Superantigen-fused T cell engagers for tumor antigen-mediated robust T cell activation and tumor cell killing.

Inadequate T cell activation has severely limited the success of T cell engager (TCE) therapy, especially in solid tumors. Enhancing T cell activity while maintaining the tumor specificity of TCEs is the key to improving their clinical efficacy. However, currently, there needs to be more effective strategies in clinical practice. Here, we design novel superantigen-fused TCEs that display robust tumor antigen-mediated T cell activation effects. These innovative drugs are not only armed with the powerful T cell activation ability of superantigens but also retain the dependence of TCEs on tumor antigens, realizing the ingenious combination of the advantages of two existing drugs. Superantigen-fused TCEs have been preliminarily proven to have good (>30-fold more potent) and specific (>25-fold more potent) antitumor activity in vitro and in vivo. Surprisingly, they can also induce the activation of T cell chemotaxis signals, which may promote T cell infiltration and further provide an additional guarantee for improving TCE efficacy in solid tumors. Overall, this proof-of-concept provides a potential strategy for improving the clinical efficacy of TCEs.

BR109, a Novel Fully Humanized T-Cell-Engaging Bispecific Antibody with GPRC5D Binding, Has Potent Antitumor Activities in Multiple Myeloma.

At present, multiple myeloma (MM) is still an essentially incurable hematologic malignancy. Although BCMA-targeted therapies have achieved remarkable results, BCMA levels were found to be downregulated in patients with MM who relapsed after these treatments. Therefore, the search for other antigens specific to MM has become a priority. Independently of BCMA expression, G-protein-coupled receptor family C group 5 member D (GPRC5D) is mainly expressed in the plasma cells of MM patients, while it is expressed in a limited number of normal tissues. Combining MM-specific antigen GPRC5D and T-cell-mediated therapies would be a promising therapeutic strategy for MM. Recently, we constructed a new anti-GPRC5D × anti-CD3 T-cell-engaging bispecific antibody (TCB), BR109, which was capable of binding to human GPRC5D and human CD3ε. Moreover, BR109 was proven to have relatively good stability and antitumor activity. BR109 could specifically trigger T-cell-mediated cytotoxicity against many GPRC5D-positive MM cells in vitro. Meanwhile, antitumor activity was demonstrated in MM cell line xenograft mouse models with human immune cell reconstitution. These preclinical studies have formed a solid foundation for the evaluation of MM treatment efficacy in clinical trials.

Improving the tumor selectivity of T cell engagers by logic-gated dual tumor-targeting.

Targeting single tumor antigens makes it difficult to provide sufficient tumor selectivity for T cell engagers (TCEs), leading to undesirable toxicity and even treatment failure, which is particularly serious in solid tumors. Here, we designed novel trispecific TCEs (TriTCEs) to improve the tumor selectivity of TCEs by logic-gated dual tumor-targeting. TriTCE can effectively redirect and activate T cells to kill tumor cells (∼18 pM EC50) by inducing the aggregation of dual tumor antigens, which was ∼70- or 750- fold more effective than the single tumor-targeted isotype controls, respectively. Further in vivo experiments indicated that TriTCE has the ability to accumulate in tumor tissue and can induce circulating T cells to infiltrate into tumor sites. Hence, TriTCE showed a stronger tumor growth inhibition ability and significantly prolonged the survival time of the mice. Finally, we revealed that this concept of logic-gated dual tumor-targeted TriTCE can be applied to target different tumor antigens. Cumulatively, we reported novel dual tumor-targeted TriTCEs that can mediate a robust T cell response by simultaneous recognition of dual tumor antigens at the same cell surface. TriTCEs allow better selective T cell activity on tumor cells, resulting in safer TCE treatment.

Optimization strategies for expression of a novel bifunctional anti-PD-L1/TGFBR2-ECD fusion protein.

