One-step knock-in of two antimicrobial peptide transgenes at multiple loci of catfish by CRISPR/Cas9-mediated multiplex genome engineering

CRISPR/Cas9-mediated multiplex genome editing (MGE) conventionally uses multiple single-guide RNAs (sgRNAs) for gene-targeted mutagenesis via the non-homologous end joining (NHEJ) pathway. MGE has been proven to be highly efficient for functional gene disruption/knockout (KO) at multiple loci in mammalian cells or organisms. However, in the absence of a DNA donor, this approach is limited to small indels without transgene integration. Here, we establish the linear double-stranded DNA (dsDNA) and double-cut plasmid (dcPlasmid) combination-assisted MGE in channel catfish (Ictalurus punctatus), allowing combinational deletion mutagenesis and transgene knock-in (KI) at multiple sites through NHEJ/homology-directed repair (HDR) pathway in parallel. In this study, we used single-sgRNA-based genome editing (ssGE) and multi-sgRNA-based MGE (msMGE) to replace the luteinizing hormone (lh) and melanocortin-4 receptor (mc4r) genes with the cathelicidin (As-Cath) transgene and the myostatin (two target sites: mstn1, mstn2) gene with the cecropin (Cec) transgene, respectively. A total of 9000 embryos were microinjected from three families, and 1004 live fingerlings were generated and analyzed. There was no significant difference in hatchability (all P > 0.05) and fry survival (all P > 0.05) between ssGE and msMGE. Compared to ssGE, CRISPR/Cas9-mediated msMGE assisted by the mixture of dsDNA and dcPlasmid donors yielded a higher knock-in (KI) efficiency of As-Cath (19.93 %, [59/296] vs. 12.96 %, [45/347]; P = 0.018) and Cec (22.97 %, [68/296] vs. 10.80 %, [39/361]; P = 0.003) transgenes, respectively. The msMGE strategy can be used to generate transgenic fish carrying two transgenes at multiple loci. In addition, double and quadruple mutant individuals can be produced with high efficiency (36.3 % ∼ 71.1 %) in one-step microinjection. In conclusion, we demonstrated that the CRISPR/Cas9-mediated msMGE allows the one-step generation of simultaneous insertion of the As-Cath and Cec transgenes at four sites, and the simultaneous disruption of the lh, mc4r, mstn1 and mstn2 alleles. This msMGE system, aided by the mixture donors, promises to pioneer a new dimension in the drive and selection of multiple designated traits in other non-model organisms.

Effects of co-infection with Clonorchis sinensis on T cell exhaustion levels in patients with chronic hepatitis B

To investigate the effects of co-infection with Clonorchis sinensis (C. sinensis) on T cell exhaustion levels in patients with chronic hepatitis B, we enrolled clinical cases in this study, including the patients with concomitant C. sinensis and HBV infection. In this study, we detected inhibitory receptors and cytokine expression in circulating CD4+ and CD8+ T cells by flow cytometry. PD-1 and TIM-3 expression levels were significantly higher on CD4+ T and CD8+ T cells from co-infected patients than on those from the HBV patients. In addition, CD4+ T cells and CD8+ T cells function were significantly inhibited by C. sinensis and HBV co-infection compared with HBV single infection, secreting lower levels of Interferon gamma (IFN-γ), Interleukin-2 (IL-2), and TNF-α. Our current results suggested that C. sinensis co-infection could exacerbate T cell exhaustion in patients with chronic hepatitis B. PD-1 and TIM-3 could be novel biomarkers for T cell exhaustion in patients with Clonorchis sinensis and chronic hepatitis B co-infection. Furthermore, it may be one possible reason for the weaker response to antiviral therapies and the chronicity of HBV infection in co-infected patients. We must realize the importance of C. sinensis treatment for HBV-infected patients. It might provide useful information for clinical doctors to choose the right treatment plans.

Allergen sensitization study in Dongying, China: An epidemiological study

BACKGROUND

To explore the relationship between specific immunoglobulin E levels in response to prevalent pollen and food allergens among patients suffering from localized allergic diseases in the Dongying area of China, and to analyze the interconnectivity among these factors.

METHODS

This research encompassed allergic patients who visited the Allergy Department of Shengli Oilfield Central Hospital from January 2022 to January 2023. We examined the specific immunoglobulin E levels in the blood of 230 patients utilizing the Fobock platform provided by Jiangsu Haoeubo Company. Statistical analysis was conducted with SPSS 25.0 statistical software. The chi-square test evaluated the relevance of differences in gender and age. A value of P < .05 was considered statistically significant.

RESULTS

In this study, eggs emerged as the allergen with the highest number of sensitized individuals, closely followed by dust mite. Conversely, the least sensitized allergen was the cypress tree, closely followed by mango. Notably, male patients exhibited higher sensitivities to cottonwood (P < .05) and egg (P < .001) compared to female patients. Children aged 0 to 10 years showed increased sensitivity to variety of allergens. A significant correlation was observed among different allergens. The top ten allergen pairs with the highest correlation included Birch Tree and Cottonwood (0.88, P < .001), Cottonwood and Pine Tree (0.86, P < .001), Birch Tree and Pine Tree (0.84, P < .001), Pine Tree and Paulownia (0.81, P < .001), Dust Mite and House Dust Mite (0.76, P < .001), Birch Tree and Paulownia (0.73, P < .001), Cashew and Pistachio (0.71, P < .001), Apple and Hazelnut (0.71, P < .001), Cottonwood and Paulownia (0.71, P < .001), and Pine Tree and Ordinary Ragweed (0.70, P < .001).

CONCLUSION

This research sheds light on the patterns of allergen sensitization in Dongying, Shandong, highlighting that egg is the most prevalent sensitizing allergen. A notably high correlation was observed between Birch Tree and Cottonwood. This study enhanced the understanding of allergic diseases, explored the causes and mechanisms of allergies, strengthened the management of allergic diseases. Furthermore, it offers valuable insights for the clinical diagnosis and prevention of allergic diseases.

Use of a catch-up programme to improve routine immunization in 13 provinces of Papua New Guinea, 2020-2022

Objective

Routine immunization coverage in Papua New Guinea has decreased in the past 5 years. This persistently low routine immunization coverage has resulted in low population immunity and frequent outbreaks of vaccine-preventable disease across the country. We describe the use of a catch-up programme to improve routine immunization during the coronavirus disease pandemic in Papua New Guinea during 2020-2022.

Methods

In June 2020, 13 provinces of Papua New Guinea were selected to undergo a vaccination catch-up programme, with technical support from the World Health Organization (WHO) and the United Nations Children's Fund. Twelve provinces received financial and logistic support through the Accelerated Immunization and Health Systems Strengthening programme, and one received support from WHO. All stakeholders were involved in planning and implementing the catch-up programme.

Results

Between July 2020 and June 2022, about 340 health facilities conducted catch-up activities. The highest number of children aged under 1 year were vaccinated in 2022 (n = 33 652 for third dose of pentavalent vaccine). The national coverage of routine immunization (including the catch-up vaccinations) increased between 2019 and 2020 - by 5% for the third dose of pentavalent vaccine, 11% for the measles-rubella vaccine and 16% for the inactivated poliovirus vaccine. The coverage declined slightly in 2021 before increasing again in 2022.

Discussion

The catch-up programme was an instrumental tool to improve routine immunization coverage between 2020 and 2022 and during the pandemic in Papua New Guinea. With appropriate technical and logistic support, including financial and human resources, catch-up programmes can strengthen routine immunization coverage across the country.

CRISPR/Cas9-mediated knock-in of masu salmon (Oncorhyncus masou) elongase gene in the melanocortin-4 (mc4r) coding region of channel catfish (Ictalurus punctatus) genome

Channel catfish, Ictalurus punctatus, have limited ability to synthesize Ω-3 fatty acids. The ccβA-msElovl2 transgene containing masu salmon, Oncorhynchus masou, elongase gene driven by the common carp, Cyprinus carpio, β-actin promoter was inserted into the channel catfish melanocortin-4 receptor (mc4r) gene site using the two-hit two-oligo with plasmid (2H2OP) method. The best performing sgRNA resulted in a knockout mutation rate of 92%, a knock-in rate of 54% and a simultaneous knockout/knock-in rate of 49%. Fish containing both the ccβA-msElovl2 transgene knock-in and mc4r knockout (Elovl2) were 41.8% larger than controls at 6 months post-hatch (p = 0.005). Mean eicosapentaenoic acid (EPA, C20:5n-3) levels in Elov2 mutants and mc4r knockout mutants (MC4R) were 121.6% and 94.1% higher than in controls, respectively (p = 0.045; p = 0.025). Observed mean docosahexaenoic acid (DHA, C22:6n-3) and total EPA + DHA content was 32.8% and 45.1% higher, respectively, in Elovl2 transgenic channel catfish than controls (p = 0.368; p = 0.025). To our knowledge this is the first example of genome engineering to simultaneously target transgenesis and knock-out a gene in a commercially important aquaculture species for multiple improved performance traits. With a high transgene integration rate, improved growth, and higher omega-3 fatty acid content, the use of Elovl2 transgenic channel catfish appears beneficial for application on commercial farms.

