Production, Passaging Stability, and Histological Analysis of Madin-Darby Canine Kidney Cells Cultured in a Low-Serum Medium.

Madin-Darby canine kidney (MDCK) cells are commonly used to produce cell-based influenza vaccines. However, the role of the low-serum medium on the proliferation of MDCK cells and the propagation of the influenza virus has not been well studied. In the present study, we used 5 of 15 culture methods with different concentrations of a mixed medium and neonatal bovine serum (NBS) to determine the best culture medium. We found that a VP:M199 ratio of 1:2 (3% NBS) was suitable for culturing MDCK cells. Furthermore, the stable growth of MDCK cells and the production of the influenza virus were evaluated over long-term passaging. We found no significant difference in terms of cell growth and virus production between high and low passages of MDCK cells under low-serum culture conditions, regardless of influenza virus infection. Lastly, we performed a comparison of the transcriptomics and proteomics of MDCK cells cultured in VP:M199 = 1:2 (3% NBS) with those cultured in VP:M199 = 1:2 (5% NBS) before and after influenza virus infection. The transcriptome analysis showed that differentially expressed genes were predominantly enriched in the metabolic pathway and MAPK signaling pathway, indicating an activated state. This suggests that decreasing the concentration of serum in the medium from 5% to 3% may increase the metabolic activity of cells. Proteomics analysis showed that only a small number of differentially expressed proteins could not be enriched for analysis, indicating minimal difference in the protein levels of MDCK cells when the serum concentration in the medium was decreased from 5% to 3%. Altogether, our findings suggest that the screening and application of a low-serum medium provide a background for the development and optimization of cell-based influenza vaccines.

Exploratory research of intelligent gecko-inspired robot based on integrated design and experiment.

A quadruped robot with intelligent properties is developed using a bionics approach to explore the potential value of gecko-like machinery. The robot structure incorporates mechanical links, steering engines, and wheel groups, which can expand the movement function of its leg joint. A pneumatic control circuit that can generate negative pressure is built by a vacuum pump, electromagnetic valve, sucker, hose, and others, to enable mobile climbing and adsorption of the gecko-inspired robot. By integrating gait planning, program compilation, Arduino board development, theoretical calculation, and digital modeling, the robot incorporates several practical functions such as "adsorption climbing, ultrasonic obstacle avoidance, remote control, Bluetooth communication, WiFi wireless image transmission, and multi-terrain maneuvering," which give a basis to realize the multi-dimensional integrated design of "machine, electricity, gas and intelligence" of biomimetic gecko. The experimental prototype of the gecko-inspired robot is designed and manufactured with 3D printing, combined with virtual prototype development, mechanism trajectory verification, finite element analysis, and CFD hydrodynamic simulation. Test results indicate that the biomimetic body has ideal characteristics of intelligent control and maneuvering response in the natural environment, which specifically manifested as that the robot can carry out stable adsorption and climb on the vertical wall, respond quickly to avoid obstacles intelligently, and detect and monitor the external environment in real-time with the help of a mobile phone control terminal. This work is promising for solving high-risk social production and engineering operation challenges.

Chitosan-derived N-doped carbon supported Cu/Fe co-doped MoS2 nanoparticles as peroxymonosulfate activator for efficient dyes degradation.

Peroxymonosulfate (PMS), which is dominated by free radical (SO4•-) pathway, has a good removal effect on organic pollutants in complex water matrices. In this article, a new catalyst (CFM@NC) was synthesized by hydrothermal carbonization method with chitosan (CS) as N and C precursors, and used to activate PMS to degrade dye wastewater. CFM@NC/PMS system can degrade 50 mg·L-1 rhodamine B by 99.59 % within 30 min, and the degradation rate remains as high as 97.32 % after 5 cycles. It has good complex background matrices, acid-base anti-interference ability (pH 2.6-10.1), universality and reusability. It can degrade methyl orange and methylene blue by >98 % within 30 min. The high efficiency of the composite is due to the fact that CS-modified MoS2 as a carrier exposes a large number of active sites, which not only disperses CuFe2O4 nanoparticles and improves the stability of the catalyst, but also provides abundant electron rich groups, which promotes the activation of PMS and the production of reactive oxygen species (ROS). PMS is effectively activated by catalytic sites (Cu+/Cu2+, Fe2+/Fe3+, Mo4+/Mo6+, pyridine N, pyrrole N, edge sulfur and hydroxyl group) to produce a large number of radicals to attack RhB molecules, causing chromophore cleavage, ring opening, and mineralization. Among them, free radical SO4•- is the main ROS for RhB degradation. This work is expected to provide a new idea for the design and synthesis of environmentally friendly and efficient heterogeneous catalysts.