The novel anti-PD-L1/TGFBR2-ECD fusion protein (BR102) comprises an anti-PD-L1 antibody (HS636) which is fused at the C terminus of the heavy chain to a TGF-ß1 receptor Ⅱ ectodomain (TGFBR2-ECD), and which can sequester the PD-1/PD-L1 pathway and TGF-ß bioactivity in the immunosuppressive tumor microenvironment. In the expression of TGFBR2-ECD wild-type fused protein (BR102-WT), a 50 kDa clipped species was confirmed to be induced by proteolytic cleavage at a "QKS" site located in the N-terminus of the ectodomain, which resulted in the formation of IgG-like clipping. The matrix metalloproteinase-9 was determined to be associated with BR102-WT digestion. In addition, it was observed that the N-glycosylation modifications of the fusion protein were tightly involved in regulating proteolytic activity and the levels of cleavage could be significantly suppressed by MMP-inhibitors. To avoid proteolytic degradation, eliminating protease-sensitive amino acid motifs and introducing potential glycosylation were performed. Three sensitive motifs were mutated, and the levels of clipping were strongly restrained. The mutant candidates exhibited similar binding affinities to hPD-L1 and hTGF-ß1 as well as highly purified BR102-WT2. Furthermore, the mutants displayed more significant proteolytic resistance than that of BR102-WT2 in the lysate incubation reaction and the plasma stability test. Moreover, the bifunctional candidate Mu3 showed an additive antitumor effect in MC38/hPD-L1 bearing models as compared to that of with anti-PD-L1 antibody alone. In conclusion, in this study, the protease-sensitive features of BR102-WT were well characterized and efficient optimization was performed. The candidate BR102-Mutants exhibited advanced druggability in drug stability and displayed desirable antitumor activity.

Microvessel Density: Integrating Sex-Based Differences and Elevated Cardiovascular Risks in Metabolic Syndrome.

Metabolic syndrome (MetS) is a complex pathological state consisting of metabolic risk factors such as hypertension, insulin resistance, and obesity. The interconnectivity of cellular pathways within various biological systems suggests that each individual component of MetS may share common pathological sources. Additionally, MetS is closely associated with vasculopathy, including a reduction in microvessel density (MVD) (rarefaction) and elevated risk for various cardiovascular diseases. Microvascular impairments may contribute to perfusion-demand mismatch, where local metabolic needs are insufficiently met due to the lack of nutrient and oxygen supply, thus creating pathological positive-feedback loops and furthering the progression of disease. Sexual dimorphism is evident in these underlying cellular mechanisms, which places males and females at different levels of risk for cardiovascular disease and acute ischemic events. Estrogen exhibits protective effects on the endothelium of pre-menopausal women, while androgens may be antagonistic to cardiovascular health. This review examines MetS and its influences on MVD, as well as sex differences relating to the components of MetS and cardiovascular risk profiles. Finally, translational relevance and interventions are discussed in the context of these sex-based differences.

Development of a Recombinant RBD Subunit Vaccine for SARS-CoV-2.

The novel coronavirus pneumonia (COVID-19) pandemic is a great threat to human society and now is still spreading. Although several vaccines have been authorized for emergency use, only one recombinant subunit vaccine has been permitted for widespread use. More subunit vaccines for COVID-19 should be developed in the future. The receptor binding domain (RBD), located at the S protein of SARS-CoV-2, contains most of the neutralizing epitopes. However, the immunogenicity of RBD monomers is not strong enough. In this study, we fused the RBD-monomer with a modified Fc fragment of human IgG1 to form an RBD-Fc fusion protein. The recombinant vaccine candidate based on the RBD-Fc protein could induce high levels of IgG and neutralizing antibody in mice, and these could last for at least three months. The secretion of IFN-γ, IL-2 and IL-10 in the RBD-stimulated splenocytes of immunized mice also increased significantly. Our results first showed that the RBD-Fc vaccine could induce both humoral and cellular immune responses and might be an optional strategy to control COVID-19.

Soluble Expression of Fc-Fused T Cell Receptors Allows Yielding Novel Bispecific T Cell Engagers.

