Construction of Switch Modules for CAR-T Cell Treatment Using a Site-Specific Conjugation System.

Chimeric antigen receptor T-cell (CAR-T cell) therapy has become a promising treatment option for B-cell hematological tumors. However, few optional target antigens and disease relapse due to loss of target antigens limit the broad clinical applicability of CAR-T cells. Here, we conjugated an antibody (Ab) fusion protein, consisting of an Ab domain and a SpyCatcher domain, with the FITC-SpyTag (FITC-ST) peptide to form a bispecific safety switch module using a site-specific conjugation system. We applied the safety switch module to target CD19, PDL1, or Her2-expressing tumor cells by constructing FMC63 (anti-CD19), antiPDL1, or ZHER (anti-Her2)-FITC-ST, respectively. Those switch modules significantly improved the cytotoxic effects of anti-FITC CAR-T cells on tumor cells. Additionally, we obtained the purified CD8+ T cells by optimizing a shorter version of the CD8-binding aptamer to generate anti-FITC CD8-CAR-T cells, which combined with the CD4-FITC-ST switch module (anti-CD4) to eliminate the CD4-positive tumor cells in vitro and in vivo. Overall, we established a novel safety switch module by site-specific conjugation to enhance the antitumor function of universal CAR-T cells, thereby expanding the application scope of CAR-T therapy and improving its safety and efficacy.

Construction of a versatile fusion protein for targeted therapy and immunotherapy.

Antibody (Ab)-based drugs have been widely used in targeted therapies and immunotherapies, leading to significant improvements in tumor therapy. However, the failure of Ab therapy due to the loss of target antigens or Ab modifications that affect its function limits its application. In this study, we expanded the application of antibodies (Abs) by constructing a fusion protein as a versatile tool for Ab-based target cell detection, delivery, and therapy. We first constructed a SpaC Catcher (SpaCC for short) fusion protein that included the C domains of Staphylococcal protein A (SpaC) and the SpyCatcher. SpaCC conjugated with SpyTag-X (S-X) to form the SpaCC-S-X complex, which binds non-covalently to an Ab to form the Ab-SpaCC-S-X protein complex. The "X" can be a variety of small molecules such as fluoresceins, cell-penetrating peptide TAT, Monomethyl auristatin E (MMAE), and DNA. We found that Ab-SpaCC-S-FITC(-TAT) could be used for target cell detection and delivery. Besides, we synthesized the Ab-SpaCC-SN3-MMAE complex by linking Ab with MMAE by SpaCC, which improved the cytotoxicity of small molecule toxins. Moreover, we constructed an Ab-DNA complex by conjugating SpaCC with the aptamer (Ap) and found that Ab-SpaCC-SN3-Ap boosted the tumor-killing function of T-cells by retargeting tumor cells. Thus, we developed a multifunctional tool that could be used for targeted therapies and immunotherapies, providing a cheap and convenient novel drug development strategy.

CAR-Aptamers Enable Traceless Enrichment and Monitoring of CAR-Positive Cells and Overcome Tumor Immune Escape.

Chimeric antigen receptor (CAR)-positive cell therapy, specifically with anti-CD19 CAR-T (CAR19-T) cells, achieves a high complete response during tumor treatment for hematological malignancies. Large-scale production and application of CAR-T therapy can be achieved by developing efficient and low-cost enrichment methods for CAR-T cells, expansion monitoring in vivo, and overcoming tumor escape. Here, novel CAR-specific binding aptamers (CAR-ap) to traceless sort CAR-positive cells and obtain a high positive rate of CAR19-T cells is identified. Additionally, CAR-ap-enriched CAR19-T cells exhibit similar antitumor capacity as CAR-ab (anti-CAR antibody)-enriched CAR-T cells. Moreover, CAR-ap accurately monitors the expansion of CAR19-T cells in vivo and predicts the prognosis of CAR-T treatment. Essentially, a novel class of stable CAR-ap-based bispecific circular aptamers (CAR-bc-ap) is constructed by linking CAR-ap with a tumor surface antigen (TSA): protein tyrosine kinase 7 (PTK7) binding aptamer Sgc8. These CAR-bc-aps significantly enhance antitumor cytotoxicity with a loss of target antigens by retargeting CAR-T cells to the tumor in vitro and in vivo. Overall, novel CAR-aptamers are screened for traceless enrichment, monitoring of CAR-positive cells, and overcoming tumor cell immune escape. This provides a low-cost and high-throughput approach for CAR-positive cell-based immunotherapy.

