Broad neutralization of SARS-CoV-2 variants by an inhalable bispecific single-domain antibody.

The effectiveness of SARS-CoV-2 vaccines and therapeutic antibodies have been limited by the continuous emergence of viral variants and by the restricted diffusion of antibodies from circulation into the sites of respiratory virus infection. Here, we report the identification of two highly conserved regions on the Omicron variant receptor-binding domain recognized by broadly neutralizing antibodies. Furthermore, we generated a bispecific single-domain antibody that was able to simultaneously and synergistically bind these two regions on a single Omicron variant receptor-binding domain as revealed by cryo-EM structures. We demonstrated that this bispecific antibody can be effectively delivered to lung via inhalation administration and exhibits exquisite neutralization breadth and therapeutic efficacy in mouse models of SARS-CoV-2 infections. Importantly, this study also deciphered an uncommon and highly conserved cryptic epitope within the spike trimeric interface that may have implications for the design of broadly protective SARS-CoV-2 vaccines and therapeutics.

Intrahepatic homeobox protein MSX-1 is a novel host restriction factor of hepatitis B virus.

Chronic hepatitis B virus (HBV) infection (CHB) is a risk factor for the development of liver fibrosis, cirrhosis, and hepatocellular carcinoma. Covalently closed circular DNA serves as the sole transcription template for all viral RNAs and viral transcription is driven and enhanced by viral promoter and enhancer elements, respectively. Interactions between transcription factors and these cis-elements regulate their activities and change the production levels of viral RNAs. Here, we report the identification of homeobox protein MSX-1 (MSX1) as a novel host restriction factor of HBV in liver. In both HBV-transfected and HBV-infected cells, MSX1 suppresses viral gene expression and genome replication. Mechanistically, MSX1 downregulates enhancer II/core promoter (EnII/Cp) activity via direct binding to an MSX1 responsive element within EnII/Cp, and such binding competes with hepatocyte nuclear factor 4α binding to EnII/Cp due to partial overlap between their respective binding sites. Furthermore, CHB patients in immune active phase express higher levels of intrahepatic MSX1 but relatively lower levels of serum and intrahepatic HBV markers compared to those in immune tolerant phase. Finally, MSX1 was demonstrated to induce viral clearance in two mouse models of HBV persistence, suggesting possible therapeutic potential for CHB.IMPORTANCECovalently closed circular DNA plays a key role for the persistence of hepatitis B virus (HBV) since it serves as the template for viral transcription. Identification of transcription factors that regulate HBV transcription not only provides insights into molecular mechanisms of viral life cycle regulation but may also provide potential antiviral targets. In this work, we identified host MSX1 as a novel restriction factor of HBV transcription. Meanwhile, we observed higher intrahepatic MSX1 expression in chronic hepatitis B virus (CHB) patients in immune active phase compared to those in immune tolerant phase, suggesting possible involvement of MSX1 in the regulation of HBV activity by the host. Lastly, intrahepatic overexpression of MSX1 delivered by recombinant adenoviruses into two mouse models of HBV persistence demonstrated MSX1-mediated repression of HBV in vivo, and MSX1-induced clearance of intrahepatic HBV DNA in treated mice suggested its potential as a therapeutic target for the treatment of CHB.

Mast cell stabilizer, an anti-allergic drug, reduces ventricular arrhythmia risk via modulation of neuroimmune interaction.

Mast cells (MCs) are important intermediates between the nervous and immune systems. The cardiac autonomic nervous system (CANS) crucially modulates cardiac electrophysiology and arrhythmogenesis, but whether and how MC-CANS neuroimmune interaction influences arrhythmia remain unclear. Our clinical data showed a close relationship between serum levels of MC markers and CANS activity, and then we use mast cell stabilizers (MCSs) to alter this MC-CANS communication. MCSs, which are well-known anti-allergic agents, could reduce the risk of ventricular arrhythmia (VA) after myocardial infarction (MI). RNA-sequencing (RNA-seq) analysis to investigate the underlying mechanism by which MCSs could affect the left stellate ganglion (LSG), a key therapeutic target for modulating CANS, showed that the IL-6 and γ-aminobutyric acid (GABA)-ergic system may be involved in this process. Our findings demonstrated that MCSs reduce VA risk along with revealing the potential underlying antiarrhythmic mechanisms.

High mobility group AT-hook 1 (HMGA1) is an important positive regulator of hepatitis B virus (HBV) that is reciprocally upregulated by HBV X protein.