The specific recognition of T cell receptors (TCR) and peptides presented by human leukocyte antigens (pHLAs) is the core step for T cell triggering to execute anti-tumor activity. However, TCR assembly and soluble expression are challenging, which precludes the broad use of TCR in tumor therapy. Herein, we used heterodimeric Fc to assist in the correct assembly of TCRs to achieve the stable and soluble expression of several TCRs in mammalian cells, and the soluble TCRs enable us to yield novel bispecific T cell engagers (TCR/aCD3) through pairing them with an anti-CD3 antibody. The NY-ESO-1/LAGE-1 targeted TCR/aCD3 (NY-TCR/aCD3) that we generated can redirect naïve T cells to specific lysis antigen-positive tumor cells, but the potency of the NY-TCR/aCD3 was disappointing. Furthermore, we found that the activation of T cells by NY-TCR/aCD3 was mild and unabiding, and the activity of NY-TCR/aCD3 could be significantly improved when we replaced naïve T cells with pre-activated T cells. Therefore, we employed the robust T cell activation ability of staphylococcal enterotoxin C2 (SEC2) to optimize the activity of NY-TCR/aCD3. Moreover, we found that the secretions of SEC2-activated T cells can promote HLA-I expression and thus increase target levels, which may further contribute to improving the activity of NY-TCR/aCD3. Our study described novel strategies for soluble TCR expression, and the optimization of the generation and potency of TCR/aCD3 provided a representative for us to fully exploit TCRs for the precision targeting of cancers.

Specific Inhibition of Tumor Growth by T Cell Receptor-Drug Conjugates Targeting Intracellular Cancer-Testis Antigen NY-ESO-1/LAGE-1.

Despite the significant therapeutic advances in T-cell immunotherapy, many malignancies remain unresponsive, which might be because of the negative regulation of T cells by the tumor microenvironment (TME). T cells discriminate tumor cells and normal cells through T-cell receptors (TCRs); therefore, we generated a novel type of TCR-drug conjugates (TDCs) by referring antibody-drug conjugations (ADCs) to overcome the effects of the TME on T cells while preserving the specificity of TCR for tumor recognition. We selected HLA-A2/NY-ESO-1157-165 (peptide NY-ESO-1157-165 in complex with human leukocyte antigen serotype HLA-A*02:01) as the antigen and the antigen-specific TCR (1G4113) as the carrier. By sortase A-mediated ligation, we obtained three NY-TCR-vcMMAEs and further studied their properties, antitumor activity, and toxicity in vitro and in vivo. We found that all the NY-TCR-vcMMAEs had high endocytosis efficiency and specifically killed HLA-A2/NY-ESO-1157-165 positive tumor cells. In xenograft models, one of the TDCs, NY-TCR-2M, was effectively and specifically distributed into tumor tissues and inhibited tumor growth without inducing obvious toxicity. Our results demonstrated that TCRs can be carriers of toxic payloads and that the TDCs thus formed can specifically inhibit tumor growth, neglecting the immune microenvironment.

Osteological Re-Assessment and Taxonomic Revision of "Tanius laiyangensis" (Ornithischia: Hadrosauroidea) from the Upper Cretaceous of Shandong, China.

Tanius is the earliest named ornithischian genus from China. Since 1929, three species of this genus, namely T. sinensis (the type species), "T. chingkankouensis" and "T. laiyangensis", have been reported based on remains from the Wangshi Group of Shandong, China, and were previously recognized as hadrosaurines. Following the recent achievement of consensus on the phylogenetic placement of T. sinensis outside Hadrosauridae, the assignments of the "T. chingkankouensis" and "T. laiyangensis" material of hadrosaurid origin to the genus Tanius become problematic. Related taxonomic issues of "T. laiyangensis" therefore need re-appraisals. Here, we provide an overall taxonomic revision of "T. laiyangensis" from the Jingangkou Formation of northeast Shandong, by means of approaches of comparative anatomy, phylogeny and geometric morphometrics. Our osteological comparisons confirm the hadrosaurine affinity of "T. laiyangensis", given the presence of a suite of characters largely typical of Hadrosaurinae in the single specimen (i.e., a nearly complete sacrum and a partial right ilium), including a dorsoventrally narrow central plate of the ilium with the depth/length ratio <0.80. In the proposed phylogenetic framework, "T. laiyangensis" is inferred to be a member of Kritosaurini within Hadrosaurinae, as the sister taxon to Secernosaurus koerneri. The relative warp analysis on the lateral outline of the supraacetabular process also reveals a close resemblance of shape between the two species. Based on these different lines of evidence and considering no identification of any diagnostic characters from the specimen, we argue that the "T. laiyangensis" material comes from an indeterminate kritosaurin hadrosaurine in Asia. Anat Rec, 303:790-800, 2020. © 2019 Wiley Periodicals, Inc.

