Microneedle Patch for Transdermal Sequential Delivery of KGF-2 and aFGF to Enhance Burn Wound Therapy.

Severe burn wounds usually destroy key cells' functions of the skin resulting in delayed re-epithelization and wound regeneration. Promoting key cells' activities is crucial for burn wound repair. It is well known that keratinocyte growth factor-2 (KGF-2) participates in the proliferation and morphogenesis of epithelial cells while acidic fibroblast growth factor (aFGF) is a key mediator for fibroblast and endothelial cell growth and differentiation. However, thick eschar and the harsh environment of a burn wound often decrease the delivery efficiency of fibroblast growth factor (FGF) to the wound site. Therefore, herein a novel microneedle patch for sequential transdermal delivery of KGF-2 and aFGF is fabricated to enhance burn wound therapy. aFGF is first loaded in the nanoparticle (NPaFGF) and then encapsulated NPaFGF with KGF-2 in the microneedle patch (KGF-2/NPaFGF@MN). The result shows that KGF-2/NPaFGF@MN can successfully get across the eschar and sequentially release KGF-2 and aFGF. Additional data demonstrated that KGF-2/NPaFGF@MN achieved a quicker wound closure rate with reduced necrotic tissues, faster re-epithelialization, enhanced collagen deposition, and increased neo-vascularization. Further evidence suggests that improved wound healing is regulated by significantly elevated expressions of hypoxia-inducible factor-1 alpha (HIF-1ɑ) and heat shock protein 90 (Hsp90) in burn wounds. All these data proved that KGF-2/NPaFGF@MN is an effective treatment for wound healing of burns.

Exercise preference in stroke survivors: a concept analysis.

Background: Exercise preference in stroke survivors is related to their adherence to long-term rehabilitation regimen and functional recovery. Although explored recently, the term exercise preference still lacks a clear definition. Objective: The aim of this study is to conceptualize exercise preference in stroke survivors. Methods: The Walker and Avant method was applied as a framework for the conceptual analysis of exercise preference. Data from 34 publications were collected using seven databases (PubMed, Web of Science, Embase, CINAHL, CNKI, Wanfang Data, and CBM) and applied in the analysis. The search period was from the inception of the database to April 30, 2023. Results: Exercise preference in stroke survivors was defined according to four attributes: priority of choice, behavioral tendency, affective priming, and patience in adherence. The common antecedents of the concept of exercise preference in stroke survivors were classified into patient-related, therapy-related, and environmental-related categories and the consequences were classified into three categories: patient-related, rehabilitation provider-related, and rehabilitation service system-related. Conclusion: Exercise preference in stroke survivors refers to the patient's choice, tendency, affective response, and attitude toward engagement in the recommended rehabilitation regimen. It is beneficial for understanding the essential attributes of exercise preference in stroke survivors by clarifying the concept. In addition, it will facilitate the development of instruments for assessing exercise preference in stroke survivors and the construction of theory-based intervention programs that can improve adherence to exercise rehabilitation.

Drug cross-linking electrospun fiber for effective infected wound healing.

The management of infected wounds is still an intractable challenge in clinic. Development of antibacterial wound dressing is of great practical significance for wound management. Herein, a natural-derived antibacterial drug, tannic acid (TA), was incorporated into the electrospun polyvinyl alcohol (PVA) fiber (TA/PVA fiber, 952 ± 40 nm in diameter). TA worked as a cross-linker via hydrogen bonding with PVA to improve the physicochemical properties of the fiber and to reach a sustained drug release (88% release of drug at 48 h). Improved mechanical property (0.8-1.2 MPa) and computational simulation validated the formation of the hydrogen bonds between TA and PVA. Moreover, the antibacterial and anti-inflammatory characteristics of TA laid the foundation for the application of TA/PVA fiber in repairing infected wounds. Meanwhile, in vitro studies proved the high hemocompatibility and cytocompatibility of TA/PVA fiber. Further in vivo animal investigation showed that the TA/PVA fiber promoted the repair of infected wound by inhibiting the bacterial growth, promoting granulation formation, and collagen matrix deposition, accelerating angiogenesis, and inducing M2 macrophage polarization within 14 days. All the data demonstrated that the TA cross-linked fiber would be a potent dressing for bacteria-infected wound healing.

