BACKGROUND: Severe acute pancreatitis (SAP) is associated with tremendous systemic inflammation, T-helper 17 (Th17) cells, and regulatory T (Treg) cells play an essential role in the inflammatory responses. Meanwhile, soluble fibrinogen-like protein 2 (Sfgl2) is a critical immunosuppressive effector cytokine of Treg cells and modulates immune responses. However, the impact of SAP induction on Sfgl2 expression and the role of Sfgl2 in immunomodulation under SAP conditions are largely unknown. METHODS: A taurocholate-induced mouse SAP model was established. The ratios of CD4+CD25+Foxp3+ Treg cells or CD4+IL-17+ Th17 cells in blood and pancreatic tissues as well as surface expression of CD80, CD86, and major histocompatibility complex class II (MHC-II) were determined by flow cytometry. Gene mRNA expression was determined by qPCR. Serum amylase and soluble factors were quantitated by commercial kits. Bone marrow-derived dendritic cells (DCs) were generated, and NF-κB/p65 translocation was measured by immunofluorescence staining. RESULTS: SAP induction in mice decreased the Th17/Treg ratio in the pancreatic tissue and increased the Th17/Treg ratio in the peripheral blood. In addition, SAP was associated with a reduced level of Sfgl2 in the pancreatic tissue and blood: higher levels of serum IL-17, IL-2, IFN-α, and TNF-α, and lower levels of serum IL-4 and IL-10. Furthermore, the SAP-induced reduction in Sfgl2 expression was accompanied by dysregulated maturation of bone marrow-derived DCs. CONCLUSIONS: SAP causes reduced Sfgl2 expression and Th17/Treg imbalance, thus providing critical insights for the development of Sfgl2- and Th17/Treg balance-targeted immunotherapies for patients with SAP.
Objective: To analyze the potential factors influencing the diagnostic capability of endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) and provide medication treatment recommendations for patients with pancreatic solid mass lesions. Methods: A retrospective analysis was conducted on clinical data of 92 patients with pancreatic solid mass lesions who underwent EUS-FNA examination after detection by imaging studies. The diagnostic effectiveness of EUS-FNA was evaluated based on cytological or histological examination results. Logistic regression analysis was subsequently performed to analyze the potential factors influencing the diagnostic capability of EUS-FNA in patients with pancreatic solid mass lesions. Results: EUS-FNA was successfully performed in all 92 patients, with a puncture success rate of 100.00%. Only one patient experienced transient hyperamylasemia, which resolved with conservative treatment. No other serious complications were observed. Among the 92 patients, 70 patients obtained a definite diagnosis after EUS-FNA (Group A), while 22 patients did not achieve a definite diagnosis (Group B) after the procedure. Univariate analysis showed that lesion size, dilation of the pancreatic duct or bile duct, negative pressure, and suction method were significantly different between Group A and Group B (P < .05). Multivariate logistic regression analysis revealed that lesion size, dilation of the pancreatic duct or bile duct, negative pressure, and suction method were potential factors influencing the diagnostic ability of EUS-FNA in patients with solid pancreatic lesions (P < .05). Conclusion: EUS-FNA has a high diagnostic value in the evaluation of solid pancreatic lesions. Lesion size, dilation of the pancreatic duct or bile duct, negative pressure, and suction method are potential factors influencing the diagnostic ability of EUS-FNA in patients with solid pancreatic lesions. In terms of medical treatment, specific treatment methods and drug choices should be based on a comprehensive evaluation of the nature of the patient's lesions and the severity of the condition.
