Crystal structure of Trichinella spiralis calreticulin and the structural basis of its complement evasion mechanism involving C1q.

Helminths produce calreticulin (CRT) to immunomodulate the host immune system as a survival strategy. However, the structure of helminth-derived CRT and the structural basis of the immune evasion process remains unclarified. Previous study found that the tissue-dwelling helminth Trichinella spiralis produces calreticulin (TsCRT), which binds C1q to inhibit activation of the complement classical pathway. Here, we used x-ray crystallography to resolve the structure of truncated TsCRT (TsCRTΔ), the first structure of helminth-derived CRT. TsCRTΔ was observed to share the same binding region on C1q with IgG based on the structure and molecular docking, which explains the inhibitory effect of TsCRT on C1q-IgG-initiated classical complement activation. Based on the key residues in TsCRTΔ involved in the binding activity to C1q, a 24 amino acid peptide called PTsCRT was constructed that displayed strong C1q-binding activity and inhibited C1q-IgG-initiated classical complement activation. This study is the first to elucidate the structural basis of the role of TsCRT in immune evasion, providing an approach to develop helminth-derived bifunctional peptides as vaccine target to prevent parasite infections or as a therapeutic agent to treat complement-related autoimmune diseases.

Unusual Case of Esophageal Foreign Body: A Whole Mantis Shrimp.

Esophageal foreign bodies (FBs) are one of the common emergencies in otolaryngology, usually involving objects accidentally swallowed, and generally do not result in severe respiratory distress. This article presents an extremely rare case of an esophageal FB, where a 44-year-old man accidentally ingested an entire mantis shrimp while sucking its flavored tail, and was sent to the emergency department for severe throat pain and difficulty breathing. We immediately performed a laryngoscopy that revealed the FB that obstructs the entrance of the esophagus, obstructing the glottis due to the long shape of the shrimp. The mantis shrimp had barbs on its shell and trying to remove it intact would cause significant damage to the pharyngeal mucosa. Therefore, we extracted the mantis shrimp in segments under general anesthesia and applied electrocoagulation to stop bleeding from the damaged and bleeding posterior pharyngeal mucosa. As an esophagography was performed the following day, there were no signs of esophageal perforation. Through the detailed description and analysis of this case, our aim is to raise clinical awareness among physicians of such rare occurrences. Most important, appropriate examination and procedures of FBs should be performed based on the type, shape, and location of the FB.

Bosea beijingensis sp. nov., Telluria beijingensis sp. nov. and Agrococcus beijingensis sp. nov., isolated from baijiu mash.

The baijiu fermentation environment hosts a variety of micro-organisms, some of which still remain uncultured and uncharacterized. In this study, the isolation, cultivation and characterization of three novel aerobic bacterial strains are described. The cells of strain REN20T were Gram-negative, strictly aerobic, motile and grew at 26-37 °C, at pH 6.0-9.0 and in the presence of 0-5.0   % (w/v) NaCl. The cells of strain REN29T were Gram-negative, strictly aerobic, motile and grew at 15-30 °C, at pH 6.0-9.0 and in the presence of 0-10.0   % (w/v) NaCl. The cells of strain REN33T were Gram-positive, strictly aerobic, motile and grew at 15-37 °C, at pH 5.0-10.0 and in the presence of 0-7.0   % (w/v) NaCl. The digital DNA-DNA hybridization and average nucleotide identity by orthology values between type strains in related genera and REN20T (20.3-36.8 % and 79.8-89.9  %), REN29T (20.3-36.8  % and 74.5-88.5  %) and REN33T (22.6-48.6  % and 75.8-84.2  %) were below the standard cut-off criteria for the delineation of bacterial species, respectively. Based on polyphasic taxonomy analysis, we propose three new species, Bosea beijingensis sp. nov. (=REN20T=GDMCC 1.2894T=JCM 35118T), Telluria beijingensis sp. nov. (=REN29T=GDMCC 1.2896T=JCM 35119T) and Agrococcus beijingensis sp. nov. (=REN33T=GDMCC 1.2898T=JCM 35164T), which were recovered during cultivation and isolation from baijiu mash.

Evaluation of Exploratory Fluid Biomarker Results from a Phase 1 Senolytic Trial in Mild Alzheimer's Disease.

