Genome-wide identification and examination of the wheat glycosyltransferase family 43 regulation during Fusarium graminearum infection.

In Arabidopsis and rice, the glycosyltransferase (GT) 43 family is involved in xylan synthesis. However, there have been limited reports on the study of the TaGT43 family in wheat. In this study, 28 TaGT43 family members were identified in wheat (Triticum aestivum L.) and clustered into three major groups based on the similarity of amino acid sequences. The results of the TaGT43 family's conserved motif and gene structure analyses agree with this result. Collinearity analysis revealed segmental duplications mainly promoted TaGT43 family expansion. cis-Acting element analysis revealed that the TaGT43 genes were involved in the light response, phytohormone response, abiotic/biotic stress response, and growth and development. The TaGT43 family showed a tissue-specific expression pattern, primarily expressed in roots and stems. Besides, the transcriptional and expression levels of multiple TaGT43 genes were upregulated during the infection of F. graminearum. According to metabolomics studies, F. graminearum infection affected the phenylpropanoid biosynthesis pathway in wheat, a critical factor in cell wall construction. Furthermore, GO enrichment analysis indicated that the TaGT43 genes play a significant role in cell wall organization. Based on these results, it may be concluded that the TaGT43 family mediates cell wall organization in response to F. graminearum infection.

An Atypical Incontinentia Pigmenti Female with Persistent Mucocutaneous Hyperinflammation and Immunodeficiency Caused by a Novel Germline IKBKG Missense Mutation.

While most missense mutations of the IKBKG gene typically result in Ectodermal Dysplasia with Immunodeficiency, there have been rare reported instances of missense mutations of the IKBKG gene causing both Incontinentia Pigmenti (IP) and immunodeficiency in female patients. In this study, we described an atypical IP case in a 19-year-old girl, characterized by hyperpigmented and verrucous skin areas over the entire body. Remarkably, she experienced recurrent red papules whenever she had a feverish upper respiratory tract infection. Immunohistochemical staining unveiled a substantial accumulation of CD68+ macrophages alongside the TNF-α positive cells in the dermis tissue of new pustules, with increased apoptotic basal keratinocytes in the epidermis tissue of these lesions. Starting from the age of 8 years old, the patient suffered from severe and sustained chronic respiratory mucous membrane scar hyperplasia and occluded subglottic lumen. In addition to elevated erythrocyte sedimentation rate values, inflammatory cells were observed in the pathologic lesions of endobronchial biopsies and Bronchoalveolar Lavage Fluid (BALF) smear. Further histological analysis revealed a destructive bronchus epithelium integrity with extensive necrosis. Simultaneously, the patient experienced recurrent incomplete intestinal obstructions and lips contracture. The patient's BALF sample displayed an augmented profile of proinflammatory cytokines and chemokines, suggesting a potential link to systemic hyperinflammation, possibly underlying the pathogenic injuries affecting the subglottic, respiratory, and digestive systems. Furthermore, the patient presented with recurrent pneumonias and multiple warts accompanied by a T+BlowNKlow immunophenotype. Next generation sequencing showed that the patient carried a novel de novo germline heterozygous missense mutation in the IKBKG gene (c. 821T>C, p. L274P), located in the highly conserved CC2 domain. TA-cloning sequencing of patient's cDNA yielded 30 mutant transcripts out of 44 clones. In silico analysis indicated that the hydrogen bond present between Ala270 and Leu274 in the wild-type NEMO was disrupted by the Leu274Pro mutation. However, this mutation did not affect NEMO expression in peripheral blood mononuclear cells (PBMCs). Moreover, patient PBMCs exhibited significantly impaired TNF-α production following Lipopolysaccharide (LPS) stimulation. X-chromosome inactivation in T cells and neutrophils were not severely skewed. Reduced levels of IκBα phosphorylation and degradation in patient's PBMCs were observed. The NF-κB luciferase reporter assay conducted using IKBKG-deficient HEK293T cells revealed a significant reduction in NF-kB activity upon LPS stimulation. These findings adds to the ever-growing knowledge on female IP that might contribute to the better understanding of this challenging disorder.