MicroRNA-2738 regulates gene expression in the sex determination pathway in Bombyx mori.

MicroRNAs (miRNAs) are a class of short, non-coding transcripts that bind to 3'-untranslated regions to trigger messenger RNA degradation or translational inhibition. Here we explored how miRNAs regulate sex determination in Bombyx mori, a lepidopteran model insect. Genes known to be involved in sex determination, BmPSI, Bmdsx, and BmMasc, are predicted targets of the species-specific miR-2738. Using a dual luciferase reporter assay in HEK293T cells, we confirmed that miR-2738 suppressed transcription of BmPSI, Bmdsx, and BmMasc. The levels of BmPSI and BmMasc were significantly down-regulated in B. mori miR-2738 overexpression. In contrast, the genetic disruption of miR-2738 using the clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 transgenic system increased the levels of BmPSI and BmMasc transcripts, whereas splicing of Bmdsx was unaltered by miR-2738 depletion or overexpression. Taken together, this study implicates miR-2738 as a minor regulator of sex determination genes in the silkworm.

The Antitumor Activity of TCR-Mimic Antibody-Drug Conjugates (TCRm-ADCs) Targeting the Intracellular Wilms Tumor 1 (WT1) Oncoprotein.

Wilms tumor 1 (WT1) oncoprotein is an intracellular oncogenic transcription factor which is barely expressed in normal adult tissues but over expressed in a variety of leukemias and solid cancers. WT1-derived HLA-A*02:01 T cell epitope, RMFPNAPYL (RMF), is a validated target for T cell-based immunotherapy. We generated two T cell receptor mimic antibody-drug conjugates (TCRm-ADCs), ESK-MMAE, and Q2L-MMAE, against WT1 RMF/HLA-A*02:01 complex with distinct affinities, which mediate specific antitumor activity. Although ESK-MMAE showed higher tumor growth inhibition ratio in vivo, the efficacy of them was not so promising, which might be due to low expression of peptide/HLA targets. Therefore, we explored a bispecific TCRm-ADC that exerted more potent tumor cytotoxicity compared with TCRm-ADCs. Hence, our findings validate the feasibility of the presenting intracellular peptides as the targets of ADCs, which broadens the antigen selection range of antibody-based drugs and provides new strategies for precision medicine in tumor therapy.

Meta-analysis and systematic review of the efficacy and resistance for human immunodeficiency virus type 1 integrase strand transfer inhibitors.

Integrase strand transfer inhibitors (INSTIs) are the most recent class of antiretroviral drugs with potent and durable antiviral activity used to treat human immunodeficiency virus type 1 (HIV-1) infection. However, development of drug resistance increases the risk of treatment failure, disease progression and mortality. A better understanding of drug efficacy and resistance against INSTIs is crucial for their efficient use and the development of new antiretrovirals. A meta-analysis of studies reporting efficacy and resistance data on INSTI use in HIV-infected patients was performed. Odds ratios (ORs) of efficacy outcome data favouring INSTI use in different clinical settings demonstrated that INSTIs have higher efficacy compared with drugs of other classes. For combination antiretroviral therapy-naïve patients and virologically-suppressed patients who switched to INSTI-based therapy, the OR was 1.484 (95% CI 1.229-1.790) and 1.341 (95% CI 0.913-1.971), respectively. ORs of resistance data indicated decreased treatment-emergent resistance development to dolutegravir (DTG) upon virological failure than to non-INSTIs (OR = 0.081, 95% CI 0.004-1.849), whereas the opposite was observed for raltegravir (RAL) (OR = 3.137, 95% CI 1.827-5.385) and elvitegravir (EVG) (OR = 1.886, 95% CI 0.569-6.252). Pooled analysis of resistance data indicated that development of resistance to DTG and bictegravir was rare, whereas EVG and RAL had low genetic barriers to resistance and the intensive cross-resistance between them limits INSTI efficiency. Efficient means of monitoring the emergence of resistance to INSTIs and the development of drugs with high genetic barriers are clear paths for future research.