Clinical application of improved VSD and VSD in the treatment of SSI after abdominal surgery: A retrospective randomized clinical study

By comparing the efficacy and cost of improved vacuum-sealing drainage devices and vacuum-sealing drainage (VSD) devices in the treatment of postoperative abdominal surgical site infection, the clinical applicability and promotion of improved vacuum-sealing drainage devices were assessed. In our institution, between October 2019 and December 2021, 55 patients with surgical site infection after abdominal surgery were retrospectively analyzed, including 30 patients treated with improved VSD and 25 patients treated with VSD. The efficacy of wound healing, total dressing change cost throughout therapy, total hospital costs, hospital days, and bacterial culture results of wound secretions before and after treatment were compared between the 2 groups. Both groups achieved wound healing following vacuum sealing-drainage treatment, with no significant differences in wound healing time or secondary suture rate. However, the total hospitalization and dressing change costs in the improved VSD group were significantly lower than those in the VSD group. Similar to VSD, improved VSD is effective in the treatment of surgical site infections after abdominal surgery. Compared with VSD, the improved VSD device has lower dressing change costs and total hospitalization costs during the treatment process. The improved VSD has a wide range of applications and is suitable for clinical use and promotion.

A New Strategy for Increasing Knock-in Efficiency: Multiple Elongase and Desaturase Transgenes Knock-in by Targeting Long Repeated Sequences

CRISPR/Cas9-mediated knock-in (KI) has a wide application in gene therapy, gene function study, and transgenic breeding programs. Unlike gene therapy, which requires accurate KI to correct gene mutation, transgenic breeding programs can accept robust KI as long as integration does not interrupt normal gene functions and result in any negative pleiotropic effects. High KI efficiency is required to reduce the breeding cost and shorten the breeding period, especially in transferring multiple foreign genes to a single individual. To elevate the KI efficacy and achieve multiple gene KIs simultaneously, we introduced a new strategy that enables transgene integration into numerous sites of the genome by targeting long repeated sequences (LRSs). Using this simple strategy, for the first time we successfully generated transgenic fish carrying the masu salmon (Oncorhynchus masou) elovl2 gene and rabbitfish (Siganus canaliculatus) Δ4 fad and Δ6 fad genes, and achieved robust target KI of elovl2 and Δ6 fad genes at multiple sites of LRS1 and LRS3, respectively, in the initial generation. This demonstrated that donor plasmid homology arms, which were nearly identical but not completely the same as the genome sequence, still led to on-target KI. Although the target KI efficiencies at LRS1, LRS2, and LRS3 sites were still relatively low in the current study, it is very promising that 100% KI efficiency in the future could be realized and perfected by selection of better LRSs and optimization of sgRNAs.

Coinfection of Clonorchis sinensis and hepatitis B virus: clinical liver indices and interaction in hepatic cell models

BACKGROUND

In China, people infected with hepatitis B virus (HBV) are commonly found in areas with a high prevalence of Clonorchis sinensis, a trematode worm. Published studies have reported that the progression of hepatitis B is affected by coinfection C. sinensis.

METHODS

Clinical data from a total of 72 patients with C. sinensis and HBV (as sole infection or with coinfections) and 29 healthy individuals were analysed. We also incubated the hepatic stellate cell line LX-2 with total proteins from C. sinensis adult worms (CsTPs) and HBV-positive sera. In addition, the human hepatoblastoma cell line HepG2.2.15 was treated with the antiviral drug entecavir (ETV), CsTPs and the anti-C. sinensis drug praziquantel (PZQ).

RESULTS

Our clinical data indicated that the levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bilirubin (TB) and hyaluronic acid (HA) were significantly higher in patients with coinfection than in those infected with HBV only. In cell models, compared with the model in which LX-2 cells were incubated with HBV-positive sera (HBV group), transcripts of alpha-smooth muscle actin and types I and III collagen were significantly elevated in the models of LX-2 cells treated with CsTPs and HBV-positive sera (CsTP+HBV group), while the messenger RNA levels of tumour necrosis factor-α, interleukin (IL)-1β and IL-6 in the CsTP+HBV group were clearly lower. The HBV surface antigen and hepatitis B e-antigen levels were higher in the HepG2.2.15 cells treated with ETV and CsTPs than in those in the ETV group and in the cells administered a mixture of ETV, CsTPs and PZQ.

CONCLUSIONS

These results confirmed that C. sinensis and HBV coinfection could aggravate the progression of liver fibrosis. CsTPs might promote chronic inflammation of the liver in individuals with HBV infection, resulting in the development of hepatic fibrosis.

The mechanisms on evasion of anti-tumor immune responses in gastric cancer

The immune system and the tumor have been at each other's throats for so long that the neoplasm has learned to avoid detection and avoid being attacked, which is called immune evasion. Malignant tumors, such as gastric cancer (GC), share the ability to evade the body's immune system as a defining feature. Immune evasion includes alterations to tumor-associated antigens (TAAs), antigen presentation mechanisms (APMs), and the tumor microenvironment (TME). While TAA and APM are simpler in nature, they both involve mutations or epigenetic regulation of genes. The TME is comprised of numerous cell types, cytokines, chemokines and extracellular matrix, any one of which might be altered to have an effect on the surrounding ecosystem. The NF-kB, MAPK, PI3K/AKT, JAK/STAT, Wnt/β-catenin, Notch, Hippo and TGF-β/Smad signaling pathways are all associated with gastric cancer tumor immune evasion. In this review, we will delineate the functions of these pathways in immune evasion.

CircRNA ITCH: Insight Into Its Role and Clinical Application Prospect in Tumor and Non-Tumor Diseases

CircRNA E3 ubiquitin protein ligase (ITCH) (circRNA ITCH, circ-ITCH), a stable closed-loop RNA derived from the 20q11.22 region of chromosome 20, is a new circRNA discovered in the cytoplasm in recent decades. Studies have shown that it does not encode proteins, but regulates proteins expression at different levels. It is down-regulated in tumor diseases and is involved in a number of biological activities, including inhibiting cell proliferation, migration, invasion, and promoting apoptosis. It can also alter disease progression in non-tumor disease by affecting the cell cycle, inflammatory response, and critical proteins. Circ-ITCH also holds a lot of promise in terms of tumor and non-tumor clinical diagnosis, prognosis, and targeted therapy. As a result, in order to aid clinical research in the hunt for a new strategy for diagnosing and treating human diseases, this study describes the mechanism of circ-ITCH as well as its clinical implications.

Feminization of channel catfish with 17β-oestradiol involves methylation and expression of a specific set of genes independent of the sex determination region

Exogenous oestrogen 17β-oestradiol (E2) has been shown to effectively induce feminization in teleosts. However, the molecular mechanisms underlying the process remain unclear. Here, we determined global DNA methylation and gene expression profiles of channel catfish (Ictalurus punctatus) during early sex differentiation after E2 treatment. Overall, the levels of global DNA methylation after E2 treatment were not significantly different from those of controls. However, a specific set of genes were differentially methylated, which included many sex differentiation-related pathways, such as MARK signalling, adrenergic signalling, Wnt signalling, GnRH signalling, ErbB signalling, and ECM-receptor interactions. Many genes involved in these pathways were also differentially expressed after E2 treatment. Specifically, E2 treatments resulted in upregulation of female-related genes and downregulation of male-related genes in genetic males during sex reversal. However, E2-induced sex reversal did not cause sex-specific changes in methylation profiles or gene expression within the sex determination region (SDR) on chromosome 4, suggesting that E2-induced sex reversal was a downstream process independent of the sex determination process that was regulated by sex-specific methylation within the SDR.

A Comprehensive Analysis of HAVCR1 as a Prognostic and Diagnostic Marker for Pan-Cancer

Hepatitis A virus cellular receptor (HAVCR1) is a type-1 integral membrane glycoprotein that plays a key role in immunity and renal regeneration and is abnormally expressed in various tumor types. Nonetheless, the function of HAVCR1 in pan-cancer remains unknown. In this study, we comprehensively analyzed the expression and promoter methylation level of HAVCR1 and assessed the immune cell infiltration, correlation between stromal and immune cell admixture, CD (Cluster of Differentiation) and HAVCR1 expression and prognostic value of HAVCR1 mRNA expression in Liver hepatocellular carcinoma (LIHC) and Pancreatic adenocarcinoma (PAAD). Our results showed that HAVCR1 was overexpressed while the promoter methylation of HAVCR1 was decreased in Liver hepatocellular carcinoma and Pancreatic adenocarcinoma. HAVCR1 was associated with increased infiltration of B cells, CD8 cells, macrophages, neutrophils and Dendritic cells in Liver hepatocellular carcinoma and Pancreatic adenocarcinoma. HAVCR1 expression was positively correlated with the immune, stromal and estimate scores of Pancreatic adenocarcinoma and the stromal and estimate scores of Liver hepatocellular carcinoma. Furthermore, HAVCR1 expression was correlated with other immune molecules such as HHLA2 (Human endogenous retrovirus-H long terminal repeat-associating protein 2), CD44 and TNFRSF4 (TNF Receptor Superfamily Member 4) in Liver hepatocellular carcinoma and Pancreatic adenocarcinoma. During Kaplan-Meier analysis, high HAVCR1 expression in Liver hepatocellular carcinoma and Pancreatic adenocarcinoma correlated with poor survival. A marginally significant p-value (p = 0.051) was obtained when the relationship between HAVCR1 expression in Liver hepatocellular carcinoma and prognosis was analyzed, attributed to the small sample size. Overall, we provided compelling evidence that HAVCR1 could be a prognostic and diagnostic marker for Liver hepatocellular carcinoma and Pancreatic adenocarcinoma.