DeepHipp: accurate segmentation of hippocampus using 3D dense-block based on attention mechanism.

BACKGROUND: The hippocampus is a key area of the brain responsible for learning, memory, and other abilities. Accurately segmenting the hippocampus and precisely calculating the volume of the hippocampus is of great significance for predicting Alzheimer's disease and amnesia. Most of the segmentation algorithms currently involved are based on templates, such as the more popular FreeSufer. METHODS: This study proposes Deephipp, a deep learning network based on a 3D dense block using an attention mechanism for accurate segmentation of the hippocampus. DeepHipp is based on the following novelties: (i) DeepHipp adopts powerful data augmentation schemes to enhance the segmentation ability. (ii) DeepHipp is designed to incorporate 3D dense-block to capture multiple-scale features of the hippocampus. (iii) DeepHipp creatively uses the attention mechanism in the field of hippocampal image segmentation, extracting useful hippocampus information in a massive feature map, and improving the accuracy and sensitivity of the model. CONCLUSIONS: We describe the illustrative results and show extensive qualitative and quantitative comparisons with other methods. Our achievement demonstrates that the accuracy of DeepHipp can reach 83.63%, which is superior to most existing methods in terms of accuracy and efficiency of hippocampus segmentation. It is noticeable that deep learning can potentially lead to an effective segmentation of medical images.

Antennae-enriched expression of candidate odorant degrading enzyme genes in the turnip aphid, Lipaphis erysimi.

Aphids heavily rely on their olfactory system for foraging behavior. Odorant-degrading enzymes (ODEs) are essential in preserving the olfactory acuity of aphids by removing redundant odorants in the antennae. Certain enzymes within this group stand out as being enriched and/or biased expressed in the antennae, such as carboxylesterases (CXEs), cytochrome P450 (CYPs), glutathione S-transferases (GSTs), and UDP-glycosyltransferases (UGTs). Here, we performed a comparative transcriptome analysis of antennae and body tissue to isolate the antennal ODE genes of turnip aphid Lipaphis erysimi. A dataset of one CXE, seven CYPs, two GSTs, and five UGTs enriched in the antennae was identified and subjected to sequence analysis. Furthermore, qRT-PCR analyses showed that 13 ODE genes (LeCXE6, LeCYP4c1, LeCYP6a2, LeCYP6a13, LeCYP6a14.2, LeCYP6k1, LeCYP18a1, LeGST1, LeUGT1-7, LeUGT2B7, LeUGT2B13, LeUGT2C1.1, and LeUGT2C1.2) were specifically or significantly elevated in antennal tissues. Among these antennae-enriched ODEs, LeCYP4c1, LeCYP6a2, LeCYP6a13, LeCYP6a14.2, LeCYP18a1, LeUGT2B7, and LeUGT2B13 were found to exhibit significantly higher expression levels in alate aphids compared to apterous and nymph aphids, suggesting their putative role in detecting new host plant location. The results presented in this study highlight the identification and expression of ODE genes in L. erysimi, paving the path to investigate their functional role in odorant degradation during the olfactory processes.

CTCs Detection and Whole-exome Sequencing Might Be Used to Differentiate Benign and Malignant Pulmonary Nodules.

