SARS-CoV-2 prevalence in wildlife 2020-2022: a worldwide systematic review and meta-analysis

The widespread transmission of SARS-CoV-2 in humans poses a serious threat to public health security, and a growing number of studies have discovered that SARS-CoV-2 infection in wildlife and mutate over time. This article mainly reports the first systematic review and meta-analysis of the prevalence of SARS-CoV-2 in wildlife. The pooled prevalence of the 29 included articles was calculated by us using a random effects model (22.9%) with a high heterogeneity (I2 = 98.7%, p = 0.00). Subgroup analysis and univariate regression analysis found potential risk factors contributing to heterogeneity were country, wildlife species, sample type, longitude, and precipitation. In addition, the prevalence of SARS-CoV-2 in wildlife increased gradually over time. Consequently, it is necessary to comprehensively analyze the risk factors of SARS-CoV-2 infection in wildlife and develop effective control policies, as well as to monitor the mutation of SARS-CoV-2 in wildlife at all times to reduce the risk of SARS-CoV-2 transmission among different species.

The protective effect of intranasal immunization with influenza virus recombinant adenovirus vaccine on mucosal and systemic immune response

Influenza virus is a kind of virus that poses several hazards of animal and human health. Therefore, it is important to develop an effective vaccine to prevent influenza. To this end we successfully packaged recombinant adenovirus rAd-NP-M2e-GFP expressing multiple copies of influenza virus conserved antigens NP and M2e and packaged empty vector adenovirus rAd-GFP. The effect of rAd-NP-M2e-GFP on the activation of dendritic cell (DC) in vitro and in vivo was detected by intranasal immunization. The results showed that rAd-NP-M2e-GFP promoted the activation of DC in vitro and in vivo. After the primary immunization and booster immunization of mice through the nasal immune way, the results showed that rAd-NP-M2e-GFP induced enhanced local mucosal-specific T cell responses, increased the content of SIgA in broncho alveolar lavage fluids (BALF) and triggered the differentiation of B cells in the germinal center. It is proved that rAd-NP-M2e-GFP can significantly elicit mucosal immunity and systemic immune response. In addition, rAd-NP-M2e-GFP could effectively protect mice after H1N1 influenza virus challenge. To lay the foundation and provide reference for further development of influenza virus mucosal vaccine in the future.

Gut microbiota-derived LCA mediates the protective effect of PEDV infection in piglets

BACKGROUND

The gut microbiota is a critical factor in the regulation of host health, but the relationship between the differential resistance of hosts to pathogens and the interaction of gut microbes is not yet clear. Herein, we investigated the potential correlation between the gut microbiota of piglets and their disease resistance using single-cell transcriptomics, 16S amplicon sequencing, metagenomics, and untargeted metabolomics.

RESULTS

Porcine epidemic diarrhea virus (PEDV) infection leads to significant changes in the gut microbiota of piglets. Notably, Landrace pigs lose their resistance quickly after being infected with PEDV, but transplanting the fecal microbiota of Min pigs to Landrace pigs alleviated the infection status. Macrogenomic and animal protection models identified Lactobacillus reuteri and Lactobacillus amylovorus in the gut microbiota as playing an anti-infective role. Moreover, metabolomic screening of the secondary bile acids' deoxycholic acid (DCA) and lithocholic acid (LCA) correlated significantly with Lactobacillus reuteri and Lactobacillus amylovorus, but only LCA exerted a protective function in the animal model. In addition, LCA supplementation altered the distribution of intestinal T-cell populations and resulted in significantly enriched CD8+ CTLs, and in vivo and in vitro experiments showed that LCA increased SLA-I expression in porcine intestinal epithelial cells via FXR receptors, thereby recruiting CD8+ CTLs to exert antiviral effects.

CONCLUSIONS

Overall, our findings indicate that the diversity of gut microbiota influences the development of the disease, and manipulating Lactobacillus reuteri and Lactobacillus amylovorus, as well as LCA, represents a promising strategy to improve PEDV infection in piglets. Video Abstract.

Lactobacillus plantarum surface-displayed Eimeria tenella profilin antigens with FliC flagellin elicit protection against coccidiosis in chickens

Coccidiosis is a parasitic disease in the intestine caused by the genus Eimeria that poses a substantial economic threat to the broiler breeding industry. The misuse of chemoprophylaxis and live oocyst vaccines has a negative impact on chicken reproductivity. Therefore, there is a pressing need to develop safe, convenient, and effective vaccines. Lactic acid bacteria can be used as a means to deliver mucosal vaccines against intestinal pathogens, which is a promising strategy. In this study, a recombinant Lactobacillus plantarum (L. plantarum) with surface-expressed antigens constructed from the fusion of Eimeria tenella (E. tenella) antigen profilin and the Salmonella enterica serovar Typhimurium flagellin protein FliC was created. After oral immunization with the recombinant L. plantarum, T-cell differentiation was analyzed by flow cytometry, and specific antibody levels were determined via indirect ELISA. Oocyst shedding, body weight, and cecum lesions were assessed as measures of protective immunity after challenge with E. tenella. The results of this study demonstrate the effectiveness of recombinant L. plantarum as an immunization agent for chickens. Specific IgA titers in the intestine and specific IgG antibody titers in the serum were significantly higher in chickens immunized with recombinant L. plantarum (P < 0.001). Additionally, the levels of IL-2 (P < 0.05) and IFN-γ (P < 0.01) in the serum were markedly increased. Recombinant L. plantarum induced T-cell differentiation, resulting in a higher proportion of CD4+ and CD8+ T cells in splenocytes (P < 0.001). Fecal oocyst shedding in the immunized group was significantly reduced (P < 0.001). Additionally, recombinant L. plantarum significantly relieved pathological damage in the cecum, as evidenced by lesion scores (P < 0.01) and histopathological cecum sections. In conclusion, the present study provides evidence to support the possibility of using L. plantarum as a promising carrier for the delivery of protective antigens to effectively protect chickens against coccidiosis.

NLRP3 Plays a Key Role in Antihelminth Immunity in the Enteral and Parenteral Stages of Trichinella spiralis-Infected Mice

Trichinellosis is an important foodborne zoonosis, and no effective treatments are yet available. Nod-like receptor (NLR) plays a critical role in the host response against nematodes. Therefore, we aimed to explore the role of the NLRP3 inflammasome (NLRP3) during the adult, migrating, and encysted stages of Trichinella spiralis infection. The mice were treated with the specific NLRP3 inhibitor MCC950 after inoculation with T. spiralis. Then, the role that NLRP3 plays during T. spiralis infection of mice was evaluated using enzyme-linked immunosorbent assay (ELISA), Western blotting, flow cytometry, histopathological evaluation, bone marrow-derived macrophage (BMDM) stimulation, and immunofluorescence. The in vivo results showed that NLRP3 enhanced the Th1 immune response in the adult and migrating stages and weakened the Th2 immune response in the encysted stage. NLRP3 promoted the release of proinflammatory factors (interferon gamma [IFN-γ]) and suppressed the release of anti-inflammatory factors (interleukin 4 [IL-4]). Pathological changes were also improved in the absence of NLRP3 in mice during T. spiralis infection. Importantly, a significant reduction in adult worm burden and muscle larvae burden at 7 and 35 days postinfection was observed in mice treated with the specific NLRP3 inhibitor MCC950. In vitro, we first demonstrated that NLRP3 in macrophages can be activated by T. spiralis proteins and promotes IL-1β and IL-18 release. This study revealed that NLRP3 is involved in the host response to T. spiralis infection and that targeted inhibition of NLRP3 enhanced the Th2 response and accelerated T. spiralis expulsion. These findings may help in the development of protocols for controlling trichinellosis.

