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Biology subjects

Yin, Y.

Publications and source records attributed to Yin, Y..

At least 91 records · Page 5Linked to original sources

Targeting SLC7A11-mediated cysteine metabolism for the treatment of trastuzumab resistant HER2 positive breast cancer

Trastuzumab resistance remains a challenge for HER2 positive breast cancer treatment. Targeting metabolic reprogramming would provide novel insights for therapeutic strategies. Here, we integrated metabolomics, transcriptomics and epigenomics data of trastuzumab sensitive and primary resistant HER2 positive breast cancer to identify metabolic alterations. Aberrant cysteine metabolism was discovered in trastuzumab primary resistant breast cancer at both circulating and intracellular levels. The inhibition of SLC7A11 and cysteine starvation could synergize with trastuzumab to induce ferroptosis. Mechanistically, increased H3K4me3 and decreased DNA methylation enhanced SLC7A11 transcription and cystine uptake in trastuzumab resistant breast cancer. The regulation of epigenetic modifications modulated cysteine metabolism and ferroptosis sensitivity. These results revealed an innovative approach for overcoming trastuzumab resistance by targeting specific amino acid metabolism.

cancer biology↗

Neratinib, a clinical drug against breast cancer, protects against atherosclerosis via ASK1 inhibition

Atherosclerosis commences with endothelial dysfunction and the retention of cholesterol within the vessel wall, followed by a chronic inflammatory response. Cholesterol-lowering strategies (such as statins and PCSK9 inhibitors) are primarily used for treating patients with atherosclerotic cardiovascular diseases, but leaving the therapeutic dilemma of residual inflammatory risk. To address this challenge, we employed Connectivity Map (CMap) screening for inflammation mechanism-based anti-atherosclerotic compounds using perturbational datasets obtained from TNF and IL-1{beta}-stimulated human endothelial cells. This screening process allow us to identify Neratinib, a clinical drug against breast cancer, as the hit compound with potential anti-inflammatory actions in endothelial cells. Further studies reveal that Neratinib inhibited endothelial cell inflammation elicited by three different pro-inflammatory stimuli (TNF, IL-1{beta} and LPS). Intriguingly, the anti-inflammatory effect of Neratinib was independent of its classical target HER2/ERBB2 inhibition. Mechanistically, Neratinib directly binds ASK1 and suppresses ASK1 activation. In both male and female Ldlr-/- mice, treatment with Neratinib decreased the plaque area, reduced the necrotic core size and mitigated macrophage infiltration to stabilize plaques. Lastly, we observed that Neratinib, in conjunction with the use of Rosuvastatin (a standard lipid-lowering drug), led to a reduction in serum lipids, and produced synergistic anti-atherosclerotic effects. Olink proteomics study suggested that combination treatment alleviated inflammation-related cytokines/chemokines in the serum from Ldlr-/- mice. Taken together, these findings support the concept that Neratinib could be tested for its potential as a "repurposed" drug for vascular inflammation and atherosclerosis, thereby streamlining efforts to translate preclinical discoveries to clinical testing in humans. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=108 SRC="FIGDIR/small/622073v1_ufig1.gif" ALT="Figure 1"> View larger version (28K): org.highwire.dtl.DTLVardef@78ef07org.highwire.dtl.DTLVardef@194f56forg.highwire.dtl.DTLVardef@7d65e4org.highwire.dtl.DTLVardef@ac7fe3_HPS_FORMAT_FIGEXP M_FIG C_FIG One Sentence SummaryNeratinib protects against atherosclerosis by reducing endothelial inflammation via ASK1 inhibition

pharmacology and toxicology↗

Evolutionarily guided transcription factor design programs novel T cell states

Protein-coding genes in the human genome evolved via modular rearrangement of domains from ancestral genes1. Here, we develop a scalable, evolutionarily guided method to assemble novel protein-coding genes from constituent domains within a protein family, termed DESynR (Domain Engineered via Synthesis and Recombination) genes. Using primary human chimeric antigen receptor T cells as a model system, we find that the expression of DESynR Activator Protein-1 (AP-1) transcription factors (TFs) significantly outperforms the overexpression of natural AP-1 TFs in multiple functional assays in vitro and in vivo. Top DESynR AP-1 TFs exhibit non-intuitive architectures of constituent domains, including from TFs that are not canonically expressed in T cells. DESynR AP-1 TFs induce broad transcriptional and epigenetic reprogramming of T cells and, in some cases, lead to the development of non-natural T cell states, engaging gene expression modules from disparate human cell types. Taken together, we demonstrate that novel configurations of existing protein domains may uncover non-evolved genes that program cell states with therapeutically relevant functions.