BACKGROUND: Low-density computed tomography (LDCT) improved early lung cancer diagnosis but introduces an excess of false-positive pulmonary nodules data. Hence, accurate diagnosis of early-stage lung cancer remains challenging. The purpose of the study was to assess the feasibility of using circulating tumour cells (CTCs) to differentiate malignant from benign pulmonary nodules. METHODS: 122 patients with suspected malignant pulmonary nodules detected on chest CT in preparation for surgery were prospectively recruited. Peripheral blood samples were collected before surgery, and CTCs were identified upon isolation by size of epithelial tumour cells and morphological analysis. Laser capture microdissection, MALBAC amplification, and whole-exome sequencing were performed on 8 samples. The diagnostic efficacy of CTCs counting, and the genomic variation profile of benign and malignant CTCs samples were analysed. RESULTS: Using 2.5 cells/5 mL as the cut-off value, the area under the receiver operating characteristic curve was of 0.651 (95% confidence interval: 0.538-0.764), with a sensitivity and specificity of 0.526 and 0.800, respectively, and positive and negative predictive values of 91.1% and 30.3%, respectively. Distinct sequence variations differences in DNA damage repair-related and driver genes were observed in benign and malignant samples. TP53 mutations were identified in CTCs of four malignant cases; in particular, g.7578115T>C, g.7578645C>T, and g.7579472G>C were exclusively detected in all four malignant samples. CONCLUSIONS: CTCs play an ancillary role in the diagnosis of pulmonary nodules. TP53 mutations in CTCs might be used to identify benign and malignant pulmonary nodules.

Prognostic and predictive significance of circulating biomarkers in patients with advanced upper gastrointestinal cancer undergoing systemic chemotherapy.

Objective: The prognosis of patients with advanced cancers of the upper gastrointestinal (UGI) tract is poor. Systemic chemotherapy forms the basis for their treatment, with limited efficacy. Biomarkers have been introduced into clinical practice for cancer management. This study aimed to investigate the predictive and prognostic values of circulating biomarkers in patients with advanced esophageal and gastric cancers receiving chemotherapy. Design: Overall, 92 patients with advanced esophageal squamous cell carcinoma (ESCC; n = 38) and gastric adenocarcinoma (GAC; n = 54) were enrolled. We analyzed the association of circulating lymphocyte subsets, inflammatory markers, and blood cell counts with treatment efficacy and patient survival. Results: Significant differences were identified in peripheral blood parameters between the groups with different clinicopathological features. Hemoglobin (Hb, p = 0.014), eosinophil counts (p = 0.028), CD4+CD28+T/CD4+T percentage (p = 0.049), CD8+CD38+T/CD8+T percentage (p = 0.044), memory CD4+T (p = 0.007), and CD4+CD28+T (p = 0.007) were determined as predictors for achieving non-PD (progression disease) in the ESCC cohort. High levels of eosinophils (p = 0.030) and memory CD4+T cells (p = 0.026) and high eosinophil-to-lymphocyte ratio (ELR, p = 0.013) were predictors of non-PD in patients with GAC. The combined detection models exhibited good ability to distinguish between partial response (PR)/non-PR and PD/non-PD in patients with ESCC and GAC, respectively. Using the multivariate Cox model, the Eastern Cooperative Oncology Group (ECOG) score status (hazard ratio [HR]: 4.818, 95% confidence intervals [CI]: 2.076-11.184, p < 0.001) and eosinophil count (HR: 0.276, 95% CI: 0.120-0.636, p = 0.003) were independent prognostic factors of progression-free survival (PFS) in patients with ESCC. Metastatic sites (HR: 2.092, 95% CI: 1.307-3.351, p = 0.002) and eosinophil-to-lymphocyte ratio (ELR; HR: 0.379, 95% CI: 0.161-0.893, p = 0.027) were independent prognostic factors for overall survival (OS) in patients with ESCC. Differentiation (HR: 0.041, 95% CI: 0.200-0.803, p = 0.010), memory CD4+T (HR: 0.304, 95% CI: 0.137-0.675, p = 0.003), NK cells (HR: 2.302, 95% CI: 1.044-3.953, p = 0.037), and C-reactive protein-to-lymphocyte ratio (CLR; HR: 2.070, 95% CI: 1.024-4.186, p = 0.043) were independent prognostic factors for PFS in patients with GAC. Total lymphocyte counts (HR: 0.260, 95% CI: 0.086-0.783, p = 0.017), CD8+T (HR: 0.405, 95% CI: 0.165-0.997, p = 0.049), NK cells (HR: 3.395, 95% CI: 1.592-7.238, p = 0.002), and monocyte-to-lymphocyte ratio (MLR; HR: 3.076, 95% CI: 1.488-6.360, p = 0.002) were identified as independent prognostic factors associated with OS of GAC. Conclusion: Lymphocyte subsets, blood cell counts, and inflammatory parameters may predict the chemotherapeutic response and prognosis in ESCC and GAC. A combination of these markers can be used to stratify patients into risk groups, which could improve treatment strategies.