The global prevalence of highly pathogenic avian influenza A (H5N8) infection in birds: A systematic review and meta-analysis

The zoonotic pathogen avian influenza A H5N8 causes enormous economic losses in the poultry industry and poses a serious threat to the public health. Here, we report the first systematic review and meta-analysis of the worldwide prevalence of birds. We filtered 45 eligible articles from seven databases. A random-effects model was used to analyze the prevalence of H5N8 in birds. The pooled prevalence of H5N8 in birds was 1.6%. In the regions, Africa has the highest prevalence (8.0%). Based on the source, village (8.3%) was the highest. In the sample type, the highest prevalence was organs (79.7%). In seasons, the highest prevalence was autumn (28.1%). The largest prevalence in the sampling time was during 2019 or later (7.0%). Furthermore, geographical factors also were associated with the prevalence. Therefore, we recommend site-specific prevention and control tools for this strain in birds and enhance the surveillance to reduce the spread of H5N8.

Characterization and pathogenicity of the porcine epidemic diarrhea virus isolated in China

Piglet diarrhea caused by the porcine epidemic diarrhea virus (PEDV) is a common problem on pig farms in China associated with high morbidity and mortality rates. In this study, three PEDV isolates were successfully detected after the fourth blind passage in Vero cells. The samples were obtained from infected piglet farms in Jilin (Changchun), and Shandong (Qingdao) Provinces of China and were designated as CH/CC-1/2018, CH/CC-2/2018, and CH/QD/2018. According to the analysis of the complete S protein gene sequence, the CH/CC-1/2018 and CH/CC-2/2018 were allocated to the G2b branch, while CH/QD/2018 was located in the G1a interval and was closer to the vaccine strain CV777. Successful detection and identification of the isolated strains were carried out using electron microscopy and indirect immunofluorescence. Meanwhile, animal challenge experiments and viral RNA copies determination were used to compare the pathogenicity. The results showed that CH/CC-1/2018 in Changchun was more pathogenic than CH/QD/2018 in Qingdao. In conclusion, the discovery of these new strains is conducive to the development of vaccines to prevent the pandemic of PEDV, especially that the CH/CC-1/2018, and CH/CC-2/2018 were not related to the classical vaccine strain CV777.

Immunogenicity of engineered probiotics expressing conserved antigens of influenza virus and FLIC flagellin against H9N2 AIVinfection in mice

Avian influenza virus (AIV)is easy to cause diseases in birds and humans.It causes great economic losses to the poultry farms and leads to public health problems. Using vaccines is the main approach to control the prevalence of AIV. In our previously published article, a recombinant Lactobacillus plantarum (L. plantarum) expressing the NP-M2 peptide ofH9N2 AIV was generated, and its protective effect was evaluated in a chicken model. In this study, the protective effect was estimated in mice model. Humoral and cellular immune response parameters were measured using flow cytometry adding to body weight loss, survival rate, virus load, and histopathological changes in the lung. The obtained results elucidated that, the recombinant L. plantarum can promote the activation of dendritic cells (DC), proliferation of T and B cells adding to eliciting protective secretory IgA (sIgA) and humeral IgG level in mice model. Accordingly, it could be used as a patent vaccine to control the AIV infection.

[Analysis of epidemiological characteristics of pulmonary tuberculosis patients in Fengtai District, Beijing City from 2011 to 2021]

Objective: To analyze the epidemiological characteristics of pulmonary tuberculosis (PTB) in Fengtai District from 2011 to 2021. Methods: A retrospective study was conducted, the data of PTB patients in Fengtai District from 2011 to 2021 were collected in Chinese disease prevention and Control Information System, which included etiological classification, gender, age, occupation, onset time, demographic information etc. the epidemiological characteristics of reported PTB patients was analysis. Results: A total of 10 342 cases of PTB were reported from 2011 to 2021 in Fengtai District, with an average annual reported incidence rate of 42.87/ 100 000. The incidence rate was the highest in 2012(75.89/100 000), and significantly declined from 2013, which declined to 29.70/100 000 in 2017. It showed a slow rise from 2018 to 2021. The difference was statistically significant (χ²=1 471.77,P<0.001).There were 2 975 cases of etiologic positive PTB from 2011 to 2021, and 76 cases of Rifampicin-resistant PTB from 2017 to 2021. The ratio of male cases to female was 1.75, the average annual incidence rate of male (53.94/100 000) was higher, than female(31.57/100 000).(χ²=704.01,P<0.001). Among all age groups, 25-29 years group, 20-24 years group and 30-34 years group had the highest proportion, which were 1 506 cases (14.56%) , 1 292 cases (12.49%) and 1 024 cases (9.90%) respectively. The average annual incidence rate was the lowest in the group less than 10 years old (1.43/100 000), and the highest in the group 85 years old and over (195.20/100 000), the difference was statistically significant(χ²=3164.24, P<0.001). The top occupations from high to low were housework and unemployment (2 917 cases, 28.21%), retirees (2 308 cases, 22.32%), workers (1 047 cases, 10.12%), cadres and staff (950 cases, 9.19%), farmers (860 cases, 8.32%), business services (698 cases, 6.75%), teachers and students (455 cases, 4.40%). Conclusion: From 2011 to 2021, the incidence rate of PTB was decreased from 2012 to 2017, and slowly increased lately in Fengtai District. The epidemiological characteristics of PTB vary in different age and gender.

Trichinella spiralis infection ameliorates the severity of Citrobacter rodentium-induced experimental colitis in mice

Trichinellosis is a food-borne zoonotic parasitic disease that causes serious harm to human health and the pig breeding industry. However, there are reports that Trichinella spiralis (T. spiralis) infection can treat autoimmune diseases, including enteritis and experimental autoimmune encephalitis (EAE). However, research on the mechanism of T. spiralis infection in infectious enteritis has not been fully elucidated. Therefore, this experiment used Citrobacter rodentium (C. rodentium) to induce colitis in mouse models and explored its underlying mechanisms. In this experiment, a total of 72 C57BL/6 mice were randomly divided into four groups. Experimental mice in the TS and TS + CR groups were orally inoculated with individual T. spiralis larvae. At 21 days postinfection (dpi) with T. spiralis, experimental animals in the CR and TS + CR groups were inoculated by orogastric gavage with C. rodentium. The control group received PBS only. The results indicated that the weight loss and macroscopic and microscopic colon damage of mice in the TS + CR group were significantly decreased compared with those observed in the CR group. The results of flow cytometry showed that the expression levels of IL-4, IL-10 and CD4+CD25+Foxp3+ Tregs were increased (P < 0.05), while the expression levels of IFN-γ, IL-12 and IL-17 were decreased in the spleens and MLNs of the TS + CR experimental mice compared with the colitis model mice. ELISA results revealed that the TS + CR group not only elicited a strong IgG1 response (P < 0.01) but also a low level of IgG2a response (P < 0.05) relative to the CR group. The above results demonstrated that prior exposure of mice to T. spiralis infection ameliorated the severity of C. rodentium-induced infectious colitis.

Lactiplantibacillus plantarum 0111 Protects Against Influenza Virus by Modulating Intestinal Microbial-Mediated Immune Responses

There are some limitations of traditional influenza vaccines concerning novel mutant strains. Therefore, it is particularly important to develop preventive means for antigen-unrelated types of influenza viruses. Recent studies have shown that probiotics can modulate the immune system and reduce the severity of viral infections. In this study, we investigated the potential of Lactiplantibacillus plantarum 0111 against influenza virus H9N2. Challenge experiments showed that L. plantarum 0111 pretreatments could effectively improve mice’s survival rate and weight loss and reduce the inflammatory cytokines IL-6 and TNF-α in the lungs and bronchoalveolar lavage fluid (BALF) along with the degree of lung and intestinal injury. FMT experiment demonstrates that the protective effect produced by L. plantarum 0111 is associated with gut microorganisms. In addition, 16S high-throughput sequencing of the mouse intestinal microbiota showed that L. plantarum 0111 remodeled the intestinal microbiota after H9N2 infection and maintained the gut microbiota balance. In a mouse model, the oral administration of L. plantarum 0111 increased IFN-β expression in the serum and BALF. At the same time, the transcript levels of IFN-β and related ISGs in the intestine and lungs of mice were also increased. In addition, the activation and polarization of T cells in mesenteric lymph nodes (MLNs) and the spleen were detected by flow cytometry, and the results showed that L. plantarum 0111 modulated cytokines in T cells and increased IgA expression in B cells in the MLNs and spleen. Thus, L. plantarum 0111 may improve gut microbiota-mediated immune responses and thus, resist infection by the influenza virus, and it could be used as an effective preventive measure against the influenza virus.