Hyaluronan size alters chondrogenesis of mesenchymal stem cells cultured on tricalcium phosphate-collagen-hyaluronan scaffolds

Hyaluronan (HA) provides a favorable environment for chondrogenesis of bone marrow mesenchymal stem cells (BMSCs). A previous report from our group indicated that addition of HA increases the chondro-inductive capacity of scaffolds. Therefore, this study aimed to investigate whether the Mw of the HA could affect chondrogenesis of BMSCs seeded on TCP-COL-HA scaffolds. Human BMSCs (hBMSCs) and rabbit BMSCs (rBMSCs) were isolated and expanded. TCP-COL scaffolds and TCP-COL-HA scaffolds with two different HA Mws were assessed for their capacity to induce cartilage regeneration from hBMSCs in vitro and in vivo. The results showed that about 96.96% of hBMSCs expressed CD44. Moreover, Hyal-1 and chondrogenic marker genes expressions were increased in hMSCs seeded on TCP-COL-HA scaffolds, and blocking the HA-CD44 interaction with an anti-CD44 antibody reduced the expression levels of Hyal-1 and chondrogenic marker genes. Additionally, TCP-COL-HA scaffolds with 2000 kDa Mw showed greater induction of BMSC chondrogenesis induction compared with those with 80 kDa Mw. Similar results were observed in an ectopic implantation nude mouse model. In a rabbit osteochondral defect repair model, rBMSCs seeded on TCP-COL-HA scaffolds with 2000 kDa Mw showed greater cartilage regeneration than those seeded with 80 kDa Mw. In addition, hBMSC-seeded TCP-COL-HA scaffolds with 2000 kDa Mw showed a significantly higher mechanical strength than those with 80 kDa Mw. Collectively, these results indicate that the Mw of HA could affect chondrogenesis of BMSCs seeded on TCP-COL-HA scaffolds. The TCP-COL-HA scaffolds might be used as allogenic off the shelf products in cartilage tissue engineering in future.

Up-regulation of BTLA expression in myeloid dendritic cells associated with the treatment outcome of neonatal sepsis

Dentritic cells (DCs) dysfunction has been verified detrimental for sepsis and B and T lymphocyte attenuator (BTLA) is an immune-regulatory receptor shown to be associated with DCs dysfunction. However, the role of BTLA expression in myeloid DCs (mDCs) in neonatal sepsis is unknown. In the current study, we found BTLA-expressing mDCs were elevated in neonates with sepsis and the BTLA expression level in mDCs was positively correlated to the severity of sepsis. The presence of BTLA negatively regulated the phagocytosis capacity and bactericidal ability of mDCs as well as the maturation markers expression of mDCs. Our data also showed BTLA⁺mDCs shifted into an anti-inflammatory phenotype with decreased expression of IL-6, TNF-α and IL-12, but increased IL-10. in addition, we found BTLA expression indeedly altered the mDCs allo-stimulatory capacity. Therefore, BTLA expression in mDCs could be a useful predictive marker for neonatal sepsis and targeting BTLA expression in mDCs may be a new therapeutic strategy.

The NF-κB signalling pathway and TM7SF3 contribute to liver fibrosis caused by secreted phospholipase A2 of Clonorchis sinensis

Background

The NF-κB signalling pathway has been reported to be related to liver fibrosis, and we investigated whether the NF-κB signalling pathway is involved in liver fibrosis caused by secreted phospholipase A2 of Clonorchis sinensis (CssPLA2). Furthermore, expression of the receptor of CssPLA2 on the cell surface of hepatic stellate cells (HSCs) may greatly contribute to liver fibrosis.

Methods

CssPLA2 was administered to BALB/c mice by abdominal injection. The levels of markers of NF-κB signalling pathway activation in mouse liver tissue were measured by quantitative RT-PCR, ELISA and western blot. Additionally, HSCs were incubated with CssPLA2, and an NF-κB signalling inhibitor (BAY 11-7082) was applied to test whether the NF-κB signalling pathway plays a role in the effect of CssPLA2. Then, the interaction between CssPLA2 and its receptor transmembrane 7 superfamily member 3 (TM7SF3) was confirmed by co-immunoprecipitation (co-IP) and GST pull-down. To determine how TM7SF3 influences the ability of CssPLA2 to cause liver fibrosis, a TM7SF3 antibody was used to block TM7SF3.

Results

The levels of the NF-ΚB signalling pathway activation markers TNF-α, IL-1β and phospho-p65 were increased by CssPLA2 in the context of liver fibrosis. In addition, the interaction between TM7SF3 and CssPLA2 was confirmed by co-IP and GST pull-down. When TM7SF3 was blocked by an antibody targeting 1–295 amino acids of TM7SF3, activation of HSCs caused by CssPLA2 was alleviated.

Conclusions

The NF-ΚB signalling pathway is involved in the activation of HSCs by CssPLA2. TM7SF3, the receptor of CssPLA2, plays important roles in liver fibrosis caused by CssPLA2.

The storage stability of Bacillus subtilis spore displaying cysteine protease of Clonorchis sinensis and its effect on improving the gut microbiota of mice

Bacillus subtilis (B. subtilis) spore can serve as an ideal vehicle for expressing heterologous antigens, and elicit specific immune responses by oral administration. In previous studies, we successfully constructed the recombinant B. subtilis spores expressing cysteine protease of Clonorchis sinensis (C. sinensis, B.s-CsCP), and confirmed that oral administration of B.s-CsCP could elicit good protective immune responses in mice. In this study, Gram staining was used to observe the morphology of B.s-CsCP in different form, and the storage of liquid spores and lyophilized spores at different temperatures was compared. The mice were orally immunized with three different doses of spores (2×10⁸, 1×10⁹, and 5×10⁹ CFU/day) for three times in total at biweekly interval. Then, antibody levels of mice were measured, the safety of spores was evaluated, and the changes of gut microbiota after oral gavage of spores (1×10⁹ dose) were investigated. Results showed that B. subtilis was a typical Gram-positive bacterium, and its spore had good resistance to chemical dye. Liquid B. subtilis spores resuspended in sterile water could be stored for a long time at 4 °C or below, while lyophilized spores could be well stored even at RT and better at lower temperatures. Oral administration of B. subtilis spores to mice could stimulate both local mucosal and systemic immune responses in a dose-dependent manner without toxic side effects. Besides, beneficial bacteria producing butyrate such as Odoribacter were increased, while potential pathogens such as Escherichia-Shigella were decreased in mice intestine. Therefore, our work further confirmed that B. subtilis spores expressing CsCP could be a promising oral vaccine against C. sinensis with the advantages of stability, safety, easy storage, and promotion of intestinal health.Key Points• Recombinant CsCP B. subtilis spores could be easily preserved in either liquid or freeze-dried state.• Oral immunization of recombinant spores in mice could increase both local and system immune levels in a dose-dependent manner.• Oral administration of recombinant spores increased the number of beneficial bacteria and reduced the number of harmful bacteria in the intestinal tract of mice.

Comparative Transcriptome Analysis During the Seven Developmental Stages of Channel Catfish (Ictalurus punctatus) and Tra Catfish (Pangasianodon hypophthalmus) Provides Novel Insights for Terrestrial Adaptation

Tra catfish (Pangasianodon hypophthalmus), also known as striped catfish, is a facultative air-breather that uses its swim bladder as an air-breathing organ (ABO). A related species in the same order (Siluriformes), channel catfish (Ictalurus punctatus), does not possess an ABO and thus cannot breathe in the air. Tra and channel catfish serve as great comparative models for investigating possible genetic underpinnings of aquatic to land transitions, as well as for understanding genes that are crucial for the development of the swim bladder and the function of air-breathing in tra catfish. In this study, hypoxia challenge and microtomy experiments collectively revealed critical time points for the development of the air-breathing function and swim bladder in tra catfish. Seven developmental stages in tra catfish were selected for RNA-seq analysis based on their transition to a stage that could live at 0 ppm oxygen. More than 587 million sequencing clean reads were generated, and a total of 21,448 unique genes were detected. A comparative genomic analysis between channel catfish and tra catfish revealed 76 genes that were present in tra catfish, but absent from channel catfish. In order to further narrow down the list of these candidate genes, gene expression analysis was performed for these tra catfish-specific genes. Fourteen genes were inferred to be important for air-breathing. Of these, HRG, GRP, and CX3CL1 were identified to be the most likely genes related to air-breathing ability in tra catfish. This study provides a foundational data resource for functional genomic studies in air-breathing function in tra catfish and sheds light on the adaptation of aquatic organisms to the terrestrial environment.

Lactic Acid Bacteria Isolated From Korean Kimchi Activate the Vitamin D Receptor-autophagy Signaling Pathways

BACKGROUND

Probiotic lactic acid bacteria (LAB) have been used in the anti-inflammation and anti-infection process of various diseases, including inflammatory bowel disease (IBD). Vitamin D receptor (VDR) plays an essential role in pathogenesis of IBD and infectious diseases. Previous studies have demonstrated that the human VDR gene is a key host factor to shape gut microbiome. Furthermore, intestinal epithelial VDR conditional knockout (VDRΔIEC) leads to dysbiosis. Low expressions of VDR is associated with impaired autophagy, accompanied by a reduction of ATG16L1 and LC3B. The purpose of this study is to investigate probiotic effects and mechanism in modulating the VDR-autophagy pathways.