BACKGROUND: Prone positioning (PP) has been proven to be a beneficial approach in enhancing survival outcomes for patients with severe acute respiratory distress syndrome (ARDS) who need venovenous extracorporeal membrane oxygenation (V-V ECMO) support. The study utilized bedside lung ultrasound (LUS) to evaluate changes in lung aeration caused by PP in ARDS patients receiving V-V ECMO. METHODS: This retrospective single-center study involved adult ARDS patients requiring V-V ECMO. The assessment of LUS involved examining specific dorsal lung regions, encompassing 16 areas, during three pre-defined time points: baseline (10 minutes prior), three-hour PP positioning, and 10-minute post-supine repositioning, all within the initial three days. Based on the oxygenation response to PP, patients were categorized into responder and non-responder groups. The primary outcome was LUS score changes during the initial three-day period. Secondary outcomes examined the impact of PP on the partial pressure of oxygen (PaO2)/fraction of inspired oxygen (FiO2) (P/F) ratio, V-V ECMO weaning success, length of ICU stay, and hospital survival. RESULTS: Among the enrolled patients (27 in total), 16 were responders and 11 were non-responders. In the responder group, the global LUS score underwent a significant reduction from 26.38 ± 4.965 at baseline to 20.75 ± 3.337 (p < 0.001) after the first PP session, which further decreased to 15.94 ± 2.816 (p< 0.001) after three days. However, no significant differences were observed among PP non-responders. The oxygenation reaction yielded comparable results. There was a significant correlation between the duration of daily PP and the reduction in global LUS score among PP responders (r = -0.855, p < 0.001). In cases where the global LUS score decreased by > 7.5 after three days of PP, the area under the receiver operating characteristic curve (AUROC) for predicting ECMO weaning success was 0.815, while it was 0.761 for predicting hospital survival. CONCLUSION: LUS has the potential to predict the response to PP and evaluate the prognosis of ARDS patients with V-V ECMO, although more studies are demanded in the future.
Human cytomegalovirus (HCMV) is a leading infectious cause of birth defects and the most common opportunistic infection that causes life-threatening diseases post-transplantation; however, an effective vaccine remains elusive. V160 is a live-attenuated replication defective HCMV vaccine that showed a 42.4% efficacy against primary HCMV infection among seronegative women in a phase 2b clinical trial. Here, we integrated the multicolor flow cytometry, longitudinal T cell receptor (TCR) sequencing, and single-cell RNA/TCR sequencing approaches to characterize the magnitude, phenotype, and functional quality of human T cell responses to V160. We demonstrated that V160 de novo induces IE-1 and pp65 specific durable polyfunctional effector CD8 T cells that are comparable to those induced by natural HCMV infection. We identified a variety of V160-responsive T cell clones which exhibit distinctive "transient" and "durable" expansion kinetics, and revealed a transcriptional signature that marks durable CD8 T cells post-vaccination. Our study enhances the understanding of human T-cell immune responses to V160 vaccination.
INTRODUCTION: Esophageal tuberculosis (ET) is a rare form of infectious esophagitis. Here, we present a case of primary ET in an immunocompetent patient with dysphagia. CASE PRESENTATION: Esophagogastroduodenoscopy (EGD) revealed a submucosal tumor (SMT)-like lesion in the distal esophagus. Subsequent endoscopic ultrasonography (EUS) showed ulceration, esophageal wall discontinuities, thickening, and hypoechoic masses. Histopathological analysis confirmed a tuberculoid granuloma within the lesion. Imaging studies ruled out pulmonary tuberculosis and lymph node involvement. The patient received six months of antituberculosis treatment, resulting in significant improvement on follow-up EGD. DISCUSSION: ET is often misdiagnosed due to its rarity and nonspecific symptoms. In this case, the clinical presentation of dysphagia, combined with the characteristic findings on EGD and EUS, led to the diagnosis of primary esophageal tuberculosis. CONCLUSION: Prompt consideration of ET in dysphagia patients with SMT-like lesions and timely initiation of appropriate antituberculosis treatment can improve clinical outcomes and help avoid unnecessary surgeries.
The immune checkpoint leukocyte immunoglobulin-like receptor B4 (LILRB4) is found specifically on the cell surface of acute monocytic leukemia (monocytic AML), an aggressive and common subtype of AML. We have developed a humanized monoclonal IgG1 LILRB4-blocking antibody (h128-3), which improved immune regulation but reduced cell surface expression of LILRB4 in monocytic AML models by 40-60%. Interestingly, most of this effect was neutralized by mutation of the Fc region of the antibody (h128-3/N297A), which prevents interaction with Fc gamma receptors (FcγRs). This suggested that there is FcγR-dependent antigenic modulation underlying h128-3's effects, a mechanism known to alter the function of antibodies targeting B-cell malignancies. We disrupted the Fc-FcγR interaction pharmacologically and with stable CRISPR-Cas9-mediated genetic knockout of FcγRs in monocytic AML cell lines to investigate the role of FcγR-dependent antigenic modulation in the regulation of LILRB4 by h128-3. When FcγRI is inhibited or removed from the surface of monocytic AML cells, h128-3 cannot optimally perform its blocking function, resulting in activation of the LILRB4 inhibitory receptor and leading to a 15-25% decrease in T-cell-mediated cytotoxicity in vitro. In the absence of FcγRI, scaffolding by FcγRIIa allows h128-3 to maintain LILRB4-blocking function. Here we define a FcγR-dependent antigenic modulation mechanism underlying the function of an immunoreceptor blocking antibody for the first time in myeloid malignancy. This research will facilitate the development of safe, precision-targeted antibody therapeutics in myeloid malignancies with greater potency and efficacy.