Riboflavin Attenuates Influenza Virus Through Cytokine-Mediated Effects on the Diversity of the Gut Microbiota in MAIT Cell Deficiency Mice

Influenza is a serious respiratory disease that continues to threaten global health. Mucosa-associated invariant T (MAIT) cells use T-cell receptors (TCRs) that recognize microbial riboflavin derived intermediates presented by the major histocompatibility complex (MHC) class I-like protein MR1. Riboflavin synthesis is broadly conserved, but the roles or mechanisms of riboflavin in MR1^–/– mouse influenza infection are not well understood. In our study, immunofluorescence techniques were applied to analyze the number and distribution of viruses in lung tissue. The amount of cytokine expression was assessed by flow cytometry (FCM), ELISA, and qPCR. The changes in the fecal flora of mice were evaluated based on amplicon sequencing of the 16S V3-V4 region. Our study showed that MAIT cell deficiency increased mortality and that riboflavin altered these effects in microbiota-depleted mice. The oral administration of riboflavin inhibited IL-1β, IL-17A, and IL-18 production but significantly increased the expression of IFN-γ, TNF-α, CCL2, CCL3, and CCL4 in a mouse model. The analysis of the mouse flora revealed that riboflavin treatment significantly increased the relative abundance of Akkermansia and Lactobacillus (p < 0.05) and decreased that of Bacteroides. In contrast, MR1^–/– mice exhibited a concentrated aggregation of Bacteroides (p < 0.01), which indicated that MAIT cell deficiency reduced the diversity of the bacterial population. Our results define the functions of MAIT cells and riboflavin in resistance to influenza virus and suggest a potential role for riboflavin in enhancing MAIT cell immunity and the intestinal flora diversity. Gut populations can be expanded to enhance host resistance to influenza, and the results indicate novel interactions among viruses, MAIT cells, and the gut microbiota.

Oral Vaccination of Mice With Trichinella spiralis Putative Serine Protease and Murine Interleukin-4 DNA Delivered by Invasive Lactiplantibacillus plantarum Elicits Protective Immunity

Trichinellosis is a serious zoonotic parasitic disease caused by Trichinella spiralis (T. spiralis) that causes considerable economic losses for the global pig breeding and food industries. As such, there is an urgent need for a vaccine that can prevent T. spiralis infection. Previous studies have reported that recombinant invasive Lactococcus lactis (LL) expressing Staphylococcus aureus fibronectin binding protein A (LL-FnBPA+) can transfer DNA vaccines directly to dendritic cells (DCs) across an epithelial cell monolayer, leading to significantly higher amounts of heterologous protein expression compared to non-invasive Lactococcus lactis. In this study, the invasive bacterium Lactiplantibacillus plantarum (L. plantarum) expressing FnBPA was used as a carrier to deliver a novel oral DNA vaccine consisting of T. spiralis adult putative serine protease (Ts-ADpsp) and murine interleukin (IL)-4 DNA to mouse intestinal epithelial cells. Experimental mice were orally immunized 3 times at 10-day intervals. At 10 days after the last vaccination, mice were challenged with 350 T. spiralis infective larvae by oral inoculation. Immunization with invasive L. plantarum harboring pValac-Ts-ADpsp/pSIP409-FnBPA induced the production of anti-Ts-ADpsp-specific IgG of serum, type 1 and 2 helper T cell cytokines of mesenteric lymph node (MLN) and spleen, secreted (s) IgA of intestinal lavage, and decreased T. spiralis burden and intestinal damage compared to immunization with non-invasive L. plantarum expressing Ts-ADpsp (pValac-Ts-ADpsp/pSIP409). Thus, invasive L. plantarum expressing FnBPA and IL-4 stimulates both mucosal and cellular immune response to protect against T. spiralis infection, highlighting its therapeutic potential as an effective DNA vaccine for trichinellosis.

Gut Bacterial Composition and Functional Potential of Tibetan Pigs Under Semi-Grazing

Gut bacterial community plays a key role in maintaining host health. The Tibetan pig (Sus scrofa), an ancient breed in China, has been known for its high adaptability to harsh environments and for its meat quality. To understand the underlying mechanisms facilitating to shape these unique features, in this study, 16S rRNA sequencing using pigs feces and subsequent bacterial functional prediction were performed. Also, the gut bacteria of two other breeds of pigs, Barkshire and Landrace, were examined for comparison. It was revealed that the structure of bacterial community in Tibetan pigs appeared to be more complex; the relative abundances of dominant bacterial families varied inversely with those of the other pigs, and the proportion of Firmicutes in Tibetan pigs was lower, but Bacteroides, Fibrobacterota, Lachnospiraceae, Oscillospiraceae, and Ruminococcaceae were higher. Bacterial functional prediction revealed that the dominant flora in the Tibetan pigs was more correlated with functions regulating the hosts’ immune and inflammatory responses, such as NOD-like_receptor_signaling_pathway and vitamin metabolism. In addition, in Tibetan pigs, the taxonomic relationships in the gut bacteria on day 350 were closer than those on earlier stages. Furthermore, gender played a role in the composition and function of bacterial inhabitants in the gut; for boars, they were more correlated to drug resistance and xenobiotics metabolism of the host compared to the sows. In sum, our preliminary study on the gut bacterial composition of the Tibetan pigs provided an insight into the underlying host–microorganism interactions, emphasizing the role of intestinal bacteria in the context of modulating the host’s immune system and host development.

Immune Evaluation of Recombinant Lactobacillus plantarum With Surface Display of HA1-DCpep in Mice

Avian influenza viruses can be efficiently transmitted through mucous membranes, and conventional vaccines are not effective in protecting against mucosal infection by influenza viruses. To induce multiple immune responses in an organism, we constructed a recombinant Lactobacillus plantarum expressing the influenza virus antigen HA1 with the adjuvant dendritic cell-targeting peptide (DCpep). The recombinant L. plantarum strains NC8Δ-pWCF-HA1 and NC8Δ-pWCF-HA1-DCpep were used to immunize mice via oral administration, and the humoral, cellular and mucosal immune responses were evaluated. In addition, the serum levels of specific antibodies and hemagglutination inhibition (HI) levels were also measured. Our results showed that recombinant L. plantarum activated dendritic cells in Peyer's patches (PPs), increased the numbers of CD4⁺IFN-γ⁺ and CD8⁺IFN-γ⁺ cells in the spleen and mesenteric lymph nodes (MLNs), and affected the ability of CD4⁺ and CD8⁺ cells to proliferate in the spleen and MLNs. Additionally, recombinant L. plantarum increased the number of B220⁺IgA⁺ cells in PPs and the level of IgA in the lungs and different intestinal segments. In addition, specific IgG, IgG1 and IgG2a antibodies were induced at high levels in the mice serum, specific IgA antibodies were induced at high levels in the mice feces, and HI potency was significantly increased. Thus, the recombinant L. plantarum strains NC8Δ-pWCF-HA1 and NC8Δ-pWCF-HA1-DCpep have potential as vaccine candidates for avian influenza virus.

Lactobacillus rhamnosus GG Promotes Early B Lineage Development and IgA Production in the Lamina Propria in Piglets

Gut microbes play an important role in the development of host B cells. It has been controversial whether GALT is the development site of B cells in pigs. By investigating the relationship between gut microbes and the development of B cells in the GALT of piglets, we found, to our knowledge for the first time, that early B cells exist in the gut lamina propria (LP) in pigs at different ages. We further used Lactobacillus rhamnosus GG (LGG) to treat piglets. The results showed that LGG promotes the development of the early B lineage, affects the composition of the Ig CDR3 repertoires of B cells, and promotes the production of IgA in the intestinal LP. Additionally, we found that the p40 protein derived from LGG can activate the EGFR/AKT and NF-κB signaling pathways, inducing porcine intestinal epithelial cells (IPEC-J2) to secrete a proliferation-inducing ligand (APRIL), which promotes IgA production in B cells. Finally, we identified ARF4 and DIF3 as candidates for p40 receptors on IPEC-J2 by GST pull-down, liquid chromatography-mass spectrometry/mass spectrometry analysis, and coimmunoprecipitation. In conclusion, LGG could promote early B cell differentiation and development in the intestinal LP in piglets and might contribute to promoting IgA production via secretion of p40, which interacts with the membrane receptors on IPEC-J2 and induces them to secrete APRIL. Our study will provide insight to aid in better utilization of probiotics to increase human health.