Cooperative amplification of Prussian blue as a signal indicator and functionalized metal-organic framework-based electrochemical biosensor for an ultrasensitive HE4 assay.

Human epididymis protein 4 (HE4), a diagnostic biomarker of ovarian cancer, is crucial for monitoring the early stage of the disease. Hence, it is highly important to develop simple, inexpensive, and user-friendly biosensors for sensitive and quantitative HE4 assays. Herein, a new sandwich-type electrochemical immunosensor based on Prussian blue (PB) as a signal indicator and functionalized metal-organic framework nanocompositesas efficient signal amplifiers was fabricated for quantitative analysis of HE4. In principle, ketjen black (KB) and AuNPs modified on TiMOF (TiMOF-KB@AuNPs) could accelerate electron transfer on the electrode surface and act as a matrix for the immobilization of antibodies via cross-linking to improve the determination sensitivity. The PB that covalently binds to labeled antibodies endows the biosensors with intense electrochemical signals. Furthermore, the concentration of HE4 could be indirectly detected by monitoring the electroactivity of PB. Benefiting from the high signal amplification ability of the PB and MOF nanocomposites, this strategy displayed a wide linear range (0.1-80 ng mL-1) and a lower detection limit (0.02 ng mL-1). Hence, this study demonstrated great promise for application in clinical ovarian cancer diagnosis and treatment, and provided a new platform for detecting other cancer biomarkers.

Preparation of Ti/SnO2-Sb2O4-La Electrode with TiO2 Nanotubes Intermediate Layer and the Electrochemical Oxidation Performance of Rhodamine B.

A La-doped Ti/SnO2-Sb2O4 electrode with TiO2-NTs intermediate layer (Ti/TiO2-NTs/SnO2-Sb2O4-La) was created via the electrodeposition technique. The physicochemical and electrochemical properties of the electrode were analyzed through FESEM, XRD, XPS, CV, and LSV electrochemical tests. The results showed that TiO2-NTs were tightly packed on the surface of Ti substrate, thus improving the binding force of the SnO2-Sb2O4-La coating, offering greater specific surface area, more active spots, higher current response, and longer lifespan for the degradation of rhodamine B. The lifespan of the Ti/TiO2-NTs/SnO2-Sb2O4-La electrode reached 200 min (1000 mA cm-2, 1 M H2SO4), while the actual service life was up to 3699 h. Under the conditions of initial pH 3.0, Na2SO4 concentration of 0.1 M, current density of 30 mA cm-2, and initial rhodamine B concentration of 20 mg L-1, the color and TOC removal rate of rhodamine B reached 100% and 86.13% within 15 and 30 min, respectively. Rhodamine B was decomposed into acids, esters, and other molecular compounds under the action of •OH and SO4•- free radicals and electrocatalysis, and finally completely mineralized into CO2 and H2O. It is anticipated that this work will yield a novel research concept for producing DSA electrodes with superior catalytic efficacy and elevated stability.

Chitosan derived N-doped carbon anchored Co3O4-doped MoS2 nanosheets as an efficient peroxymonosulfate activator for degradation of dyes.