Clinical features and prognosis of lung cancer in patients with connective tissue diseases: a retrospective cohort study.

Background: Studies have demonstrated a close association between connective tissue diseases (CTDs) and lung cancer (LC). Evidence supports that poor survival may be associated with the presence of CTDs in patients with LC. Methods: This retrospective cohort study investigated 29 patients with LC with CTDs, and 116 patients with LC without CTDs were enrolled as case-matched control cohorts. Medical records, therapeutic efficacy of cancer, and outcomes were analyzed. Results: The median duration from the diagnosis of CTDs to LC was 17 years. The Eastern Cooperative Oncology Group (ECOG) performance score for LC-CTD patients was worse than that for matched non-CTD LC patients. The median progression-free survival (mPFS) and overall survival (mOS) of first-line chemotherapy did not differ between patients with lung adenocarcinoma (AC) with and without CTDs. A significant difference was observed in mPFS [4 months vs. 17 months; hazard ratio (HR), 9.987; p = 0.004] and mOS (6 months vs. 35 months; HR, 26.009; p < 0.001) of first-line epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) treatment between patients with AC with and without CTDs. The presence of CTD, sex, ECOG performance status, and tumor-node-metastasis clinical stage were the independent prognostic factors in all patients with non-small cell LC (NSCLC). ECOG performance status was determined to be an independent prognostic factor in patients with LC-CTD. In patients with NSCLC with CTD (n = 26), sex (male) and worse ECOG score were the independent poor prognostic factors. Conclusions: CTDs were associated with poor survival in patients with LC. The therapeutic efficacy of first-line EGFR-TKI therapy was significantly worse in patients with lung AC with CTDs than in those without CTDs. ECOG performance status was determined as an independent prognostic factor for patients with LC and CTDs.

Strain improvement of Trichoderma harzianum for enhanced biocontrol capacity: Strategies and prospects.

In the control of plant diseases, biocontrol has the advantages of being efficient and safe for human health and the environment. The filamentous fungus Trichoderma harzianum and its closely related species can inhibit the growth of many phytopathogenic fungi, and have been developed as commercial biocontrol agents for decades. In this review, we summarize studies on T. harzianum species complex from the perspective of strain improvement. To elevate the biocontrol ability, the production of extracellular proteins and compounds with antimicrobial or plant immunity-eliciting activities need to be enhanced. In addition, resistance to various environmental stressors should be strengthened. Engineering the gene regulatory system has the potential to modulate a variety of biological processes related to biocontrol. With the rapidly developing technologies for fungal genetic engineering, T. harzianum strains with increased biocontrol activities are expected to be constructed to promote the sustainable development of agriculture.

Candidate odorant-binding protein and chemosensory protein genes in the turnip aphid Lipaphis erysimi.

The turnip aphid, Lipaphis erysimi Kaltenbach, inflicts heavy damage on cruciferous crops worldwide. In these insects, olfactory perception is crucial for mating, host location, and oviposition. Both odorant-binding proteins (OBPs) and chemosensory proteins (CSPs) are responsible for the delivery of host odorants and pheromones during initial molecular interactions. In this study, antennal and body transcriptomes of L. erysimi were generated through the deep sequencing of RNA libraries. A dataset of 11 LeryOBP and four LeryCSP transcripts was identified among assembled unigenes and subjected to sequence analysis. Phylogenetic analysis found a one-to-one orthologous relationship between LeryOBP/LeryCSP and its corresponding homologs from other aphid species. Further quantitative real-time PCR analyses across developmental stages and tissues showed that five LeryOBP genes (i.e., LeryGOBP, LeryOBP6, LeryOBP7, LeryOBP9, and LeryOBP13) and LeryCSP10 were specifically or significantly elevated in the antennae compared with other tissues. Moreover, two transcripts (i.e., LeryGOBP and LeryOBP6) exhibited remarkably higher expression levels in alate aphids, implying their potentially functional role in the perception of new host plant locations. These results present the identification and expression of OBP/CSP genes in L. erysimi, providing valuable insights into their putative role in olfactory signal transduction.