[Chemical composition and antioxidant activity of different parts of Prunella vulgaris by UPLC-Q-TOF-MS/MS and UPLC].

Prunellae Spica is the dried spica of Prunella vulgaris belonging to Labiatae and it is widely used in pharmaceutical and general health fields. As a traditional Chinese medicine cultivated on a large scale, it produces a large amount of non-medicinal parts, which are discarded because they are not effectively used. To analyze the chemical constituents in the different samples from spica, seed, stem, and leaf of P. vulgaris, and explore the application value and development prospect of these parts, this study used ultrahigh performance liquid chromatography-tandem quadrupoles time of flight mass spectrometry(UPLC-Q-TOF-MS/MS) to detect chemical constituents in different parts of P. vulgaris. As a result, 117 compounds were detected. Among them, 87 compounds were identified, including 32 phenolic acids, 8 flavonoids, and 45 triterpenoid saponins. Some new triterpenoid saponins containing the sugar chain with 4-6 sugar units were found. Further, multivariate statistical analysis was conducted on BPI chromatographic peaks of multiple batches of different parts, and the results showed that spica had the most abundant chemical constituents, including salviaflaside and linolenic acid highly contained in the seed and phenolic acids, flavonoids, and triterpenoid saponins in the stem and leaf. In general, the constituents in the spica were composed of those in the seed, stem, and leaf. UPLC was used to determine the content of 6 phenolic acids(danshensu, protocatechuic acid, protocatechuic aldehyde, caffeic acid, salviaflaside, and rosmarinic acid) in different parts. The content of other phenolic acids in the seed was generally lower than that in the spica except that of salviaflaside. The content of salviaflaside in the spica was higher than that in the stem and leaf, but the content of other phenolic acids in the spica was not significantly different from that in the stem. The content of protocatechuic aldehyde and caffeic acid in the spica was lower than that in the leaf. DPPH free radical scavenging method was used to detect the antioxidant activity of four parts, and there was no significant difference in the antioxidant activity between the spica and the stem and leaf, but that was significantly higher than the seed. Moreover, the antioxidant activity of these parts was correlated with the content of total phenolic acids. Based on the above findings, the stem and leaf of P. vulgaris have potential application value. Considering the traditional medication rule, it is feasible to use the whole plant as a medicine. Alternatively, salviaflaside, occurring in the seed, can be used as a marker compound for the quality evaluation of Prunellae Spica, if only using spica as the medicinal part of P. vulgaris, as described in the Chinese Pharmacopoeia(2020 edition).

Anti-CD79b/CD3 bispecific antibody combined with CAR19-T cells for B-cell lymphoma treatment.

CD19 CAR-T (chimeric antigen receptor-T) cell immunotherapy achieves a remission rate of approximately 70% in recurrent and refractory lymphoma treatment. However, the loss or reduction of CD19 antigen on the surface of lymphoma cells results in the escape of tumor cells from the immune killing of CD19 CAR-T cells (CAR19-T). Therefore, novel therapeutic strategies are urgently required. In this study, an anti-CD79b/CD3 bispecific antibody (BV28-OKT3) was constructed and combined with CAR19-T cells for B-cell lymphoma treatment. When the CD19 antigen was lost or reduced, BV28-OKT3 redirected CAR19-T cells to CD79b+ CD19- lymphoma cells; therefore, BV28-OKT3 overcomes the escape of CD79b+ CD19- lymphoma cells by the killing action of CAR19-T cells in vitro and in vivo. Furthermore, BV28-OKT3 triggered the antitumor function of CAR- T cells in the infusion product and boosted the antitumor immune response of bystander T cells, markedly improving the cytotoxicity of CAR19-T cells to lymphoma cells in vitro and in vivo. In addition, BV28-OKT3 elicited the cytotoxicity of donor-derived T cells toward lymphoma cells in vitro, which depended on the presence of tumor cells. Therefore, our findings provide a new clinical treatment strategy for recurrent and refractory B-cell lymphoma by combining CD79b/CD3 BsAb with CAR19-T cells.