Peroxymonosulfate (PMS), which is dominated by non-free radical pathway, has a good removal effect on organic pollutants in complex water matrices. In this article, a biodegradable cobalt-based catalyst (Co3O4/MoS2@NCS) was synthesized by a simple hydrothermal method with chitosan (CS) as nitrogen­carbon precursor and doped with Cobaltic­cobaltous oxide (Co3O4) and Molybdenum disulfide (MoS2), and was used to activate PMS to degrade dye wastewater. Electrochemical tests showed that Co3O4/MoS2@NCS exhibited higher current density and cycling area than MoS2@NCS and MoS2. In the Co3O4/MoS2@NCS/PMS system, the degradation rate of 30 mg·L-1 rhodamine B (RhB) reached 97.75 % within 5 min, and kept as high as 94.34 % after 5 cycles. Its rate constant was 1.91 and 8.37 times that of MoS2@NCS/PMS and MoS2/PMS, respectively. It had good complex background matrices and acid-base anti-interference ability, and had good universality and reusability. The degradation rate of methyl orange (MO) and methylene blue (MB) were more than 91 % within 5 min at pH 4.8. The experimental results demonstrated that MoS2-modified CS as a carrier exposed a large number of active sites, which not only dispersed Co3O4 nanoparticles and improved the stability of the catalyst, but also provided abundant electron rich groups, and promoted the activation of PMS and the production of reactive oxygen species (ROS). PMS was effectively activated by catalytic sites (Co3+/Co2+, Mo4+/Mo5+/Mo6+, CO, pyridine N, pyrrole N, hydroxyl group and unsaturated sulfur), producing a large number of radicals that attack RhB molecules, causing chromophore cleavage, ring opening, and mineralization. Among them, non-free radical 1O2 was the main ROS for RhB degradation. This work is expected to provide a new idea for the design and synthesis of environmentally friendly and efficient MoS2-modified cobalt-based catalysts.

Preparation of La-doped Ti/SnO2-Sb2O4 anode and its electrochemical oxidation performance of rhodamine B.

In this paper, La-doped Ti/SnO2-Sb2O4 electrode was prepared by electrodeposition and used for electrochemical degradation of rhodamine B. The optimum preparation conditions of the electrode were optimized as deposition time of 15 min and calcination at 500 ℃ for 2 h. The water treatment conditions were selected as initial pH 3.0, electrolyte Na2SO4 concentration 0.1 M, current density 30 mA cm-2, and initial rhodamine B concentration 20 mg L-1; the color and TOC removal of RhB reached 99.78% and 82.41% within 30 min. The FESEM, XRD, XPS, CV, LSV, and EIS characterization studies demonstrated that Ti/SnO2-Sb2O4-1%La electrode had a dense structure and the highest oxygen evolution potential (2.14 V) and lowest charge transfer resistance (0.198 Ω cm-2), indicating that doped La has lower energy consumption. Moreover, La doping can expand the specific surface area, active site, performance of pollutant degradation, and service life of the electrode. Especially, the service life of Ti/SnO2-Sb2O4-1%La is increased by three times, and the maximum life span reaches 90 min (1000 mA cm-2, 1 M H2SO4). Free radical quenching experiments show that ·OH plays a major role in the degradation of RhB. The Ti/SnO2-Sb2O4-1%La electrode prepared in this paper and its results will provide data support and reference for the design of efficient electrocatalytic electrode.

Enhanced Downstream Processing for a Cell-Based Avian Influenza (H5N1) Vaccine.

H5N1 highly pathogenic avian influenza virus (HPAIV) infections pose a significant threat to human health, with a mortality rate of around 50%. Limited global approval of H5N1 HPAIV vaccines, excluding China, prompted the need to address safety concerns related to MDCK cell tumorigenicity. Our objective was to improve vaccine safety by minimizing residual DNA and host cell protein (HCP). We developed a downstream processing method for the cell-based H5N1 HPAIV vaccine, employing CaptoTM Core 700, a multimodal resin, for polishing. Hydrophobic-interaction chromatography (HIC) with polypropylene glycol as a functional group facilitated the reversible binding of virus particles for capture. Following the two-step chromatographic process, virus recovery reached 68.16%. Additionally, HCP and DNA levels were reduced to 2112.60 ng/mL and 6.4 ng/mL, respectively. Western blot, high-performance liquid chromatography (HPLC), and transmission electron microscopy (TEM) confirmed the presence of the required antigen with a spherical shape and appropriate particle size. Overall, our presented two-step downstream process demonstrates potential as an efficient and cost-effective platform technology for cell-based influenza (H5N1 HPAIV) vaccines.

Immunosuppressants exert antiviral effects against influenza A(H1N1)pdm09 virus via inhibition of nucleic acid synthesis, mRNA splicing, and protein stability.