Metformin plays an antitumor role by downregulating inhibitory cells and immune checkpoint molecules while activating protective immune responses in breast cancer.

This study seeks to test the effect of metformin treatment on the outcomes of breast cancer in BALB/c mice bearing 4 T1 breast cancer cells. The survival rate and tumor size of mice were compared, as well as evaluation of the changes of immune cells in spleens and the microenvironment of tumors using flow cytometry and ELISA. Our results demonstrate that metformin prolongs mouse survival. A significant decrease in M2-like macrophages (F4/80+CD206+) was found in mice spleen treated with metformin. The treatment also inhibited monocytic myeloid-derived suppressor cells (M-MDSCs, CD11b+Gr-1+) and regulatory T cells (Tregs, CD4+CD25+Foxp3+). Metformin treatment resulted in an increase in the level of IFN-γ and a decrease in IL-10. Expression of the immune checkpoint molecule PD-1 on T cells was inhibited following treatment. Metformin enhances local antitumor activity in the tumor microenvironment, and our data supports the drug as a candidate for evaluation in the treatment of breast cancer.

Engineered Cleistogamy in Camelina sativa for bioconfinement.

Camelina sativa is a self-pollinating and facultative outcrossing oilseed crop. Genetic engineering has been used to improve camelina yield potential for altered fatty acid composition, modified protein profiles, improved seed and oil yield, and enhanced drought resistance. The deployment of transgenic camelina in the field posits high risks related to the introgression of transgenes into non-transgenic camelina and wild relatives. Thus, effective bioconfinement strategies need to be developed to prevent pollen-mediated gene flow (PMGF) from transgenic camelina. In the present study, we overexpressed the cleistogamy (i.e. floral petal non-openness)-inducing PpJAZ1 gene from peach in transgenic camelina. Transgenic camelina overexpressing PpJAZ1 showed three levels of cleistogamy, affected pollen germination rates after anthesis but not during anthesis, and caused a minor silicle abortion only on the main branches. We also conducted field trials to examine the effects of the overexpressed PpJAZ1 on PMGF in the field, and found that the overexpressed PpJAZ1 dramatically inhibited PMGF from transgenic camelina to non-transgenic camelina under the field conditions. Thus, the engineered cleistogamy using the overexpressed PpJAZ1 is a highly effective bioconfinement strategy to limit PMGF from transgenic camelina, and could be used for bioconfinement in other dicot species.

Stink bean (Parkia speciosa) empty pod: a potent natural antidiabetic agent for the prevention of pancreatic and hepatorenal dysfunction in high fat diet/streptozotocin-induced type 2 diabetes in rats.

The present study investigated the effect of polyphenol-rich extract of Parkia speciosa (PPS) against pancreatic and hepatorenal dysfunction in high-fat diet (HFD)/streptozotocin (STZ)-induced diabetes. Diabetic rats were treated with PPS (100 and 400 mg/kg) and glibenclamide. The results revealed that diabetic rats displayed marked hyperglycaemia, hyperlipidaemia, hypoinsulinemia as well as alterations in serum renal and kidney function markers. Furthermore, diabetic rats showed significant increase in hepatorenal level of malonaldehyde as well as suppression of antioxidant enzyme activities. Whereas, diabetic rats that received PPS displayed marked attenuation in most of the aforementioned parameters compared to the untreated diabetic rats. Additionally, histological examination revealed restoration of histopathological alterations of the pancreas, liver, and kidney of PPS treated diabetic rats. In conclusion, the results demonstrated that PPS could decrease serum lipids and blood glucose level, enhance insulin level and hepatorenal antioxidant capacity, as well as ameliorate hepatorenal dysfunction in rats.