Regulation of Osteoimmune Microenvironment and Osteogenesis by 3D-Printed PLAG/black Phosphorus Scaffolds for Bone Regeneration.

The treatment of bone defects remains a significant challenge to be solved clinically. Immunomodulatory properties of orthopedic biomaterials have significance in regulating osteoimmune microenvironment for osteogenesis. A lactic acid-co-glycolic acid (PLGA) scaffold incorporates black phosphorus (BP) fabricated by 3D printing technology to investigate the effect of BP on osteoimmunomodulation and osteogenesis in site. The PLGA/BP scaffold exhibits suitable biocompatibility, biodegradability, and mechanical properties as an excellent microenvironment to support new bone formation. The studies' result also demonstrate that the PLGA/BP scaffolds are able to recruit and stimulate macrophages M2 polarization, inhibit inflammation, and promote human bone marrow mesenchymal stem cells (hBMSCs) proliferation and differentiation, which in turn promotes bone regeneration in the distal femoral defect region of steroid-associated osteonecrosis (SAON) rat model. Moreover, it is screened and demonstrated that PLGA/BP scaffolds can promote osteogenic differentiation by transcriptomic analysis, and PLGA/BP scaffolds promote osteogenic differentiation and mineralization by activating PI3K-AKT signaling pathway in hBMSC cells. In this study, it is shown that the innovative PLGA/BP scaffolds are extremely effective in stimulating bone regeneration by regulating macrophage M2 polarization and a new strategy for the development of biomaterials that can be used to repair bone defects is offered.

A novel His-tag-binding aptamer for recombinant protein detection and T cell-based immunotherapy.

Screening novel aptamers for recombinant protein detection is of great significance in industrial mass production of antibody drugs. In addition, construction of structurally stable bispecific circular aptamers (bc-apts) may provide a tumor-targeted treatment strategy by simultaneously binding two different cell types. In this study, we obtained a high-affinity hexahistidine tag (His-tag)-binding aptamer 20S and explored its application in recombinant protein detection and T cell-based immunotherapy. We developed a new molecular beacon (MB) 20S-MB to detect His-tagged proteins in vitro and in vivo with high sensitivity and specificity, and the results showed high consistency with the enzyme-linked immunosorbent assay (ELISA). Moreover, we constructed two kinds of bc-apts by cyclizing 20S or another His-tag-binding aptamer, 6H5-MU, with Sgc8, which specifically recognizes protein tyrosine kinase 7 (PTK7) on tumor cells. After forming a complex with His-tagged OKT3, an anti-CD3 antibody for T cell activation, we utilized these aptamer-antibody complexes (ap-ab complex) to enhance cytotoxicity of T cells by linking T cells and target cells together, and 20S-sgc8 exhibited antitumor efficacy superior to that of 6H5-sgc8. In conclusion, we screened a novel His-tag-binding aptamer and used it to construct a new type of MB for rapid detection of recombinant proteins, as well as establish a feasible approach for T cell-based immunotherapy.

Formaldehyde Cross-Linking-Assisted Phase Separation for Protein Aptamer Selection.

With the merits of easy synthesis, strong modifiability, and high affinity, aptamers have been broadly applied for protein targeting in bioanalysis, diagnosis, and therapeutics. The selection of protein-targeted aptamers is currently largely dependent on solid-liquid separation by using different types of nano- or micro-beads. However, the use of beads inescapably introduces unwanted nonspecific binding and thus affects selection efficiency. In order to sidestep this obstacle, we herein report an integrated technique to facilitate the discovery and development of protein-targeting aptamers by incorporating formaldehyde cross-linking with phase separation (FCPS). The feasibility and universality of FCPS were confirmed by the successful selection of two aptamers that could target various antibodies. Unlike traditional approaches, the proposed technique avoids the use of beads and enables the rapid generation of aptamers after only one to three rounds of selection. The as-selected aptamers were further used to regulate and control antibody activity, showing potential applications in biomedicine.

Application of a Novel Aptamer Beacon for Rapid Detection of IgG1 Antibody Drugs.