Chronic infection with hepatitis B virus (HBV) is associated with liver cirrhosis and hepatocellular carcinoma. Upon infection of hepatocytes, HBV covalently closed circular DNA (cccDNA) exists as histone-bound mini-chromosome, subjected to transcriptional regulation similar to chromosomal DNA. Here we identify high mobility group AT-hook 1 (HMGA1) protein as a positive regulator of HBV transcription that binds to a conserved ATTGG site within enhancer II/core promoter (EII/Cp) and recruits transcription factors FOXO3α and PGC1α. HMGA1-mediated upregulation of EII/Cp results in enhanced viral gene expression and genome replication. Notably, expression of endogenous HMGA1 was also demonstrated to be upregulated by HBV, which involves HBV X protein (HBx) interacting with SP1 transcription factor to activate HMGA1 promoter. Consistent with these in vitro results, chronic hepatitis B patients in immune tolerant phase display both higher intrahepatic HMGA1 protein levels and higher serum HBV markers compared to patients in inactive carrier phase. Finally, using a mouse model of HBV persistence, we show that targeting endogenous HMGA1 through RNA interference facilitated HBV clearance. These data establish HMGA1 as an important positive regulator of HBV that is reciprocally upregulated by HBV via HBx and also suggest the HMGA1-HBV positive feedback loop as a potential therapeutic target.

Construction and efficacy testing of DNA vaccines containing HLA-A*02:01-restricted SARS-CoV-2 T-cell epitopes predicted by immunoinformatics.

Vaccines play essential roles in the fight against the COVID-19 pandemic. The development and assessment of COVID-19 vaccines have generally focused on the induction and boosting of neutralizing antibodies targeting the SARS-CoV-2 spike (S) protein. Due to rapid and continuous variation in the S protein, such vaccines need to be regularly updated to match newly emerged dominant variants. T-cell vaccines that target MHC I- or II-restricted epitopes in both structural and non-structural viral proteins have the potential to induce broadly cross-protective and long-lasting responses. In this work, the entire proteome encoded by SARS-CoV-2 (Wuhan-hu-1) is subjected to immunoinformatics-based prediction of HLA-A*02:01-restricted epitopes. The immunogenicity of the predicted epitopes is evaluated using peripheral blood mononuclear cells from convalescent Wuhan-hu-1-infected patients. Furthermore, predicted epitopes that are conserved across major SARS-CoV-2 lineages and variants are used to construct DNA vaccines expressing multi-epitope polypeptides. Most importantly, two DNA vaccine constructs induce epitope-specific CD8 + T-cell responses in a mouse model of HLA-A*02:01 restriction and protect immunized mice from challenge with Wuhan-hu-1 virus after hACE2 transduction. These data provide candidate T-cell epitopes useful for the development of T-cell vaccines against SARS-CoV-2 and demonstrate a strategy for quick T-cell vaccine candidate development applicable to other emerging pathogens.

Percutaneous endoscopic lumbar discectomy for single and double segment lumbar disc herniation with sciatic scoliosis in adults: a retrospective study.

OBJECTIVE: Sciatic scoliosis can be seen in patients with lumbar disc herniation. Percutaneous endoscopic lumbar discectomy (PELD) is a common surgical method for the treatment of lumbar disc herniation. The difference between single-segment lumbar disc herniation and double-segment lumbar disc herniation with Sciatic Scoliosis in adults after PELD needs further study. The aim of this study was to compare the imaging features of single-segment and double-segment lumbar disc herniation with Sciatic Scoliosis in adults and to further explore the clinical outcomes of functional improvement and scoliosis imaging parameters of the two groups after PELD. METHODS: Adult patients with lumbar disc herniation with sciatic scoliosis who received PELD from January 2019 to June 2022 were analyzed retrospectively. According to the number of operative segments, the patients were divided into a single-segment group and a double-segment group. Perioperative parameters were observed and compared between the two groups. The Visual Analogue Scale (VAS) score, Oswestry dysfunction index (ODI), Japanese Orthopaedic Association scores (JOA) and imaging parameters of the two groups were recorded and compared before the operation and during the follow-up. RESULTS: A total of 53 patients with single segments and 21 patients with double segments were included in this study. During the follow-up, the VAS score, ODI index and JOA score of the two groups were significantly improved as compared with those before the operation(P < 0. 05). Ninety-two point five percent of single-segment patients and 90.5% of double segment patients returned to normal scoliosis within 12 months after the operation. The operation time, number of intraoperative fluoroscopy times and the amount of intraoperative blood loss in single-segment patients were better than those in double-segment group(P < 0. 05). At the last follow-up, the AVT, CBD and SVA in the double-segment group were 5.2 ± 2.3, 5.1 ± 1.0 and 12.2 ± 3.0 mm, respectively, which were higher than those in the single-segment group (1.9 ± 0.4, 1.1 ± 1.6 and 3.9 ± 2.1 mm) (P < 0. 05). CONCLUSION: PELD is an effective treatment for single-segment and double-segment lumbar disc herniation with Sciatic scoliosis. Double-segment patients can enjoy similar clinical efficacy to single-segment patients, avoiding complications caused by decompression, fusion, and internal fixation. Scoliosis was corrected spontaneously within 12 months after operation, and the sagittal curve was significantly improved in both groups. The improvement of coronal and sagittal balance in double -segment patients may take longer.