Effects of nutritional interventions on the physical development of preschool children: a systematic review and meta-analysis.

Background: There is a significant correlation between diet and delayed growth and development in children. However, the evidence for the crucial role of dietary interventions in children's growth and development health remains inconclusive. This meta-analysis sought to comprehensively evaluate the effects of nutritional interventions on children's physical development. Methods: Articles published from January 2007 to December 2022 were retrieved from the PubMed, Embase, Cochrane Library, Wanfang, and China National Knowledge Infrastructure (CNKI) databases. Statistical analysis was conducted using Stata/SE 16.0 software, as well as Review Manager 5.4 software. Results: The meta-analysis included a total of 8 original studies. The total sample comprised 6,645 children aged <8 years. The results of meta-analysis were as follows: (I) there was no significant difference in the body mass index (BMI)-for-age z scores between the nutritional intervention group and the control group [mean difference (MD) =0.12, 95% confidence interval (CI): -0.07, 0.30]. Thus, the nutritional interventions did not significantly improve the BMI-for-age z scores; (II) when the nutritional intervention period was <6 months, there was no significant difference in the weight-for-height z scores between the nutritional intervention group and the control group (MD =0.47, 95% CI: -0.07, 1.00), but when the nutritional intervention period was ≥6 months, the nutritional interventions significantly improved the weight-for-height z scores (MD =0.36, 95% CI: 0.00, 0.72); (III) a nutritional intervention period ≥6 months cannot significantly improved children's height-for-age z scores; (4) When the nutritional intervention period was <6 months, there was no statistically significant difference in the weight-for-age z scores between the nutritional intervention group and the control group (MD =-0.20, 95% CI: -0.60, 0.20), but when the nutritional intervention period was ≥6 months, the nutritional interventions significantly increased children's weight-for-age (mean difference =2.23, 95% CI: 0.01, 4.44). Conclusions: Different nutritional interventions had a slight improvement effect on children's physical growth and development. However, the effect of the short-term nutritional interventions (<6 months) was not obvious. In clinical practice, it is recommended that nutritional intervention programs be formulated that can be implemented for longer periods. However, due to the limited literature included, further research is needed.

Analysis of Microbial Diversity and Metabolites in Sauerkraut Products with and without Microorganism Addition.

The microbial compositions and metabolites of fermented sauerkraut with and without the addition of microorganisms have been compared. The OTU clustering, nonvolatile compounds, volatile compounds and associations between bacterial taxa and metabolites were analyzed by 16S rRNA high-throughput sequencing technology, ultra performance liquid chromatography (UPLC), gas chromatography ion mobility mass spectrometry (GC-IMS) and the O2PLS model studies. The results showed that at the phylum level, the microbial species in the four sauerkraut types consisted mainly of the phyla Firmicutes and Proteobacteria, but different modes of microbial addition formed their own unique microbial communities. There were significant differences in the microbial communities among different northeast China sauerkraut samples, and different microbial communities exerted similar effects to inhibit Firmicutes production. At the genus level, sauerkraut without added microorganisms had the lowest microbial diversity. A total of 26 amino acids and 11 organic acids were identified and were more abundant in nonmicrobially fermented sauerkraut; 88 volatile organic compounds were identified in the 4 types of sauerkraut, with the microbially fermented sauerkraut being richer in alcohols, esters and acids. Different brands of sauerkraut contain their own unique flavor compounds. Cystine and tyrosine, ascorbic acid and acetic acid, and alcohols and esters are closely related to a wide range of microorganisms in sauerkraut. Elucidating the correlations among microbiota and metabolites will help guide future improvements in sauerkraut fermentation processes.