Antibody drugs have been widely used to treat many diseases and are the fastest-growing drug class. IgG1 is the most common type of antibody because of its good serum stability; however, effective methods for the rapid detection of IgG1-type antibodies are lacking. In this study, we designed two aptamer molecules derived from the reported aptamer probe that has been proven to bind to the Fc fragment of the IgG1 antibody. The results showed that Fc-1S could specifically bind to the human IgG1 Fc proteins. In addition, we modified the structure of Fc-1S and constructed three aptamer molecular beacons that could quantitatively detect IgG1-type antibodies within a short time. Furthermore, we unveiled that the Fc-1S37R beacon has the highest sensitivity for IgG1-type antibodies with a detection limit of 48.82813 ng/mL and can accurately detect serum antibody concentrations in vivo with consistent results to ELISA. Therefore, Fc-1S37R is an efficient method for the production monitoring and quality control of IgG1-type antibodies to enable the large-scale production and application of antibody drugs.

A novel aptamer beacon for rapid screening of recombinant cells and in vivo monitoring of recombinant proteins.

Recombinant protein drugs, which are typically produced by mammalian host cells, have been approved for the treatment of a range of diseases. Accordingly, systems for selecting recombinant cell lines with efficient protein expression and for testing the content of recombinant proteins in vivo are crucial to the large-scale production and application of protein-based therapeutic drugs. In this study, we designed three aptamer beacons to detect His-tag, a common label of recombinant proteins. We found that all three beacons could specifically and quantitatively measure the His-tagged recombinant proteins with a short reaction time. Among these three beacons, the 6H5-MU beacon had the highest sensitivity for His polypeptides with a detection limit of 250 ng/mL and the shortest detection time within 1 min. Furthermore, we established a rapid and highly effective recombinant cell line construction system, which could obtain monoclonal cell lines with high yields of target proteins within 21 days, by combining 6H5-MU with pSB, a novel plasmid composed of a Sleeping Beauty transposase and a transposon. Finally, 6H5-MU also discriminately tested the serum concentration of His-tagged recombinant proteins in vivo, with consistent results compared to enzyme-linked immunosorbent assay (ELISA). We thus established a rapid and high-throughput method for generating recombinant cell lines and in vivo monitoring of recombinant protein levels, thereby providing a new platform for the development and preparation of recombinant protein drugs. KEY POINTS: • The 6H5-MU aptamer beacon rapidly and accurately binds to His-tagged recombinant proteins. • A system for rapid and high-throughput generation of recombinant cell lines is established using 6H5-MU and pSB. • 6H5-MU allows in vivo monitoring of recombinant protein levels.

Histone Deacetylase9 Represents the Epigenetic Promotion of M1 Macrophage Polarization and Inflammatory Response via TLR4 Regulation.

Atherosclerosis is a chronic inflammatory response mediated by various factors, where epigenetic regulation involving histone deacetylation is envisaged to modulate the expression of related proteins by regulating the binding of transcription factors to DNA, thereby influencing the development of atherosclerosis. The mechanism of atherosclerosis by histone deacetylation is partly known; hence, this project aimed at investigating the role of histone deacetylase 9 (HDAC9) in atherosclerosis. For this purpose, serum was separated from blood samples following clotting and centrifugation from atherosclerotic and healthy patients (n = 40 each), and then, various tests were performed. The results indicated that toll-like receptor 4 (TLR4) was not only positively correlated to the HDAC9 gene, but was also upregulated in atherosclerosis, where it was also significantly upregulated in the atherosclerosis cell model of oxidized low-density lipoprotein-induced macrophages. Conversely, the TLR4 was significantly downregulated in instances of loss of HDAC9 function, cementing the bridging relationship between HDAC9 and macrophage polarization, where the HDAC9 was found to upregulate M1 macrophage polarization which translated into the release of higher content of proinflammatory cytokines such as interleukin-1beta (IL-1ß) and tumor necrosis factor-alpha (TNF-α), which tend to significantly decrease following the deletion of TLR4. Hence, this study reports novel relation between epigenetic control and atherosclerosis, which could partly be explained by histone deacetylation.

Asymmetric impact of pandemics-related uncertainty on CO2 emissions: evidence from top-10 polluted countries.