Senescent cell accumulation contributes to the progression of age-related disorders including Alzheimer's disease (AD). Clinical trials evaluating senolytics, drugs that clear senescent cells, are underway, but lack standardized outcome measures. Our team recently published data from the first open-label trial to evaluate senolytics (dasatinib plus quercetin) in AD. After 12-weeks of intermittent treatment, we reported brain exposure to dasatinib, favorable safety and tolerability, and modest post-treatment changes in cerebrospinal fluid (CSF) inflammatory and AD biomarkers using commercially available assays. Herein, we present more comprehensive exploratory analyses of senolytic associated changes in AD relevant proteins, metabolites, lipids, and transcripts measured across blood, CSF, and urine. These analyses included mass spectrometry for precise quantification of amyloid beta (Aß) and tau in CSF; immunoassays to assess senescence associated secretory factors in plasma, CSF, and urine; mass spectrometry analysis of urinary metabolites and lipids in blood and CSF; and transcriptomic analyses relevant to chronic stress measured in peripheral blood cells. Levels of Aß and tau species remained stable. Targeted cytokine and chemokine analyses revealed treatment-associated increases in inflammatory plasma fractalkine and MMP-7 and CSF IL-6. Urinary metabolites remained unchanged. Modest treatment-associated lipid profile changes suggestive of decreased inflammation were observed both peripherally and centrally. Blood transcriptomic analysis indicated downregulation of inflammatory genes including FOS, FOSB, IL1ß, IL8, JUN, JUNB, PTGS2. These data provide a foundation for developing standardized outcome measures across senolytic studies and indicate distinct biofluid-specific signatures that will require validation in future studies. ClinicalTrials.gov: NCT04063124.

Evaluation of a novel Tc-24 recombinant antigen ELISA for serologic testing for Trypanosoma cruzi in dogs.

Chagas disease is a parasitic infection caused by Trypanosoma cruzi. Diagnosis of chronic Chagas disease in dogs relies on limited serological test options. This study used a new Tc-24 recombinant antigen ELISA on an archival set of 70 dog serum samples from multi-dog kennel environments in Texas subjected to three existing Chagas serological tests. Tc-24 ELISA produced a quantitative result and could detect anti-T. cruzi antibodies in dogs with high sensitivity and specificity. Comparing individual tests to Tc-24 ELISA resulted in strong associations and correlations, which suggest that Tc-24 ELISA is a reliable and accurate diagnostic tool for dogs with a single test.

Therapeutic effect of Echinococcus granulosus cyst fluid on bacterial sepsis in mice.

BACKGROUND: The primary pathophysiological process of sepsis is to stimulate a massive release of inflammatory mediators to trigger systemic inflammatory response syndrome (SIRS), the major cause of multi-organ dysfunction and death. Like other helminths, Echinococcus granulosus induces host immunomodulation. We sought to determine whether E. granulosus cyst fluid (EgCF) displays a therapeutic effect on sepsis-induced inflammation and tissue damage in a mouse model. METHODS: The anti-inflammatory effects of EgCF were determined by in vitro culture with bone marrow-derived macrophages (BMDMs) and in vivo treatment of BALB/C mice with cecal ligation and puncture (CLP)-induced sepsis. The macrophage phenotypes were determined by flow cytometry, and the levels of cytokines in cell supernatants or in sera of mice were measured (ELISA). The therapeutic effect of EgCF on sepsis was evaluated by observing the survival rates of mice for 72 h after CLP, and the pathological injury to the liver, kidney, and lung was measured under a microscope. The expression of TLR-2/MyD88 in tissues was measured by western blot to determine whether TLR-2/MyD88 is involved in the sepsis-induced inflammatory signaling pathway. RESULTS: In vitro culture with BMDMs showed that EgCF promoted macrophage polarization to M2 type and inhibited lipopolysaccharide (LPS)-induced M1 macrophages. EgCF treatment provided significant therapeutic effects on CLP-induced sepsis in mice, with increased survival rates and alleviation of tissue injury. The EgCF conferred therapeutic efficacy was associated with upregulated anti-inflammatory cytokines (IL-10 and TGF-ß) and reduced pro-inflammatory cytokines (TNF-α and INF-γ). Treatment with EgCF induced Arg-1-expressed M2, and inhibited iNOS-expressed M1 macrophages. The expression of TLR-2 and MyD88 in EgCF-treated mice was reduced. CONCLUSIONS: The results demonstrated that EgCF confers a therapeutic effect on sepsis by inhibiting the production of pro-inflammatory cytokines and inducing regulatory cytokines. The anti-inflammatory effect of EgCF is carried out possibly through inducing macrophage polarization from pro-inflammatory M1 to regulatory M2 phenotype to reduce excessive inflammation of sepsis and subsequent multi-organ damage. The role of EgCF in regulating macrophage polarization may be achieved by inhibiting the TLR2/MyD88 signaling pathway.