genetics↗

Clinical characteristics, drug-resistance genes and virulence analysis of carbapenem-resistant Klebsiella pneumoniae

OBJECTIVEThe aim was to investigate the clinical infection characteristics, risk factors and convergence of carbapenem-resistant and hypervirulent Klebsiella pneumoniae(hv-CRKP) in our hospital, in order to provide scientific basis for the rational use of antibiotics in the clinic. METHODSCRKP strains were isolated from clinical specimens of 44 patients in central intensive care unit (CICU), neurosurgery intensive care unit (NICU) and emergency intensive care unit (EICU) of our hospital in 41 months. The clinical manifestations of the patients were analyzed, and the hypermucoviscous phenotype was defined by string test. The drug resistance gene, virulence gene and capsular specific serotype of the isolated strains were detected by polymerase chain reaction (PCR) technology, and the gene of CRKP producing KPC enzyme was sequence. RESULTSThe incidence of sepsis in 44 patients with CRKP infection was 25.0%, and the overall treatment failure rate was 38.6%. All the 44 strains of CRKP produced KPC enzyme, and all of them were blaKPC-2 (100%);14 strains (31.8%) were positive in string test; 23 strains (52.3%) were found to have virulence related genes, including 10 strains (22.7%) of rmpA, 16 strains (36.4%) of iucA and 19 strains (43.2%) of peg-344. 5 strains (11.4%) were capsule-specific serotypes and 13 strains (29.5%) were identified as hv-CRKP. CONCLUSIONThe mechanism of CRKP resistance in our hospital is blaKPC-2, the detection rates of virulence gene, string test positive and hypervirulent capsular specific serotype are all relatively high in CRKP, there are not a few Klebsiella pneumoniae with carbapenem-resistant and hypervirulent.

microbiology↗

Pharmacological inhibition of Fms-like kinase 3 (FLT3) promotes neuronal maturation and suppresses seizure in a mouse model

Fms-like tyrosine kinase 3 (FLT3) is a receptor tyrosine kinase predominantly expressed in blood and brain cells. While the FLT3 signaling pathway has been extensively studied in blood cell development and leukemia, its role in the brain remains largely unexplored. Through our groups previous high-throughput drug screening work unexpectedly found that several small molecule FLT3 inhibitors (FLT3i), including KW-2449 and Sunitinib, enhance expression of the gene encoding chloride transporter KCC2 in neurons. KCC2 is crucial for brain development and function, and its dysregulation is linked to many brain diseases. These findings suggest previously unrecognized roles of FLT3 signaling in brain health and disease that have yet to be systematically studied. In this study, we utilized a functional genomics approach to investigate the transcriptomic changes induced by pharmacological inhibition of the FLT3 pathway in brain cells, including cultured primary mouse neurons, a human stem cell-derived neuronal model of Rett syndrome (RTT), and human stem cell-derived microglia cultures. Our results show that treating human or mouse neurons with FLT3i drugs significantly upregulates genes crucial for brain development while downregulating genes linked to neuroinflammation. In contrast, FLT3i treatment of human microglia, which do not express FLT3, has no effect on their gene expression, highlighting the cell type-specific roles of FLT3 signaling in the brain. To further understand how FLT3 signaling regulates the expression of neuronal maturation genes such as KCC2, we conducted a curated CRISPR screen that identified a number of transcription factors involved in FLT3i-mediated KCC2 activation in neurons. The mRNA and protein levels of several neurodevelopmental disorder (NDD) risk genes are significantly upregulated in FLT3i-treated neurons, indicating potential therapeutic applications of FLT3i in rescuing underexpression and/or haploinsufficiency of disease-associated genes. In our in vivo studies, we evaluated the efficacy of the FLT3i drug KW-2449 in mice, demonstrating that it can effectively cross the blood-brain barrier, induce KCC2 protein expression for up to 24 hours after a single injection, and reduces seizure activity in a chemoconvulsant-induced mouse model of temporal lobe epilepsy. Collectively, our findings uncover previously unrecognized roles of neuron-specific FLT3 signaling in promoting neuronal maturation and reducing neuroinflammation. These results suggest that FLT3 kinase signaling regulates a transcriptional program vital for brain development and function, position it as a promising therapeutic target for NDD treatment.