METHODS

Five LAB strains were isolated from Korean kimchi. Conditional medium (CM) from these strains was used to treat a human cell line HCT116 or intestinal organoids to measure the expression of VDR and autophagy. Mouse embryonic fibroblast (MEF) cells with or without VDR were used to investigate the dependence on the VDR signaling. To test the role of LAB in anti-inflammation, VDR+/+ organoids were treated with 121-CM before infection with Salmonella enterica serovar Enteritidis. In vivo, the role of LAB in regulating VDR-autophagy signaling was examined using LAB 121-CM orally administrated to VDRLoxp and VDRΔIEC mice.

RESULTS

The LAB-CM-treated groups showed higher mRNA expression of VDR and its target genes cathelicidin compared with the control group. LAB treatment also enhanced expressions of Beclin-1 and ATG16L1 and changed the ratio of LC3B I and II, indicating the activation of autophagic responses. Furthermore, 121-CM treatment before Salmonella enterica serovar Enteritidis infection dramatically increased VDR and ATG16L1 and inhibited the inflammation. Administration of 121-CM to VDRLoxp and VDRΔIEC mice for 12 and 24 hours resulted in an increase of VDR and LC3B II:I ratio. Furthermore, we identified that probiotic proteins P40 and P75 in the LAB-CM contributed to the anti-inflammatory function by increasing VDR.

CONCLUSIONS

Probiotic LAB exert anti-inflammation activity and induces autophagy. These effects depend on the VDR expression. Our data highlight the beneficial effects of these 5 LAB strains isolated from food in anti-infection and anti-inflammation.

Amino acids serve as an important energy source for adult flukes of Clonorchis sinensis

Clonorchiasis, caused by chronic infection with Clonorchis sinensis (C. sinensis), is an important food-borne parasitic disease that seriously afflicts more than 35 million people globally, resulting in a socioeconomic burden in endemic regions. C. sinensis adults long-term inhabit the microaerobic and limited-glucose environment of the bile ducts. Energy metabolism plays a key role in facilitating the adaptation of adult flukes to crowded habitat and hostile environment. To understand energy source for adult flukes, we compared the component and content of free amino acids between C. sinensis-infected and uninfected bile. The results showed that the concentrations of free amino acids, including aspartic acid, serine, glycine, alanine, histidine, asparagine, threonine, lysine, hydroxylysine, and urea, were significantly higher in C. sinensis-infected bile than those in uninfected bile. Furthermore, exogenous amino acids could be utilized by adult flukes via the gluconeogenesis pathway regardless of the absence or presence of exogenous glucose, and the rate-limiting enzymes, such as C. sinensis glucose-6-phosphatase, fructose-1,6-bisphosphatase, phosphoenolpyruvate carboxykinase, and pyruvate carboxylase, exhibited high expression levels by quantitative real-time PCR analysis. Interestingly, no matter whether exogenous glucose was present, inhibition of gluconeogenesis reduced the glucose and glycogen levels as well as the viability and survival time of adult flukes. These results suggest that gluconeogenesis might play a vital role in energy metabolism of C. sinensis and exogenous amino acids probably serve as an important energy source that benefits the continued survival of adult flukes in the host. Our study will be a cornerstone for illuminating the biological characteristics of C. sinensis and the host-parasite interactions.

Clonorchiasis, closely related to cholangiocarcinoma and hepatocellular carcinoma, has led to a negative socioeconomic impact in global areas especially some Asian endemic regions. Owing to the emergence of drug resistance and hypersensitivity reactions after the massive and repeated use of praziquantel as well as the lack of effective vaccines, searching for new strategies that prevent and treat clonorchiasis has become an urgent matter. Clonorchis sinensis, the causative agent of clonorchiasis, long-term inhabits the microaerobic and limited-glucose environment of the bile ducts. Adequate nutrients are essential for adult flukes to resist the adverse condition and survive in the crowed habitat. Studies on energy metabolism of adult flukes are beneficial for further exploring host-parasite interactions and developing novel anti-parasitic drugs. Our results suggest that gluconeogenesis probably plays a vital role in energy metabolism of Clonorchis sinensis and exogenous amino acids might be an essential energy source for adult flukes to successfully survive in the host. Our foundational study opens a new avenue for explaining energy metabolism of Clonorchis sinensis and provides a valuable strategy that the gluconeogenesis pathway will be a potential and novel target for the prevention and treatment of clonorchiasis.

In vivo and in vitro studies using Clonorchis sinensis adult-derived total protein (CsTP) on cellular function and inflammatory effect in mouse and cell model

Clonorchis sinensis (C. sinensis) can induce a food-borne parasitic disease (clonorchiasis). Numerous studies have analyzed functional proteins, immunologic factors, pro-inflammatory cytokines, and cell signaling transduction that promote the development of clonorchiasis. In a previous study, it was shown that C. sinensis adult-derived total protein (CsTP) might be involved in the pathogenesis and development of liver fibrosis via bringing about Th2 immune response. In the present study, further investigation of CsTP on cellular function and inflammatory effect in vitro and in vivo has been elicited. CsTP induced inflammation and autophagy as evidenced by upregulation of TNF-α, IFN-γ, and autophagic markers LC3B and P62. Exposed to CsTP upregulated the antiapoptotic gene Bcl-2 expression, diminished the apoptosis induced by H₂O₂, but promoted the proliferation and migration of LX-2 cells in proper concentration range. Additionally, the protein levels of p-AKT and p-mTOR were repressed in response to CsTP, suggesting a correlation of blocking the activation of mTOR/AKT signaling pathway. These results revealed that CsTP might exacerbate hepatic pathological changes by regulating cell proliferation, apoptosis, autophagy, and inflammation in the liver and LX-2 cells. Some effects might be partially involved in the mTOR and AKT pathways.

Oral delivery of Bacillus subtilis spores expressing Clonorchis sinensis paramyosin protects grass carp from cercaria infection

Clonorchis sinensis (C. sinensis), an important fishborne zoonotic parasite threatening public health, is of major socioeconomic importance in epidemic areas. Effective strategies are still urgently expected to prevent against C. sinensis infection. In the present study, paramyosin of C. sinensis (CsPmy) was stably and abundantly expressed on the surface of Bacillus subtilis spores. The recombinant spores (B.s-CotC-CsPmy) were incorporated in the basal pellets diet in three different dosages (1 × 10⁵, 1 × 10⁸, 1 × 10¹¹ CFU/g pellets) and orally administrated to grass carp (Ctenopharyngodon idella). The immune responses and intestinal microbiota in the treated grass carp were investigated. Results showed that specific anti-CsPmy IgM levels in sera, skin mucus, bile, and intestinal mucus, as well as mRNA levels of IgM and IgZ in the spleen and head kidney, were significantly increased in B.s-CotC-CsPmy-10¹¹ group. Besides, transcripts levels of IL-8 and TNF-αin the spleen and head kidney were also significantly elevated than the control groups. Moreover, mRNA levels of tight junction proteins in the intestines of B.s-CotC-CsPmy-10¹¹ group increased. Potential pathogenetic bacteria with lower abundance and higher abundances of candidate probiotics and bacteria associated with digestion in 1 × 10¹¹ CFU/g B.s-CotC-CsPmy spores administrated fishes could be detected compared with control group. The amount of metacercaria in per gram fish flesh was statistically decreased in 1 × 10¹¹ CFU/g B.s-CotC-CsPmy spores orally immunized group. Our work demonstrated that B. subtilis spores presenting CsPmy on the surface could be a promising effective, safe, and needle-free candidate vaccine against C. sinensis infection for grass carp.

Genetic diversity and population structure of native mitten crab (Eriocheir sensu stricto) by microsatellite markers and mitochondrial COI gene sequence

Mitten crab (Eriocheir sensu stricto) is an indigenous and economically important species in East Asia. The genetic diversity and population structure of four wild native Eriocheir s. s. populations, from Yangtze (YZ), Oujiang (OJ), Minjiang (MJ), and Nanliujiang (NLJ) River basin, were studied. Genetic diversity of the four populations was evaluated by eight microsatellite and mitochondrial cytochrome oxidase subunits I (COI) markers. The polymorphism information content (PIC) values ranged from 0.7827 to 0.8580 and Shannon Wiener index (I) values varied from 2.0722 to 2.4088 respectively, according to microsatellite markers analysis. The haplotype diversity (h) values ranged from 0.52101 to 0.87097, while the values of nucleotide diversity (π) varied from 0.00139 to 0.02796 based on mitochondrial COI gene sequence. Four wild Eriocheir s. s. populations all showed high genetic diversity. As microsatellite analysis results, pair-wise F_ST values of YZ, OJ, MJ and NLJ populations were 0.1347, 0.1103 and 0.0943 respectively, which indicated that they were in medium genetic differentiation (0.05 < F_ST < 0.15). This was consistent with mitochondrial COI gene's conclusion. The bottleneck analysis was a hint that Eriocheir s. s. experienced bottleneck effect under SMM models of Sign Test and Wilcoxon Sign-rank Test. Based on genetic structure, YZ, OJ and MJ populations were in the same cluster separated from NLJ population. In summary, by microsatellite and mitochondrial COI markers analysis, all four Eriocheir s. s. populations had high genetic diversity, and genetic differentiation was consistent with geographical distance. Populations OJ and MJ were closer to population YZ genetically, and they had large genetic distance with NLJ population. This study provides a particularly important basis for mitten crab resources conservation and utilization in south China.

Influenza vaccine effectiveness among patients with high-risk medical conditions in the United States, 2012-2016

BACKGROUND

Annual influenza vaccination has been recommended for persons with high-risk conditions since the 1960s. However, few estimates of influenza vaccine effectiveness (VE) for persons with high-risk conditions are available.