In situ and Real-time Monitoring the Chemical and Thermal Evolution of Lithium-ion Batteries with Single-crystalline Ni-rich Layered Oxide Cathode.

High-capacity Ni-rich layered oxides are promising cathode materials for fabrication of lithium-ion batteries (LIBs) with high energy density. However, thermal runaway of LIBs with these cathodes leads to great safety concerns. In this study, single crystalline LiNi0.9Co0.05Mn0.05O2 (NCM-SC) has been prepared and a flexible optical fiber was buried inside the pouch-type LIBs with NCM-SC cathode to in situ study its real-time temperature evolution during charge/discharge process. NCM-SC exhibits an enhanced Li+ ions transportation efficiency and electrode reaction kinetics, which can effectively reduce the generation of polarization heat and mitigate the internal temperature rise of the pouch-type battery. Meanwhile, solid-electrolyte interface (SEI) film decomposition and gas accumulation are effectively alleviated, due to the enhanced thermal stability of SEI film formed on NCM-SC. Moreover, the single crystal architecture can effectively retard layered to spinal and rock-salt phase transition, mitigate the crack formation and structural collapse. Consequently, NCM-SC exhibits an excellent electrochemical performance and enhanced thermal stability.

Stabilizing Ni-rich Single-crystalline LiNi0.83 Co0.07 Mn0.10 O2 Cathodes using Ce/Gd Co-doped High-entropy Composite Surfaces.

Ni-rich layered oxides are promising lithium-ion batteries (LIBs) cathode materials for their high reversible capacity, but they suffer from fast structural degradation during cycling. Here, we report the Ce/Gd incorporated single-crystalline LiNi0.83 Co0.07 Mn0.10 O2 (SC-NCM) cathode materials with significantly enhanced cycling stability. The Gd ions are adequately incorporated in SC-NCM while Ce ions are prone to aggregate in the outer surface, resulting in the formation of a high-entropy zone in the near-surface of SC-NCM, including a Gd doped LiCeO2 (LCGO) shell and Ce/Gd dopant-concentrated layer. The high-entropy zone can effectively inhibit the oxygen evolution and prevent the formation of oxygen vacancies. Meanwhile, it leads to a greatly improved H2-H3 phase transformation reversibility and mitigated stress/strain caused by Li-ion extraction/insertion during (de)lithiation process. The synergetic effects of reduced oxygen vacancies concentration and mitigated stress/strain can effectively prevent the in-plane migration of TM ions, lattice planar gliding as well as the formation of intragranular nanocracks. Consequently, Ce/Gd incorporated SC-NCM (SC-NCM@CG2) delivers a high initial discharge specific capacity of 219.7 mAh g-1 at 0.1 C and an excellent cycling stability with a capacity retention of 90.2 % after 100 cycles at 1.0 C.

HBV covalently closed circular DNA minichromosomes in distinct epigenetic transcriptional states differ in their vulnerability to damage.

