Biology subjects

Banerjee, P.

Publications and source records attributed to Banerjee, P..

4 recordsLinked to original sources

bioRxiv2020

Inhibition of the av integrin-TGF-b axis improves natural killer cell function against glioblastoma stem cells

Glioblastoma, the most aggressive brain cancer, often recurs because glioblastoma stem cells (GSCs) are resistant to all standard therapies. Here, we show that patient-derived GSCs, but not normal astrocytes, are highly sensitive to lysis by healthy allogeneic natural killer (NK) cells in vitro. In contrast, single cell analysis of autologous, tissue infiltrating NK cells isolated from surgical samples of high-grade glioblastoma patient tumors using mass cytometry and single cell RNA sequencing revealed an abnormal phenotype associated with impaired lytic function compared with peripheral blood NK cells from GBM patients or healthy donors. This immunosuppression was attributed to an integrin-TGF-{beta} mechanism, activated by direct cell-cell contact between GSCs and NK cells. Treatment of GSC-engrafted mice with allogeneic NK cells in combination with inhibitors of integrin or TGF-{beta} signaling, or with TGF-{beta} receptor 2 gene-edited NK cells prevented GSC-induced NK cell dysfunction and tumor growth. Collectively, our findings reveal a novel mechanism of NK cell immune evasion by GSCs and implicate the integrin-TGF-{beta} axis as a useful therapeutic target to eliminate GSCs in this devastating tumor.

immunology↗

bioRxiv2020

CIS checkpoint deletion enhances the fitness of cord blood derived natural killer cells transduced with a chimeric antigen receptor

Immune checkpoint therapy has produced remarkable improvements in the outcome for certain cancers. To broaden the clinical impact of checkpoint targeting, we devised a strategy that couples targeting of the cytokine-inducible SH2-containing (CIS) protein, a key negative regulator of interleukin (IL)-15 signaling, with chimeric antigen receptor (CAR) engineering of natural killer (NK) cells. This combined strategy boosted NK cell effector function through enhancing the Akt/mTORC1 axis and c-MYC signaling, resulting in increased aerobic glycolysis. When tested in a lymphoma mouse model, this combined approach improved NK cell anti-tumor activity more than either alteration alone, eradicating lymphoma xenografts without signs of any measurable toxicity. We conclude that combining CIS checkpoint deletion with CAR engineering promotes the metabolic fitness of NK cells in an otherwise suppressive tumor microenvironment. This approach, together with the prolonged survival afforded by CAR modification, represents a promising milestone in the development of the next generation of NK cells for cancer immunotherapy.

immunology↗

bioRxiv2020

Excessive O-GlcNAcylation causes heart failure and sudden death

BackgroundHeart failure is a leading cause of death worldwide and is associated with the rising prevalence of obesity, hypertension and diabetes. O-GlcNAcylation, a post-translational modification of intracellular proteins, serves as a potent transducer of cellular stress. Failing myocardium is marked by increased O-GlcNAcylation, but it is unknown if excessive O-GlcNAcylation contributes to cardiomyopathy and heart failure. The total levels of O-GlcNAcylation are determined by nutrient and metabolic flux, in addition to the net activity of two enzymes, O-GlcNAc transferase (OGT) and O-GlcNAcase (OGA). MethodsWe developed two new transgenic mouse models with myocardial overexpression of OGT and OGA to control O-GlcNAclyation independent of pathological stress. ResultsWe found that OGT transgenic hearts showed increased O-GlcNAcylation, and developed severe dilated cardiomyopathy, ventricular arrhythmias and premature death. In contrast, OGA transgenic hearts had O-GlcNAcylation and cardiac function similar to wild type littermate controls. However, OGA trangenic hearts were resistant to pathological stress induced by pressure overload and had attenuated myocardial O-GlcNAcylation levels, decreased pathological hypertrophy and improved systolic function. Interbreeding OGT with OGA transgenic mice rescued cardiomyopathy and premature death despite persistant elevation of myocardial OGT. Transcriptomic and functional studies revealed disrupted mitochondrial energetics with impairment of complex I activity in hearts from OGT transgenic mice. Complex I activity was rescued by OGA transgenic interbreeding, suggesting an important role for mitochondrial complex I in O-GlcNAc mediated cardiac pathology. ConclusionsOur data provide evidence that excessive O-GlcNAcylation causes cardiomyopathy, at least in part, due to defective energetics. Enhanced OGA activity is well tolerated and attenuation of O-GlcNAcylation is an effective therapy against pressure overload induced heart failure. Attenuation of excessive O-GlcNAcylation may represent a novel therapeutic approach for cardiomyopathy. Clinical PerspectiveO_ST_ABSWhat is new?C_ST_ABSO_LICardiomyopathy from diverse causes is marked by increased O-GlcNAcylation. Here we provide new genetic mouse models to control myocardial O-GlcNAcylation independent of pathological stress. C_LIO_LIGenetically increased myocardial O-GlcNAcylation causes progressive dilated cardiomyopathy and premature death, while genetic reduction of myocardial O-GlcNAcylation is protective against pathological hypertrophy caused by transaortic banding. C_LIO_LIExcessive myocardial O-GlcNAcylation decreases activity and expression of mitochondrial complex I. C_LI What are the clinical implications?O_LIIncreased myocardial O-GlcNAcylation has been shown to be associated with a diverse range of clinical heart failure including aortic stenosis, hypertension, ischemia and diabetes. C_LIO_LIUsing novel genetic mouse models we have provided new proof of concept data that excessive O-GlcNAcylation is sufficient to cause cardiomyopathy. C_LIO_LIWe have shown myocardial over-expression of O-GlcNAcase, an enzyme that reverses O-GlcNAcylation, is well tolerated at baseline, and improves myocardial responses to pathological stress. C_LIO_LIOur findings suggest reversing excessive myocardial O-GlcNAcylation could benefit diverse etiologies of heart failure. C_LI

molecular biology↗

bioRxiv2019

Multifaceted genome-wide study identifies novel regulatory loci for body mass index in Indians

Obesity, a risk factor for various human diseases originates through complex interactions between genes and prevailing environment that varies across populations. Indians exhibit a unique obesity phenotype likely attributed by specific gene pool and environmental factors. Here, we present genome-wide association study (GWAS) of 7,259 Indians to understand the genetic architecture of body mass index (BMI) in the population. Our study revealed novel association of variants in BAI3 (rs6913677) and SLC22A11 (rs2078267) at GWAS significance, and of ZNF45 (rs8100011) with near GWAS significance. As genetic loci may dictate the phenotype through modulation of epigenetic processes, we overlapped discovered genetic signatures with DNA methylation patterns of 236 Indian individuals, and analyzed expression of the candidate genes using publicly available data. The variants in BAI3 and SLC22A11 were found to dictate methylation patterns at unique CpGs harboring critical cis- regulatory elements. Further, BAI3, SLC22A11 and ZNF45 variants were found to overlie repressive chromatin, active enhancer, and active chromatin regions, in that order, in human subcutaneous adipose tissue in ENCODE database. Besides, the identified genomic regions represented potential binding sites for key transcription factors implicated in obesity and/or metabolic disorders. Interestingly, rs8100011 (ZNF45) acted as a robust cis-expression quantitative trait locus (cis-eQTL) in subcutaneous adipose tissue in GTEx portal, and ZNF45 gene expression showed an inverse correlation with BMI in skeletal muscle of Indian subjects. Further, gene-based GWAS analysis revealed CPS1 and UPP2 as additional leads regulating BMI in Indians. Our study decodes potential genomic mechanisms underlying obesity phenotype in Indians.

genomics↗