Streptococcus pneumoniae is an opportunistic pathogen that causes substantial illness and death among children worldwide. The genetic backgrounds of pneumococci that cause infection versus asymptomatic carriage vary substantially. To determine the evolutionary mechanisms of opportunistic pathogenicity, we conducted a genomic surveillance study in China. We collected 783 S. pneumoniae isolates from infected and asymptomatic children. By using a 2-stage genomewide association study process, we compared genomic differences between infection and carriage isolates to address genomic variation associated with pathogenicity. We identified 8 consensus k-mers associated with adherence, antimicrobial resistance, and immune modulation, which were unevenly distributed in the infection isolates. Classification accuracy of the best k-mer predictor for S. pneumoniae infection was good, giving a simple target for predicting pathogenic isolates. Our findings suggest that S. pneumoniae pathogenicity is complex and multifactorial, and we provide genetic evidence for precise targeted interventions.
Biological Evolution , Streptococcus pneumoniae , Child , Humans , Streptococcus pneumoniae/genetics , China/epidemiology , Genome-Wide Association Study , Genetic Variation
OBJECTIVES: To explore the molecular characteristics of Staphylococcus aureus (S. aureus) in children, and to compare the molecular characteristics of different types of strains (infection and colonization strains) so as to reveal pathogenic molecular markers of S. aureus. METHODS: A cross-sectional study design was used to conduct nasopharyngeal swab sampling from healthy children in the community and clinical samples from infected children in the hospital. Whole genome sequencing was used to detect antibiotic resistance genes and virulence genes. A random forest method to used to screen pathogenic markers. RESULTS: A total of 512 S. aureus strains were detected, including 272 infection strains and 240 colonization strains. For virulence genes, the carrying rates of enterotoxin genes (seb and sep), extracellular enzyme coding genes (splA, splB, splE and edinC), leukocytotoxin genes (lukD, lukE, lukF-PV and lukS-PV) and epidermal exfoliating genes (eta and etb) in infection strains were higher than those in colonization strains. But the carrying rates of enterotoxin genes (sec, sec3, seg, seh, sei, sel, sem, sen, seo and seu) were lower in infection strains than in colonization strains (P<0.05). For antibiotic resistance genes, the carrying rates of lnuA, lnuG, aadD, tetK and dfrG were significantly higher in infection strains than in colonization strains (P<0.05). The accuracy of cross-validation of the random forest model for screening pathogenic markers of S. aureus before and after screening was 69% and 68%, respectively, and the area under the curve was 0.75 and 0.70, respectively. The random forest model finally screened out 16 pathogenic markers (sem, etb, splE, sep, ser, mecA, lnuA, sea, blaZ, cat(pC233), blaTEm-1A, aph(3')-III, ermB, ermA, ant(9)-Ia and ant(6)-Ia). The top five variables in the variable importance ranking were sem (OR=0.40), etb (OR=3.95), splE (OR=1.68), sep (OR=3.97), and ser (OR=1.68). CONCLUSIONS: The random forest model can screen out pathogenic markers of S. aureus and exhibits a superior predictive performance, providing genetic evidence for tracing highly pathogenic S. aureus and conducting precise targeted interventions.