Oral vaccination with attenuated Salmonella encoding the Trichinella spiralis 43-kDa protein elicits protective immunity in BALB/c mice

A vaccine against Trichinella spiralis infection is urgently needed to interrupt its transmission from domestic animals to humans. However, no vaccine against T. spiralis is currently available. Our previous study demonstrated that the use of the 43-kDa glycoprotein present in excretory-secretory (ES) proteins of muscle larvae (ML) as an intramuscular DNA vaccine led to a 52.1% protection rate against T. spiralis infection. Attenuated Salmonella strains have the advantage of eliciting mucosal immunity, which is important for controlling T. spiralis infections at the intestinal stage and can be provided as vaccines via oral or intranasal routes. Therefore, in this study, complete 43-kDa glycoprotein (Ts43) sequences of T. spiralis were cloned into the vector pYA3681, and the recombinant plasmid pYA3681-Ts43 was transformed into the attenuated Salmonella typhimurium strain χ11802. The results showed that oral vaccination of mice with attenuated Salmonella carrying the recombinant plasmid pYA3681-Ts43 induced an evident elevation of the local intestinal mucosal sIgA and serum IgG antibody responses. The flow cytometry results showed that the percentages of CD4⁺ T cells and secreted IFN-γ, IL-4, and IL-17A in CD4⁺ T cells were significantly increased in the spleen and mesenteric lymph node (MLN) lymphocytes of the vaccinated groups. In addition, increased levels of the IFN-γ, IL-4, and IL-17A cytokines were also observed in the serum of the immunized groups. The above immune response results in the immunized groups demonstrated that protective immunity was elicited in this study. Finally, vaccinated mice demonstrated a significant 45.9% reduction in ML burden after infection with T. spiralis. This study demonstrated that oral vaccination with Ts43 delivered by attenuated Salmonella elicited local and systemic concurrent Th1/Th2/Th17 immune responses and provided partial protection against T. spiralis infection in BALB/c mice. This is a prospective strategy for the prevention and control of trichinellosis.

Oral vaccination with invasive Lactobacillus plantarum delivered nucleic acid vaccine co-expressing SS1 and murine interleukin-4 elicits protective immunity against Trichinella spiralis in BALB/c mice

Trichinellosis is a foodborne zoonosis caused by Trichinella spiralis (T. spiralis) that not only causes considerable economic losses for the global pig breeding and food industries, but also seriously threats the health of human. Therefore, it is very necessary to develop an effective vaccine to prevent trichinellosis. In this study, the invasive Lactobacillus plantarum (L. plantarum) expressing fibronectin-binding protein A (FnBPA) was served as a live bacterial vector to deliver DNA to the host to produce a novel oral DNA vaccine. Co-expressing T. spiralis SS1 and murine interleukin-4 (mIL-4) of DNA vaccine were constructed and subsequently delivered to intestinal epithelial cells via invasive L. plantarum. At 10 days after the third immunization, the experimental mice were challenged with 350 T. spiralis infective larvae. The results found that the mice orally vaccinated with invasive L. plantarum harboring pValac-SS1/pSIP409-FnBPA not only stimulated the production of anti-SS1-specific IgG, Th1/Th2 cell cytokines, and secreted(s) IgA but also decreased worm burden and intestinal damage. However, the mice inoculated with invasive L. plantarum co-expressing SS1 and mIL-4 (pValac-SS1-IL-4/pSIP409-FnBPA) induced the highest protective immune response against T. spiralis infection. The DNA vaccine delivered by invasive L. plantarum provides a novel idea for the prevention of T. spiralis infection.

Improved pathogenicity of H9N2 subtype of avian influenza virus induced by mutations occurred after serial adaptations in mice

H9N2 subtype, a low pathogenic avian influenza virus, is emerging as a major causative agent circulating poultry workplaces across China and other Asian countries. Increasing case number of interspecies transmissions to mammals reported recently provoked a great concern about its risks inducing global pandemics. In an attempt to understand the underlying mechanism of how the H9N2 virus disrupts the interspecies segregation to transmit to mammals. A mutant H9N2 strain was obtained by passaging the wildtype H9N2 A/chicken/Hong Kong/G9/1997 eight times from lung to lung in BALB/c mice. Our finding revealed that mice manifested severe clinical symptoms including losses of body weight, pathological damages in pulmonary sites and all died within two weeks after infected with the mutated H9N2, whereas all mice survived upon infected with wildtype strain in comparison, which suggested increased pathogenicity of the mutant strain. In addition, mice showed enhanced levels of proinflammatory cytokines in sera, including IL-6, TNF-α and IL-1β compared to those subjected to wildtype viral infections. Sequence analysis showed that five amino acid substitutions occurred at PB2₆₂₇, HA_87, HA₂₃₄, NP₃₈₇ and M₁₅₆, and a deletion mutation happened in the M gene (M₁₅₇). Of these mutations, PB2 E627K played key roles in modulating lethality in mice. Taken together, the mutant H9N2 strain obtained by serial passaging of its wildtype in mice significantly increased its virulence leading to death of mice, which might be associated the accumulated mutations occurred on its genome.

Lactobacillus plantarum surface-displayed ASFV (p54) with porcine IL-21 generally stimulates protective immune responses in mice

African classical swine fever virus (ASFV) has spread seriously around the world and has dealt with a heavy blow to the pig breeding industry due to the lack of vaccines. In this study, we produced recombinant Lactobacillus plantarum (L. plantarum) expressing an ASFV p54 and porcine IL-21 (pIL-21) fusion protein and evaluated the immune effect of NC8-pSIP409-pgsA'-p54-pIL-21 in a mouse model. First, we verified that the ASFV p54 protein and p54-pIL-21 fusion protein were anchored on the surface of L. plantarum NC8 by flow cytometry, immunofluorescence and Western blotting. Then, the results were verified by flow cytometry, ELISA and MTT assays. Mouse-specific humoral immunity and mucosal and T cell-mediated immune responses were induced by recombinant L. plantarum. The results of feeding mice recombinant L. plantarum showed that the levels of serum IgG and mucosal secreted IgA (SIgA), the number of CD4 and CD8 T cells, and the expression of IFN-γ in CD4 and CD8 T cells increased significantly, and lymphocyte proliferation occurred under stimulation with the ASFV p54 protein. Our data lay a foundation for the development of oral vaccines against ASFV in the future.

Higher mucosal type II immunity is associated with increased gut microbiota diversity in BALB/c mice after Trichinella spiralis infection

Understanding the interaction between the gut microbiota and Trichinella spiralis is of interest for the early diagnosis and development of therapeutics for trichinellosis and to reveal the potential role of microbiota in the mechanism of immunomodulation of this tissue-dwelling helminth. In this study, we utilized 16S rRNA gene sequencing to monitor the dynamics of the microbes in BALB/c mice challenged with T. spiralis. Flow cytometry and ELISA were used to analyze cytokines at the same time. Histopathological analysis of the duodenum was also conducted. We found that microbial perturbations occurred during infection. The abundance of the Lachnospiraceae NK4A136 group, Ruminococcus 1 and Lactococcus decreased. However, the abundance of proinflammatory Parabacteroides increased over time after infection. T. spiralis infection also tended to inhibit IFN-γ production, and promote IL-4 and IL-10 levels. In total, T. spiralis disrupts gut homeostasis and impairs the development of the intestinal ecosystem. Defining the bacterial populations affected by T. spiralis infection might help identify microbial markers for diagnosis of the disease, and the populations could also be further exploited as a novel option to treat T. spiralis infection.