Influenza A virus (IAV) poses a threat to patients receiving immunosuppressive medications since they are more susceptible to infection with severe symptoms, and even death. Understanding the direct effects of immunosuppressants on IAV infection is critical for optimizing immunosuppression in these patients who are infected or at risk of influenza virus infection. We profiled the effects of 10 immunosuppressants, explored the antiviral mechanisms of immunosuppressants, and demonstrated the combined effects of immunosuppressants with the antiviral drug oseltamivir in IAV-infected cell models. We found that mycophenolic acid (MPA) strongly inhibits viral RNA replication via depleting cellular guanosine pool. Treatment with 6-Thioguanine (6-TG) promoted viral protein degradation through a proteasomal pathway. Filgotinib blocked mRNA splicing of matrix protein 2, resulting in decreased viral particle assembly. Furthermore, combined treatment with immunosuppressants and oseltamivir inhibits IAV viral particle production in an additive or synergic manner. Our results suggest that MPA, 6-TG, and filgotinib could be the preferential choices for patients who must take immunosuppressants but are at risk of influenza virus infection.

Polymer-Entangled Spontaneous Pseudo-Planar Heterojunction for Constructing Efficient Flexible Organic Solar Cells.

Flexible organic solar cells (FOSCs) have attracted considerable attention from researchers as promising portable power sources for wearable electronic devices. However, insufficient power conversion efficiency (PCE), intrinsic stretchability, and mechanical stability of FOSCs remain severe obstacles to their application. Herein, an entangled strategy is proposed for the synergistic optimization of PCE and mechanical properties of FOSCs through green sequential printing combined with polymer-induced spontaneous gradient heterojunction phase separation morphology. Impressively, the toughened-pseudo-planar heterojunction (Toughened-PPHJ) film exhibits excellent tensile properties with a crack onset strain (COS) of 11.0%, twice that of the reference bulk heterojunction (BHJ) film (5.5%), which is among the highest values reported for the state-of-the-art polymer/small molecule-based systems. Finite element simulation of stress distribution during film bending confirms that Toughened-PPHJ film can release residual stress well. Therefore, this optimal device shows a high PCE (18.16%) with enhanced (short-circuit current density) JSC and suppressed energy loss, which is a significant improvement over the conventional BHJ device (16.99%). Finally, the 1 cm2 flexible Toughened-PPHJ device retains more than 92% of its initial PCE (13.3%) after 1000 bending cycles. This work provides a feasible guiding idea for future flexible portable power supplies.

Human monoclonal antibody F61 nasal spray effectively protected high-risk populations from SARS-CoV-2 variants during the COVID-19 pandemic from late 2022 to early 2023 in China.

Following the national dynamic zero-COVID strategy adjustment, the utilization of broad-spectrum nasal neutralizing antibodies may offer an alternative approach to controlling the outbreak of Omicron variants between late 2022 and early 2023 in China. This study involved an investigator-initiated trial (IIT) to assess the pharmacokinetic, safety and efficacy of the F61 nasal spray. A total of 2,008 participants were randomly assigned to receive F61 nasal spray (24 mg/0.8 mL/dose) or normal saline (0.8 mL/dose) and 1336 completed the follow-up in the IIT. Minimal absorption of F61 antibody into the bloodstream was detected in individuals receiving F61 nasal spray for seven consecutive days. No treatment-emergent adverse reactions of grade 3 severity or higher were reported. In the one-dose cohort, the 7-day cumulative SARS-CoV-2 infection rate was 79.0% in the F61 group and 82.6% in the placebo group, whereas, in the multiple-dose (once daily for 7 consecutive days) cohort, the rates were 6.55% in the F61 group and 23.83% in the placebo group. The laboratory-confirmed efficacy of F61 was 3.78% (-3.74%-10.75%) in the one-dose cohort and 72.19% (57.33%-81.87%) in the multiple-dose cohort. In the real-world study, 60,225 volunteers in four different regions were administered the F61 nasal spray based on the subject's wishes, over 90% efficacy rate was observed against different Omicron variants. The F61 nasal spray, with its favourable safety profile, could be a promising prophylactic monoclonal antibody against SARS-CoV-2 VOCs.

