were receiving anticoagulants. Clinicians' mean (SD) age was 44.8 (13.2) years; 75 clinicians (53.2%) were men, and 111 (76%) practiced as physicians, with approximately half (69 48.9%) specializing in either internal medicine or cardiology. Cost conversations occurred in 639 encounters (77.0%) and were more likely in the SDM arm (378 90% vs 261 64%; OR, 9.69; 95% CI, 5.77-16.29). In multivariable analysis, cost conversations were more likely to occur with female clinicians (66 47%; OR, 2.85; 95% CI, 1.21-6.71); consultants vs in-training clinicians (113 75%; OR, 4.0; 95% CI, 1.4-11.1); clinicians practicing family medicine (24 16%; OR, 12.12; 95% CI, 2.75-53.38), internal medicine (35 23%; OR, 3.82; 95% CI, 1.25-11.70), or other clinicians (21 14%; OR, 4.90; 95% CI, 1.32-18.16) when compared with cardiologists; and for patients with an annual household income between $40 000 and $99 999 (249 82.2%; OR, 1.86; 95% CI, 1.05-3.29) compared with income below $40 000 or above $99 999. More patients who had cost conversations reported cost as a factor in their decision (244 89.1% vs 327 69.0%; OR 3.66; 95% CI, 2.43-5.50), but cost conversations were not associated with the choice of anticoagulation agent.
Cost conversations were common, particularly for middle-income patients and with female and consultant-level primary care clinicians, as well as in encounters using an SDM tool; they were associated with patients' consideration of treatment cost burden but not final treatment choice. With increasing costs of care passed on to patients, these findings can inform efforts to promote cost conversations in practice.
ClinicalTrials.gov Identifier: NCT02905032.
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