Oral immunization with recombinant Lactobacillus plantarum expressing Nudix hydrolase and 43 kDa proteins confers protection against Trichinella spiralis in BALB/c mice

Trichinellosis is a significant food-borne zoonotic parasitic disease caused by parasite Trichinella. Given the side effects of anti-Trichinella drugs (e.g., Mebendazole) aroused in the course of treatments, an effective vaccine against the parasite is called for. The therapies available to date are in most instances targeting a single stage of Trichinella, resulting in an incomplete protective immunity against the parasite in terms of the complexity of its developmental stages. In this study, a recombinant dual-expression double anchor vector NC8-pLp-TsNd-S-pgsA'-gp43 was constructed carrying two antigen genes from Trichinella spiralis (T. spiralis), encoding the gp43 and T. spiralis Nudix hydrolase (TsNd) proteins which were mainly expressed in muscle larva (ML) and intestinal infective larva stages of the parasite respectively. These two proteins were to be expressed by Lactobacillus plantarum NC8 (L. plantarum NC8) which was designed to express the two anchored peptides, a truncated poly-γ-glutamic acid synthetase A (pgsA') and the surface layer protein of Lactobacillus acidophilus (SlpA), on its surface for attaching expressed foreign proteins. Oral immunization with the above recombinant vaccine induced higher levels of specific serum IgG and mucosal secretory IgA (SIgA) in BALB/c mice. In addition, cytokines, interferon-γ (IFN- γ), interleukin-4 (IL-4) and IL-17 released by lymphocytes, and CD4+ levels displayed on the surfaces of splenic and mesenteric lymph cells were significantly enhanced by the vaccination. Moreover, after larval challenges, a 75.67 % reduction of adult worms (AW) at 7 days post-infection (dpi) and 57.14 % reduction of ML at 42 dpi were observed in mice immunized with the recombinant vaccine. Furthermore, this oral vaccination reduced the counts of encysted larvae presented in tongue and masseter muscles after infected with T. spiralis in mice. The overall results demonstrated that the recombinant vaccine developed in this study could induce specific humoral, mucosal, and cellular immune responses, and provides protections against different stages (adult worms and muscle larva) of T. spiralis infections in BALB/c mice, which could make it a promising oral vaccine candidate against trichinellosis.

MicroRNA and circRNA Expression Analysis in a Zbtb1 Gene Knockout Monoclonal EL4 Cell Line

Zinc finger and BTB domain containing 1(Zbtb1) is a transcriptional suppressor protein, and a member of the mammalian Zbtb gene family. Previous studies have shown that Zbtb1 is essential for T-cell development. However, the role of Zbtb1 in T-cell lymphoma is undetermined. In this study, an EL4 cell line with Zbtb1 deletion was constructed using the CRISPR-Cas9 technique. The expression profiles of microRNA and circRNA produced by the control and gene deletion groups were determined by RNA-seq. In general, 24 differentially expressed microRNA and 16 differentially expressed circRNA were found between normal group and gene deletion group. Through further analysis of differentially expressed genes, GO term histogram and KEGG scatter plot were drawn, and three pairs of miRNA and circRNA regulatory relationships were found. This study describes the differentially expressed microRNA and circRNA in normal and Zbtb1-deficient EL4 cell lines, thus providing potential targets for drug development and clinical treatment of T-cell lymphoma.

Induction of the IL-10-producing regulatory B cell phenotype following Trichinella spiralis infection

Regulatory B cells (Bregs), a subset of B lymphocytes discovered in the past few decades, have the capacity to suppress the immune response and dampen inflammation by secreting cytokines (IL-10 and TGF-β). Whether Bregs are involved in Trichinella spiralis infection and the phenotypic characteristics of these cells after infection are still unknown. We investigated the phenotype of and dynamic changes in IL-10-producing Bregs in Trichinella spiralis infection in BALB/c mice. We used multicolour fluorescence immunostaining of microwave-treated paraffin sections to investigate the number of Bregs in T. spiralis infection. Flow cytometry (FCM) was used to determine the frequency of Bregs and related subgroups and cytokines in the spleen and mesenteric lymph nodes (MLNs). High levels of IL-10 were detected in the spleen and MLNs of mice after infection with T. spiralis. Furthermore, the frequencies of IL-10-producing CD19⁺CD1d^highCD5⁺ regulatory B cells and CD19⁺ cells were increased during T. spiralis infection. We also showed that the induced phenotype was similar to that of transitional type 2 marginal zone precursor B cells (T-MZP) cells after T. spiralis infection in mice. This study is the first demonstration of the expansion of Bregs following T. spiralis infection.

Depiction of Vaginal Microbiota in Women With High-Risk Human Papillomavirus Infection

Persistent infection with the carcinogenic human papillomavirus (HPV) is a prerequisite for the progression of cervical lesions and cancer. A growing body of research has focused on the functional role of the vaginal microbiota in the persistence of HPV infection. Understanding the microbial composition and structure in women with high-risk (hr)-HPV infection may help reveal associations between the vaginal microbiota and HPV infection, and identify potential biomarkers. Our study investigated the vaginal microbial community in women with and without hr-HPV infection, by using 16s rRNA gene sequencing. We found that microbial perturbations occurred in the early phase of hr-HPV infection. Lactobacillus and Sporolactobacillus were decreased, while bacteria related to bacterial vaginosis (BV), such as Gardnerella, Prevotella, Dialister, Slackia, Actinomyces, Porphyromonas, Peptoniphilus, Anaerococcus, Peptostreptococcus, Streptococcus, Ureaplasma, Megasphaera, and Mycoplasma were increased. Our results could offer insights into the correlations between hr-HPV and the vaginal microbiota in the early infection period, and provide indications that the predominance of some BV-associated bacteria during hr-HPV infection may increase the risk for cervical neoplasia.

Probiotic Lactobacillus rhamnosus GG Promotes Mouse Gut Microbiota Diversity and T Cell Differentiation

Lactic acid bacteria (LAB) are the primary genera of the intestinal flora and have many probiotic functions. In the present study, Lactobacillus rhamnosus GG (LGG) ATCC 53103 was used to treat BALB/c mice. After LGG intervention, both low and high LGG doses were shown to improve the observed OTU, Chao1, ACE, and Shannon indices, while the Simpson index decreased, demonstrating that LGG can promote intestinal microbiota abundance and diversity. Furthermore, LGG treatment increased the abundances of intestinal Firmicutes, Bacteroides and Actinomycetes while reducing that of Proteobacteria. In addition to its effect on gut the microbiota, LGG could also regulate the host immune system. In the present study, we showed that LGG could affect the percentage of CD3⁺ T lymphocytes in the spleens (SPLs), mesenteric lymph nodes (MLNs), Peyer’s patches (PPs) and lamina propria lymphocytes (LPLs) of mice, including total CD3⁺ T, CD3⁺CD4⁺ T, and CD3⁺CD8⁺ T lymphocytes. Furthermore, LGG could effectively increase the expression of Th1-type cytokines (IFN-γ) and Th2 cytokines (IL-4) in CD4⁺ T cells, indicating that the proportion of Th1 and Th2 cells in mice with LGG treatment was in a high equilibrium state compared to the control group. In addition, the IFN-γ/IL-4 ratio was greater than 1 in mice with LGG intervention, suggesting that LGG tends to mediate the Th1 immune response. The results of the present study also showed that LGG upregulated the expression of IL-17 in CD4⁺ T cells and regulated the percentage of CD4⁺CD25⁺Foxp3⁺ Treg cells in various secondary immunological organs, indicating that LGG may promote the balance of Th-17 and Treg cells.

Lactobacillus plantarum surface-displayed influenza antigens (NP-M2) with FliC flagellin stimulate generally protective immune responses against H9N2 influenza subtypes in chickens

The H9N2 avian influenza virus (AIV) causes serious economic losses to the poultry industry every year. Vaccines that induce a mucosal immune response may be successful against influenza virus infection because its transmission occurs primarily in the mucosa. To develop novel and potent oral vaccines based on Lactobacillus plantarum (L. plantarum) to control the spread of AIV in poultry industry, in the present study, we constructed and expressed fusions of the influenza antigens NP and M2 with the Salmonella Typhimurium flagellinprotein FliC on the surface of L. plantarum. Oral immunization of chicks was performed, and serum antibodies, mucosal antibodies, and specific cellular immunity were detected. Immunizing chicks with avian influenza virus was evaluated. The results showed high levels of IgG in addition to high levels of secretory immunoglobulin A (sIgA) in chickens orally administered recombinant L. plantarum. In addition, the fusion may significantly increase the levels of NP- and M2-specific T cell-mediated immunity in the case of mucosal administration of NC8-pSIP409-pgsA'-NP-M2-FliC. Recombinant NC8-pSIP409-pgsA'-NP-M2-FliC mediated effectively protected chickens against influenza virus and reduced virus titers in the lung. Our study outcomes indicate that the expression of influenza NP-M2 and a mucosal adjuvant (FliC), by L. plantarum could generate a mucosal vaccine candidate for animals in the future to defend against AIVs.