Associations between human leukocyte antigen polymorphisms and hypersensitivity to antiretroviral therapy in patients with human immunodeficiency virus: a meta-analysis.

BACKGROUND: Human leukocyte antigen (HLA) alleles are implicated in drug-induced hypersensitivity, including by nevirapine and abacavir. The purpose of this meta-analysis was to evaluate the relationship between HLA polymorphisms and hypersensitivity to antiretroviral therapy in human immunodeficiency virus (HIV)-infected patients. METHODS: We conducted a systematic search of PubMed, Embase, Web of Science, and the Cochrane Library for studies that evaluated the associations of HLA polymorphisms with antiretroviral therapy-induced hypersensitivity published in April 2019. The summary odds ratios (ORs) with 95% confidence intervals (CIs) were considered as estimates of the effect. RESULTS: The meta-analysis included 17 studies that assessed a total of 4273 patients. First, carriers of HLA-A *24 were associated with an increased risk of hypersensitivity among patients with HIV who received antiretroviral therapy (OR: 12.12; P = 0.018). Second, five SNPs of HLA-B genotypes, including *18 (OR: 1.63; P = 0.028), *35 (OR: 2.31; P = 0.002), *39 (OR: 11.85; P = 0.040), *51 (OR: 1.66; P = 0.028), and *81 (OR: 8.11; P = 0.021), were associated with an increased risk of hypersensitivity. Conversely, carriers of HLA-B *15 were associated with a reduced risk of hypersensitivity (OR: 0.43; P < 0.001). Third, HLA-C *04 was associated with an increased risk of hypersensitivity (OR: 3.09; P < 0.001), whereas a lower risk for hypersensitivity was observed in patients who were carriers of HLA-C *02 (OR: 0.22; P = 0.030), *03 (OR: 0.53; P = 0.049), and *07 (OR: 0.61; P = 0.044). Finally, carriers of HLA-DRB1 *05 (OR: 0.18; P = 0.006) and *15 (OR: 0.23; P = 0.013) were associated with a reduced risk of hypersensitivity among patients receiving antiretroviral therapy. CONCLUSIONS: The findings of this meta-analysis indicated patients carrying HLA-A *24, HLA-B *18, *35, *39, *51, *81, HLA-C *04 were associated with a higher risk of hypersensitivity. Conversely, subjects carrying HLA-B *15, HLA-C *02, *03, *07, HLA-DRB1 *05, *15 were associated with a reduced risk of hypersensitivity.

Influence of OATP1B1 and OATP1B3 mutations and glomerular filtration rate on trough serum digoxin concentration in the Chinese population: A prospective cohort study.

Polymorphisms of organic anion transporting polypeptides (OATPs) have been reported to affect trough serum digoxin concentration (SDC). However, the association of these polymorphisms with trough SDC in Chinese heart failure patients has not been studied. We aim to explore whether OATP1B1 388A>G, OATP1B1 521T>C, and OATP1B3 699G>A influence trough SDC in Chinese heart failure patients and to make clinical recommendations.Chinese patients (n = 104) diagnosed with heart failure under long-term digoxin therapy (0.125 mg daily) were enrolled in this study. Blood samples were collected for the analysis of trough SDC (immunofluorescence) and the polymorphisms of OATP1B1 388A>G, OATP1B1 521T>C, and OATP1B3 699G>A (PCR-RFLP and Sanger sequencing).Patients with glomerular filtration rate (GFR) under 30 mL/min had significantly higher trough SDC (1.20 ±â€Š0.50 ng/mL) than recommended trough SDC for heart failure patients. Trough SDC was not significantly influenced by mutations of OATP1B1 388A>G (P = .890), 521T>C (P = .054), and OATP1B3 699G>A (P = .854). Patients with OATP1B1 521T>C mutant-type carrier had slightly higher trough SDC (0.98 ±â€Š0.53 ng/mL) than those with wild-type carrier (0.74 ±â€Š0.40 ng/mL) when they have repaired renal function.Heart failure patients with severe renal dysfunction (GFR<60 mL/min) and/or OATP1B1 521T>C mutant-type carriers are recommended a smaller dosage of digoxin and strict therapeutic drug monitoring.