BACKGROUND AND AIMS: HBV covalently closed circular DNA (cccDNA) is a major obstacle for a cure of chronic hepatitis B. Accumulating evidence suggests that epigenetic modifications regulate the transcriptional activity of cccDNA minichromosomes. However, it remains unclear how the epigenetic state of cccDNA affects its stability. APPROACHES AND RESULTS: By using HBV infection cell models and in vitro and in vivo recombinant cccDNA (rcccDNA) and HBVcircle models, the reduction rate of HBV cccDNA and the efficacy of apolipoprotein B mRNA editing enzyme catalytic subunit 3A (APOBEC3A)-mediated and CRISPR/CRISPR-associated 9 (Cas9)-mediated cccDNA targeting were compared between cccDNAs with distinct transcriptional activities. Interferon-α treatment and hepatitis B x protein (HBx) deletion were applied as two strategies for cccDNA repression. Chromatin immunoprecipitation and micrococcal nuclease assays were performed to determine the epigenetic pattern of cccDNA. HBV cccDNA levels remained stable in nondividing hepatocytes; however, they were significantly reduced during cell division, and the reduction rate was similar between cccDNAs in transcriptionally active and transcriptionally repressed states. Strikingly, HBV rcccDNA without HBx expression exhibited a significantly longer persistence in mice. The cccDNA with low transcriptional activity exhibited an epigenetically inactive pattern and was more difficult to access by APOBEC3A and engineered CRISPR-Cas9. The epigenetic regulator activating cccDNA increased its vulnerability to APOBEC3A. CONCLUSIONS: HBV cccDNA minichromosomes in distinct epigenetic transcriptional states showed a similar reduction rate during cell division but significantly differed in their accessibility and vulnerability to targeted nucleases and antiviral agents. Epigenetic sensitization of cccDNA makes it more susceptible to damage and may potentially contribute to an HBV cure.

Lipid nanoparticle-mediated delivery of IL-21-encoding mRNA induces viral clearance in mouse models of hepatitis B virus persistence.

Hepatitis B virus (HBV) covalently closed circular DNA (cccDNA), the transcription template for all viral mRNAs, is highly stable and current treatment options cannot effectively induce its clearance. Previously, we established an HBV persistence mouse model based on a clinical isolate (termed BPS) and identified interleukin-21 (IL-21) as a potent inducer of HBV clearance. Lipid nanoparticle (LNP) mediated delivery of mRNA has proven to be a highly safe and effective delivery platform. This work explored the applicability and effectiveness of the mRNA-LNP platform in IL-21-based HBV therapies. First, LNP-encapsulated murine IL-21 mRNA (LNP-IL-21) was prepared, characterized, and demonstrated to engender IL-21 expression in vitro and in vivo. Next, LNP-IL-21 was shown to induce clearance of both serum and intrahepatic HBV antigen and DNA in two HBV persistence mouse models based on BPS and recombinant cccDNA (rcccDNA), respectively, which was associated with HBV-specific humoral and cellular immune responses. Furthermore, peripheral blood mononuclear cells from BPS persistence mice treated ex vivo with LNP-IL-21 and HBV surface antigen (HBsAg) could induce similar HBV clearance upon infusion into recipient mice. These findings indicated that IL-21 combined with mRNA-LNP platform represents a valid and promising strategy for developing novel therapeutics against chronic HBV infection.

Periostin promotes nucleus pulposus cells apoptosis by activating the Wnt/ß-catenin signaling pathway.

Intervertebral disc (IVD) degeneration (IVDD) is closely linked to degenerative spinal disease, resulting in disability, poor quality of life, and financial burden. Apoptosis of nucleus pulposus (NP) cells (NPCs) is a key pathological basis of IVDD. Periostin (POSTN), an extracellular matrix protein, is expressed in many tissues, whereas its abnormal expression is associated with IVDD. The conventional Wnt/ß-catenin pathway is also involved in IVDD and contributes to NPCs apoptosis. However, research on the mechanisms of POSTN in IVDD is lacking. This study investigated the relationship between POSTN and ß-catenin expression in degenerated IVDs. We detected the expression of POSTN, ß-catenin, and cleaved-caspase-3 (C-caspase3) in degenerated and non-degenerated IVD tissues of different grades (n = 8) using RT-qPCR, immunohistochemical staining, and western blotting analysis. Next, we explored the effects of recombinant periostin (rPOSTN) and isoquercitrin (Iso), an inhibitor of the Wnt/ß-catenin pathway, on NPCs apoptosis. Finally, we inhibited the expression of POSTN in degenerated NPCs in vivo and investigated the anti-apoptotic effect. The expression of ß-catenin, POSTN, and C-caspase3 in severe degenerative IVDs was significantly higher than that in mild degenerative IVDs. These findings were confirmed in rat and cell-based degenerative models. When treated with rPOSTN, the Wnt/ß-catenin pathway activity and cell apoptosis were time- and dose-dependent. However, rPOSTN-induced NPCs apoptosis decreased after iso-induced inhibition of the Wnt/ß-catenin pathway. POSTN inhibition reduced apoptosis but was restored by rPOSTN re-addition. Lastly, POSTN inhibition ameliorated puncture-induced IVDD in vivo. Overall, our study demonstrated that POSTN promotes NPCs apoptosis and aggravates degeneration by activating the Wnt/ß-catenin pathway.