Immunological evaluation of invasive Lactobacillus plantarum co-expressing EtMIC2 and chicken interleukin-18 against Eimeria tenella

Chicken coccidiosis is a protozoan parasitic disease that leads to considerable economic losses in the poultry industry. In this study, we used invasive Lactobacillus plantarum (L.P) expressing the FnBPA protein as a novel bacterial carrier for DNA delivery into epithelial cells to develop a live oral DNA vaccine. A fusion DNA vaccine co-expressing EtMIC2 and chicken IL-18 (chIL-18) was constructed and then delivered to the host by invasive L.P. Its efficacy against Eimeria tenella challenge was evaluated in chickens by examining the relative weight gain rate; caecal lesion score; OPG; anti-coccidial index (ACI); levels of EtMIC2 antibody, FnBPA, IL-4, IL-18, IFN-γ and SIgA; and proliferation ability and percentages of CD4⁺ and CD8⁺ splenocytes. The experimental results showed that chickens immunized with invasive L.P carrying the eukaryotic expression vector pValac-EtMIC2 (pValac-EtMIC2/pSIP409-FnBPA) had markedly improved immune protection against challenge compared with that of chickens immunized with non-invasive L.P (pValac-EtMIC2/pSIP409). However, invasive L.P co-expressing EtMIC2 with the chIL-18 vector exhibited the highest protection efficiency against E. tenella. These results indicate that invasive Lactobacillus-expressing FnBPA improved humoural and cellular immunity and enhanced resistance to E. tenella. The DNA vaccine delivered by invasive Lactobacillus provides a new concept and method for the prevention of E. tenella.

A potential vaccine candidate towards chicken coccidiosis mediated by recombinant Lactobacillus plantarum with surface displayed EtMIC2 protein

Eimeria tenella (E. tenella) has caused severe economic loss in chicken production, especially after the forbidden use of antibiotics in feed. Considering the drug resistant problem caused by misuse of chemoprophylaxis and live oocyst vaccines can affect the productivity of chickens, also it has the risk to reversion of virulence, the development of efficacious, convenient and safe vaccines is still deeply needed. In this study, the EtMic2 protein of E. tenella was anchored on the surface of Lactobacillus plantarum (L. plantarum) NC8 strain. The newly constructed strain was then used to immunize chickens, followed by E. tenella challenge. The results demonstrated that the recombinant strain could provide efficient protection against E. tenella, shown by increased relative body weight gains, percentages of CD4⁺ and CD8⁺ T cells, humoral immune response and inflammatory cytokines. In addition, decreased cecum lesion scores and fecal oocyst shedding were also observed during the experiment. In conclusion, this study proves the possibility to use L. plantarum as a vessel to deliver protective antigen to protect chickens against coccidiosis.

Surface-Displayed Porcine IFN-λ3 in Lactobacillus plantarum Inhibits Porcine Enteric Coronavirus Infection of Porcine Intestinal Epithelial Cells

Interferon (IFN)-λ plays an essential role in mucosal cells which exhibit strong antiviral activity. Lactobacillus plantarum (L. plantarum) has substantial application potential in the food and medical industries because of its probiotic properties. Alphacoronaviruses, especially porcine epidemic diarrhea virus (PEDV) and transmissible gastroenteritis virus (TGEV), cause high morbidity and mortality in piglets resulting in economic loss. Co-infection by these two viruses is becoming increasingly frequent. Therefore, it is particularly important to develop a new drug to prevent diarrhea infected with mixed viruses in piglets. In this study, we first constructed an anchored expression vector with CWA (C-terminal cell wall anchor) on L. plantarum. Second, we constructed two recombinant L. plantarum strains that anchored IFN-λ3 via pgsA (N-terminal transmembrane anchor) and CWA. Third, we demonstrated that both recombinant strains possess strong antiviral effects against coronavirus infection in the intestinal porcine epithelial cell line J2 (IPEC-J2). However, recombinant L. plantarum with the CWA anchor exhibited a more powerful antiviral effect than recombinant L. plantarum with pgsA. Consistent with this finding, Lb.plantarum-pSIP-409-IFN-λ3-CWA enhanced the expression levels of IFN-stimulated genes (ISGs) (ISG15, OASL, and Mx1) in IPEC-J2 cells more than did recombinant Lb.plantarum-pSIP-409-pgsA'-IFN-λ3. Our study verifies that recombinant L. plantarum inhibits PEDV and TGEV infection in IPEC-J2 cells, which may offer great potential for use as a novel oral antiviral agent in therapeutic applications for combating porcine epidemic diarrhea and transmissible gastroenteritis. This study is the first to show that recombinant L. plantarum suppresses PEDV and TGEV infection of IPEC-J2 cells.

Dissection of the cecal microbial community in chickens after Eimeria tenella infection

Background

Eimeria spp. are responsible for chicken coccidiosis which is the most important enteric protozoan disease resulting in tremendous economic losses in the poultry industry. Understanding the interaction between the avian cecal microbiota and coccidia is of interest in the development of alternative treatments that do not rely on chemotherapeutics and do not lead to drug resistance.

Methods

We utilized 16S rRNA gene sequencing to detect the dynamics of the cecal microbial community in AA broilers challenged with Eimeria tenella. Histopathological analysis of the cecum was also conducted.

Results

We found that microbial shifts occur during the infection. Lactobacillus, Faecalibacterium, Ruminococcaceae UCG-013, Romboutsia and Shuttleworthia decreased in abundance. However, the opportunistic pathogens Enterococcus and Streptococcus increased in abundance over time in response to the infection.

Conclusions

Eimeria tenella disrupts the integrity of the cecal microbiota and could promote the establishment and growth of potentially pathogenic bacteria. Defining bacterial populations affected by coccidial infection might help identify bacterial markers for intestinal disease as well as populations or species that could be beneficial in maintaining and restoring gut homeostasis during and after infection with E. tenella.

[Clinical effects of application of antibiotic bone cement in wounds of diabetic foot ulcers]

Objective: To explore the clinical effects of antibiotic bone cement in the treatment of diabetic foot ulcers. Methods: According to the treatment methods, 18 patients with diabetic foot ulcers (11 males and 7 females, aged 53-79 years), who were conformed to the study criteria and admitted to our hospital from January 2016 to January 2017, were enrolled in traditional group; 18 patients with diabetic foot ulcers (11 males and 7 females, aged 55-80 years), who were conformed to the study criteria and admitted to our hospital from February 2017 to February 2018, were enrolled in bone cement group. Wounds of patients in traditional group were treated with vacuum sealing drainage after conventional debridement. Wounds of patients in bone cement group were covered with antibiotic bone cement after conventional debridement. The number of patients with positive bacterial culture in wound exudate in the 2 groups on admission and 3, 6, 9, and 15 days after surgery, the length of hospital stay, the number of operation, and the wound complete healing time were retrospectively recorded. Data were processed with Fisher's exact probability test and independent sample t test. Results: Compared with (29±10) d and (4.6±1.2) times of patients in traditional group, the length of hospital stay [(9±3) d] of patients was obviously shortened, the number of operation [(1.3±0.6) times] of patients was obviously reduced, the number of patients with positive bacterial culture in wound exudate at each time point post surgery was obviously reduced (t=8.177, 9.896, P<0.05 or P<0.01) in bone cement group. There were no statistically significant differences in the number of patients with positive bacterial culture in wound exudate on admission and wound complete healing time between patients in the 2 groups (t=0.175, P>0.05). Conclusions: The antibiotic bone cement treatment of diabetic foot ulcers can reduce the number of patients with positive bacterial culture in wound exudate and the number of operation, as well as shorten the length of hospital stay.