Identification of a germline-expression promoter for genome editing in Bombyx mori.

Identification of stage- and tissue-specific cis-regulatory elements will enable more precise genomic editing. In previous studies of the silkworm Bombyx mori, we identified and characterized several tissue- and sex-specific cis-regulatory elements using transgenic technology, including a female- and fat body-specific promoter, vitellogenin, testis-specific promoters, Radial spoke head 1 (BmR1) and beta-tubulin 4 (Bmß4). Here we report a cis-regulatory element specific for a somatic and germ cell-expressed promoter, nanos (Bmnos). We investigated activities of three truncated promoter sequences upstream of the transcriptional initiation site sequences of Bmnos in vitro (nos-0.6kb, nos-1kb and nos-2kb) and in vivo (nos-2kb). In BmN cultured cells, all three lengths drove expression of the gene encoding enhanced green fluorescence protein (EGFP), although nos-2kb had the highest fluorescence activity. In transgenic silkworms, nos-2kb drove EGFP expression at the early embryonic stage, and fluorescence was concentrated in the gonads at later embryonic stages. In addition, this cis-regulatory element was not sex differentiated. The fluorescence intensity gradually weakened following the larval developmental stage in the gonads and were broadly expressed in the whole body. The nos-2kb promoter drove the Cas9 system with efficiency comparable to that of the broad-spectrum strong IE1 promoter. These results indicate that Bmnos is an effective endogenous cis-regulatory element in the early embryo and in the gonad that can be used in applications involving the clustered, regularly interspaced, short palindromic repeats (CRISPR)/Cas9 system.

Genetic Polymorphisms and In Silico Mutagenesis Analyses of CYP2C9, CYP2D6, and CYPOR Genes in the Pakistani Population.

Diverse distributions of pharmacogenetically relevant variants of highly polymorphic CYP2C9, CYP2D6 and CYPOR genes are responsible for some varied drug responses observed across human populations. There is limited data available regarding the pharmacogenetic polymorphisms and frequency distributions of major allele variants in the Pakistani population. The present in silico mutagenesis study conducted on genotype pharmacogenetic variants and comparative analysis with a global population aims to extend the currently limited pharmacogenetic available evidence for the indigenous Pakistani population. Extracted genomic DNA from 244 healthy individuals' venous blood samples were amplified for distinct variant loci in the CYP2C9, CYP2D6 and CYPOR genes. Two-way sequencing results were compared with standard PubMed data and sequence variant loci confirmed by Chromas. This study revealed significant variations in CYP2C9 (rs1799853, rs1057910 and rs72558189), CYP2D6 (rs16947 and rs1135840), and CYPOR (rs1057868, rs781919285 and rs562750402) variants in intraethnic and interethnic frequency distributions. In silico mutagenesis and three-dimensional protein structural alignment analysis approaches clearly exposed the possible varied impact of rare CYPOR (rs781919285 and rs562750402) single nucleotide polymorphisms (SNPs) and confirmed that the influences of CYP2C9 and CYP2D6 variants are consistent with what was found in earlier studies. This investigation highlighted the need to study pharmacogenetic relevance loci and documentation since evidence could be utilized to elucidate genetic backgrounds of drug metabolism, and provide a basis for future pharmacogenomic studies and adequate dose adjustments in Pakistani and global populations.

Association between SLCO1B1 T521C polymorphism and risk of statin-induced myopathy: a meta-analysis.