A Novel Soybean Diacylglycerol Acyltransferase 1b Variant with Three Amino Acid Substitutions Increases Seed Oil Content.

Improving soybean (Glycine max) seed composition by increasing the protein and oil components will add significant value to the crop and enhance environmental sustainability. Diacylglycerol acyltransferase (DGAT) catalyzes the final rate-limiting step in triacylglycerol (TAG) biosynthesis and has a major impact on seed oil accumulation. We previously identified a soybean DGAT1b variant with 14 amino acid substitutions (GmDGAT1b-MOD) that increases total oil content by 3 percentage points when overexpressed in soybean seeds. In the present study, additional GmDGAT1b variants were generated to further increase oil with a reduced number of substitutions. Variants with one to four amino acid substitutions were screened in the model systems S. cerevisiae and transient N. benthamiana leaf. Promising GmDGAT1b variants resulting in high oil accumulation in the model systems were selected for over-expression in soybeans. One GmDGAT1b variant with three novel amino acid substitutions (GmDGAT1b-3aa) increased total soybean oil to levels near the previously discovered GmDGAT1b-MOD variant. In a multiple location field trial, GmDGAT1b-3aa transgenic events had significantly increased oil and protein by up to 2.3 and 0.6 percentage points, respectively. Modeling of the GmDGAT1b-3aa protein structure provided insights into the potential function of the three substitutions. These findings will guide efforts to improve soybean oil content and overall seed composition by CRISPR editing.

Excretory/secretory products from Trichinella spiralis adult worms ameliorate myocardial infarction by inducing M2 macrophage polarization in a mouse model.

BACKGROUND: Ischemia-induced inflammatory response is the main pathological mechanism of myocardial infarction (MI)-caused heart tissue injury. It has been known that helminths and worm-derived proteins are capable of modulating host immune response to suppress excessive inflammation as a survival strategy. Excretory/secretory products from Trichinella spiralis adult worms (Ts-AES) have been shown to ameliorate inflammation-related diseases. In this study, Ts-AES were used to treat mice with MI to determine its therapeutic effect on reducing MI-induced heart inflammation and the immunological mechanism involved in the treatment. METHODS: The MI model was established by the ligation of the left anterior descending coronary artery, followed by the treatment of Ts-AES by intraperitoneal injection. The therapeutic effect of Ts-AES on MI was evaluated by measuring the heart/body weight ratio, cardiac systolic and diastolic functions, histopathological change in affected heart tissue and observing the 28-day survival rate. The effect of Ts-AES on mouse macrophage polarization was determined by stimulating mouse bone marrow macrophages in vitro with Ts-AES, and the macrophage phenotype was determined by flow cytometry. The protective effect of Ts-AES-regulated macrophage polarization on hypoxic cardiomyocytes was determined by in vitro co-culturing Ts-AES-induced mouse bone marrow macrophages with hypoxic cardiomyocytes and cardiomyocyte apoptosis determined by flow cytometry. RESULTS: We observed that treatment with Ts-AES significantly improved cardiac function and ventricular remodeling, reduced pathological damage and mortality in mice with MI, associated with decreased pro-inflammatory cytokine levels, increased regulatory cytokine expression and promoted macrophage polarization from M1 to M2 type in MI mice. Ts-AES-induced M2 macrophage polarization also reduced apoptosis of hypoxic cardiomyocytes in vitro. CONCLUSIONS: Our results demonstrate that Ts-AES ameliorates MI in mice by promoting the polarization of macrophages toward the M2 type. Ts-AES is a potential pharmaceutical agent for the treatment of MI and other inflammation-related diseases.