The recent COVD-19 pandemic has been a major shock, affecting various macroeconomic indicators, including the environmental quality. The question of how the pandemics-related uncertainty will affect the environment is of paramount importance. The study analyzes the asymmetric impact of pandemic uncertainty on CO2 emissions in top-10 polluted economies (China, USA, India, Russia, Germany, Japan, Iran, South Korea, Indonesia, and Saudi Arabia). Taking panel data from 1996 to 2018, a unique technique, 'Quantile-on-Quantile (QQ)', is employed. CO2 emissions are used as an indicator of environmental quality. The outcomes define how the quantiles of pandemic uncertainty impact the quantiles of carbon emissions asymmetrically by providing an effective paradigm for comprehending the overall dependence framework. The outcomes reveal that pandemic uncertainty promotes environmental quality by lowering CO2 emissions in our sample countries at various quantiles. However, Japan shows mixed findings. The effect of PUN on CO2 is substantially larger in India, Germany, and South Korea and lower in Russia and Saudi Arabia. Furthermore, the magnitude of asymmetry in the pandemic uncertainty-CO2 emissions association differs by economy, emphasizing that government must pay particular caution and prudence when adopting pandemics-related uncertainty and environmental quality policies.

Efficacy of angiotensin receptor neprilysin inhibitor in Asian patients with refractory hypertension.

Sacubitril/valsartan, simultaneously inhibits neprilysin and angiotensin II receptor, showed an effect in reducing blood pressure (BP). The authors aimed to study whether it can be used as an antihypertensive agent in patients with refractory hypertension who have already been treated. A total of 66 Chinese patients with refractory hypertension were enrolled. Patients received sacubitril/valsartan  200 instead of angiotensin II receptor blocker or angiotensin converting enzyme inhibitor while other agents continued. If BP was uncontrolled after 4 weeks, sacubitril/valsartan was increased to 400 mg. The BP reduction was evaluated by office BP and ambulatory BP monitoring after 8-week treatment. The baseline office BP and mean arterial pressure (MAP) were 150.0/95.0 mmHg and 113.3 mmHg. BP and MAP reduced to 130.6/83.2 mmHg and 99.0 mmHg at week 8. Office BP and MAP reductions were 19.4/11.8 mmHg and 14.3 mmHg at endpoint (all p < .001). The 24-h, daytime and nighttime ambulatory BP were 146.2/89.1, 148.1/90.3, and 137.5/83.7 mmHg, respectively at baseline, and BP reduced to 129.6/79.8, 130.6/81.1, and 121.7/75.8 mmHg, respectively at week 8. The 24-h, daytime and nighttime ambulatory BP reductions were 16.6/9.3, 17.5/9.2, and 15.8/7.9 mmHg, respectively at endpoint (all p < .001). Sacubitril/valsartan significantly reduced office and ambulatory BP in refractory hypertension patients. Our study provided new evidence for sacubitril/valsartan in refractory hypertension.

The Clinical Effects of Intravascular Ultrasound-Guided Percutaneous Coronary Intervention in Patients with Chronic Total Occlusion: A Meta-Analysis.

Background: The clinical effects of intravascular ultrasound (IVUS)-guided percutaneous coronary intervention (PCI) in patients with chronic total occlusion (CTO) lesions remain unclear. Methods: We identified all full-text published studies that compared the effects of IVUS-guided CTO-PCI with angiography-guided CTO-PCI by searching electric databases including PubMed, Embase, Cochrane Library, and ISI Web of Science from the establishment to Nov 2021. There was no language limitation. The endpoints included the incidence of major adverse cardiac events (MACE), cardiac death, all-cause death, myocardial infarction (MI), and target vessel revascularization (TVR). Results: Five studies involving a total of 2320 patients were included in this meta-analysis. Compared to the angiography-guided group, IVUS-guided PCI showed no significant reduction in the incidence of MACE (I 2 = 27.4%, P = 0.239; RR 0.929, 95% CI 0.765 to 1.128, P = 0.457), cardiac death (I 2 = 0.0%, P = 0.459; RR 0.574, 95% CI 0.299 to 1.103, P = 0.096), all-cause death (I 2 = 0.0%, P = 0.964; RR 0.677, 95% CI 0.395 to 1.163, P = 0.158), MI (I 2 = 46.7%, P = 0.131; RR0.836, 95% CI 0.508 to 1.377, P = 0.482), and TVR (I 2 = 21.2%, P = 0.279; RR 0.929, 95% CI 0.679 to 1.272, P = 0.648). Conclusions: IVUS-guided PCI demonstrated no significant benefit on MACE, cardiac death, all-cause death, MI, and TVR in patients with CTO lesions. However, given the study's limitations, additional high-quality RCTs are needed.