neuroscience↗

Characterization of the cellular and subcellular distribution of fms-like tyrosine kinase 3 (FLT3) and other neuronal proteins using an alkaline phosphatase (AP) immunolabeling method

Precisely localizing the spatial distribution of proteins within various cell types in the brain, and in sub-cellular compartments such as the synapses, is critical for generating and testing hypothesis to elucidating the function of target proteins in the brain. The fms-like tyrosine kinase-3 (FLT3) has been studied extensively in the context of blood cell development and leukemia pathogenesis, but little is known about its role in the brain. Previous work characterizing FLT3 protein expression in the brain have not yielded convincing results, mainly limited by the low expression level of FLT3 and poor sensitivity of standard immunolabeling method using fluorescent secondary antibody. In this study, we report the systematic characterization of FLT3 protein localization during brain development using a highly sensitive immunolabeling methodology based on alkaline phosphatase (AP) polymer biochemistry. Our results reveal a previously unknown neuron-selective FLT3 expression pattern in both mouse and human cerebellum tissue samples, and demonstrate a gradual increase in the total FLT3 protein level and a cytosolic-to-dendritic change in subcellular FLT3 distribution during mouse cerebellum development. Through combining the AP immunolabeling of FLT3 with standard immunostaining of various cell type markers to achieve hybrid co-labeling of multiple antigens in tissue sections, we demonstrate that the main cell type that express FLT3 in the cerebellum is PV+, Calbindin+ Purkinje cells. To expand the use case of AP immunolabeling method in labeling neuronal proteins, we show robust labeling of Kir2.1, a potassium channel protein that is expressed at low level in neurons, in brain tissue sections collected from mouse, pig, and human brains. We further established that the AP immunolabeling method can be used in human stem cell-derived neurons to detect postsynaptic density scaffold protein PSD95 within fine subcellular structures such as dendritic spines and synapses, in cultured primary mouse cortical neurons and human stem cell-derived neurons. To our knowledge, our work represents the first report of applying AP immunolabeling to detect neuronal protein expression in brain tissue and cell samples. Moreover, our work reveals a previously unknown neuron-specific pattern of FLT3 expression in the brain, providing the foundation for further mechanistic studies to uncover its role in brain development and functioning.

neuroscience↗

The clinical antiprotozoal drug halofuginone promotes weight loss by elevating GDF15 and FGF21

Obesity is a debilitating disease with increasing worldwide prevalence. Despite its high prevalence, specific pharmacologic intervention for obesity is challenging. Here, we report that halofuginone, an FDA-approved anti-scleroderma and anti-protozoal drug, is a promising anti-obesity agent in rodent models. Halofuginone suppressed food intake, increased energy expenditure, and resulted in weight loss in preclinical diet-induced obese mouse models, while also decreasing insulin resistance and hepatic steatosis. By combining genetic and pharmacological tools with transcriptomics, we identified that halofuginone increases FGF21 and GDF15 levels via ATF4. Using knockout mice, we show these hormones are both necessary for its anti-obesity effects. Thus, our study first reports the beneficial metabolic effects of halofuginone and underscores its utility to treat obesity and its associated metabolic complications.

pharmacology and toxicology↗

MLCK/MLCP regulates mammalian axon regeneration via the redistribution of the growth cone F-actin

Axon regrowth is a key determinant of the restoration of the biological function of the nervous system after trauma. However, mature mammalian neurons have limited capacity for axon regeneration. We have previously demonstrated that neuronal axon growth both in the central and the peripheral nervous systems is markedly enhanced when non-muscle myosin II (NMII) is inhibited with blebbistatin. The activity of NMII is primarily regulated by MLCK and MLCP via the phosphorylation and dephosphorylation of its light chain, respectively; however, the functional roles of MLCK and MLCP in mammalian axonal regeneration remain unknown. In the present study, we provide strong evidence that the inhibition of MLCK activity significantly blocks axon regeneration in mice. Conversely, the inhibition of MLCP promotes axon regrowth of both the peripheral and central nervous system. Our findings further indicate that the MLCK/MLCP regulates axon regeneration and redistributes the growth cone F-actin, and this result suggests that direct regulation of the growth cone machinery is a potential strategy to promote axon regeneration.

physiology↗

CDK4/6 inhibitors promote PARP1 degradation and act synergistically with PARP inhibitors in non-small cell lung cancer