Staphylococcal Infections , Staphylococcus aureus , Child , Humans , Staphylococcus aureus/genetics , Cross-Sectional Studies , Enterotoxins/genetics , Whole Genome Sequencing
OBJECTIVES: To investigate the potential relationship between age and Streptococcus pneumoniae vaccination coverage in kindergarten children, and to provide a basis for guiding vaccination and developing new protein vaccines. METHODS: The stratified cluster random sampling method was used to select 1 830 healthy children from six kindergartens in Shunde District, Foshan City, China, and nasopharyngeal swabs were collected for the isolation and identification of Streptococcus pneumoniae. The logistic regression model based on restricted cubic spline was used to analyze the dose-response relationship between age and Streptococcus pneumoniae vaccination coverage. RESULTS: The rate of nasal Streptococcus pneumoniae carriage was 22.46% (411/1 830) among the kindergarten children, with the predominant serotypes of 6B, 19F, 15A, 23A, 34, and 23F. The coverage rates of 10-valent pneumococcal conjugate vaccine (PCV10) and 13-valent pneumococcal conjugate vaccine (PCV13) were 53.0% and 57.9%, respectively, and there was a significant non-linear dose-response relationship between age and the coverage rates of PCV10 and PCV13 (P<0.05), with a higher coverage rate of PCV10 (88.0%) and PCV13 (91.1%) in the children aged 2 years. There was a significant non-linear dose-response relationship between age and the coverage rates of pilus islet 1 (PI-1) and pilus islet 2 (PI-2) (P<0.05), with a lower vaccination coverage rate for PI-1 (37.7%) and PI-2 (16.1%). The coverage rates of PI-1 (13.0%-58.5%) and PI-2 (6.0%-29.4%) were lower in all age groups. The virulence genes lytA (99.5%) and ply (99.0%) associated with candidate protein vaccines showed higher vaccination coverage rates. CONCLUSIONS: There is a significant non-linear dose-response relationship between the age of kindergarten children and the coverage rates of PCV10 and PCV13 serotypes, and kindergarten children aged 2 years have a relatively high coverage rate of PCV. The high prevalence of the virulence genes lytA and ply shows that they are expected to become candidate virulence factors for the development of a new generation of recombinant protein vaccines.
Pneumococcal Infections , Streptococcus pneumoniae , Humans , Child , Infant , Streptococcus pneumoniae/genetics , Pneumococcal Infections/prevention & control , Pneumococcal Infections/epidemiology , Vaccination Coverage , Pneumococcal Vaccines , Serogroup , Vaccination , Nasopharynx , Carrier State/epidemiology
NLRC4 gain-of-function variants are known to cause various autoinflammatory phenotypes, including familial cold autoinflammatory syndrome (FCAS4) and NLRC4 macrophage activation syndrome (NLRC4-MAS). However, to date, no study has linked NLRC4 gain-of-function variants to systemic lupus erythematosus (SLE). In this study, we identified a novel NLRC4 W655S variant in an SLE patient and her son, who had neonatal lupus complicated with macrophage activation syndrome. Our in vitro experiments demonstrated that the W655S NLRC4 increased ASC speck formation and mature IL-1ß secretion compared to the wild-type NLRC4. In addition, the patient had elevated levels of IL-1ß and IL-18 in both serum and PBMCs. RNA sequencing showed that NF-κB and interferon signaling pathways were significantly activated in the patient compared to healthy controls. Furthermore, gene set enrichment analysis revealed upregulation of NLRC4-related pathways in patient PBMCs. In conclusion, our study identified the NLRC4 W655S variant in a patient with SLE. This is the first report linking inflammasomopathy to monogenic SLE. Our findings suggest that inflammasome activation may be a critical driver in the pathogenicity of lupus, and autoinflammatory pathways may play important roles in the development of the disease.
Cryopyrin-Associated Periodic Syndromes , Inflammasomes , Lupus Erythematosus, Systemic , Macrophage Activation Syndrome , Female , Humans , Infant, Newborn , Calcium-Binding Proteins/genetics , CARD Signaling Adaptor Proteins/genetics , Gain of Function Mutation , Inflammasomes/genetics , Inflammasomes/metabolism , Lupus Erythematosus, Systemic/genetics , Lupus Erythematosus, Systemic/metabolism , Macrophage Activation Syndrome/genetics
Klebsiella aerogenes is a common infectious bacterium that poses a threat to human health. Nevertheless, there are limited data on the population structure, genetic diversity, and pathogenicity of K. aerogenes, especially among men who have sex with men (MSM). The present study aimed to clarify the sequence types (STs), clonal complexes (CCs), resistance genes, and virulence factors of popular strains. Multilocus sequence typing was used to describe the population structure of K. aerogenes. The Virulence Factor Database and Comprehensive Antibiotic Resistance Database were used to assess the virulence and resistance profiles. In this study, next-generation sequencing was performed on nasal swabs specimens collected in an HIV Voluntary Counseling Testing outpatient department in Guangzhou, China, from April to August 2019. The identification results showed that a total of 258 K. aerogenes isolates were collected from 911 participants. We found that the isolates were most resistant to furantoin (89.53%, 231/258) and ampicillin (89.15%, 230/258), followed by imipenem (24.81%, 64/258) and cefotaxime (18.22%, 47/258). The most common STs in carbapenem-resistant K. aerogenes were ST4, ST93, and ST14. The population has at least 14 CCs, including several novel ones identified in this study (CC11-CC16). The main mechanism of drug resistance genes was antibiotic efflux. Based on the presence of the iron carrier production genes irp and ybt, we identified two clusters according to virulence profiles. In cluster A, CC3 and CC4 carry the clb operator encoding the toxin. Increased monitoring is needed for the three main ST type strains carried by MSM. The main clone group CC4 has a large number of toxin genes, and it spreads among MSM. Caution is needed to prevent further spread of this clone group in this population. In sum, our results may provide a foundation for the development of new therapeutic and surveillance strategies for treating MSM.