Achieving Desired Pseudo-Planar Heterojunction Organic Solar Cells via Binary-Dilution Strategy.

The sequential deposition process has demonstrated the great possibility to achieve a photolayer architecture with an ideal gradient phase separation morphology, which has a vital influence on the physical processes that determine the performance of organic solar cells (OSCs). However, the controllable preparation of pseudo-planar heterojunction (P-PHJ) with gradient distribution has not been effectively elucidated. Herein, a binary-dilution strategy is proposed, the PM6 solution with micro acceptor BO-4Cl and the L8-BO solution with micro donor PM6 respectively, to form P-PHJ film. This architecture exists good donor (D) and acceptor (A) vertical gradient distribution and larger D/A interpenetrating regions, which promotes exciton generation and dissociation, shortens charge transport distance and optimizes carrier dynamics. Moreover, the dilution of PM6 by BO-4Cl promotes the regulation of active layer aggregation size and phase purity, thus alleviating energy disorder and voltage loss. As a result, the P-PHJ device exhibits an outstanding power conversion efficiency of 19.32% with an excellent short-circuit current density of 26.92 mA cm-2 , much higher than planar binary heterojunction (17.67%) and ternary bulk heterojunction (18.49%) devices. This research proves a simple but effective method to provide an avenue for constructing desirable active layer morphology and high-performance OSCs.

TRAF3 deficiency in MDCK cells improved sensitivity to the influenza A virus.

Tumor necrosis factor receptor-associated factor 3 (TRAF3), an adaptor protein, has significant and varying effects on immunity depending on cell types. The role of TRAF3 in Madin-Darby Canine Kidney Epithelial (MDCK) cell resistance to influenza A virus (IVA) remains elusive. In the present study, CRISPR-Cas9 gene editing technology was used to construct the TRAF3 knockout MDCK cells (MDCK-TRAF3-/-). Hemagglutination assay, plaque assay, transcriptome, and quantitative real-time PCR were performed after IVA infection. The results showed that after IVA infection, HA titers and virus titers were promoted, interferon I-related pathways were significantly blocked, and transcription of several antiviral-related genes was significantly decreased in MDCK-TRAF3-/- cells. Thus, our study suggests that TRAF3 gene knockout reduced MDCK cell's resistance to IVA, thereby resulting in a promising way for IVA isolation and vaccine manufacturing.

Metabolomics profiling reveals differences in proliferation between tumorigenic and non-tumorigenic Madin-Darby canine kidney (MDCK) cells.

Background: Madin-Darby canine kidney (MDCK) cells are a cellular matrix in the production of influenza vaccines. The proliferation rate of MDCK cells is one of the critical factors that determine the vaccine production cycle. It is yet to be determined if there is a correlation between cell proliferation and alterations in metabolic levels. This study aimed to explore the metabolic differences between MDCK cells with varying proliferative capabilities through the use of both untargeted and targeted metabolomics. Methods: To investigate the metabolic discrepancies between adherent cell groups (MDCK-M60 and MDCK-CL23) and suspension cell groups (MDCK-XF04 and MDCK-XF06), untargeted and targeted metabolomics were used. Utilizing RT-qPCR analysis, the mRNA expressions of key metabolites enzymes were identified. Results: An untargeted metabolomics study demonstrated the presence of 81 metabolites between MDCK-M60 and MDCK-CL23 cells, which were mainly affected by six pathways. An analysis of MDCK-XF04 and MDCK-XF06 cells revealed a total of 113 potential metabolites, the majority of which were impacted by ten pathways. Targeted metabolomics revealed a decrease in the levels of choline, tryptophan, and tyrosine in MDCK-CL23 cells, which was in accordance with the results of untargeted metabolomics. Additionally, MDCK-XF06 cells experienced a decrease in 5'-methylthioadenosine and tryptophan, while S-adenosylhomocysteine, kynurenine, 11Z-eicosenoic acid, 3-phosphoglycerate, glucose 6-phosphate, and phosphoenolpyruvic acid concentrations were increased. The mRNA levels of MAT1A, MAT2B, IDO1, and IDO2 in the two cell groups were all increased, suggesting that S-adenosylmethionine and tryptophan may have a significant role in cell metabolism. Conclusions: This research examines the effect of metabolite fluctuations on cell proliferation, thus offering a potential way to improve the rate of MDCK cell growth.