Despite the widespread deregulation of CDK4/6 activity in non-small cell lung cancer (NSCLC), the clinical trials with CDK4/6 inhibitors (CDK4/6is) as a monotherapy have shown poor antitumor activity. However, our preclinical studies have revealed a significant potential for CDK4/6is to collaborate by influencing DNA damage repair pathways during radiotherapy. Given the considerable upregulation of PARP1 expression in NSCLC, we analyzed the efficacy of combined PARP and CDK4/6 inhibition in NSCLC models. Our findings demonstrate that CDK4/6is synergize with PARP inhibitors (PARPis) to inhibit the clonogenic growth of RB-proficient NSCLC models. This synergy is associated with increased accumulation of DNA damage, interrupted cell-cycle checkpoints, and enhanced apoptotic cell death. We showed that CDK4/6is mechanically promote PARP1 protein degradation, leading to decreased availability of DNA repair factors involved in homologous recombination and suppression of DNA repair competency. Furthermore, we showed that PARP trapping is required for this synergy. We then confirmed that combining PARPi and CDK4/6i blocked the growth of NSCLC xenografts in vivo and patient-derived explant models ex vivo. These findings reveal a previously uncharacterized impact of CDK4/6i on PARP1 levels in RB-proficient NSCLC models and the requirement of PARP trapping to render synergy between CDK4/6i and PARPi. Our research suggests that combining CDK4/6i with PARPi could be a promising therapeutic strategy for patients with RB-proficient NSCLC, potentially opening up new and more effective avenues for treatment.

cancer biology↗

Endothelial cell Piezo1 promotes vascular smooth muscle cell differentiation on large arteries

Vascular stabilization is a mechanosensitive process, in part driven by blood flow. Here, we demonstrate the involvement of the mechanosensitive ion channel, Piezo1, in promoting arterial accumulation of vascular smooth muscle cells (vSMCs) during zebrafish development. Using a series of small molecule antagonists or agonists to temporally regulate Piezo1 activity, we identified a role for the Piezo1 channel in regulating klf2a levels and altered targeting of vSMCs between arteries and veins. Increasing Piezo1 activity suppressed klf2a and increased vSMC association with the cardinal vein, while inhibition of Piezo1 activity increased klf2a levels and decreased vSMC association with arteries. We supported the small molecule data with in vivo genetic suppression of piezo1 and 2 in zebrafish, resulting in loss of transgelin+ vSMCs on the dorsal aorta. Further, endothelial cell (EC)-specific Piezo1 knockout in mice was sufficient to decrease vSMC accumulation along the descending dorsal aorta during development, thus phenocopying our zebrafish data, and supporting functional conservation of Piezo1 in mammals. To determine mechanism, we used in vitro modeling assays to demonstrate that differential sensing of pulsatile versus laminar flow forces across endothelial cells changes the expression of mural cell differentiation genes. Together, our findings suggest a crucial role for EC Piezo1 in sensing force within large arteries to mediate mural cell differentiation and stabilization of the arterial vasculature.

developmental biology↗

Multi-omics reveals AKR1B1-regulated galactose metabolic as a driver of gastrointestinal stromal tumor progression

The underlying mechanism of malignant progression in gastrointestinal stromal tumors (GISTs) is not fully understood. Despite recent advancements, a comprehensive profile of metabolome, transcriptome, and proteome of GISTs is lacking. This study conducted an integrated multi-omics analysis of GISTs across different risk classifications. By integrating metabolomics, transcriptomics, and proteomics, we identify distinct metabolic patterns and associated biological pathways implicated in the malignant progression of GISTs. Moreover, we identified galactose metabolism and the pivotal rate-limiting enzyme AKR1B1 is dysregulated in GISTs progression. AKR1B1 was upregulated and predicted poor prognosis in GISTs. In addition, AKR1B1 knockdown resulted in trehalose accumulation in GIST cells, thereby inhibiting cell proliferation and mitosis. These findings not only enhance our comprehension of the underlying mechanisms governing GIST progression from a metabolic reprogramming standpoint but also furnish prognostic biomarkers and potential therapeutic targets for GISTs.