Protective Effect of Trimetazidine on Potassium Ion Homeostasis in Myocardial Tissue in Mice with Heart Failure.

The occurrence of heart failure (HF) is closely correlated with the disturbance of mitochondrial energy metabolism, and trimetazidine (TMZ) has been regarded as an effective agent in treating HF. Intracellular potassium ion (K+) homeostasis, which is modulated by K+ channels and transporters, is crucial for maintaining normal myocardial function and can be disrupted by HF. This study is aimed at exploring the protective effect of TMZ on K+ homeostasis within myocardial tissue in mice with HF. We observed the pathological changes of myocardial tissue under microscopes and further measured the content of adenosine triphosphate (ATP), the activity of Na+-K+ ATPase, and the expression of ATP1α1 at the mRNA and protein levels. Moreover, we also analyzed the changes in K+ flux across the myocardial tissue in mice. As a result, we found that there was a large amount of myocardial fiber lysis and fracture in HF myocardial tissue. Meanwhile, the potassium flux of mice with HF was reduced, and the expression of ATP1α1, the activity of Na+-K+ ATPase, and the supply and delivery of ATP were also decreased. In contrast, TMZ can effectively treat HF by restoring K+ homeostasis in the local microenvironment of myocardial tissues.

Effects of Liraglutide on Left Ventricular Function: A Meta-Analysis of Randomized, Placebo-Controlled Trials.

BACKGROUND: The effects of liraglutide treatment on the left ventricular systolic and diastolic function remain unclear. METHODS: This meta-analysis was conducted according to the preferred reporting items for systematic reviews and meta-analysis (PRISMA) statement. All relevant randomized, placebo-controlled trials (RCTs) were identified by searching PubMed, EMBASE, Cochrane Library, and ISI Web of Science from the establishment to January 2021 without language limitations. The weighted mean difference (WMD) with 95% confidence intervals (CIs) was calculated. RESULTS: Ten placebo-controlled RCTs involving a total of 732 cases were included in the meta-analysis. Compared with the placebo group, liraglutide therapy showed no beneficial effect on the left ventricular ejection fraction (LVEF) at the end of the study (WMD: 2.120, 95% CI: -0.688 to 4.929, P=0.139) and ΔLVEF during the trial period (WMD: -0.651, 95% CI: -1.649 to 0.348, P=0.202). Similarly, no statistical differences were noted in diastolic function parameters between the two groups, including the value early diastolic filling velocity (E)/the mitral annular early diastolic velocity (e') (WMD: -0.763, 95% CI: -2.157 to 0.630, P=0.283), Δe' (WMD: -0.069, 95% CI: -0.481 to 0.343, P=0.742), and ΔE/e' (WMD: -0.683, 95% CI: -1.663 to 0.298, P=0.172). CONCLUSIONS: Liraglutide treatment did not improve the left ventricular systolic and diastolic function. Given the study's limitations, further investigation may be warranted.

Anonymous Asynchronous Ratchet Tree Protocol for Group Messaging.

Signal is the first application that applies the double ratchet for its end-to-end encryption protocol. The core of the double ratchet protocol is then applied in WhatsApp, the most popular messaging application around the world. Asynchronous Ratchet Tree (ART) is extended from ratchet and Diffie-Hellman tree. It is the first group protocol that applies Forward Secrecy (FS) with Post-Compromised Security (PCS). However, it does not consider protecting the privacy of user identity. Therefore, it makes sense to provide anonymous features in the conditions of FS and PCS. In this paper, the concepts of Internal Group Anonymity (IGA) and External Group Anonymity (EGA) are formalized. On the basis of IGA and EGA, we develop the "Anonymous Asynchronous Ratchet Tree (AART)" to realize anonymity while preserving FS and PCS. Then, we prove that our AART meets the requirements of IGA and EGA as well as FS and PCS. Finally, the performance and related issues of AART are discussed.

Suppression of c-Met-Overexpressing Tumors by a Novel c-Met/CD3 Bispecific Antibody.