Effects of Yoga exercise on anxiety and fetus growth in pregnant women with small for gestational age fetus.

OBJECTIVE: To investigate the effect of yoga on anxiety and fetal weight of pregnant women carrying fetus small for gestational age (SGA). METHODS: In this retrospective analysis, a total of 186 pregnant women with SGA fetus in our hospital from January 2015 to December 2017 were enrolled in this study. Among them, 90 patients received routine check-up were included in the control group, and the other 96 patients who had professional yoga exercise were included in the observation group. The differences of anxiety scale scores and fetal weight between the two groups before and after intervention were compared. RESULTS: There was no significant difference in scores of anxiety scale (SAS) between the two groups before intervention. After intervention, the SAS score of pregnant women in intervention group was (46.48±3.79) was significantly lower than that in control group (60.13±4.25). There was also significant difference in fetal growth trajectory between the two groups, with a significant increase of 1021.36 g in the intervention group compared with 795.62 g in the control group (P<0.05). Furthermore, single regression analysis showed that average gestational weeks (r=0.064. P=0.011), yoga exercise (r=0.043, P<0.001), forceps use (r=0.338, P<0.001) and conversion to cesarean section (r=0.431, P<0.001) showed a significant correlation with anxiety and fetus growth in pregnant women carrying SGA fetus. Multiple regression analysis showed that yoga exercise (P<0.001) was selected as independent variables in the multiple regression model of anxiety and fetus growth in pregnant women with SGA fetus. CONCLUSION: Yoga can effectively reduce the anxiety of pregnant women with small gestational age fetus and good for the growth and development of the fetus.

Regulation of the sensitivity of hepatocarcinoma cells by ORMDL3, to sorafenib by autophagy.

Serum orosomucoid1-like protein 3 (ORMDL3) is a membrane protein in the endoplasmic reticulum, known to regulate many important signal transduction processes and autophagy regulation, but it is unclear whether it is involved in the intratumoral microenvironment and cancer drug resistance. Our present study found that silencing ORMDL3 increases the inhibitory effect of sorafenib on the viability and proliferation in HCC cells, and increases the sensitivity of HCC cells to sorafenib. In addition, silencing ORMDL3 can increase ROS levels by inhibiting autophagy, thereby increasing sorafenib-induced apoptosis of HCC cells. Further, our study also found that ORMDL3 silencing inhibits autophagy through the PERK-ATF4-Beclin1 pathway, thus affecting sorafenib sensitivity. The in vivo effects of sorafenib were tested by xenografting using nude mice. It showed that silencing ORMDL3 in HCC cells could increase the inhibitory effect of sorafenib on the growth of tumors. This is the first report to describe the relationships among ORMDL3, autophagy, and sorafenib resistance. This study provides available targets that might have a synergetic effect with sorafenib.

Serum Cystatin C as a predictor of acute kidney injury in neonates: a meta-analysis

Abstract Objective: The objective of this meta-analysis is to evaluate the diagnostic value of serum Cystatin C in acute kidney injury (AKI) in neonates Sources: PubMed, Embase, Cochrane Library, Web of Science, China National Knowledge Infrastructure (CNKI), and WanFang Database were searched to retrieve the literature related to the diagnostic value of Cystatin C for neonatal AKI from inception to May 10, 2021. Subsequently, the quality of included studies was determined using the QUADAS-2 tool. Stata 15.0 statistical software was used to calculate the combined sensitivity (SEN), specificity (SPE), positive likelihood ratio (PLR), negative likelihood ratio (NLR), and diagnostic odds ratio (DOR). Additionally, meta-regression analysis and subgroup analysis contributed to explore the sources of heterogeneity Summary of the findings: Twelve articles were included. The pooled sensitivity was 0.84 (95%CI: 0.74-0.91), the pooled specificity was 0.81 (95%CI: 0.75-0.86), the pooled PLR was 4.39 (95%CI: 3.23-5.97), the pooled NLR was 0.19 (95%CI: 0.11-0.34), and the DOR was 22.58 (95%CI: 10.44-48.83). The area under the receiver operating characteristic curve (AUC) was 0.88 (95%CI: 0.85-0.90). No significant publication bias was identified (p > 0.05).