cancer biology↗

Errors of attention adaptively warp spatial memory

Adaptation is the process by which we adjust internal models of the body, world, and mind in response to sensory feedback. While adaptation is studied extensively in the context of motor control, there is limited evidence that cognitive functions such as working memory are subject to the same error-driven adaptive control mechanism. To examine the possibility that internal spatial representations undergo adaptation, we had participants perform a task that interleaved a perceptual discrimination task and a spatial working memory task. Perceptual discrimination trials (85% of trials) presented an initial peripheral cue to exogenously capture attention, immediately followed by a displaced target stimulus. This sequence of events served to repeatedly induce a covert attentional allocation error. Interleaved spatial working memory trials (15% of trials) presented a stimulus at a pseudorandom peripheral location followed by a delay interval. On half of the working memory trials, the stimulus was surreptitiously presented at the same location as the initial attentional cue. We found that as attentional errors accumulated over the course of the experiment, participants spatial recall shifted to counteract the attentional error. The magnitude of this shift was proportional to the number of induced errors. Recall performance rapidly recovered following the offset of error trials. Multiple control experiments ruled out alternative explanations for these results, such as oculomotor confounds and attentional biases unrelated to error. These findings indicate that the computational mechanisms governing the adaptation of motor commands appear to similarly serve to adjust and calibrate spatial cognition.

neuroscience↗

Asymmetric binding of coactivator SRC1 to FXR-RXR and allosteric communication within the complex

Farnesoid X receptor (FXR) is a promising target for treatment of metabolic associated fatty liver disease (MAFLD). In this study, we employed an integrative approach to investigate the interaction between FXR-RXR-hSHP-1 complex and the entire coactivator SRC1-NRID (nuclear receptor interaction domain). We constructed a multi-domain model of FXR120-RXR98-hSHP-1, highlighting the interface between FXR-DBD and LBD. Using HDX-MS, XL-MS, and biochemical assays, we revealed the allosteric communications in FXR-RXR-hSHP-1 upon agonist and DNA binding. We then demonstrated that SRC1 binds only to the coactivator binding surface of FXR within the FXR-RXR heterodimer, with the NR-box2 and NR-box3 of SRC1 as the key binding motifs. Our findings, which provide the first model of SRC1-NRID in complex with FXR-RXR-hSHP-1, shed light on the molecular mechanism through which the coactivator asymmetrically interacts with nuclear receptors and provide structural basis for further understanding the function of FXR and its implications in diseases.

biophysics↗

Exosomal miRNA-124 is involved in the immune regulation of cervical cancer by regulating CD45 alternative splicing

ObjectiveTo investigate the regulatory mechanism of miRNA-124 in tumor immune regulation of cervical cancer. MethodsPeripheral blood samples of cervical cancer patients and transient infection controls were collected to extract exosomal miR-124 and Stem-loop Q-PCR to detect the expression level of miR-124. QPCR, WB, and flow cytometry were used to detect the mRNA and protein expression of Th cell differentiation and function-related genes. Transfection, QPCR, and flow cytometry were used to detect the effects of miR-124 overexpression and silencing on the differentiation of Th immune memory cells. In vitro, cell-killing experiments were performed to detect the tumor-killing activity of TH immune memory cells co-cultured with the Hela cell line, and the downstream target genes of miR-124 were predicted and verified by luciferase. Multiplex PCR was used to detect the genotype of miR-124 SNP in peripheral blood DNA. QPCR and WB were used to detect the mRNA and protein expression and phosphorylation of miR-124 target gene GSK3-PSF-CD45 pathway, and GSK3 inhibitor was used to block the pathway. ResultsWe found that exosomal miRNA-124 was significantly downregulated in cervical cancer tissues and affected Th cell immune function and memory cell generation. The overexpression of miRNA-124 can directly target GSK3, phosphorylate the target gene, and inhibit the expression of GSK3, thereby increasing the expression of CD45, increasing the ability of Th immune cells to recognize and kill the HPV virus, and significantly inhibiting the proliferation and migration of cervical cancer cells.

molecular biology↗

Regulation of angiogenesis by endocytic trafficking mediated by cytoplasmic dynein 1 light intermediate chain 1

Dynein cytoplasmic 1 light intermediate chain 1 (LIC1, DYNC1LI1) is a core subunit of the dynein motor complex. The LIC1 subunit also interacts with various cargo adaptors to regulate Rab-mediated endosomal recycling and lysosomal degradation. Defects in this gene are predicted to alter dynein motor function, Rab binding capabilities, and cytoplasmic cargo trafficking. Here, we have identified a dync1li1 zebrafish mutant, harboring a premature stop codon at the exon 12/13 splice acceptor site, that displays increased angiogenesis. In vitro, LIC1-deficient human endothelial cells display increases in cell surface levels of the pro-angiogenic receptor VEGFR2, SRC phosphorylation, and Rab11-mediated endosomal recycling. In vivo, endothelial-specific expression of constitutively active Rab11a leads to excessive angiogenesis, similar to the dync1li1 mutants. Increased angiogenesis is also evident in zebrafish harboring mutations in rilpl1/2, the adaptor proteins that promote Rab docking to Lic1 to mediate lysosomal targeting. These findings suggest that LIC1 and the Rab-adaptor proteins RILPL1 and 2 restrict angiogenesis by promoting degradation of VEGFR2-containing recycling endosomes. Disruption of LIC1- and RILPL1/2-mediated lysosomal targeting increases Rab11-mediated recycling endosome activity, promoting excessive SRC signaling and angiogenesis.