METHODS

Data from the U.S. Influenza Vaccine Effectiveness Network from 2012 to 2016 were analyzed to compare VE of standard-dose inactivated vaccines against medically-attended influenza among patients aged ≥6 months with and without high-risk medical conditions. Patients with acute respiratory illness were tested for influenza by RT-PCR. Presence of high-risk conditions and vaccination status were obtained from medical records. VE by influenza virus type/subtype and age group was calculated for patients with and without high-risk conditions using the test-negative design. Interaction terms were used to test for differences in VE by high-risk conditions.

RESULTS

Overall, 9643 (38%) of 25,369 patients enrolled during four influenza seasons had high-risk conditions; 2213 (23%) tested positive for influenza infection. For all ages, VE against any influenza was lower among patients with high-risk conditions (41%, 95% CI: 35-47%) than those without (48%, 95% CI: 43-52%; P-for-interaction = 0.02). For children aged <18 years, VE against any influenza was 51% (95% CI: 39-61%) and 52% (95% CI: 39-61%) among those with and without high-risk conditions, respectively (P-for-interaction = 0.54). For adults aged ≥18 years, VE against any influenza was 38% (95% CI: 30-45%) and 44% (95% CI: 38-50%) among those with and without high-risk conditions, respectively (P-for-interaction = 0.21). For both children aged <18 and adults aged ≥18 years, VEs against illness related to influenza A(H3N2), A(H1N1)pdm09, and influenza B virus infection were similar among those with and without high-risk conditions.

CONCLUSIONS

Influenza vaccination provided protection against medically-attended influenza among patients with high-risk conditions, at levels approaching those observed among patients without high-risk conditions. Results from our analysis support recommendations of annual vaccination for patients with high-risk conditions.

Estimation of Lung Volume in Normal Population Using MSCT

OBJECTIVES

To estimate lung volume in normal population by a combination of multi-slice spiral CT and Pulmo software.

METHODS

Scans of the lung were performed on 45 normal individuals using Emotion 16-slice spiral CT and Pulmo software. A measurement instrument of work station was used to measure the vertical diameter of left and right lungs, the maximum anteroposterior and transverse diameters at the layers of apex pulmonis 1 cm below, arcus aortae, subcarinal and diaphragmatic dome, and the lung volume. Regression analysis was performed on normal lung volume and each measured parameter by SPSS 20.0 and an optimal model was selected.

RESULTS

The goodness of fit between the best curvilinear equations of the normal bilateral lung volumes was 0.981. The goodness of fit between the curvilinear equations of the normal bilateral lung volume and the product of the vertical diameter and the maximum transverse diameter of diaphragmatic dome were 0.977 and 0.972, respectively. Fifteen cases were selected to make a retrospective test on the 3 models. No significant difference was found between the estimated and measured with Pulmo software lung volumes.

CONCLUSIONS

The normal lung volume before injury can be estimated by the curvilinear equations established in this study. The percentage of lung compression can be measured based on the volume of compressed lung, which can provide a reference for the identification of lung compression degree.

[5-HT(2A) receptor/protein kinase C pathway in mediating long-term facilitation of carotid sinus nerve discharge in chronic intermittent hypoxia rats]

Objective: To explore the role of 5-HT(2A)R/PKC pathway in mediating long-term facilitation (LTF) of carotid sinus nerve (CSN) discharge in chronic intermittent hypoxia (CIH) rats. Methods: With number table, 24 adult SD rats were randomly divided into saline control group (group A, n=6), 5-HT(2A)R antagonist (ketanserin) group (group B, n=6), PKC inhibitor (PKC θ-pseudosubstrate) group (group C, n=6) and combined ketanserin with PKC θ-pseudosubstrate group (group D, n=6). All rats were placed into the animal chambers for CIH treatment, 8 h per day (from 9: 00 to 17: 00) for 4 consecutive weeks. 28 days later, 5 min × 3 times of stimulation with acute intermittent hypoxia (AIH) were given, after that, stable CSN discharge activities were recorded and compared before and after intravenous injection of saline (group A), ketanserin (group B), PKC θ-pseudosubstrate (group C) or ketanserin + PKC θ-pseudosubstrate (group D), respectively. Results: There were no significant difference in the baseline (before AIH stimulation) average peak amplitude of CSN discharge among the four groups (P>0.05). In group A, the amplitude of CSN discharge at 30 min and 60 min after AIH were (5.01 ± 0.53) μV and (4.95 ± 0.34) μV respectively, which were significantly higher than that before AIH (P<0.01). The results implied that the CSN LTF could be induced by AIH in CIH pre-treatment rats. In group B, the amplitude of CSN discharge at 30 min and 60 min after AIH were (3.79 ± 0.42) μV and (3.73 ± 0.46) μV, respectively, which were still significantly higher than that before AIH (P<0.01), showing that carotid sinus nerve LTF couldn't be completely blocked by 5-HT(2A)R antagonist in rats. After injection of PKC θ-pseudosubstrate or ketanserin + PKC θ-pseudosubstrate in group C or D, there were no significant differences in CSN discharge amplitude before and after AIH (P>0.01), suggesting that inhibition of PKC alone or 5-HT(2A)R/PKC pathway could completely block the LTF of CSN. Conclusion: 5-HT(2A)R/PKC pathway was involved in mediating long-term facilitation of carotid sinus nerve discharge in CIH rats.

Repressible Transgenic Sterilization in Channel Catfish, Ictalurus punctatus, by Knockdown of Primordial Germ Cell Genes with Copper-Sensitive Constructs

Repressible knockdown approaches were investigated to manipulate for transgenic sterilization in channel catfish, Ictalurus punctatus. Two primordial germ cell (PGC) marker genes, nanos and dead end, were targeted for knockdown and an off-target gene, vasa, was monitored. Two potentially copper-sensitive repressible promoters, yeast ctr3 (M) and ctr3-reduced (Mctr), were coupled with four knockdown strategies separately including: ds-sh RNA targeting the 5' end (N1) or 3' end (N2) of channel catfish nanos, full-length cDNA sequence of channel catfish nanos for overexpression (cDNA), and ds-sh RNA-targeting channel catfish dead end (DND). Each construct had an untreated group and treated group with copper sulfate as the repressor compound. Spawning rates of full-sibling P₁ fish exposed or not exposed to the constructs as treated and untreated embryos were 85 and 54%, respectively, indicating potential sterilization of fish and repression of the constructs. In F₁ fish, mRNA expressions of PGC marker genes for most constructs were downregulated in the untreated group and the knockdown was repressed in the treated group. Gonad development in transgenic, untreated F₁ channel catfish was reduced compared to non-transgenic fish for MctrN2, MN1, MN2, and MDND. For 3-year-old adults, gonad size in the transgenic untreated group was 93.4% smaller than the non-transgenic group for females and 92.3% for males. However, mean body weight of transgenic females (781.8 g) and males (883.8 g) was smaller than of non-transgenic counterparts (984.2 and 1254.3 g) at 3 years of age, a 25.8 and 41.9% difference for females and males, respectively. The results indicate that repressible transgenic sterilization is feasible for reproductive control of fish, but negative pleiotropic effects can result.

Testicular germ line cell identification, isolation, and transplantation in two North American catfish species

Our aim was to transplant blue catfish germ line stem cells into blastulae of triploid channel catfish embryos to produce interspecific xenogenic catfish. The morphological structure of the gonads of blue catfish (Ictalurus furcatus) in ~ 90- to 100-day-old juveniles, two-year-old juveniles, and mature adults was studied histologically. Both oogonia (12-15 μm, diameter with distinct nucleus 7-8 μm diameter) and spermatogonia (12-15 μm, with distinct nucleus 6-7.5 μm diameter) were found in all ages of fish. The percentage of germ line stem cells was higher in younger blue catfish of both sexes. After the testicular tissue was trypsinized, a discontinuous density gradient centrifugation was performed using 70, 45, and 35% Percoll to enrich the percentage of spermatogonial stem cells (SSCs). Four distinct cell bands were generated after the centrifugation. It was estimated that 50% of the total cells in the top band were type A spermatogonia (diameter 12-15 μm) and type B spermatogonia (diameter 10-11 μm). Germ cells were confirmed with expression of vasa. Blastula-stage embryos of channel catfish (I. punctatus) were injected with freshly dissociated blue catfish testicular germ cells as donor cells for transplantation. Seventeen days after the transplantation, 33.3% of the triploid channel catfish fry were determined to be xenogenic catfish. This transplantation technique was efficient, and these xenogenic channel catfish need to be grown to maturity to verify their reproductive capacity and to verify that for the first time SSCs injected into blastulae were able to migrate to the genital ridge and colonize. These results open the possibility of artificially producing xenogenic channel catfish males that can produce blue catfish sperm and mate with normal channel catfish females naturally. The progeny would be all C × B hybrid catfish, and the efficiency of hybrid catfish production could be improved tremendously in the catfish industry.

Influenza-Associated Pediatric Deaths in the United States, 2010-2016

BACKGROUND

Influenza-associated pediatric deaths became a notifiable condition in the United States in 2004.

METHODS

We analyzed deaths in children aged <18 years with laboratory-confirmed influenza virus infection reported to the Centers for Disease Control and Prevention during the 2010-2011 to 2015-2016 influenza seasons. Data were collected with a standard case report form that included demographics, medical conditions, and clinical diagnoses.