A Recombinant Protein XBB.1.5 RBD/Alum/CpG Vaccine Elicits High Neutralizing Antibody Titers against Omicron Subvariants of SARS-CoV-2.

(1) Background: We previously reported the development of a recombinant protein SARS-CoV-2 vaccine, consisting of the receptor-binding domain (RBD) of the SARS-CoV-2 spike protein, adjuvanted with aluminum hydroxide (alum) and CpG oligonucleotides. In mice and non-human primates, our wild-type (WT) RBD vaccine induced high neutralizing antibody titers against the WT isolate of the virus, and, with partners in India and Indonesia, it was later developed into two closely resembling human vaccines, Corbevax and Indovac. Here, we describe the development and characterization of a next-generation vaccine adapted to the recently emerging XBB variants of SARS-CoV-2. (2) Methods: We conducted preclinical studies in mice using a novel yeast-produced SARS-CoV-2 XBB.1.5 RBD subunit vaccine candidate formulated with alum and CpG. We examined the neutralization profile of sera obtained from mice vaccinated twice intramuscularly at a 21-day interval with the XBB.1.5-based RBD vaccine, against WT, Beta, Delta, BA.4, BQ.1.1, BA.2.75.2, XBB.1.16, XBB.1.5, and EG.5.1 SARS-CoV-2 pseudoviruses. (3) Results: The XBB.1.5 RBD/CpG/alum vaccine elicited a robust antibody response in mice. Furthermore, the serum from vaccinated mice demonstrated potent neutralization against the XBB.1.5 pseudovirus as well as several other Omicron pseudoviruses. However, regardless of the high antibody cross-reactivity with ELISA, the anti-XBB.1.5 RBD antigen serum showed low neutralizing titers against the WT and Delta virus variants. (4) Conclusions: Whereas we observed modest cross-neutralization against Omicron subvariants with the sera from mice vaccinated with the WT RBD/CpG/Alum vaccine or with the BA.4/5-based vaccine, the sera raised against the XBB.1.5 RBD showed robust cross-neutralization. These findings underscore the imminent opportunity for an updated vaccine formulation utilizing the XBB.1.5 RBD antigen.

Transcriptomic Response of Clonostachys rosea Mycoparasitizing Rhizoctonia solani.

Clonostachys rosea is an important mycoparasitism biocontrol agent that exhibits excellent control efficacy against numerous fungal plant pathogens. Transcriptomic sequencing may be used to preliminarily screen mycoparasitism-related genes of C. rosea against fungal pathogens. The present study sequenced and analyzed the transcriptome of C. rosea mycoparasitizing a Basidiomycota (phylum) fungal pathogen, Rhizoctonia solani, under three touch stages: the pre-touch stage, touch stage and after-touch stage. The results showed that a number of genes were differentially expressed during C. rosea mycoparasitization of R. solani. At the pre-touch stage, 154 and 315 genes were up- and down-regulated, respectively. At the touch stage, the numbers of up- and down-regulated differentially expressed genes (DEGs) were 163 and 188, respectively. The after-touch stage obtained the highest number of DEGs, with 412 and 326 DEGs being up- and down-regulated, respectively. Among these DEGs, ABC transporter-, glucanase- and chitinase-encoding genes were selected as potential mycoparasitic genes according to a phylogenetic analysis. A comparative transcriptomic analysis between C. rosea mycoparasitizing R. solani and Sclerotinia sclerotiorum showed that several DEGs, including the tartrate transporter, SDR family oxidoreductase, metallophosphoesterase, gluconate 5-dehydrogenase and pyruvate carboxylase, were uniquely expressed in C. rosea mycoparasitizing R. solani. These results significantly expand our knowledge of mycoparasitism-related genes in C. rosea and elucidate the mycoparasitism mechanism of C. rosea.

The Adenylate Cyclase-Encoding Gene crac Is Involved in Clonostachys rosea Mycoparasitism.