Serum Cystatin C as a predictor of acute kidney injury in neonates: a meta-analysis.

OBJECTIVES: The objective of this meta-analysis is to evaluate the diagnostic value of serum Cystatin C in acute kidney injury (AKI) in neonates. SOURCES: PubMed, Embase, Cochrane Library, Web of Science, China National Knowledge Infrastructure (CNKI), and WanFang Database were searched to retrieve the literature related to the diagnostic value of Cystatin C for neonatal AKI from inception to May 10, 2021. Subsequently, the quality of included studies was determined using the QUADAS-2 tool. Stata 15.0 statistical software was used to calculate the combined sensitivity (SEN), specificity (SPE), positive likelihood ratio (PLR), negative likelihood ratio (NLR), and diagnostic odds ratio (DOR). Additionally, meta-regression analysis and subgroup analysis contributed to explore the sources of heterogeneity. SUMMARY OF THE FINDINGS: Twelve articles were included. The pooled sensitivity was 0.84 (95%CI: 0.74-0.91), the pooled specificity was 0.81 (95%CI: 0.75-0.86), the pooled PLR was 4.39 (95%CI: 3.23-5.97), the pooled NLR was 0.19 (95%CI: 0.11-0.34), and the DOR was 22.58 (95%CI: 10.44-48.83). The area under the receiver operating characteristic curve (AUC) was 0.88 (95%CI: 0.85-0.90). No significant publication bias was identified (p > 0.05). CONCLUSIONS: Serum Cystatin C has a good performance in predicting neonatal AKI; therefore, it can be used as a candidate biomarker after the optimal level is determined by large prospective studies.

Detection of the microbial diversity and flavour components of northeastern Chinese soybean paste during storage.

A combination of 16S rDNA and GC-IMS was used to study the changes in the composition of microorganisms and volatile organic compounds (VOCs) during the storage of northeastern Chinese soybean paste. Firmicutes and Actinobacteriota dominated the microbial communities of the soybean paste at the phylum level, bacterial profiles of different samples were different at genus level. Fifty-one VOCs were identified from soybean paste, most of which existed in the early storage stage. Most esters and alcohols decreased with the extension of the storage time, while acids and pyrazines accumulated in the later period of storage. Esters, alcohols, acids and aldehyde compounds are the key substances in the volatile components of soybean paste, which give the soybean paste the sour, sweet, rose, mushroom and smoky flavor characteristics. The biomarker Bacillus-velezensis in soybean paste is directly related to ester features; Kroppenstedtia, Sporolactobacillus-nakayamae, and Corynebacterium-stationis are positively associated with the biosynthesis of aldehydes.

Association between the use of antibiotics during pregnancy and obesity in 5-year-old children.

BACKGROUND: Obesity is an epidemic that must arouse our attention. The purpose of this research is to investigate the relationship between antibiotic use during pregnancy and childhood obesity in 5-year-old Chinese children. METHODS: A total of 132 5-year-old children born in our hospital from January 2014 to January 2016 were included. The children's genders, nationalities, chronic diseases, and other factors were collected as adjusted covariates. We also collected the pre-pregnancy body mass indexes (BMIs) of pregnant women, diagnosis of diabetes mellitus or gestational diabetes mellitus (GDM), maternal smoking, mode of delivery (cesarean section and vaginal delivery), and weight gain during pregnancy, which may affect childhood obesity. A linear mixed effect regression model was used to test the correlation between antibiotic use during pregnancy and the BMI of 5-year-old children, and a logistic mixed effect regression model was used to evaluate the correlation between antibiotic use during pregnancy and obesity outcome. RESULTS: When adjusted for the child's gender, birth weight, cesarean section, chronic diseases, maternal smoking during pregnancy, pre-pregnancy BMI, diagnosis of diabetes or GDM, mode of delivery (cesarean section and vaginal delivery), and weight gain during pregnancy (Model 3), antibiotic use during pregnancy was positively correlated with the BMI of 5-year-old children (ß=0.01, 95% CI: 0.01-0.03, P=0.04). Antibiotic use during pregnancy increased the risk of obesity by 4% in 5-year-old children (OR =1.04, 95% CI: 1.01-1.16, P=0.02). CONCLUSIONS: The use of antibiotics during pregnancy is positively correlated with the risk of obesity in 5-year-old children. KEYWORDS: Antibiotics; pregnancy; obesity; children.