Despite the widespread implementation of pneumococcal vaccines, hypervirulent Streptococcus pneumoniae serotype 19A is endemic worldwide. It is still unclear whether specific genetic elements contribute to complex pathogenicity of serotype 19A isolates. We performed a large-scale pan-genome-wide association study (pan-GWAS) of 1,292 serotype 19A isolates sampled from patients with invasive disease and asymptomatic carriers. To address the underlying disease-associated genotypes, a comprehensive analysis using three methods (Scoary, a linear mixed model, and random forest) was performed to compare disease and carriage isolates to identify genes consistently associated with disease phenotype. By using three pan-GWAS methods, we found consensus on statistically significant associations between genotypes and disease phenotypes (disease or carriage), with a subset of 30 consistently significant disease-associated genes. The results of functional annotation revealed that these disease-associated genes had diverse predicted functions, including those that participated in mobile genetic elements, antibiotic resistance, virulence, and cellular metabolism. Our findings suggest the multifactorial pathogenicity nature of this hypervirulent serotype and provide important evidence for the design of novel protein-based vaccines to prevent and control pneumococcal disease. IMPORTANCE It is important to understand the genetic and pathogenic characteristics of S. pneumoniae serotype 19A, which may provide important information for the prevention and treatment of pneumococcal disease. This global large-sample pan-GWAS study has identified a subset of 30 consistently significant disease-associated genes that are involved in mobile genetic elements, antibiotic resistance, virulence, and cellular metabolism. These findings suggest the multifactorial pathogenicity nature of hypervirulent S. pneumoniae serotype 19A isolates and provide implications for the design of novel protein-based vaccines.
Pneumococcal Infections , Streptococcus pneumoniae , Humans , Serogroup , Genome-Wide Association Study , Pneumococcal Vaccines/genetics , Serotyping
BACKGROUND: The association between vitamin C and the risk of developing non-alcoholic fatty liver disease remains controversial. The aim of the present study is to examine any correlation between serum vitamin C and the risk of non-alcoholic fatty liver disease. METHODS: Our study enrolled 3374 participants aged ≥ 20 years from the National Health and Nutritional Survey (2003-2006). Nonalcoholic fatty liver disease was defined as the US Fatty Liver Index ≥ 30 in the absence of other chronic liver disease. Multivariate logistic regression and the fitted smoothing curves were adopted for analyzing the correlation between serum vitamin C levels and the risk of developing non-alcoholic fatty liver disease. RESULTS: After adjusting for all the covariates, it was discovered that serum vitamin C was negatively correlated with the risk of nonalcoholic fatty liver disease (odds ratio: 0.664, 95% CI: 0.512-0.860, P = .002). Through smooth curve fitting, it was further noticed that the relationship between serum vitamin C and the risk of non-alcoholic fatty liver disease was non-linear. The inflection point was 0.92, and to its left, a negative correlation was seen between vitamin C and non-alcoholic fatty liver disease (odds ratio: 0.451, 95% CI: 0.288- 0.706, P = .001). To the right of the inflection point, however, the correlation between vitamin C and non-alcoholic fatty liver disease was not found to be significant. CONCLUSION: The correlation was non-linear between serum vitamin C levels and the risk of developing non-alcoholic fatty liver disease. Serum vitamin C was negatively correlated with the risk of non-alcoholic fatty liver disease when its level was less than 0.92 mg/dL.