Numerous studies have illustrated the relationship between SLCO1B1 T521C polymorphism and statin-induced myopathy risk; however, this association is not consistent. Three electronic databases (PubMed, EMBASE, and the Cochrane Library) were searched from inception to October 2017 to identify potential studies. The summary odds ratios (ORs) with 95% confidence intervals (CIs) were calculated from different genetic models by using a random-effects model. Fourteen studies comprising 3265 myopathy patients and 7743 controls were included. The summary ORs suggested that 521CC (OR: 2.31; 95% CI: 1.15-4.63; P = 0.019), 521TC (OR: 1.34; 95% CI: 1.02-1.76; P = 0.034), and 521CC + TC (OR: 1.82; 95% CI: 1.32-2.51; P < 0.001) were associated with a greater risk of statin-induced myopathy than 521TT. The higher incidence of statin-induced myopathy was found to be significantly correlated with the C allele compared with the T allele (OR: 1.89; 95% CI: 1.36-2.62; P < 0.001). In addition, we observed that 521CC + TC was associated with an increased risk of myopathy in individuals who received simvastatin (OR: 2.35; 95% CI: 1.08-5.12; P = 0.032) or rosuvastatin (OR: 1.69; 95% CI: 1.07-2.67; P = 0.024) when compared with 521TT. The 521C allele was associated with a greater risk of cerivastatin-induced myopathy than the T allele (OR: 1.95; 95% CI: 1.47-2.57; P < 0.001). The findings of this study indicated that SLCO1B1 T521C was associated with a significantly higher risk of statin-induced myopathy, especially for simvastatin, rosuvastatin, and cerivastatin. Future studies should be conducted in subjects receiving specific types of drugs, and any potential adverse events need to be explored.

Elimination of melanoma by sortase A-generated TCR-like antibody-drug conjugates (TL-ADCs) targeting intracellular melanoma antigen MART-1.

Most tumor-associated proteins are located inside tumor cells and thus are not accessible to current marketed therapeutic monoclonal antibodies or their cytotoxic conjugates. Human leukocyte antigen (HLA) class I can present peptides derived from intracellular tumor-associated proteins and somatically mutated proteins on the cell's surface, forming an HLA/peptide complex as tumor-specific antigens for T cell receptor (TCR) recognition. Therefore, HLA-mediated presentation of intracellular tumor antigen peptides provides a viable way to distinguish tumor cells from normal cells, which is important for broadening antigen selection, especially for antibody-drug conjugates (ADCs) regarding their highly cytotoxic payload. We applied sortase A-mediated conjugation to develop TCR-like ADCs (i.e., EA1 HL-vcMMAE) targeting intracellular MART-1 protein, a melanocyte-differentiating antigen specific for metastatic melanomas, via the cell surface HLA-A2/MART-126-35 peptide complex. Homogenous EA1 HL-vcMMAE (drug to antibody ratio of 4) efficiently eliminated melanoma cells in xenograft mouse models with no obvious toxicity at the therapeutic dosage. Trametinib, an MEK inhibitor serving as an HLA expression enhancing agent, augmented the TL-ADCs' efficacy both in vitro and in vivo by upregulating MART-126-35 peptide presentation, thus providing a strategy for overcoming the limitation of antigen presentation level for TL-ADCs. Hence, our findings validate the strategy of using sortase A-generated TL-ADCs to target tumor-specific intracellular proteins, with or without agents present, to increase presenting TCR epitope peptides.

In situ quantitative bioanalysis of monomethyl auristatin E-conjugated antibody-drug conjugates by flow cytometry.

Antibody-drug conjugates (ADCs) consist of cytotoxic agents covalently conjugated to monoclonal antibodies that substantially improve antitumour activity and reduce systemic toxicity. With the growing number of ADCs in clinical applications, more accurate bioanalysis data are urgently needed to facilitate the development and rational use of ADCs. Herein, we used antigen-positive cells as antigen carriers and ofatumumab (OFA-HL) and ofatumumab-based ADC (OFA-HL-MMAE) as examples to establish a new ligand-binding assay (LBA) method based on flow cytometry. We proved that the new method met the required analytical performance criteria and the lower limit of quantitation (LOQ) was 0.2 µg/mL. In addition, the LOQ of the quantitative OFA-HL flow cytometry method was reduced to 0.025 µg/mL by choosing an optimized fluorescent antibody, which indicated that the LOQ of the new method can be improved. What's more, the new method showed good stability and specificity when we used it to determine the concentrations of OFA-HL and OFA-HL-MMAE in mouse serum. During the bioanalysis of ADCs, various factors should be considered. Therefore, choosing optimal methods for ADC bioanalysis is necessary. This new method using in situ antigens not only extends the scope of application of the conventional LBA methods by avoiding the need for soluble antigens, but also improves the authenticity of ADC bioanalysis as a supplementary approach, which is valuable for developing accurate ADC assays.