Clonostachys rosea is an excellent biocontrol fungus against numerous fungal plant pathogens. The cAMP signaling pathway is a crucial signal transduction pathway in fungi. To date, the role of the cAMP signaling pathway in C. rosea mycoparasitism remains unknown. An adenylate cyclase-encoding gene, crac (an important component of the cAMP signaling pathway), was previously screened from C. rosea 67-1, and its expression level was dramatically upregulated during the C. rosea mycoparasitization of the sclerotia of Sclerotinia sclerotiorum. In this study, the function of crac in C. rosea mycoparasitism was explored through gene knockout and complementation. The obtained results show that the deletion of crac influenced the growth rate and colony morphology of C. rosea, as well as the tolerance to NaCl and H2O2 stress. The mycoparasitic effects on the sclerotia of S. sclerotiorum and the biocontrol capacity on soybean Sclerotinia stem rot in ∆crac-6 and ∆crac-13 were both attenuated compared with that of the wild-type strain and complementation transformants. To understand the regulatory mechanism of crac during C. rosea mycoparasitism, transcriptomic analysis was conducted between the wild-type strain and knockout mutant. A number of biocontrol-related genes, including genes encoding cell wall-degrading enzymes and transporters, were significantly differentially expressed during C. rosea mycoparasitism, suggesting that crac may be involved in C. rosea mycoparasitism by regulating the expression of these DEGs. These findings provide insight for further exploring the molecular mechanism of C. rosea mycoparasitism.

Effects of Alexithymia on Moral Decision-Making in Sacrificial Dilemmas: High Alexithymia is Associated with Weaker Sensitivity to Moral Norms.

Purpose: Although several studies have investigated the association between alexithymia and moral decision-making in sacrificial dilemmas, the evidence remains mixed. The current work investigated this association and how alexithymia affects moral choice in such dilemmas. Methods: The current research used a multinomial model (ie, CNI model) to disentangle (a) sensitivity to consequences, (b) sensitivity to moral norms, and (c) general preference for inaction versus action irrespective of consequences and norms in responses to moral dilemmas. Results: Higher levels of alexithymia were associated with a greater preference for utilitarian judgments in sacrificial dilemmas (Study 1). Furthermore, individuals with high alexithymia showed significantly weaker sensitivity to moral norms than did those with low alexithymia, whereas there were no significant differences in sensitivity to consequences or a general preference for inaction versus action (Study 2). Conclusion: The findings suggest that alexithymia affects moral choice in sacrificial dilemmas by blunting emotional reactions to causing harm, rather than through increased deliberative cost-benefit reasoning or general preference for inaction.

Development of chimeric protein as a multivalent vaccine for human Kinetoplastid infections: Chagas disease and leishmaniasis.

Leishmania spp. and Trypanosoma cruzi are parasitic kinetoplastids of great medical and epidemiological importance since they are responsible for thousands of deaths and disability-adjusted life-years annually, especially in low- and middle-income countries. Despite efforts to minimize their impact, current prevention measures have failed to fully control their spread. There are still no vaccines available. Taking into account the genetic similarity within the Class Kinetoplastida, we selected CD8+ T cell epitopes preserved among Leishmania spp. and T. cruzi to construct a multivalent and broad-spectrum chimeric polyprotein vaccine. In addition to inducing specific IgG production, immunization with the vaccine was able to significantly reduce parasite burden in the colon, liver and skin lesions from T. cruzi, L. infantum and L. mexicana challenged mice, respectively. These findings were supported by histopathological analysis, which revealed decreased inflammation in the colon, a reduced number of degenerated hepatocytes and an increased proliferation of connective tissue in the skin lesions of the corresponding T. cruzi, L. infantum and L. mexicana vaccinated and challenged mice. Collectively, our results support the protective effect of a polyprotein vaccine approach and further studies will elucidate the immune profile associated with this protection. Noteworthy, our results act as conceptual proof that a single multi-kinetoplastida vaccine can be used effectively to control different infectious etiologies, which in turn can have a profound impact on the development of a new generation of vaccines.

Adjuvanted Fusion Protein Vaccine Induces Durable Immunity to Onchocerca volvulus in Mice and Non-Human Primates.