RESULTS

Overall, 675 deaths were reported. The median age was 6 years (interquartile range: 2-12). The average annual incidence was 0.15 per 100 000 children (95% confidence interval: 0.14-0.16) and was highest among children aged <6 months (incidence: 0.66; 95% confidence interval: 0.53-0.82), followed by children aged 6-23 months (incidence: 0.33; 95% confidence interval: 0.27-0.39). Only 31% (n = 149 of 477) of children aged ≥6 months had received any influenza vaccination. Overall, 65% (n = 410 of 628) of children died within 7 days after symptom onset. Half of the children (n = 327 of 654) had no preexisting medical conditions. Compared with children with preexisting medical conditions, children with none were younger (median: 5 vs 8 years old), less vaccinated (27% vs 36%), more likely to die before hospital admission (77% vs 48%), and had a shorter illness duration (4 vs 7 days; P < .05 for all).

CONCLUSIONS

Each year, influenza-associated pediatric deaths are reported. Young children have the highest death rates, especially infants aged <6 months. Increasing vaccination among children, pregnant women, and caregivers of infants may reduce influenza-associated pediatric deaths.

Bacillus subtilis spore with surface display of paramyosin from Clonorchis sinensis potentializes a promising oral vaccine candidate

Background

Clonorchiasis caused by Clonorchis sinensis has become increasingly prevalent in recent years. Effective prevention strategies are urgently needed to control this food-borne infectious disease. Previous studies indicated that paramyosin of C. sinensis (CsPmy) is a potential vaccine candidate.

Methods

We constructed a recombinant plasmid of PEB03-CotC-CsPmy, transformed it into Bacillus subtilis WB600 strain (B.s-CotC-CsPmy), and confirmed CsPmy expression on the spore surface by SDS-PAGE, Western blotting and immunofluorescence assay. The immune response and protective efficacy of the recombinant spore were investigated in BALB/c mice after intragastrical or intraperitoneal immunization. Additionally, biochemical enzyme activities in sera, the intestinal histopathology and gut microflora of spore-treated mice were investigated.

Results

CsPmy was successfully expressed on the spore surface and the fusion protein on the spore surface with thermostability. Specific IgG in sera and intestinal mucus were increased after intraperitoneal and intragastrical immunization. The sIgA level in intestinal mucus, feces and bile of B.s-CotC-CsPmy orally treated mice were also significantly raised. Furthermore, numerous IgA-secreting cells were detected in intestinal mucosa of intragastrically immunized mice. No inflammatory injury was observed in the intestinal tissues and there was no significant difference in levels of enzyme-indicated liver function among the groups. Additionally, the diversity and abundance of gut microbiota were not changed after oral immunization. Intragastric and intraperitoneal immunization of B.s-CotC-CsPmy spores in mice resulted in egg reduction rates of 48.3 and 51.2% after challenge infection, respectively. Liver fibrosis degree in B.s-CotC-CsPmy spores treated groups was also significantly reduced.

Conclusions

CsPmy expressed on the spore surface maintained its immunogenicity. Both intragastrical and intraperitoneal immunization with B.s-CotC-CsPmy spores induced systemic and local mucosal immune response in mice. Although both intragastric and intraperitoneal immunization elicited a similar protective effect, intragastric immunization induced stronger mucosal immune response without side effects to the liver, intestine and gut microbiota, compared with intraperitoneal immunization. Oral immunization with B. subtilis spore expressing CsPmy on the surface was a promising, safe and needle-free vaccination strategy against clonorchiasis.

Csseverin inhibits apoptosis through mitochondria-mediated pathways triggered by Ca2 + dyshomeostasis in hepatocarcinoma PLC cells

Background

Numerous experimental and epidemiological studies have demonstrated a link between Clonorchis sinensis (C. sinensis) infestation and cholangiocarcinoma (CCA) as well as hepatocellular carcinoma (HCC). The underlying molecular mechanism involved in the malignancy of CCA and HCC has not yet been addressed. Csseverin, a component of the excretory/secretory products of C. sinensis (CsESPs), was confirmed to cause obvious apoptotic inhibition in the human HCC cell line PLC. However, the antiapoptotic mechanism is unclear. In the present study, we investigated the cellular features of the antiapoptotic mechanism upon transfection of the Csseverin gene.

Methods

In the present study, we evaluated the effects of Csseverin gene overexpression on the apoptosis of PLC cells using an Annexin PE/7-AAD assay. Western blotting was applied to quantify the activation of caspase-3 and caspase-9, the mitochondrial translocation of Bax and the release of Cyt c upon Csseverin overexpression in PLC cells. Laser scanning confocal microscopy was used to analyze the changes of intracellular calcium. Fluorescence assay and immunofluorescence assays were performed to observe the changes of the mitochondrial permeability transition pore (MPTP).

Results

The overexpression of Csseverin in PLC cells showed apoptosis resistance after the induction of apoptosis. Additionally, the activation of caspase-3 and caspase-9 was specifically weakened in Csseverin overexpression PLC cells. The overexpression of Csseverin reduced the increase in intracellular free Ca2+, thereby inhibiting MPTP opening in PLC cells. Moreover, Bax mitochondrial translocation and the subsequent release of Cyt c were downregulated in apoptotic Csseverin overexpression PLC cells.

Conclusions

The present findings suggest that Csseverin, a component of CsESPs, confers protection from human HCC cell apoptosis via the inactivation of membranous Ca²⁺ channels. Csseverin might be involved in the process of HCC through C. sinensis infestation in affected patients.

Multiple studies have contributed to the association between Clonorchis sinensis (C. sinensis) infestation and cholangiocarcinoma (CCA) as well as hepatocellular carcinoma (HCC) in past years. However, studies on the underlying pathogenic mechanisms of C. sinensis lag behind those of other parasitic diseases. The excretory/secretory products of C. sinensis (CsESPs) are pathogenic, as these products promote cell proliferation, suppress cell apoptosis and stimulate inflammation. Csseverin, a component of CsESPs, inhibited the apoptosis of the human HCC cell line PLC in our previous study. The present study illustrated that Csseverin conferred human HCC cells protection from apoptosis via an intrinsic pathway (mitochondrial-mediated) triggered by the inactivation of membranous Ca²⁺ channels.

Identification, characterization and expression analysis of TLR5 in the mucosal tissues of turbot (Scophthalmus maximus L.) following bacterial challenge

TLRs (Toll-like receptors) are very important pathogen pattern recognition receptors, which control the host immune responses against pathogens through recognition of molecular patterns specific to microorganisms. In this regard, investigation of the turbot TLRs could help to understand the immune responses for pathogen recognition. Here, transcripts of two TLR5 (TLR5a and TLR5b) were captured, and their protein structures were also predicted. Meanwhile, we characterized their expression patterns with emphasis on mucosal barriers following different bacterial infection. The phylogenetic analysis revealed the turbot TLR5 genes showed the closest relationship to Paralichthys olivaceus. These two TLR5 genes were ubiquitously expressed in healthy tissues although expression levels varied among the tested tissues. In addition, the two copies of turbot TLR5 showed different expression patterns after bacterial infections. After Vibrio anguillarum infection, TLR5a was generally up-regulated in intestine and skin while down-regulated in gill, while TLR5b showed a general down-regulation in mucosal tissues. After Streptococcus iniae infection, the TLR5a was down-regulated at 2 h while generally up-regulated after 4 h in mucosal tissues. Interestingly, the TLR5b was up-regulated in intestine while down-regulated in skin and gill after Streptococcus iniae infection. These findings suggested a possible irreplaceable role of TLR5 in the immune responses to the infections of a broad range of pathogens that include Gram-negative and Gram-positive bacteria. Future studies should apply the bacteriological and immune-histochemical techniques to study the main sites on the mucosal tissue for bacteria entry and identify the ligand specificity of the turbot TLRs after challenge.

Vitamin D/VDR, Probiotics, and Gastrointestinal Diseases

Vitamin D is an important factor in regulating inflammation, immune responses, and carcinoma inhibition via action of its receptor, vitamin D receptor (VDR). Recent studies have demonstrated the role of vitamin D/VDR in regulating host-bacterial interactions. Probiotics are beneficial bacteria with the power of supporting or favoring life on the host. In the current review, we will discuss the recent progress on the roles of vitamin D/VDR in gut microbiome and inflammation. We will summarize evidence of probiotics in modulating vitamin D/VDR and balancing gut microbiota in health and gastrointestinal diseases. Moreover, we will review the clinical application of probiotics in prevention and therapy of IBD or colon cancer. Despite of the gains, there remain several barriers to advocate broad use of probiotics in clinical therapy. We will also discuss the limits and future direction in scientific understanding of probiotics, vitamin D/VDR, and host responses.

Salt Sensitive Tet-Off-Like Systems to Knockdown Primordial Germ Cell Genes for Repressible Transgenic Sterilization in Channel Catfish, Ictalurus punctatus

Repressible knockdown approaches were investigated for transgenic sterilization in channel catfish, Ictalurus punctatus. Two primordial germ cell (PGC) marker genes, nanos and dead end, were targeted for knockdown, and an off-target gene, vasa, was monitored. Two potentially salt sensitive repressible promoters, zebrafish adenylosuccinate synthase 2 (ADSS) and zebrafish racemase (Rm), were each coupled with four knockdown strategies: ds-sh RNA targeting the 5′ end (N1) or 3′ end (N2) of channel catfish nanos, full-length cDNA sequence of channel catfish nanos for overexpression (cDNA) and ds-sh RNA targeting channel catfish dead end (DND). Each construct had an untreated group and treated group with sodium chloride as the repressor compound. Spawning rates of full-sibling P₁ fish exposed or not exposed to the constructs as treated and untreated embryos were 93% and 59%, respectively, indicating potential sterilization of fish and repression of the constructs. Although the mRNA expression data of PGC marker genes were inconsistent in P₁ fish, most F₁ individuals were able to downregulate the target genes in untreated groups and repress the knockdown process in treated groups. The results indicate that repressible transgenic sterilization is feasible for reproductive control of fish, but more data from F₂ or F₃ are needed for evaluation.