Replication of previous genome-wide association studies of HKDC1, BACE2, SLC16A11 and TMEM163 SNPs in a gestational diabetes mellitus case-control sample from Han Chinese population

Background: Four novel glucose metabolism risk loci (HKDC1 rs4746822, BACE2 rs6517656, SLC16A11 rs13342232 and TMEM163 rs998451) were identified in recent genome-wide association studies (GWAS) of Afro-Caribbean, European, Hispanic, Thai, Mexican, Latin American and Indian populations. None of the abovementioned SNPs has been reported in a Han Chinese population. Aim: To replicate the relationships between HKDC1 rs4746822, BACE2 rs6517656, SLC16A11 rs13342232 and TMEM163 rs998451 with gestational diabetes mellitus (GDM) in a Han Chinese population. Methods: This was a case-control study which enrolled 334 pregnant women with GDM and 367 pregnant women with normal glucose tolerance. The linear regression and logistic regression were used to estimate the association between SNPs with the risk of GDM, HOMA-IR and fasting insulin levels. The fasting insulin concentration and HOMA-IR were log10 transformed before analysis. Results: No significant differences in the alleles and genotypes of SLC16A11 rs13342232, HKDC1 rs4746822 and BACE2 rs6517656 were observed between cases and controls. After adjusting the weekly BMI growth, pre-pregnancy BMI and maternal age, under the additive model, SLC16A11 rs13342232 was associated with log₁₀fasting serum insulin (Beta=0.046, p=0.016), log₁₀HOMA-IR level (Beta=0.061, p=0.003) and fasting plasma glucose level (Beta=0.164, p=0.011); HKDC1 rs4746822 was associated with OGTT 2-hr plasma glucose level (Beta=0.239, p=0.016); and BACE2 rs6517656 was associated with log₁₀fasting serum insulin (Beta=-0.053, p=0.044) and log₁₀HOMA-IR level (Beta=-0.060, p=0.048). After correction for multiple testing, the associations of SLC16A11 and HKDC1 with glucose metabolism remained statistically significant. The A allele of TMEM163 rs998451 was not detected in this population. Conclusion: HKDC1 rs4746822, BACE2 rs6517656 and SLC16A11 rs13342232 are associated with glucose metabolism in pregnant women of Han Chinese.

Immune response characterization of mice immunized with Lactobacillus plantarum expressing spike antigen of transmissible gastroenteritis virus

The highly infectious porcine transmissible gastroenteritis virus (TGEV), which belongs to the coronaviruses (CoVs), causes diarrhea and high mortality rates in piglets, resulting in severe economic losses in the pork industry worldwide. In this study, we used Lactobacillus plantarum (L. plantarum) to anchor the expression of TGEV antigen (S) to dendritic cells (DCs) via dendritic cell-targeting peptides (DCpep). The results show that S antigen could be detected on the surface of L. plantarum by different detection methods. Furthermore, flow cytometry and ELISA techniques were used to measure the cellular, mucosal, and humoral immune responses of the different orally gavaged mouse groups. The obtained results demonstrated the significant effect of the constructed L. plantarum expressing S-DCpep fusion proteins in inducing high expression levels of B7 molecules on DCs, as well as high levels of IgG, secretory IgA, and IFN-γ and IL-4 cytokines compared with the other groups. Accordingly, surface expression of DC-targeted antigens successfully induced cellular, mucosal, and humoral immunity in mice and could be used as a vaccine.

Immune responses induced by recombinant Lactobacillus plantarum expressing the spike protein derived from transmissible gastroenteritis virus in piglets

Transmissible gastroenteritis coronavirus (TGEV) is one of the most severe threats to the swine industry. In this study, we constructed a suite of recombinant Lactobacillus plantarum with surface displaying the spike (S) protein coming from TGEV and fused with DC cells targeting peptides (DCpep) to develop an effective, safe, and convenient vaccine against transmissible gastroenteritis. Our research results found that the recombinant Lactobacillus plantarum (NC8-pSIP409-pgsA-S-DCpep) group expressing S fused with DCpep could not only significantly increase the percentages of MHC-II⁺CD80⁺ B cells and CD3⁺CD4⁺ T cells but also the number of IgA⁺ B cells and CD3⁺CD4⁺ T cells of ileum lamina propria, which elevated the specific secretory immunoglobulin A (SIgA) titers in feces and IgG titers in serum. Taken together, these results suggest that NC8-pSIP409-pgsA-S-DCpep expressing the S of TGEV fused with DCpep could effectively induce immune responses and provide a feasible original strategy and approach for the design of TGEV vaccines.

Commentary on "A novel treatment strategy for newly diagnosed high-grade T1 bladder cancer: Gemcitabine and cisplatin adjuvant chemotherapy-A single-institution experience."

BACKGROUND

Management of high-grade T1 (formerly T1G3) bladder cancer continues to be controversial. Should patients with T1G3 bladder cancer have an immediate radical cystectomy or should they receive intravesical bacillus Calmette-Guérin preserving bladder? Gemcitabine and cisplatin (GC) adjuvant chemotherapy may help to strike a balance between intravesical and early cystectomy. For purposes of this study, we continue to refer high-grade T1 lesion as "T1G3."

OBJECTIVE

To evaluate the characteristics and the long-term outcome of GC adjuvant chemotherapy in T1G3 bladder cancer after transurethral resection of bladder tumor (TURBT).

MATERIALS AND METHODS

We, retrospectively, reviewed 48 patients who were newly diagnosed with T1G3 bladder cancer between January 2009 and December 2012. A total of 48 patients received 4 cycles of GC adjuvant chemotherapy after TURBT. One month after 4 cycles of GC adjuvant chemotherapy, response was evaluated by re-TURBT. Median follow-up was 59.5 (range: 18-70) months, all patients have been observed for more than 3 years. Salvage cystectomy was recommended for patients with persistent disease and for tumor progression after initial complete response.

RESULT

Complete response was achieved in 44 (91.7%) patients. Of complete responders, 5 patients experienced recurrence and 5 patients showed progression. The progression rate and disease-specific survival rate were 10.4% and 91.7% at 3 years, respectively. More than 80% of survivors preserved their bladder. Kaplan-Meier curves showed that concomitant carcinoma in situ (CIS) was the only factor that had an influence on progression-free survival (P = 0.022) and disease-specific survival (P = 0.017). Concomitant CIS was the prognostic factor for progression rate and disease-specific survival rate at 3 years (P = 0.008 and P = 0.035).

CONCLUSION

GC adjuvant chemotherapy is a safe conservative treatment for T1G3 bladder cancer, but effective is really a phase II study. Patients with T1G3 bladder cancer with concomitant CIS should be treated more aggressively because of the high risk of progression.

Comparative genome analysis of Bacillus velezensis reveals a potential for degrading lignocellulosic biomass

Genomes of 24 sequenced Bacillus velezensis strains were characterized to identity shared and unique genes of lignocellulolytic enzymes and predict potential to degrade lignocellulose. All 24 strains had genes that encoded lignocellulolytic enzymes, with potential to degrade cellulose and hemicelluloses. Several lignocellulosic genes related to cellulose degradation were universally present, including one GH5 (endo-1,4-β-glucanase), one GH30 (glucan endo-1,6-β-glucosidase), two GH4 (6-phospho-β-glucosidase, 6-phospho-α-glucosidase), one GH1 (6-phospho-β-galactosidase), one GH16 (β-glucanase) and three GH32 (two sucrose-6-phosphate hydrolase and levanase). However, in the absence of gene(s) for cellobiohydrolase, it was predicted that none of the 24 strains would be able to directly hydrolyse cellulose. Regarding genes for hemicellulose degradation, four GH43 (1,4-β-xylosidase; except strain 9912D), one GH11 (endo-1,4-β-xylanase), three GH43 (two arabinan endo-1,5-α-L-arabinosidase and one arabinoxylan arabinofuranohydrolase), two GH51 (α-N-arabinofuranosidase), one GH30 (glucuronoxylanase), one GH26 (β-mannosidase) and one GH53 (arabinogalactan endo-1,4-β-galactosidase) were present. In addition, two PL1 (pectate lyase) and one PL9 (pectate lyase) with potential for pectin degradation were conserved among all 24 strains. In addition, all 24 Bacillus velezensis had limited representation of the auxiliary activities super-family, consistent with a limited ability to degrade lignin. Therefore, it was predicted that for these bacteria to degrade lignin, pretreatment of lignocellulosic substrates may be required. Finally, based on in silico studies, we inferred that Bacillus velezensis strains may degrade a range of polysaccharides in lignocellulosic biomasses.