Diagnosis, treatment, and prevention of monkeypox in children: an experts' consensus statement.

Monkeypox is a zoonotic disease. Since the first human monkeypox case was detected in 1970, it has been prevalent in some countries in central and western Africa. Since May 2022, monkeypox cases have been reported in more than 96 non-endemic countries and regions worldwide. As of September 14, 2022, there have been more than 58,200 human monkeypox cases, and there is community transmission. The cessation of smallpox vaccination in 1980, which had some cross-protection with monkeypox, resulted in a general lack of immunity to monkeypox, which caused global concern and vigilance. As of September 14, 2022, there are four monkeypox cases in China, including three in Taiwan province and one in Hong Kong city. Previous foreign studies have shown that children are vulnerable to monkeypox and are also at high risk for severe disease or complications. In order to improve pediatricians' understanding of monkeypox and achieve early detection, early diagnosis, early treatment,  and early disposal, we have organized national authoritative experts in pediatric infection, respiratory, dermatology, critical care medicine, infectious diseases, and public health and others to formulate this expert consensus, on the basis of the latest "Clinical management and infection prevention and control for monkeypox" released by The World Health Organization, the "guidelines for diagnosis and treatment of monkeypox (version 2022)" issued by National Health Commission of the People's Republic of China and other relevant documents. During the development of this consensus, multidisciplinary experts have repeatedly demonstrated the etiology, epidemiology, transmission, clinical manifestations, laboratory examinations, diagnosis, differential diagnosis, treatment, discharge criteria, prevention, disposal process, and key points of prevention and control of suspected and confirmed cases.

Structure-guided engineering of transcriptional activator XYR1 for inducer-free production of lignocellulolytic enzymes in Trichoderma reesei.

The filamentous fungus Trichoderma reesei is widely used for the production of lignocellulolytic enzymes in industry. XYR1 is the major transcriptional activator of cellulases and hemicellulases in T. reesei. However, rational engineering of XYR1 for improved lignocellulolytic enzymes production has been limited by the lack of structure information. Here, alanine 873 was identified as a new potential target for the engineering of XYR1 based on its structure predicted by AlphaFold2. The mutation of this residue to tyrosine enabled significantly enhanced production of xylanolytic enzymes in the medium with cellulose as the carbon source. Moreover, xylanase and cellulase production increased by 56.7- and 3.3-fold, respectively, when glucose was used as the sole carbon source. Under both conditions, the improvements of lignocellulolytic enzyme production were higher than those in the previously reported V821F mutant. With the enriched hemicellulases and cellulases, the crude enzymes secreted by the A873Y mutant strain produced 51 % more glucose and 52 % more xylose from pretreated corn stover than those of the parent strain. The results provide a novel strategy for engineering the lignocellulolytic enzyme-producing capacity of T. reesei, and would be helpful for understanding the molecular mechanisms of XYR1 regulation.

Customized optimization of lignocellulolytic enzyme cocktails for efficient conversion of pectin-rich biomass residues.

Pectin is a major component in many agricultural feedstocks. Despite the wide use in industrial production of cellulases and hemicellulases, the fungus Trichoderma reesei lacks a complete enzyme set for pectin degradation. In this study, three representative pectinolytic enzymes were expressed and screened for their abilities to improve the efficiency of T. reesei enzymes on the conversion of different agricultural residues. By replacing 5 % of the T. reesei proteins, endopolygalacturonase and pectin lyase remarkably increased the release of sugars from inferior tobacco leaves. In contrast, pectin methylesterase showed the strongest improving effect (by 31.1 %) on the hydrolysis of beetroot residue. The pectin in beetroot residue was only mildly degraded with the supplementation of pectin methylesterase, which allowed the extraction of pectin keeping the original emulsifying activity with a 51.1 % higher yield. The results provide a basis for precise optimization of lignocellulolytic enzyme systems for targeted valorization of pectin-rich agricultural residues.