H+ -H- Pairs in Partially Oxidized MAX Phases for Bifunctional Catalytic Conversion of Furfurals into Linear Ketones.

Currently, less favorable C=O hydrogenation and weak concerted acid catalysis cause unsatisfactory catalytic performance in the upgrading of biomass-derived furfurals (i.e., furfural, 5-methyl furfural, and 5-hydroxymethyl furfural) to ketones (i.e., cyclopentanone, 2,5-hexanedione, and 1-hydroxyl-2,5-hexanedione). A series of partially oxidized MAX phase (i.e., Ti3 AlC2 , Ti2 AlC, Ti3 SiC2 ) supporting Pd catalysts were fabricated, which showed high catalytic activity; Pd/Ti3 AlC2 in particular displayed high performance for conversion of furfurals into targeted ketones. Detailed studies of the catalytic mechanism confirm that in situ hydrogen spillover generates Frustrated Lewis H+ -H- pairs, which not only act as the hydrogenation sites for selective C=O hydrogenation but also provide acid sites for ring opening. The close intimate hydrogenation and acid sites promote bifunctional catalytic reactions, substantially reducing the reported minimum reaction temperature of various furfurals by at least 30-60 °C.

Lost Small Envelope Protein Expression from Naturally Occurring PreS1 Deletion Mutants of Hepatitis B Virus Is Often Accompanied by Increased HBx and Core Protein Expression as Well as Genome Replication.

Hepatitis B virus (HBV) transcribes coterminal mRNAs of 0.7 to 3.5 kb from the 3.2-kb covalently closed circular DNA, with the 2.1-kb RNA being most abundant. The 0.7-kb RNA produces HBx protein, a transcriptional transactivator, while the 3.5-kb pregenomic RNA (pgRNA) drives core and P protein translation as well as genome replication. The large (L) and small (S) envelope proteins are translated from the 2.4-kb and 2.1-kb RNAs, respectively, with the majority of the S protein being secreted as noninfectious subviral particles and detected as hepatitis B surface antigen (HBsAg). pgRNA transcription could inhibit transcription of subgenomic RNAs. The present study characterized naturally occurring in-frame deletions in the 3' preS1 region, which not only codes for L protein but also serves as the promoter for 2.1-kb RNA. The human hepatoma cell line Huh7 was transiently transfected with subgenomic expression constructs for envelope (and HBx) proteins, dimeric constructs, or constructs mimicking covalently closed circular DNA. The results confirmed lost 2.1-kb RNA transcription and HBsAg production from many deletion mutants, accompanied by increases in other (especially 2.4-kb) RNAs, intracellular HBx and core proteins, and replicative DNA but impaired virion and L protein secretion. The highest intracellular L protein levels were achieved by mutants that had residual S protein expression or retained the matrix domain in L protein. Site-directed mutagenesis of a high replicating deletion mutant suggested that increased HBx protein expression and blocked virion secretion both contributed to the high replication phenotype. Our findings could help explain why such deletions are selected at a late stage of chronic HBV infection and how they contribute to viral pathogenesis. IMPORTANCE Expression of hepatitis B e antigen (HBeAg) and overproduction of HBsAg by wild-type HBV are implicated in the induction of immune tolerance to achieve chronic infection. How HBV survives the subsequent immune clearance phase remains incompletely understood. Our previous characterization of core promoter mutations to reduce HBeAg production revealed the ability of the 3.5-kb pgRNA to diminish transcription of coterminal RNAs of 2.4 kb, 2.1 kb, and 0.7 kb. The later stage of chronic HBV infection often selects for in-frame deletions in the preS region. Here, we found that many 3' preS1 deletions prevented transcription of the 2.1-kb RNA for HBsAg production, which was often accompanied by increases in intracellular 3.5-, 0.7-, and especially 2.4-kb RNAs, HBx and core proteins, and replicative DNA but lost virion secretion. These findings established the biological consequences of preS1 deletions, thus shedding light on why they are selected and how they contribute to hepatocarcinogenesis.