Lactobacillus plantarum displaying conserved M2e and HA2 fusion antigens induces protection against influenza virus challenge

Avian influenza virus (AIV) can infect poultry, mammals, and other hosts and causes enormous economic losses to the global poultry industry. In this study, to develop a novel and potent oral vaccine based on Lactobacillus plantarum (L. plantarum) for controlling the spread of AIV in the poultry industry, we constructed a recombinant L. plantarum strain displaying the 3M2e-HA2 protein of the influenza virus and determined the effect of N/pgsA'-3M2e-HA2 against AIV in chicks. We first confirmed that the 3M2e-HA2 fusion protein was expressed on the surface of L. plantarum via flow cytometry and immunofluorescence experiments. Our experimental results demonstrated that chicks immunized with N/pgsA'-3M2e-HA2 could induce specific humoral, mucosal, and T cell-mediated immune responses, eliciting the host body to protect itself against AIV. Additionally, compared to oral administration, the intranasal immunization of chicks with N/pgsA'-3M2e-HA2 provided a stronger immune response, resulting in a potent protective effect that hindered the loss of body weight, decreasing pulmonary virus titers and reducing lung and throat pathological damages. Thus, our results indicate that our novel approach is an effective method of vaccine design to promote mucosal immunity.

Complete genome sequence of Bacillus velezensis 157 isolated from Eucommia ulmoides with pathogenic bacteria inhibiting and lignocellulolytic enzymes production by SSF

Bacillus velezensis 157 was isolated from the bark of Eucommia ulmoides, and exhibited antagonistic activity against a broad spectrum of pathogenic bacteria and fungi. Moreover, B. velezensis 157 also showed various lignocellulolytic activities including cellulase, xylanase, α-amylase, and pectinase, which had the ability of using the agro-industrial waste (soybean meal, wheat bran, sugarcane bagasse, wheat straw, rice husk, maize flour and maize straw) under solid-state fermentation and obtained several industrially valuable enzymes. Soybean meal appeared to be the most efficient substrate for the single fermentation of B. velezensis 157. Highest yield of pectinase (19.15 ± 2.66 U g-1), cellulase (46.69 ± 1.19 U g-1) and amylase (2097.18 ± 15.28 U g-1) was achieved on untreated soybean meal. Highest yield of xylanase (22.35 ± 2.24 U g-1) was obtained on untreated wheat bran. Here, we report the complete genome sequence of the B. velezensis 157, composed of a circular 4,013,317 bp chromosome with 3789 coding genes and a G + C content of 46.41%, one circular 8439 bp plasmid and a G + C content of 40.32%. The genome contained a total of 8 candidate gene clusters (bacillaene, difficidin, macrolactin, butirosin, bacillibactin, bacilysin, fengycin and surfactin), and dedicates over 15.8% of the whole genome to synthesize secondary metabolite biosynthesis. In addition, the genes encoding enzymes involved in degradation of cellulose, xylan, lignin, starch, mannan, galactoside and arabinan were found in the B. velezensis 157 genome. Thus, the study of B. velezensis 157 broadened that B. velezensis can not only be used as biocontrol agents, but also has potentially a wide range of applications in lignocellulosic biomass conversion.

Immunogenicity of recombinant Lactobacillus plantarum NC8 expressing goose parvovirus VP2 gene in BALB/c mice

Goose parvovirus (GPV) continues to be a threat to goose farms and has significant economic effects on the production of geese. Current commercially available vaccines only rarely prevent GPV infection. In our study, Lactobacillus (L.) plantarum NC8 was selected as a vector to express the VP2 gene of GPV, and recombinant L. plantarum pSIP409-VP2/NC8 was successfully constructed. The molecular weight of the expressed recombinant protein was approximately 70 kDa. Mice were immunized with a 2 × 10⁹ colony-forming unit/200 µL dose of the recombinant L. plantarum strain, and the ratios and numbers of CD11c⁺, CD3⁺CD4⁺, CD3⁺CD8⁺, and interferon gamma- and tumor necrosis factor alpha-expressing spleen lymphocytes in the pSIP409-VP2/NC8 group were higher than those in the control groups. In addition, we assessed the capacity of L. plantarum SIP409-VP2/NC8 to induce secretory IgA production. We conclude that administered pSIP409-VP2/NC8 leads to relatively extensive cellular responses. This study provides information on GPV infection and offers a clear framework of options available for GPV control strategies.

Construction and immunogenicity analysis of Lactobacillus plantarum expressing a porcine epidemic diarrhea virus S gene fused to a DC-targeting peptide

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The S protein of PDEV was displayed on the surface of a recombinant Lactobacillus plantarum NC8 strain.

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NC8-pSIP409-pgsA'-S-DCpep promoted DC activation in the LP.

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IgG and sIgA were significant increased in mice orally administered with the NC8-pSIP409-pgsA'-S-DCpep.

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The expression of specificity cytokines IFN-γ, IL-4 and IL-17A of MLNs was enhanced in mouse treated with the NC8-pSIP409-pgsA'-S-DCpep.

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NC8-pSIP409-pgsA'-S-DCpep might mediate B cell response in mouse.

Porcine epidemic diarrhea virus (PEDV) is one of the most important causative pathogens of swine diarrhea, which is widely prevalent throughout the world and is responsible for significant economic losses in the commercial pig industry, both domestic and abroad. The spike (S) protein in the PEDV capsid structure can carry the major B lymphocyte epitope, which induces production of neutralizing antibodies and provides immunoprotective effects. Moreover, the conserved region encoded by the S gene can be considered a target for establishing a new diagnostic method and is a new candidate for vaccine design. In this study, use of anchorin pgsA' allowed the fusion protein of S-DCpep to express on the surface of recombinant Lactobacillus plantarum (NC8-pSIP409-pgsA'-S-DCpep) NC8 strain. Mice were immunized by lavage administration of the recombinant NC8-pSIP409-pgsA'-S-DCpep, which was observed to induce DC activation and high production of sIgA and IgG antibodies in experimental animals, while also eliciting production of significantly more IgA⁺B220⁺ B cells. More importantly, secretion of cytokines IFN-γ, IL-4 and IL-17 in mice that were vaccinated with NC8-pSIP409-pgsA'-S-DCpep was remarkably increased. The results of our study suggest that NC8-pSIP409-pgsA'-S-DCpep potently triggers cellular and humoral immune responses. The obtained experimental results can provide a theoretical basis that lays the foundation for production of a novel oral vaccine against PED.

Expression and purification of swine RAG2 in E. coli for production of porcine RAG2 polyclonal antibodies

Recombination activating gene 2 (RAG2) is necessary for immature B cell differentiation. Antibodies to human and rabbit RAG2 are currently commercially available, but antibodies to swine RAG remain unavailable to date. In this study, the swine RAG2 genes sequence was synthesized and then cloned into a pET-28a vector. The recombinant fusion protein was successfully expressed in E. coli, purified through nickel column chromatography, and further digested with Tobacco Etch Virus protease. The cleaved protein was purified by molecular-exclusion chromatography and named pRAG2. We used pRAG2 to immunize rabbits, collected the serum and purified rabbit anti-pRAG2 polyclonal antibodies. The rabbit anti-pRAG2 polyclonal antibodies were tested via immunofluorescence on eukaryotic cells overexpressing pRAG2 and also able to recognize pig natural RAG2 and human RAG2 protein in western blotting. These results indicated that the prepared rabbit anti-pRAG2 polyclonal antibodies may serve as a tool to detect immature B cell differentiation of swine.