Clonorchis sinensis granulin: identification, immunolocalization, and function in promoting the metastasis of cholangiocarcinoma and hepatocellular carcinoma

Background

Long-term infections by Clonorchis sinensis are associated with cholangitis, cholecystitis, liver fibrosis, cirrhosis, and even liver cancer. Molecules from the worm play vital roles in disease progress. In the present study, we identified and explored molecular characterization of C. sinensis granulin (CsGRN), a growth factor-like protein from C. sinensis excretory/secretory products (CsESPs).

Methods

The encoding sequence and conserved domains of CsGRN were identified and analysed by bioinformatics tools. Recombinant CsGRN (rCsGRN) protein was expressed in Escherichia coli BL21 (DE3). The localisation of CsGRN in adult worms and Balb/c mice infected with C. sinensis was investigated by immunofluorescence and immunohistochemistry, respectively. Stable CsGRN-overexpressed cell lines of hepatoma cells (PLC-GRN cells) and cholangiocarcinoma cells (RBE-GRN cells) were constructed by transfection of eukaryotic expression plasmid of pEGFP-C1-CsGRN. The effects on cell migration and invasion of CsGRN were assessed through the wound-healing assay and transwell assay. The levels of matrix metalloproteinase 2 and 9 (MMP2 and MMP9) in PLC-GRN or RBE-GRN cells were detected by real-time PCR (qRT-PCR). The levels of E-cadherin, vimentin, N-cadherin, zona occludens proteins (ZO-1), β-catenin, phosphorylated ERK (p-ERK) and phosphorylated AKT (p-AKT) were analysed by Western blotting.

Results

CsGRN, including the conserved GRN domains, was confirmed to be a member of the granulin family. CsGRN was identified as an ingredient of CsESPs. CsGRN was localised in the tegument and testes of the adult worm. Furthermore, it appeared in the cytoplasm of hepatocytes and biliary epithelium cells from infected Balb/c mouse. The enhancement of cell migration and invasion of PLC-GRN and RBE-GRN cells were observed. In addition, CsGRN upregulated the levels of vimentin, N-cadherin, β-catenin, MMP2 and MMP9, while it downregulated the level of ZO-1 in PLC-GRN/RBE-GRN cells. In total proteins of liver tissue from rCsGRN immunised Balb/c mice, vimentin level decreased, while E-cadherin level increased when compared with the control groups. Meanwhile, the levels of p-ERK reached a peak at 4 weeks post immunisation and the level of p-AKT did at 2 weeks after immunisation.

Conclusions

The encoding sequence and molecular characteristics of CsGRN were identified. As a member of granulin superfamily, CsGRN induced mesenchymal characteristics of PLC and RBE cells and was found to regulate the activities of the downstream molecules of the ERK and PI3K/AKT signalling pathways, which could contribute to the enhancement of cell migration and invasion.

Electronic supplementary material

The online version of this article (doi:10.1186/s13071-017-2179-4) contains supplementary material, which is available to authorized users.

Comparative analysis of immune effects in mice model: Clonorchis sinensis cysteine protease generated from recombinant Escherichia coli and Bacillus subtilis spores

Clonorchiasis remains a nonnegligible public health problem in endemic areas. Cysteine protease of Clonorchis sinensis (CsCP) plays indispensable roles in the parasitic physiology and pathology, and has been exploited as a promising drug and vaccine candidate. In recent years, development of spore-based vaccines against multiple pathogens has attracted many investigators' interest. In previous studies, the recombinant Escherichia coli (BL21) and Bacillus subtilis spores expressing CsCP have been successfully constructed, respectively. In this study, the immune effects of CsCP protein purified from recombinant BL21 (rCsCP) and B. subtilis spores presenting CsCP (B.s-CsCP) in Balb/c mice model were conducted with comparative analysis. Levels of specific IgG, IgG1 and IgG2a were significantly increased in sera from both rCsCP and B.s-CsCP intraperitoneally immunized mice. Additionally, recombinant spores expressing abundant fusion CsCP (0.03125 pg/spore) could strongly enhance the immunogenicity of CsCP with significantly higher levels of IgG and isotypes. Compared with rCsCP alone, intraperitoneal administration of mice with spores expressing CsCP achieved a better effect of fighting against C. sinensis infection by slowing down the process of fibrosis. Our results demonstrated that a combination of Th1/Th2 immune responses could be elicited by rCsCP, while spores displaying CsCP prominently induced Th1-biased specific immune responses, and the complex cytokine network maybe mediates protective immune responses against C. sinensis. This work further confirmed that the usage of B. subtilis spores displaying CsCP is an effective way to against C. sinensis.

Secreted phospholipase A2 of Clonorchis sinensis activates hepatic stellate cells through a pathway involving JNK signalling

BACKGROUND

Secreted phospholipase A2 (sPLA2) is a protein secreted by Clonorchis sinensis and is a component of excretory and secretory products (CsESPs). Phospholipase A2 is well known for its role in liver fibrosis and inhibition of tumour cells. The JNK signalling pathway is involved in hepatic stellate cells (HSCs) activation. Blocking JNK activity with SP600125 inhibits HSCs activation. In a previous study, the protein CssPLA2 was expressed in insoluble inclusion bodies. Therefore, it's necessary to express CssPLA2 in water-soluble form and determine whether the enzymatic activity of CssPLA2 or cell signalling pathways is involved in liver fibrosis caused by clonorchiasis.

METHODS

Balb/C mice were given an abdominal injection of MBP-CssPLA2. Liver sections with HE and Masson staining were observed to detect accumulation of collagen. Western blot of mouse liver was done to detect the activation of JNK signalling pathway. In vitro, HSCs were incubated with MBP-CssPLA2 to detect the activation of HSCs as well as the activation of JNK signalling pathway. The mutant of MBP-CssPLA2 without enzymatic activity was constructed and was also incubated with HSCs to check whether activation of the HSCs was related to the enzymatic activity of MBP-CssPLA2.

RESULTS

The recombinant protein MBP-CssPLA2 was expressed soluble and of good enzymatic activity. A mutant of CssPLA2, without enzymatic activity, was also constructed. In vivo liver sections of Balb/C mice that were given an abdominal injection of 50 μg/ml MBP-CssPLA2 showed an obvious accumulation of collagen and a clear band of P-JNK1 could be seen by western blot of the liver tissue. In vitro, MBP-CssPLA2, as well as the mutant, was incubated with HSCs and it was proved that activation of HSCs was related to activation of the JNK signalling pathway instead of the enzymatic activity of MBP-CssPLA2.

CONCLUSIONS

Activation of HSCs by CssPLA2 is related to the activation of the JNK signalling pathway instead of the enzymatic activity of CssPLA2. This finding could provide a promising treatment strategy to interrupt the process of liver fibrosis caused by clonorchiasis.

Expression of Clonorchis sinensis GIIIsPLA2 protein in baculovirus-infected insect cells and its overexpression facilitating epithelial-mesenchymal transition in Huh7 cells via AKT pathway

Although prior studies confirmed that group III secretory phospholipase A₂ of Clonorchis sinensis (CsGIIIsPLA₂) had stimulating effect on liver fibrosis by binding to LX-2 cells, large-scale expression of recombinant protein and its function in the progression of hepatoma are worth exploring. Because of high productivity and low lipopolysaccharides (LPS) in the Sf9-baculovirus expression system, we firstly used this system to express the coding region of CsGIIIsPLA₂. The molecular weight of recombinant CsGIIIsPLA₂ protein was about 34 kDa. Further investigation showed that most of the recombinant protein presented intracellular expression in Sf9 insect cell nucleus and could be detected only into cell debris, which made the protein purification and further functional study difficult. Therefore, to study the role of CsGIIIsPLA₂ in hepatocellular carcinoma (HCC) progression, CsGIIIsPLA₂ overexpression Huh7 cell model was applied. Cell proliferation, migration, and the expression level of epithelial-mesenchymal transition (EMT)-related molecules (E-cadherin, N-cadherin, α-catenin, Vimentin, p300, Snail, and Slug) along with possible mechanism were measured. The results indicated that CsGIIIsPLA₂ overexpression not only inhibited cell proliferation and promoted migration and EMT but also enhanced the phosphorylation of AKT in HCC cells. In conclusion, this study supported that CsGIIIsPLA₂ overexpression suppressed cell proliferation and induced EMT through the AKT pathway.

Update: Influenza Activity - United States, October 2-December 17, 2016

This report summarizes U.S. influenza activity^* during October 2-December 17, 2016.^† Influenza activity in the United States remained low in October and has been slowly increasing since November. Influenza A viruses were identified most frequently, with influenza A (H3N2) viruses predominating. Most influenza viruses characterized during this period were genetically or antigenically similar to the reference viruses representing vaccine components recommended for production in the 2016-17 Northern Hemisphere influenza vaccines.