Onchocerciasis remains a debilitating neglected tropical disease. Due to the many challenges of current control methods, an effective vaccine against the causative agent Onchocerca volvulus is urgently needed. Mice and cynomolgus macaque non-human primates (NHPs) were immunized with a vaccine consisting of a fusion of two O. volvulus protein antigens, Ov-103 and Ov-RAL-2 (Ov-FUS-1), and three different adjuvants: Advax-CpG, alum, and AlT4. All vaccine formulations induced high antigen-specific IgG titers in both mice and NHPs. Challenging mice with O. volvulus L3 contained within subcutaneous diffusion chambers demonstrated that Ov-FUS-1/Advax-CpG-immunized animals developed protective immunity, durable for at least 11 weeks. Passive transfer of sera, collected at several time points, from both mice and NHPs immunized with Ov-FUS-1/Advax-CpG transferred protection to naïve mice. These results demonstrate that Ov-FUS-1 with the adjuvant Advax-CpG induces durable protective immunity against O. volvulus in mice and NHPs that is mediated by vaccine-induced humoral factors.

TonB-Dependent Receptor Protein Displayed on Spores of Bacillus subtilis Stimulates Protective Immune Responses against Acinetobacter baumannii.

The emergence of antibiotic-resistant Acinetobacter baumannii strains with limited treatment options has become a significant global health concern. Efforts to develop vaccines against the bacteria have centred on several potential protein targets, including the TonB-dependent receptors (TBDRs). In the present study, TBDRs from A. baumannii were displayed on the surface of Bacillus subtilis spores. The immunogenicity of the recombinant spores was evaluated in orally vaccinated mice. None of the immunized mice demonstrated signs of illness and were observed to be healthy throughout the study. Sera and the intestinal secretions from the recombinant spores-treated mice demonstrated mucosal and humoral antibody responses to the vaccine antigen. In addition, bactericidal activities of the sera against A. baumannii clinical isolates were demonstrated. These observations suggest that the B. subtilis spore-displayed TBDRs should be further explored as much-needed potential oral vaccine candidates against A. baumannii.

From concept to delivery: a yeast-expressed recombinant protein-based COVID-19 vaccine technology suitable for global access.

INTRODUCTION: The development of a yeast-expressed recombinant protein-based vaccine technology co-developed with LMIC vaccine producers and suitable as a COVID-19 vaccine for global access is described. The proof-of-concept for developing a SARS-CoV-2 spike protein receptor-binding domain (RBD) antigen as a yeast-derived recombinant protein vaccine technology is described. AREAS COVERED: Genetic Engineering: The strategy is presented for the design and genetic modification used during cloning and expression in the yeast system. Process and Assay Development: A summary is presented of how a scalable, reproducible, and robust production process for the recombinant protein COVID-19 vaccine antigen was developed. Formulation and Pre-clinical Strategy: We report on the pre-clinical and formulation strategy used for the proof-of-concept evaluation of the SARS-CoV-2 RBD vaccine antigen. Technology Transfer and Partnerships: The process used for the technology transfer and co-development with LMIC vaccine producers is described. Clinical Development and Delivery: The approach used by LMIC developers to establish the industrial process, clinical development, and deployment is described. EXPERT OPINION: Highlighted is an alternative model for developing new vaccines for emerging infectious diseases of pandemic importance starting with an academic institution directly transferring their technology to LMIC vaccine producers without the involvement of multinational pharma companies.

The Effect of Buckwheat Resistant Starch on Intestinal Physiological Function.

Resistant starch appears to have promising effects on hypertension, cardiovascular and enteric illness. The influence of resistant starch on intestinal physiological function has drawn great attention. In this study, we first analyzed the physicochemical characteristics, including the crystalline properties, amylose content, and anti-digestibility among different types of buckwheat-resistant starch. The influence of resistant starch on the physiological functions of the mouse intestinal system, contained defecation, and intestinal microbes were also evaluated. The results showed that the crystalline mold of buckwheat-resistant starch changed from A to B + V after acid hydrolysis treatment (AHT) and autoclaving enzymatic debranching treatment (AEDT). The amylose content in AEDT was higher than in AHT and raw buckwheat. Moreover, the anti-digestibility of AEDT was also stronger than that in AHT and raw buckwheat. The buckwheat-resistant starch can promote bowel intestinal tract movement. The quantity of intestinal microbe was regulated by buckwheat-resistant starch. Our research demonstrates an effective preparation method for improving the quality of buckwheat-resistant starch and found that buckwheat-resistant starch has the role of adjusting the distribution of the intestinal flora and maintaining the health of the body.