Metabolism regulator adiponectin prevents cardiac remodeling and ventricular arrhythmias via sympathetic modulation in a myocardial infarction model.

The stellate ganglia play an important role in cardiac remodeling after myocardial infarction (MI). This study aimed to investigate whether adiponectin (APN), an adipokine mainly secreted by adipose tissue, could modulate the left stellate ganglion (LSG) and exert cardioprotective effects through the sympathetic nervous system (SNS) in a canine model of MI. APN microinjection and APN overexpression with recombinant adeno-associated virus vector in the LSG were performed in acute and chronic MI models, respectively. The results showed that acute APN microinjection decreased LSG function and neural activity, and suppressed ischemia-induced ventricular arrhythmia. Chronic MI led to a decrease in the effective refractory period and action potential duration at 90% and deterioration in echocardiography performance, all of which was blunted by APN overexpression. Moreover, APN gene transfer resulted in favorable heart rate variability alteration, and decreased cardiac SNS activity, serum noradrenaline and neuropeptide Y, which were augmented after MI. APN overexpression also decreased the expression of nerve growth factor and growth associated protein 43 in the LSG and peri-infarct myocardium, respectively. Furthermore, RNA sequencing of LSG indicated that 4-week MI up-regulated the mRNA levels of macrophage/microglia activation marker Iba1, chemokine ligands (CXCL10, CCL20), chemokine receptor CCR5 and pro-inflammatory cytokine IL6, and downregulated IL1RN and IL10 mRNA, which were reversed by APN overexpression. Our results reveal that APN inhibits cardiac sympathetic remodeling and mitigates cardiac remodeling after MI. APN-mediated gene therapy may provide a potential therapeutic strategy for the treatment of MI.

Associations of Tumor Necrosis Factor Alpha Gene Polymorphisms and Ankylosing Spondylitis Susceptibility: A Meta-analysis Based on 35 Case-control Studies.

BACKGROUND: Scores of studies on tumor necrosis factor alpha (TNF-α) gene polymorphisms and AS have been performed with inconsistent results. The purpose of this study was to provide some more convincing evidence on the associations of TNF-a polymorphisms and AS by using a meta-analysis approach. METHODS: Potentially relevant studies were identified from Web of Science, PubMed, EMBASE, Wanfang, and CNKI from inception to March 5, 2020. Newcastle-Ottawa Scale (NOS) was utilized to appraise the quality of included studies. Odds ratios (ORs) with 95% confidence intervals (95%CIs) were calculated to assess the strength of the associations under five genetic models. RESULTS: Thirty-five studies with 37 independent cohorts in total were included in the meta-analysis. Based upon NOS, eligible studies were in moderate- to high quality. The merged data suggested rs1799724 polymorphisms were significantly correlated with a reduced risk of AS (C vs. T, OR = 0.55, 95%CI 0.38-0.79, P < .001, PBon = 0.005, PFDR = 0.003). Subgroup analysis by ethnicity indicated that rs1800629 polymorphism significantly increased the risk of AS in Caucasians and decreased the risk of AS in mixed populations. Besides, rs361525 and rs1800630 polymorphisms conferred to an elevated risk of AS, and rs1799724 conferred to a reduced risk of AS in Asians. CONCLUSIONS: This study suggests that rs1800629 polymorphism is associated with an increased AS risk in Caucasians, rs361525 and rs1800630 polymorphisms are linked to an elevated AS susceptibility in Asians.

Highly potent multivalent VHH antibodies against Chikungunya isolated from an alpaca naïve phage display library.

BACKGROUND: Chikungunya virus (CHIKV) is a re-emerged mosquito-borne alphavirus that can cause musculoskeletal diseases, imposing a substantial threat to public health globally. High-affinity antibodies are need for diagnosis and treatment of CHIKV infections. As a potential diagnostic and therapeutic agent, the multivalent VHH antibodies is a promising tookit in nanomedicine. Here, we developed potent multivalent VHH antibodies from an alpaca naïve phage display library targeting the E2 glycoprotein of the CHIKV virus. RESULTS: In the present study, we generated 20 VHH antibodies using a naïve phage display library for binders to the CHIKV E2 glycoprotein. Of these, multivalent VHH antibodies Nb-2E8 and Nb-3C5 had specific high-affinity binding to E2 protein within the nanomolar range. The equilibrium dissociation constant (KD) was between 2.59-20.7 nM, which was 100-fold stronger than the monovalent antibodies' affinity. Moreover, epitope mapping showed that Nb-2E8 and Nb-3C5 recognized different linear epitopes located on the E2 glycoprotein domain C and A, respectively. A facile protocol of sandwich ELISA was established using BiNb-2E8 as a capture antibody and HRP-conjugated BiNb-3C5 as a detection antibody. A good linear correlation was achieved between the OD450 value and the E2 protein concentration in the 5-1000 ng/mL range (r = 0.9864, P < 0.0001), indicating its potential for quantitative detection of the E2 protein. CONCLUSIONS: Compared to monovalent antibodies, multivalent VHH antibodies Nb-2E8 and Nb-3C5 showed high affinity and are potential candidates for diagnostic applications to better detect CHIKV virions in sera.