CDC20 is a potential target gene to inhibit the tumorigenesis of MDCK cells.

MDCK is currently the main cell line used for influenza vaccine production in culture. Previous studies have reported that MDCK cells possess tumorigenic ability in nude mice. Although complete cell lysis can be ensured during vaccine production, host cell DNA released after cell lysis may still pose a risk for tumorigenesis. Greater caution is needed in the production of human vaccines; therefore, the use of gene editing to establish cells incapable of forming tumors may significantly improve the safety of influenza vaccines. Knowledge regarding the genes and molecular mechanisms that affect the tumorigenic ability of MDCK cells is crucial; however, our understanding remains superficial. Through monoclonal cell screening, we previously obtained a cell line, CL23, that possesses significantly reduced cell proliferation, migration, and invasion abilities, and tumor-bearing experiments in nude mice showed the absence of tumorigenic cells. With a view to exploring tumorigenesis-related genes in MDCK cells, DIA proteomics was used to compare the differences in protein expression between wild-type (M60) and non-tumorigenic (CL23) cells. Differentially expressed proteins were verified at the mRNA level by RT-qPCR, and a number of genes involved in cell tumorigenesis were preliminarily screened. Immunoblotting further confirmed that related protein expression was significantly reduced in non-tumorigenic cells. Inhibition of CDC20 expression by RNAi significantly reduced the proliferation and migration of MDCK cells and increased the proliferation of the influenza virus; therefore, CDC20 was preliminarily determined to be an effective target gene for the inhibition of cell tumorigenicity. These results contribute to a more comprehensive understanding of the mechanism underlying cell tumorigenesis and provide a basis for the establishment of target gene screening in genetically engineered non-tumorigenic MDCK cell lines.

Development of MDCK-based quadrivalent split seasonal influenza virus vaccine with high safety and immunoprotection: A preclinical study.

Vaccination remains the best prevention strategy against influenza. The MDCK-based influenza vaccine prompted the development of innovative cell culture manufacturing processes. In the present study, we report the effects of multiple administrations of a candidate, seasonal, MDCK-based, quadrivalent split influenza virus vaccine MDCK-QIV in Sprague-Dawley (SD) rats. Moreover, the effects of the vaccine were evaluated in terms of fertility and early embryonic development, embryo-fetal development, and perinatal toxicity in the SD rats and immunogenicity in Wistar rats and BALB/c mice. Regarding the safety profile, MDCK-QIV demonstrated tolerance in local stimulation with repeated dose administration and presented no significant effect on the development, growth, behavior, fertility, and reproductive performance of the adult male rats, maternal rats, and their offspring. MDCK-QIV elicited strong hemagglutination inhibition neutralizing antibody response and protection against the influenza virus in the mouse model. Thus, data supported that MDCK-QIV could be further evaluated in human clinical trial, which is currently underway.

Safety and immunogenicity of rabies vaccine (PVRV-WIBP) in healthy Chinese aged 10-50 years old: Randomized, blinded, parallel controlled phase III clinical study.

This phase III clinical trial aimed to assess the safety and demonstrate the immunogenicity of a candidate freeze-dried purified Vero cell-based rabies vaccine (PVRV-WIBP) developed for human use. A cohort of 40 participants in stage 1 and 1956 subjects in stage 2 with an age range of 10-50 years were recruited for the phase III clinical trial. For safety analysis in stage 1, 20 participants received either 4-dose or 5-dose regimen of PVRV-WIBP. In stage 2, 1956 subjects were randomly divided into the 5-dose PVRV-WIBP, 5-dose PVRV-LNCD, and 4-dose PVRV-WIBP groups. The serum neutralizing antibody titer against rabies was determined on day 7 or 14 and day 35 or 42. Adverse reactions were recorded for more than 6 months. Most adverse reactions, which were mild and moderate in severity, occurred and resolved within 1 week after each injection in the PVRV-WIBP (4 and 5 doses) and PVRV-LNCD (5 doses) groups. All three groups achieved complete seroconversion 14 days after the initial dose and 14 days after completing the full vaccination schedule, the susceptible subjects in the PVRV-WIBP group (4-dose or 5-dose regimen) displayed higher neutralizing antibody titers against the rabies virus compared to those in the PVRV-LNCD group (5-dose regimen). PVRV-WIBP induced non-inferior immune responses versus PVRV-LNCD as assessed by seroconversion rate. PVRV-WIBP was well tolerated and non-inferior to PVRV-LNCD in healthy individuals aged 10-50 years. The results indicated that PVRV-WIBP (both 4- and 5-dose schedules) could be an alternative to rabies post-exposure prophylaxis.