Non-alcoholic Fatty Liver Disease , Humans , Cross-Sectional Studies , Vitamins , Ascorbic Acid , Logistic Models
Purpurogallin (PPG) has been demonstrated to exert an anti-inflammatory function in neurological diseases. This study aimed at investigating the role of PPG on microglial polarization post ischemic stroke as well as the underlying mechanism. Mouse hippocampal neurons HT-22 and microglial BV2 cells were treated by oxygen and glucose deprivation to simulate an in-vitro ischemia model. qRT-PCR and ELISA examined expression of cytokines in microglia. CCK8 and flow cytometry measured HT-22 cell viability and apoptosis, respectively. The levels of miR-124-3p and TRAF6/NF-κB were determined. A mouse cerebral ischemia model was set up using middle cerebral artery occlusion (MCAO) method. After being dealt with PPG, the neurological functions, brain edema, neuronal apoptosis, and microglia activation of the mice were evaluated. As suggested by the results, PPG transformed "M1" to "M2" polarization of BV2 cells, and abated HT-22 cell apoptosis. PPG enhanced the neurological functions, alleviated brain edema, and decreased neuroinflammatory responses, and neuronal apoptosis in the brain lesions of MCAO mice. Furthermore, PPG enhanced miR-124-3p and repressed the TRAF6/NF-κB pathway. miR-124-3p suppressed the TRAF6/NF-κB pathway by targeting TRAF6. Collectively, PPG alleviates ischemia-induced neuronal damage and microglial inflammation by modulating the miR-124-3p/TRAF6/NF-κB pathway.
Brain Edema , Brain Ischemia , MicroRNAs , Nervous System Diseases , Mice , Animals , NF-kappa B/metabolism , Microglia/metabolism , TNF Receptor-Associated Factor 6/metabolism , Signal Transduction/physiology , Brain Edema/metabolism , MicroRNAs/genetics , MicroRNAs/metabolism , Brain Ischemia/metabolism , Infarction, Middle Cerebral Artery/metabolism , Inflammation/metabolism , Nervous System Diseases/metabolism , Apoptosis
The application of single-cell RNA sequencing in COVID-19 research has greatly improved our understanding of COVID-19 pathogenesis and immunological characteristics. In this commentary, we discuss the current challenges, limitations, and perspectives in harnessing the power of single-cell RNA sequencing to accelerate both basic research and therapeutic development for COVID-19 and other emerging infectious diseases.
COVID-19 , Humans , Single-Cell Analysis , Single-Cell Gene Expression Analysis , Sequence Analysis, RNA
Purpose: Research has shown that prone positioning (PP) improves the survival of patients receiving venovenous extracorporeal membrane oxygenation (V-V ECMO) for acute respiratory distress syndrome (ARDS). However, the reported impact of PP duration on the outcome of V-V ECMO patients with ARDS varies across studies. Methods: A meta-analysis approach was used to identify studies that investigated the impact of PP duration on the outcome of ARDS patients who were treated with V-V ECMO; the following databases were used: MEDLINE, Embase, Wanfang, and the China National Knowledge Infrastructure. The primary outcome was cumulative survival. Secondary outcomes were length of stay in an intensive care unit, exchange of arterial blood gases, and adverse events. Results: A total of 8 studies were included in the final meta-analysis. Patients with longer duration of PP (≥12 h) had a longer survival period (risk ratio: 1.24; 95% confidence interval: 1.00, 1.54]) than those with PP < 12 h. There was no evidence of publication bias across the studies. Conclusion: Our results imply that a longer duration of PP ≥ 12 h might improve the outcome of patients with ARDS who receive V-V ECMO therapy.
Coxsackievirus A16 (CVA16) causes hand, foot and mouth disease in infants and young children. However, no vaccine or anti-viral agent is currently available for CVA16. Here, the functions and working mechanisms of two CVA16-specific neutralizing monoclonal antibodies (MAbs), 9B5 and 8C4, are comprehensively investigated. Both 9B5 and 8C4 display potent neutralization in vitro and prophylactic and therapeutic efficacy in a mouse model of CVA16 infection. Mechanistically, 9B5 exerts neutralization primarily through inhibiting CVA16 attachment to cell surface via blockade of CVA16 binding to its attachment receptor, heparan sulfate, whereas 8C4 functions mainly at the post-attachment stage of CVA16 entry by interfering with the interaction between CVA16 and its uncoating receptor SCARB2. Cryo-EM studies show that 9B5 and 8C4 target distinct epitopes located at the 5-fold and 3-fold protrusions of CVA16 capsids, respectively, and exhibit differential binding preference to three forms of naturally occurring CVA16 particles. Moreover, 9B5 and 8C4 are compatible in formulating an antibody cocktail which displays the ability to prevent virus escape seen with individual MAbs. Together, our work elucidates the functional and structural basis of CVA16 antibody-mediated neutralization and protection, providing important information for design and development of effective CVA16 vaccines and antibody therapies.
Coxsackievirus Infections , Enterovirus A, Human , Enterovirus , Mice , Animals , Enterovirus A, Human/chemistry , Antibodies, Neutralizing , Capsid/chemistry , Capsid Proteins/chemistry , Enterovirus/chemistry