Optimization of Early Mobilization Program for Patients With Acute Ischemic Stroke: An Orthogonal Design.

Background and purpose: Early mobilization is considered to have favorable outcomes for stroke patients, but there is currently a lack of specific data to guide this early mobilization, including the initiation time, intensity, frequency, and duration of each activity. Therefore, the optimal strategy for early mobilization is unclear. In this study, we investigated the best combination of different factors to achieve early mobilization, to develop the optimal program. Methods: We conducted an L9 (33) orthogonal experiment with a blinded follow-up assessment. Patients with ischemic stroke, admitted to a stroke unit within 24-72 h of its onset, were recruited. Eligible subjects were randomly assigned to one of nine different programs of early mobilization. The outcomes were assessed at baseline, discharge, and 1 and 3 months after discharge to observe the changes in various efficacy indicators and determine the main factors affecting outcome. Results: We analyzed 57 of 63 patients, after six were excluded for poor compliance, failure to cooperate with the study, or worsening of the disease. The initiation time, intensity, and frequency of mobilization were the main factors affecting outcome (all P < 0.05), and the duration of each activity was a secondary factor (P > 0.05). A comprehensive analysis of the various parameters showed that the optimal level of the early mobilization program was an initiation time: 24-48 h after stroke; intensity: bed and chair transfer, sitting out of bed, standing and walking or climbing stairs when mobility permitted; frequency: 2-3 times/day; duration of each mobilization: determined according to the actual situation of the patient. Conclusions: Early rehabilitation with high-intensity physical exercise at 24-48 h after the onset of stroke, 2-3 times/day, may benefit stroke patients. Applying the optimized program of early mobilization to stroke patients effectively alleviated their symptoms of neurological deficit, improved their capacity for self-care, restored their self-efficacy, improved their quality of life and social participation, and reduced post-stroke fatigue at 3 months.

Home-based nursing for improvement of quality of life and depression in patients with postpartum depression.

BACKGROUND: Postpartum depression is a common mental illness in puerpera, with an incidence of approximately 3.5%-33.0% abroad, and the incidence of postpartum depression in China is higher than the international level, reaching 10.0%-38.0%. Providing effective nursing care in clinical nursing activities is one of the key points of obstetrical care. However, little research has been designed to investigate the positive role of home-based nursing in the prevention of postpartum depression . AIM: To study the effect of home-based nursing for postpartum depression patients on their quality of life and depression. METHODS: The clinical data of 92 patients with postpartum depression treated at our hospital were retrospectively analyzed. The patients were grouped according to the nursing methods used; 40 patients receiving basic nursing were included in a basic nursing group, and 52 receiving home-based nursing were included in a home-based nursing group. Depression and anxiety were evaluated and compared between the two groups. The estradiol (E2), serotonin (5-hydroxytryptamine, 5-HT), and progesterone (PRGE) levels were measured. RESULTS: The SAS and SDS scores of the home-based nursing group were significantly lower than those of the basic nursing group (P < 0.05). The E2 and 5-HT levels of the home-based nursing group were significantly higher than those of the basic nursing group, but the PRGE level was significantly lower than that of the basic nursing group. The GQOLI-74 scores (material, social, somatic, and psychological) and nursing satisfaction were significantly higher in the home-based nursing group (P < 0.05). CONCLUSION: Postpartum depression through home-based nursing can effectively alleviate depression and improve the quality of life of patients, help modulate their serum E2, 5-HT, and PRGE levels, and improve their satisfaction with nursing care.