Liposome and QS-21 Combined Adjuvant Induces theHumoral and Cellular Responses of Acellular Pertussis Vaccine in a Mice Model.

The resurgence of pertussis in vaccinated communities may be related to the reduced long-term immunity induced by acellular pertussis vaccines. Therefore, developing improved pertussis vaccine candidates that could induce strong Th1 or Th17 cellular immunity is an urgent need. The use of new adjuvants may well meet this requirement. In this research, we developed a novel adjuvant candidate by combining liposome and QS-21 adjuvant. Adjuvant activity, protective efficacy, the level of neutralizing antibody against PT, and the resident memory T (TRM) cells in lung tissue after vaccination were studied. We then performed B. pertussis respiratory challenge in mice after they received vaccination with traditional aluminum hydroxide and the novel adjuvant combination. Results showed that the liposome + QS-21 adjuvant group had a rapid antibody and higher antibody (PT, FHA, Fim) level, induced anti-PT neutralizing antibody and recruited more IL-17A-secreting CD4+ TRM cells along with IL-17A-secreting CD8+ TRM cells in mice, which provided robust protection against B. pertussis infection. These results provide a key basis for liposome + QS-21 adjuvant as a promising adjuvant candidate for developing an acellular pertussis vaccine that elicits protective immunity against pertussis.

Suspended cell lines for inactivated virus vaccine production.

INTRODUCTION: Inactivated virus vaccines are the most widely used tool to prevent disease. To meet vaccine production demands, increasing attention has been placed on identifying methods to improve vaccine production efficiency. The use of suspended cells can greatly increase vaccine production. Suspension acclimation is a traditional method to convert adherent cells to suspension strains. Furthermore, as genetic engineering technology has developed, increasing attention has focused on the development of suspension cell lines using targeted genetic engineering techniques. AREAS COVERED: This review systematically summarizes and analyzes the development and research progress of various inactivated viral vaccine production suspension cell lines and provides protocols and candidate target genes for the engineered establishment of additional suspension cell lines for vaccine production. EXPERT OPINION: The use of suspended cells can significantly improve the production efficiency of inactivated virus vaccines and other biological products. Presently, cell suspension culture is the key component to improve many vaccine production processes.

TGM2 inhibits the proliferation, migration and tumorigenesis of MDCK cells.

Madin-Darby canine kidney (MDCK) cells are one of the main cell lines used for influenza vaccine production due to their high virus yield and low mutation resistance. Due to their high tumorigenicity, the safety of vaccines produced from these cells is controversial. TGM2 is a multifunctional protein that plays an important role in the adhesion and migration of cells and is associated with tumor formation. We found that the expression level of TGM2 was significantly up-regulated in low tumorigenic MDCK cells. We first analyzed TGM2-overexpressed and knockout MDCK cells in vitro. Scratch-wound assay and Transwell chamber experiments showed that TGM2 overexpression significantly inhibited the migration and invasion of MDCK cells and significantly reduced their proliferation. TGM2 knockout significantly enhanced cell migration, invasion, and proliferation. The tumorigenesis results in nude mice were consistent with those in vitro. TGM2 knockout significantly enhanced the tumorigenesis rate of MDCK cells in nude mice. We also investigated the effects of TGM2 gene expression on the replication of the H1N1 influenza A virus in MDCK cells. The results showed that TGM2 induced the negative regulation of H1N1 replication. These findings contribute to a comprehensive understanding of the tumor regulation mechanism and biological functions of TGM2.