Efficacy of transforaminal lumbar interbody fusion in the treatment of double-level lumbar spondylolisthesis with sagittal imbalance.

OBJECTIVE: To analyze the clinical efficacy of transforaminal lumbar interbody fusion (TLIF) in the treatment of continuous double-level lumbar spondylolisthesis with sagittal imbalance. METHODS: The clinical data of 36 patients with double-level spondylolisthesis treated with TLIF were included and divided into L3/L4 double spondylolisthesis group and L4/L5 double spondylolisthesis group according to the site of spondylolisthesis. The sagittal parameters of the patients were measured by standing anteroposterior and lateral X-rays of the whole spine, and the visual analogue scale (VAS) for lumbar and lower limb pain, Japanese Orthopaedic Association (JOA), and Oswestry Disability Index (ODI) were recorded. The imaging parameters and clinical parameters of the patients before surgery, after surgery, and at the last follow-up were compared and statistically analyzed. RESULTS: A total of 36 patients were included in the study and all had sagittal imbalance. Among them, there were 21 cases of L3 and L4 spondylolisthesis, 6 males and 15 females, with an average age of 64.7 ± 9.4 years; there were 15 cases of L4 and L5 spondylolisthesis, 4 males and 11 females, with an average age of 66.5 ± 8.0 years. 36 patients completed the operation, the operation time was 190.28 ± 6.12 min, and intraoperative blood loss was 345 ± 11 ml. Compared with preoperative, there were significant differences in SVA, TPA, T1-SPi, LL, PT, SS, PI-LL, SD, SA, and SP between patients after surgery and at the last follow-up (P < 0.05). Compared with preoperative, VAS score, JOA score, and ODI index of waist and lower limbs were significantly improved after the operation and at the last follow-up, and there was a significant difference (P < 0.05). CONCLUSION: TLIF can effectively relieve the symptoms of patients with continuous double-level lumbar spondylolisthesis, restore lumbar lordosis and sagittal spinal sequence, and improve the quality of life of patients.

Pedicle subtraction osteotomy for the corrective surgery of ankylosing spondylitis with thoracolumbar kyphosis: experience with 38 patients.

OBJECTIVE: To evaluate the sagittal parameters and clinical outcome of pedicle subtraction osteotomy (PSO) for the treatment of ankylosing spondylitis (AS) combined with thoracolumbar kyphosis. METHODS: The clinical data of 38 patients with AS combined with thoracolumbar kyphosis who underwent PSO were enrolled and divided into the lumbar lordosis group and the lumbar kyphosis group according to the preoperative sagittal morphology. They were subdivided into the lumbar lordosis T12 group, lordosis L1 group, kyphosis L2 group, and kyphosis L3 group. The spine sagittal parameters were compared between the preoperative and the postoperative. Outcome evaluation was performed by the Japanese Orthopedic Association (JOA) score, visual analogue scale (VAS), and the Oswestry Disability Index (ODI). RESULTS: A total of 38 patients with AS combined with thoracolumbar kyphosis were successfully treated by PSO, with a mean follow-up time of 26.9 ± 11.9 months. There were 30 males and 8 females with a mean age of 41.6 ± 7.1 years. Twenty patients consisted in the lumbar lordosis group and 18 patients in the lumbar kyphosis group. GK, SVA, and CBVA were improved significantly (P < 0.05) at the final follow-up between the lumbar lordosis T12 group and the L1 group. Patients in the lumbar kyphosis L2 group and L3 group all received satisfactory, including LL, GK, and SVA (P < 0.05). There was no statistically significant difference in the preoperative TK, GK, SVA, PT, and PI between the lumbar lordosis and lumbar kyphosis groups (P > 0.05). Postoperative complications occurred in three cases. CONCLUSION: PSO was a practical method for the treatment of patients with AS combined with thoracolumbar kyphosis. PSO at L3 was recommended to be selected for the lumbar kyphosis to obtain greater SVA correction. CBVA of single-segment PSO may be significantly lower than the two-segment PSO in the management of patients with kyphosis of lower CBVA.

