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.

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.

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.

[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).

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.

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 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.

STK39 is an independent risk factor for male hypertension in Han Chinese.

BACKGROUND: STK39 interacts with OXSR1 and phosphorylates the sodium-chloride co-transporter (SLC12A3), which plays a critical role in regulating the salt/water balance and blood pressure. Here we tested whether STK39, OXSR1, and SLC12A3 genetically contribute to hypertension in the Han Chinese population and how the SNP to SNP or SNP to other risk factors interacts in the pathogenesis of hypertension. METHODS AND RESULTS: Eleven tagging SNPs from STK39, OXSR1, and SLC12A3 were selected and first genotyped in 1210 hypertensive and healthy individuals by sequencing. Two SNPs of STK39, rs6433027 and rs3754777, were found to be associated with hypertension in males (P=0.008-0.024). All other SNPs were not associated with hypertension in either gender. The association of rs6433027 and rs3754777 with male hypertension was validated by genotyping another 4598 hypertensive and healthy individuals. The odds ratios (95% confidence interval, P value) in males were 1.269 (1.13-1.43; P=0.0001) and 1.231 (1.078-1.41; P=0.004) of rs6433027 and rs3754777, respectively. The allele T of rs6433027 presented a strong epistatic effect on the allele A of rs3754777 in hypertensive trait. The minor allele frequencies of two SNPs were not stratified by age, BMI, or diabetes, the three major risk factors for hypertension. CONCLUSION: Our results suggest that STK39 is an independent risk factor for hypertension in men and that its intragenic SNPs can interact and function in the control of blood pressure.

On the design of fuzzified trajectory shaping guidance law.

Midcourse guidance is commonly designed to save as much energy as possible so that the missile's final speed can be maximized while entering the homing stage. For this purpose, a competitive guidance design should be able to generate an admissible flight trajectory as to bring the interceptor to a superior altitude for a favorable target engagement. In this paper, a new adaptive trajectory shaping guidance scheme based on the adaptive fuzzy inference system, which is capable of generating a variety of trajectories for efficient target interception, is presented. The guidance law is developed with the aim of saving the interceptor's energy conservation while improving performance robustness. Applications of the presented approach have included a variety of mission oriented guidance, such as cruise missile guidance, anti-ballistic missile guidance, etc.

Validation of VKORC1 and CYP2C9 genotypes on interindividual warfarin maintenance dose: a prospective study in Chinese patients.

OBJECTIVES: To develop a warfarin-dosing algorithm that could be combined with pharmacogenomic and demographic factors, and to evaluate its effectiveness in a randomized prospective controlled clinical trial. METHODS: A pharmacogenetics-based dosing model was derived using retrospective data from 266 Chinese patients and multiple linear regression analysis. To prospectively validate this model, 156 patients with an operation of heart valve replacement were enrolled and randomly assigned to the group of pharmacogenetics-guided or traditional dosing for warfarin therapy. All patients were followed up for 50 days after initiation of warfarin therapy. The log-rank test was compared with the time-to-event (Kaplan-Meier) curves. Cox proportional hazards-regression model was used to assess the hazard ratio of the time to reach stable dose. RESULTS: The linear regression model derived from the pharmacogenomic model correlated with 54.1% of warfarin dosing variance. The final multiple linear regression model included age, body surface area, VKORC1, and CYP2C9 genotype. The study showed that the hazard ratio for the time to reach stable dose was 1.932 for the traditional dosing group versus the model-based group and a close and highly significant relationship was observed to exist between the predicted and the actual warfarin dose (R=0.454). CONCLUSION: A pharmacogenetics-based dosing algorithm has been developed for improvement in the time to reach the stable dosing of warfarin. This model may be useful in helping the clinicians to prescribe warfarin with greater safety and efficiency.