The Characterization and Functional Properties of Euglena gracilis Paramylon Treated with Different Methods.

Euglena gracilis paramylon (EGP) is a polymeric polysaccharide composed of linear ß-1,3 glucan. The water insolubility of EGP severely limits its application. This work aimed to improve the functional characteristics of EGP by hydrogen peroxide (H2O2) degradation and carboxymethylated modification. The results showed that the crystallinity of EGP degraded by H2O2 and carboxymethylated modification decreased by 14% and 46%, and the thermal degradation temperature was significantly descending in a crystallinity-dependent manner. In addition, the results showed that H2O2 degradation and carboxymethylation significantly improved the adsorption capacity of EGP for oil, dyes, and metal ions, and their water solubility increased by 9% and 85%. This result will provide a valuable theoretical basis for the development and utilization of EGP.

Characterization and Antibacterial Activities of Carboxymethylated Paramylon from Euglena gracilis.

Paramylon from Euglena gracilis (EGP) is a polymeric polysaccharide composed of linear ß-1,3 glucan. EGP has been proved to have antibacterial activity, but its effect is weak due to its water insolubility and high crystallinity. In order to change this deficiency, this experiment carried out carboxymethylated modification of EGP. Three carboxymethylated derivatives, C-EGP1, C-EGP2, and C-EGP3, with a degree of substitution (DS) of 0.14, 0.55, and 0.78, respectively, were synthesized by varying reaction conditions, such as the mass of chloroacetic acid and temperature. Fourier transform infrared spectroscopy (FTIR), gel permeation chromatography (GPC), and nuclear magnetic resonance (NMR) analysis confirmed the success of the carboxymethylated modification. The Congo red (CR) experiment, scanning electron microscopy (SEM), X-ray diffraction (XRD), and thermogravimetry (TG) were used to study the conformation, surface morphology, crystalline nature, and thermostability of the carboxymethylated EGP. The results showed that carboxymethylation did not change the triple helix structure of the EGP, but that the fundamental particles' surface morphology was destroyed, and the crystallization area and thermal stability decreased obviously. In addition, the water solubility test and antibacterial experiment showed that the water solubility and antibacterial activity of the EGP after carboxymethylation were obviously improved, and that the water solubility of C-EGP1, C-EGP2, and C-EGP3 increased by 53.31%, 75.52%, and 80.96% respectively. The antibacterial test indicated that C-EGP3 had the best effect on Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), with minimum inhibitory concentration (MIC) values of 12.50 mg/mL and 6.25 mg/mL. The diameters of the inhibition zone of C-EGP3 on E. coli and S. aureus were 11.24 ± 0.15 mm and 12.05 ± 0.09 mm, and the antibacterial rate increased by 41.33% and 43.67%.

[Expression of a SARS-CoV-2 neutralizing nanobody in Trichoderma reesei].

Nanobodies derived from camelid single-chain antibodies have the advantages of being small, simple, highly soluble and stable. Nanobodies can be administered by inhalation and therefore is potentially valuable for the prevention and control of respiratory viruses. Trichoderma reesei is a food-grade protein expression host with a cellulase production capacity of up to 80 g/L, which can be employed for low-cost production of therapeutic proteins. In this study, a codon-optimized SARS-CoV-2 neutralizing nanobody Nb20 was expressed in T. reesei under a strong constitutive promoter Pcdna1. Nb20 protein was fused downstream of the N-terminal fragment of cellobiohydrolase Ⅰ, and the fusion protein can be intracellularly cleaved by the KEX2 protease to release Nb20. In a shake-flask fermentation using glucose medium, 47.4 mg/L Nb20 was detected in the culture after 48 h of cultivation. The expressed Nb20 showed the ability to interact with the receptor-binding domain of SARS-CoV-2 spike protein, suggesting that it can be used for the neutralization of SARS-CoV-2. The results indicate that T. reesei has the potential for recombinant production of nanobodies.