Identification and expression analysis of toll-like receptor genes (TLR8 and TLR9) in mucosal tissues of turbot (Scophthalmus maximus L.) following bacterial challenge

Mucosal immune system is one of the most important components in the innate immunity and constitutes the front line of host defense against infection, especially for teleost, which are living in the pathogen-rich aquatic environment. The pathogen recognition receptors (PRRs), which can recognize the conserved pathogen-associated molecular patterns (PAMPs) of bacteria, are considered as one of the most important component for pathogen recognition and immune signaling pathways activation in mucosal immunity. In this regard, we sought to identify TLR8 and TLR9 in turbot (Scophthalmus maximus), as well as their mucosal expression patterns following different bacterial infection in mucosal tissues for the first time. The full-length TLR8 transcript consists of an open reading frame (ORF) of 3108 bp encoding the putative peptide of 1035 amino acids. While the TLR9 was 6730 bp long, containing a 3168 bp ORF that encodes 1055 amino acids. The phylogenetic analysis revealed both TLR8 and TLR9 showed the closest relationship to large yellow croaker. Moreover, both TLR8 and TLR9 could be detected in all examined healthy turbot tissues, with the lowest expression level in liver and a relatively moderate expression pattern in healthy mucosal tissues. Distinct expression patterns of TLR8 and TLR9 were comparatively observed in the mucosal tissues (intestine, gill and skin) following Vibrio anguillarum and Streptococcus iniae infection, suggesting their different roles for mucosal immunity. Further functional studies are needed to better characterize TLR8 and TLR9 and their family members, to better understand the ligand specificity and to identify their roles in different mucosal tissues in protecting fish from the pathogenically hostile environment.

Clonorchis sinensis lysophospholipase inhibits TGF-β1-induced expression of pro-fibrogenic genes through attenuating the activations of Smad3, JNK2, and ERK1/2 in hepatic stellate cell line LX-2

Liver fibrosis is a wound healing response associated with chronic liver injury. Hepatic stellate cells (HSCs) activation is a key event in the development of liver fibrosis. Since helminths have the ability to live for decades in the host by establishing an adaptive relationship in the interplay with its hosts, we hypothesize that whether Clonochis sinensis LysophospholipaseA (CsLysoPLA), a component of excretory/secretory proteins, can attenuate the fibrogenic response by inhibiting activation of LX-2 cells, thereby balancing the pro-fibrotic and anti-fibrotic response during the Clonochis sinensis (C. sinensis) infection. In the present study, LX-2 cells were stimulated with CsLysoPLA in the presence of TGF-β1, and the expressions of collagen type I (COL1A1), α-smooth muscle actin (α-SMA), and matrix metalloproteinase 2 (MMP2) were decreased. In addition, CsLysoPLA significantly inhibited the proliferation and migration of LX-2 cells stimulated by TGF-β1. Pretreatment of LX-2 cells with CsLysoPLA attenuated the phosphorylation of Smad3 as well as JNK2 and ERK1/2 in response to the stimulation of TGF-β1. For the first time, our results showed an anti-fibrogenic effect of CsLysoPLA by attenuating the response of LX-2 cells to TGF-β1 through inhibiting the activations of Smad3, ERK1/2, and JNK2.

Editing of the Luteinizing Hormone Gene to Sterilize Channel Catfish, Ictalurus punctatus, Using a Modified Zinc Finger Nuclease Technology with Electroporation

Channel catfish (Ictalurus punctatus) is the most important freshwater aquaculture species in the USA. Genetically enhanced fish that are sterile could both profit the catfish industry and reduce potential environmental and ecological risks. As the first step to generate sterile channel catfish, three sets of zinc finger nuclease (ZFN) plasmids targeting the luteinizing hormone (LH) gene were designed and electroporated into one-cell embryos, different concentrations were introduced, and the Cel-I assay was conducted to detect mutations. Channel catfish carrying the mutated LH gene were sterile, as confirmed by DNA sequencing and mating experiments. The overall mutation rate was 19.7 % for 66 channel catfish, and the best treatment was ZFN set 1 at the concentration 25 μg/ml. To our knowledge, this is the first instance of gene editing of fish via plasmid introduction instead of mRNA microinjection. The introduction of the ZFN plasmids may have reduced mosaicism, as mutated individuals were gene edited in every tissue evaluated. Apparently, the plasmids were eventually degraded without integration, as they were not detectable in mutated individuals using PCR. Carp pituitary extract failed to induce spawning and restoration of fertility, indicating the need for developing other hormone therapies to achieve reversal of sterility upon demand. This is the first sterilization achieved using ZFN technology in an aquaculture species and the first successful gene editing of channel catfish. Our results will help understand the roles of the LH gene, purposeful sterilization of teleost fishes, and is a step towards control of domestic, hybrid, exotic, invasive, and transgenic fishes.

Interleukin-13 is involved in the formation of liver fibrosis in Clonorchis sinensis-infected mice

Clonorchiasis is a chronic infection disease often accompanied by formation of liver fibrosis. Previous study has identified that Clonorchis sinensis (C. sinensis, Cs) infection and CsRNASET2 (a member of CsESPs) immunization can drive Th2 immune response. IL-13, a multifunctional Th2 cytokine, has been widely confirmed to be profibrotic mediator. We want to determine whether IL-13 is involved in the generation of liver fibrosis during C. sinensis infection. A part of mice were infected with C. sinensis or immunized with CsRNASET2, respectively. Another part of mice were intravenously injected with rIL-13. Liver tissues of C. sinensis-infected mice were stained with hematoxylin-eosin and Masson's trichrome, respectively. The transcriptional levels of collagen-I, collagen-III, α-SMA, and TIMP-1 in the livers of infected mice and rIL-13-treated mice were measured by quantitative RT-PCR. Besides, splenocytes of C. sinensis-infected and CsRNASET2-immunized mice were isolated, respectively. The levels of IL-13 in splenocytes were detected by ELISA. Our results displayed that the livers of C. sinensis-infected mice had serious chronic inflammation and collagen deposition. The transcriptional levels of collagen-I, collagen-III, α-SMA, and TIMP-1 in the livers of C. sinensis-infected mice were obviously increased. Splenocytes from both C. sinensis-infected and CsRNASET2-immunized mice expressed high levels of IL-13. Moreover, rIL-13 treatment markedly promoted the transcriptional levels of collagen-I, collagen-III, α-SMA, and TIMP-1. These data implied that hepatic fibrosis was formed in the livers of C. sinensis-infected mice, and IL-13 induced by C. sinensis infection and CsRNASET2 immunization might favor this progression.

Spermatogonial stem cells specific marker identification in channel catfish, Ictalurus punctatus and blue catfish, I. furcatus

Testicular germ cells of channel catfish, Ictalurus punctatus, and blue catfish, I. furcatus were separated into four layers with Percoll density gradient centrifugation, containing different cell types (40% in the first layer were spermatogonial stem cells, SSCs). Expression of seventeen genes was analyzed for cells from different layers by real-time quantitative PCR. Pfkfb4, Urod, Plzf, Integrin6, IntegrinV, Thy1 and Cdh1 genes showed the same expression change pattern in both channel and blue catfish as these genes were down-regulated in the spermatocytes and even more so in spermatids. Plzf and Integrin6 had especially high expression in SSCs and can be used as SSCs specific markers. Sox2 gene was up-regulated in spermatocytes and even more highly up-regulated in spermatids, which indicated it could be a spermatid marker. In contrast to channel catfish, Id4, Smad5 and Prdm14 gene expressions were strongly down-regulated in spermatocyte cells, but up-regulated in spermatid cells in blue catfish. Smad5 gene was down-regulated in spermatocytes, but up-regulated in both spermatogonia and spermatids, allowing identification as a marker for spermatocytes in blue catfish. Oct4, Id4, Gfrα2, Pum2 and Prdm14 genes showed different expression patterns in the testicular germ cells of channel and blue catfish. This may be a partial explanation to the differing responses of channel catfish and blue catfish to induced spawning technologies. The SSCs specific markers can be used for further SSCs labeling, which can increase the SSCs sorting efficiency and be applied in various studies involving SSCs and other germ cells.

Oral delivery of Bacillus subtilis spore expressing enolase of Clonorchis sinensis in rat model: induce systemic and local mucosal immune responses and has no side effect on liver function

Caused by the consumption of raw or undercooked freshwater fish containing infective metacercariae of Clonorchis sinensis, human clonorchiasis remains a major public health problem in China. In previous study, we had expressed enolase from C. sinensis (CsENO) on the surface of Bacillus subtilis spore and the recombinant spore induced a pronounced protection in terms of reduced worm burden and eggs per gram feces, suggesting B. subtilis spore as an ideal vehicle for antigen delivery by oral treatment and CsENO as a promising vaccine candidate against clonorchiasis. In the current study, we detected CsENO-specific IgG and IgA levels both in serum and in intestinal mucus from rats orally administrated with B. subtilis spore surface expressing CsENO by ELISA. Lysozyme levels in serum and in intestinal mucus were analyzed too. In addition, IgA-secreting cells in intestine epithelium of the rats were detected by immunohistochemistry assay. The intestinal villi lengths of duodenum, jejunum, and ileum were also measured. Rats orally treated with B. subtilis spore or normal saline were used as controls. Our results showed that, compared with the control groups, oral administration of B. subtilis spore expressing CsENO induced both systemic and local mucosal immune response. The recombinant spores also enhanced non-specific immune response in rats. The spores had no side effect on liver function. Moreover, it might facilitate food utilization and digestion of the rats. Our work will pave the way to clarify the involved mechanisms of protective efficacy elicited by B. subtilis spore expressing CsENO and encourage us to carry out more assessment trails of the oral treated spore to develop vaccine against clonorchiasis.