Efficacy of anterior debridement and bone grafting with fusion using internal fixation combined with anti-tuberculosis chemotherapy in the treatment of subaxial cervical tuberculosis.

BACKGROUND: To evaluate the efficacy of anterior debridement and bone grafting with fusion using internal fixation (BFIF) combined with anti-tuberculosis chemotherapy in the treatment of subaxial cervical spine tuberculosis (SCS-TB). METHODS: Clinical and radiographic data of patients with SCS-TB treated by anterior debridement and BFIF at our hospital from January 2010 to December 2017 were analyzed retrospectively. The SCS sagittal parameters at the preoperative, postoperative, and final follow-up were documented and compared, including the Occiput-C2 angle, C2-C7 Cobb angle, local Cobb angle, spinal canal angle (SCA), C2-C7 sagittal vertical axis (C2-C7 SVA), the center of gravity of the head-C7 sagittal vertical axis (CGH-C7 SVA), T1 slope (T1S), neck tilt (NT), and thoracic inlet angle (TIA). The ASIA grade, NDI index, JOA score, and VAS score were utilized to assess the postoperative function recovery, and the complications were recorded. RESULTS: A total of 23 patients were included in the study with a mean age of 46.74 ± 15.43 years, including 8 males and 15 females. All patients with SCS-TB were treated with anterior debridement and BFIF, with a mean postoperative follow-up time of 37.17 ± 12.26 months. The poisoning symptoms of TB were relieved in all patients, and ESR (42.09 ± 9.53 vs 8.04 ± 5.41, P < 0.05) and CRP (30.37 ± 16.02 vs 7.4 ± 2.68, P < 0.05) were decreased at the 3 postoperative months in the comparison of the preoperative. The C0-C2 Cobb angle, C2-C7 Cobb angle, local Cobb angle, SCA, TIS, C2-C7 SVA, and CGH-C7 SVA were corrected remarkably after surgery (P < 0.05). Further, there was a significant improvement in the JOA, VAS, and NDI with the comparison of the preoperative (P < 0.05). CONCLUSIONS: Anterior debridement and BFIF combined with anti-TB chemotherapy was a practical tool for the treatment of SCS-TB with the help of SCS sagittal parameters, which can remove the lesion completely, decompress the spinal cord compression, and correct the kyphotic deformity to restore the spine sagittal balance.

One-stage posterior surgery combined with anti-Brucella therapy in the management of lumbosacral brucellosis spondylitis: a retrospective study.

BACKGROUND: This study aimed to assess the clinical efficacy of one-stage posterior surgery combined with anti-Brucella therapy in the treatment of lumbosacral brucellosis spondylitis (LBS). METHODS: From June 2010 to June 2020, the clinical and radiographic data of patients with LBS treated by one-stage posterior surgery combined with anti-Brucella therapy were retrospectively analyzed. The visual analogue scale (VAS), Japanese Orthopaedic Association (JOA) and Oswestry Disability Index scores (ODI) were used to evaluate the clinical outcomes. Frankel's classification system was employed to access the initial and final neurologic function. Fusion of the bone grafting was classified by Bridwell's grading system. RESULTS: A total of 55 patients were included in this study with a mean postoperative follow-up time of 2.6 ± 0.8 years (range, 2 to 5). There were 40 males and 15 females with a mean age of 39.8 ± 14.7 years (range, 27 to 57). The Brucella agglutination test was ≥ 1:160 in all patients, but the blood culture was positive in 43 patients (78.1%). A statistical difference was observed in ESR, CRP, VAS, ODI, and JOA between preoperative and final follow-up (P < 0.05). Neurological function was significantly improved in 20 patients with preoperative neurological dysfunction after surgery. According to Bridwell's grading system, the fusion of bone grafting in 48 cases (87.2%) was defined as grade I, and grade II in 7 cases (12.7%). None of the infestation recurrences was observed. CONCLUSION: One-stage posterior surgery combined with anti-Brucella therapy was a practical method in the treatment of LBS with severe neurological compression and spinal sagittal imbalance.