Detection of Mitochondrial Mutations Through Isothermal Nucleic Acid Amplification Coupled With Clustered Regularly Interspaced Short Palindromic Repeat-Associated Endonuclease Cas13a.

The clustered regularly interspaced short palindromic repeat (CRISPR)-associated endonuclease Cas13a can specifically bind and cleave RNA. After nucleic acid pre-amplification, bacterial Cas13a has been used to detect genetic mutations. In our study, using a transcription-mediated amplification together with Cas13a, we can isothermally amplify and detect mitochondrial point mutations under non-denaturing conditions from human genomic DNA. Unlike previous reports, we prepared CRISPR DNA with T7 promoter sequences and generated CRISPR RNA via transcription-mediated amplification instead of synthesizing and adding CRISPR RNA in a separate step. As a proof-of-concept, we showed that both m.1494C > T and m.1555A > G mutations were detected within 90 min. In addition, we explored various designs of CRISPR DNA to improve assay specificity, including the location and number of nucleotide mismatches, length of protospacer sequence, and different buffering conditions. We also confirmed the possibility of a "one-step single-tube" reaction for mutation detection. This assay can robustly distinguish circular DNA templates that differ by a single nucleotide. It has the potential to be adapted for automated applications, such as the screening of mitochondrial diseases.

[Expression profiles of PI3K, NF-κB, and STAT1 in peripheral blood mononuclear cells in children with bronchial asthma].

OBJECTIVE: To study the expression profiles of PI3K, NF-κB, and STAT1 in peripheral blood mononuclear cells (PBMCs) in children with bronchial asthma, as well as their roles in the pathogenesis of asthma. METHODS: Thirty children with acute exacerbation of bronchial asthma were enrolled as the asthma group, and 20 healthy children were enrolled as the control group. RT-PCR and Western blot were used to measure the mRNA and protein expression levels of PI3K, NF-κB, and STAT1 in PBMCs. A spirometer was used to compare the pulmonary function between the two groups. The correlations between the mRNA expression of PI3K, NF-κB, and STAT1 and pulmonary function in children with bronchial asthma were analyzed. RESULTS: The asthma group had significantly higher mRNA and protein expression levels of PI3K, NF-κB, and STAT1 than the control group (P<0.05). Compared with the control group, the asthma group showed significant reductions in pulmonary function indices such as FEV1%, FEV1/FVC, and PEF% (P<0.05). In children with bronchial asthma, the mRNA expression levels of PI3K, NF-κB, and STAT1 were negatively correlated with FEV1%, FEV1/FVC, and PEF% (P<0.05). CONCLUSIONS: The expression levels of PI3K, NF-κB, and STAT1 increase in children with asthma, and are negatively correlated with pulmonary function indices, suggesting that PI3K, NF-κB and STAT1 are involved in the development and progression of bronchial asthma in children.

The heptide repeat 2 and upstream region of TGEV induces potent cross-neutralizing antibodies against group I coronaviruses.

The coronavirus heptide repeat (HR) region in the spike protein induces neutralizing antibodies that block the postfusion core formation and inhibit virus entry into target cells. The HR2 regions for coronaviruses of the same serogroup share high homology. We found that polyclonal antibodies derived from transmissible gastroenteritis coronavirus HR2 and upstream region were cross-reactive with the S proteins of the same serogroup in western blotting. The polyclonal antibodies also potently cross-neutralized viruses from the same serogroup. This study provides new insight for designing vaccine and therapeutic reagents against coronavirus infections.

Characterization of the antiviral activity for influenza viruses M1 zinc finger peptides.