Physicochemical characteristics and biological activities of soluble dietary fibers isolated from the leaves of different quinoa cultivars.

Quinoa leaf is consumed as a promising value-added vegetable in the diet. Although quinoa leaf is rich in soluble dietary fibers, the knowledge regarding their chemical structures and biological activities is still limited, which astricts their application in the functional food industry. Thus, to improve the precise use and application of soluble dietary fibers (SDFs) isolated from quinoa leaves in the food industry, the physicochemical structures and bioactivities of SDFs isolated from different quinoa leaves were systematically investigated. Results indicated that quinoa leaves were rich in SDFs, ranging from 3.30 % to 4.55 % (w/w). Quinoa SDFs were mainly composed of acidic polysaccharides, such as homogalacturonan and rhamnogalacturonan I, which had the molecular weights in the range of 4.228 × 104 -7.059 × 104 Da. Besides, quinoa SDFs exerted potential in vitro antioxidant activities, lipid and bile acid-adsorption capacities, immunoregulatory activities, and prebiotic effects, which might be partially associated with their molecular mass, content of uronic acid, and content of bound polyphenol. Collectively, these findings are beneficial to better understanding the chemical structures and bioactivities of SDFs extracted from different quinoa leaves, which can also provide a scientific basis for developing quinoa SDFs into functional foods in the food industry.

Echinococcus multilocularis Calreticulin Interferes with C1q-Mediated Complement Activation.

As a zoonotic disease caused by Echinococcus multilocularis larvae, alveolar echinococcosis (AE) is one of the most severe forms of parasitic infection. Over a long evolutional process E. multilocularis has developed complex strategies to escape host immune attack and survive within a host. However, the mechanisms underlying immune evasion remain unclear. Here we investigated the binding activity of E. multilocularis calreticulin (EmCRT), a highly conserved Ca2+-binding protein, to human complement C1q and its ability to inhibit classical complement activation. ELISA, Far Western blotting and immunoprecipitation results demonstrated that both recombinant and natural EmCRTs bound to human C1q, and the interaction of recombinant EmCRT (rEmCRT) inhibited C1q binding to IgM. Consequently, rEmCRT inhibited classical complement activation manifested as decreasing C4/C3 depositions and antibody-sensitized cell lysis. Moreover, rEmCRT binding to C1q suppressed C1q binding to human mast cell, HMC-1, resulting in reduced C1q-induced mast cell chemotaxis. According to these results, E. multilocularis expresses EmCRT to interfere with C1q-mediated complement activation and C1q-dependent non-complement activation of immune cells, possibly as an immune evasion strategy of the parasite in the host.

Excretory/Secretory Proteome of Females and Males of the Hookworm Ancylostoma ceylanicum.

The dynamic host-parasite mechanisms underlying hookworm infection establishment and maintenance in mammalian hosts remain poorly understood but are primarily mediated by hookworm's excretory/secretory products (ESPs), which have a wide spectrum of biological functions. We used ultra-high performance mass spectrometry to comprehensively profile and compare female and male ESPs from the zoonotic human hookworm Ancylostoma ceylanicum, which is a natural parasite of dogs, cats, and humans. We improved the genome annotation, decreasing the number of protein-coding genes by 49% while improving completeness from 92 to 96%. Compared to the previous genome annotation, we detected 11% and 10% more spectra in female and male ESPs, respectively, using this improved version, identifying a total of 795 ESPs (70% in both sexes, with the remaining sex-specific). Using functional databases (KEGG, GO and Interpro), common and sex-specific enriched functions were identified. Comparisons with the exclusively human-infective hookworm Necator americanus identified species-specific and conserved ESPs. This is the first study identifying ESPs from female and male A. ceylanicum. The findings provide a deeper understanding of hookworm protein functions that assure long-term host survival and facilitate future engineering of transgenic hookworms and analysis of regulatory elements mediating the high-level expression of ESPs. Furthermore, the findings expand the list of potential vaccine and diagnostic targets and identify biologics that can be explored for anti-inflammatory potential.