cell biology↗

ProAffinity-GNN: A Novel Approach to Structure-based Protein-Protein Binding Affinity Prediction via a Curated Dataset and Graph Neural Networks

Protein-protein interactions (PPIs) are crucial for understanding biological processes and disease mechanisms, contributing significantly to advances in protein engineering and drug discovery. The accurate determination of binding affinities, essential for decoding PPIs, faces challenges due to the substantial time and financial costs involved in experimental and theoretical methods. This situation underscores the urgent need for more effective and precise methodologies for predicting binding affinity. Despite the abundance of research on PPI modeling, the field of quantitative binding affinity prediction remains underexplored, mainly due to a lack of comprehensive data. This study seeks to address these needs by manually curating pairwise interaction labels on all available 3D structures of proteins complexes, with experimentally determined binding affinities, creating the largest dataset for structure-based pairwise protein interaction with binding affinity to date. Subsequently, we introduce "ProAffinity-GNN", a novel deep learning framework using protein language model and graph neural network (GNN) to improve the accuracy of prediction of structure-based protein-protein binding affinities. The evaluation results across several benchmark test sets demonstrate that ProAffinity-GNN not only outperforms existing models in terms of accuracy but also shows strong generalization capabilities.

bioinformatics↗

Armored Bicistronic CAR T Cells with Dominant-negative TGF-β Receptor II to Overcome Resistance in Glioblastoma.

Chimeric antigen receptor (CAR) T cells have shown significant efficacy in hematological diseases. However, CAR T therapy has demonstrated limited efficacy in solid tumors, including glioblastoma (GBM). One of the most important reasons is the immunosuppressive tumor microenvironment (TME), which promotes tumor growth and suppresses immune cells to eliminate tumor cells. The human transforming growth factor-beta (TGF-{beta}) plays a crucial role in forming the suppressive GBM TME and driving the suppression of the anti-GBM response. In order to mitigate TGF-{beta} mediated suppressive activity, we combined a dominant-negative TGF-{beta} receptor II (dnTGF{beta}RII) with our previous bicistronic CART-EGFR-IL13R2 construct, currently being evaluated in a clinical trial, to generate CART-EGFR-IL13R2-dnTGF{beta}RII, a tri-modular construct we are developing for clinical application. We hypothesized that this approach would more effectively subvert resistance mechanisms observed with GBM. Our data suggests that CART-EGFR-IL13R2-dnTGF{beta}RII significantly augmented T cell proliferation and enhanced functional responses, particularly in a TGF{beta}-rich tumor environment. Additionally, in vivo studies validated the safety and efficacy of the dnTGF{beta}RII cooperating with CARs in targeting and eradicating GBM in a NSG mouse model.

cancer biology↗

In vivo affinity maturation of the HIV-1 Env-binding domain of CD4

Many human proteins have been repurposed as biologics for clinical use. These proteins have been engineered with in vitro techniques that improve affinity for their ligands. However, these approaches do not select against properties that impair efficacy such as protease sensitivity or self-reactivity. Here we engineer the B-cell receptor of primary murine B cells to express a human protein biologic without disrupting their ability to affinity mature. Specifically, CD4 domains 1 and 2 (D1D2) of a half-life enhanced-HIV-1 entry inhibitor CD4-Ig (CD4-Ig-v0) were introduced into the heavy-chain loci of murine B cells, which were then adoptively transferred to wild-type mice. After immunization, transferred B cells proliferated, class switched, affinity matured, and efficiently produced D1D2-presenting antibodies. Somatic hypermutations found in the D1D2-encoding region of engrafted B cells improved binding affinity of CD4-Ig-v0 for the HIV-1 envelope glycoprotein (Env) and the neutralization potency of CD4-Ig-v0 by more than ten-fold across a global panel of HIV-1 isolates, without impairing its pharmacokinetic properties. Thus, affinity maturation of non-antibody protein biologics in vivo can guide development of more effective therapeutics.

bioengineering↗