We sought to investigate the cellular uptake and antiviral activity for the M1 zinc finger peptides derived from influenza A and influenza B viruses in vitro. No cellular uptake was detected by fluorescent microscopy for the synthetic zinc finger peptides. When flanked to a cell permeable peptide Tp10, the zinc finger recombinant proteins were efficiently internalized by MDCK cells. However, no antiviral activity was detected against homologous or heterologous virus infections for the synthetic peptides or the Tp10-flanked recombinant proteins, regardless treated with or without Zn(2+). Nevertheless, MDCK cell constitutively expressing the M1 zinc finger peptides in cell nuclei potently inhibited replication of homologous, but not heterologous influenza viruses. Adenoviral vector delivered M1 zinc finger peptides also exhibited potent antiviral activity against homologous viruses challenge. Transduction at 100 PFU dose of recombinant adenovirus efficiently protected 99% of the cells from 100 TCID(50) of different virus infections for both peptides. These results brought new insight to the antiviral researches against influenza virus infections.

Nsp1 proteins of group I and SARS coronaviruses share structural and functional similarities.

The nsp1 protein of the highly pathogenic SARS coronavirus suppresses host protein synthesis, including genes involved in the innate immune system. A bioinformatic analysis revealed that the nsp1 proteins of group I and SARS coronaviruses have similar structures. Nsp1 proteins of group I coronaviruses interacted with host ribosomal 40S subunit and did not inhibit IRF-3 activation. However, synthesis of host immune and non-immune proteins was inhibited by nsp1 proteins at both transcriptional and translational levels, similar to SARS coronavirus nsp1. These results indicate that different coronaviruses might employ the same nsp1 mechanism to antagonize host innate immunity and cell proliferation. However, nsp1 may not be the key determinant of viral pathogenicity, or the factor used by the SARS coronavirus to evade host innate immunity.

Monoclonal antibody, but not synthetic peptide, targeting the ectodomain of influenza B virus M2 proton channel has antiviral activity.

The proton channels of influenza A virus (A/M2) and influenza B virus (BM2) are essential for viral replication. Previously we have shown that monoclonal antibodies targeting the ectodomain of the A/M2 proton channel have antiviral activity in vitro. In this study, we generated both monoclonal antibody and phage displayed peptide against the eight amino acids comprising the ectodomain of the BM2 proton channel and investigated their antiviral activities in vitro. A cytopathic assay showed that the monoclonal antibody potently protected MDCK cells from homologous, but not heterologous, virus infections. A plaque forming assay showed that viral replication was not completely neutralized, but greatly inhibited, by the monoclonal antibody. In contrast, no antiviral activity was observed for the synthetic native or engineered peptides. These results indicate that antibody targeting the M2 proton channel is a promising therapeutic candidate for treating influenza virus infections, and that antibody structure is important for antiviral activity.

Monoclonal antibody recognizing SLLTEVET epitope of M2 protein potently inhibited the replication of influenza A viruses in MDCK cells.

The ectodomain of influenza A virus M2 protein (M2e) is composed of 24 amino acids and induces antibodies with inhibitory effect against a broad spectrum of influenza A subtypes in vitro and in vivo. Although relatively conserved, 21 M2e variants emerged in recent influenza A strains, most of the mutations appeared in the middle part of M2e domain. In this study, we characterized the in vitro inhibition efficacy of a monoclonal antibody (mAb) M2e8-7 recognizing the N terminus highly conserved epitope SLLTEVET (aa 2-9) which is common for both M1 and M2 proteins. Peptide binding assay showed that mAb M2e8-7 reacted strongly with M2e and 19 M2e variant peptides. The mAb M2e8-7 potently inhibited the replication of influenza A virus H1 and H3 subtypes in MDCK cells. Two important amino acids in M2e epitope, Threonine at position five and the Glutamic acid at position six, were identified to lead antibody-escaping variants. These results brought new insight in developing vaccine and therapeutic agents against influenza A virus infections.