INTRODUCTION: Overexpression of c-Met, or hepatocyte growth factor (HGF) receptor, is commonly observed in tumor biopsies and often associated with poor patient survival, which makes HGF/c-Met pathway an attractive molecular target for cancer therapy. A number of antibody-based therapeutic strategies have been explored to block c-Met or HGF in cancers; however, clinical efficacy has been very limited, indicating that blockade of c-Met signal alone is not sufficient. Thus, an alternative approach is to develop an immunotherapy strategy for c-Met-overexpressing cancers. c-Met/CD3 bispecific antibody (BsAb) could bridge CD3-positive T lymphocytes and tumor cells to result in potent tumor cell killing. MATERIALS AND METHODS: A bispecific antibody, BS001, which binds both c-Met and CD3, was generated using a novel BsAb platform. Western blotting and T cells-mediated killing assays were utilized to evaluate the BsAb's effects on cell proliferation, survival and signal transduction in tumor cells. Subcutaneous tumor mouse models were used to analyze the in vivo anti-tumor effects of the bispecific antibody and its combination therapy with PD-L1 antibody. RESULTS: BS001 showed potent T-cell mediated tumor cells killing in vitro. Furthermore, BS001 inhibited phosphorylation of c-Met and downstream signal transduction in tumor cells. In A549 lung cancer xenograft model, BS001 inhibited tumor growth and increased the proportion of activated CD56+ tumor infiltrating lymphocytes. In vivo combination therapy of BS001 with Atezolizumab (an anti-programmed cell death protein1-ligand (PD-L1) antibody) showed more potent tumor inhibition than monotherapies. Similarly, in SKOV3 xenograft model, BS001 showed a significant efficacy in tumor growth inhibition and tumor recurrence was not observed in more than half of mice treated with a combination of BS001 and Pembrolizumab. CONCLUSION: c-Met/CD3 bispecific antibody BS001 exhibited potent anti-tumor activities in vitro and in vivo, which was achieved through two distinguished mechanisms: through antibody-mediated tumor cell killing by T cells and through inhibition of c-Met signal transduction.

Aptamers as Versatile Molecular Tools for Antibody Production Monitoring and Quality Control.

Antibody drugs have been used to treat many diseases, and to date, this has been the most rapidly growing drug class. However, the lack of suitable methods for real-time and high-throughput monitoring of antibody production and quality control has been a hindrance to the further advancement of antibody drugs or biosimilars. Therefore, we herein report a versatile tool for one-step fluorescence monitoring of antibody production by using aptamer probes selected through the in vitro SELEX method. In this case, DNA aptamers were selected against the humanized IgG1 antibody drug trastuzumab with high specificity and affinity with a Kd value of aptamer CH1S-3 of 10.3 nM. More importantly, the obtained aptamers were able to distinguish native from heat-treated, whereas antibodies failed this test. On the basis of the advantages of rapid detection for aptamers, we designed aptamer molecular beacons for direct and sensitive detection of trastuzumab in complex samples. Unlike traditional antibody-based ELISA, the signal was observed directly upon interaction with the target without the need for time-consuming binding and multiple washing steps. To further highlight biomedical applications, the use of aptamers as potential tools for quality control and traceless purification of antibody drugs was also demonstrated. Thus, aptamers are shown to be promising alternatives for antibody production monitoring, quality control, and purification, providing technical support to accelerate antibody drug development.

Improved recombinant protein production by regulation of transcription and protein transport in Chinese hamster ovary cells.

OBJECTIVES: To identify genes that affected protein expression in Chinese hamster ovary (CHO) cells was significant, and we identified the changes in the transcriptome and the functional gene sets that would contribute to increase expression of recombinant protein. RESULTS: Here two sub-clones from a methotrexate-treated parental recombinant CHO cell line were selected. The two sub-clones, with different expression levels (qp were 42.8 pg/cell/day and 14.0 pg/cell/day), were analyzed through RNA-seq. More than 600 genes were identified as differently expressed, and we found that the differentially expressed genes were involved in processes such as RNA processing, transcription, protein catabolism, and protein transport. Among these, we cloned genes encoding proteins that were involved in transcription and protein transport to investigate their effect on protein production. CONCLUSIONS: We found that some genes involved in transcription and protein transport would improve recombinant protein production in CHO cells.