Search bioRxiv⌕ Search

Biology subjects

Yancopoulos, G. D.

Publications and source records attributed to Yancopoulos, G. D..

7 recordsLinked to original sources

Structural analysis of cancer-relevant TCR-CD3 and peptide-MHC complexes by cryoEM

The recognition of antigenic peptide-MHC (pMHC) molecules by T-cell receptors (TCR) initiates the T-cell mediated immune response. Structural characterization is key for understanding the specificity of TCR-pMHC interactions and informing the development of therapeutics. Despite the rapid rise of single particle cryoelectron microscopy (cryoEM), x-ray crystallography has remained the preferred method for structure determination of TCR-pMHC complexes. Here, we report cryoEM structures of two distinct full-length /{beta} TCR-CD3 complexes bound to their pMHC ligand, the cancer-testis antigen HLA-A2/MAGEA4 (230-239). We also determined cryoEM structures of pMHCs containing MAGEA4 (230-239) peptide and the closely related MAGEA8 (232-241) peptide in the absence of TCR, which provided a structural explanation for the MAGEA4 preference displayed by the TCRs. These findings provide insights into the TCR recognition of a clinically relevant cancer antigen and demonstrate the utility of cryoEM for high-resolution structural analysis of TCR-pMHC interactions.

biochemistry↗

Structural insights into the assembly of gp130 family cytokine signaling complexes

The gp130 family cytokine signaling complexes have limited structural information despite their crucial roles in various cellular processes. We determined cryo-EM structures of several complexes of this family, containing full ectodomains of both signaling receptors bound to their respective ligands CNTF, CLCF1, LIF, IL-27, and IL-6. Our structures reveal that gp130 serves as a central receptor by engaging Site 2 of CNTF, CLCF1, LIF, and IL-6, and Site 3 of IL-27 and IL-6. The acute bends at both signaling receptors in all complexes bring the membrane-proximal domains to a ~30 [A] range but with distinct distances and orientations, which might determine biological specificities of these cytokines. We also reveal how CLCF1 engages its secretion chaperone CRLF1. Our data provide valuable insights for therapeutically targeting gp130-mediated signaling.

biochemistry↗

In vitro and in vivo preclinical studies predict REGEN-COV protection against emergence of viral escape in humans

Monoclonal antibodies against SARS-CoV-2 are a clinically validated therapeutic option against COVID-19. As rapidly emerging virus mutants are becoming the next major concern in the fight against the global pandemic, it is imperative that these therapeutic treatments provide coverage against circulating variants and do not contribute to development of treatment emergent resistance. To this end, we investigated the sequence diversity of the spike protein and monitored emergence of minor virus variants in SARS-COV-2 isolates found in COVID-19 patients or identified from preclinical in vitro and in vivo studies. This study demonstrates that a combination of non-competing antibodies, REGEN-COV, not only provides full coverage against current variants of concern/interest but also protects against emergence of new such variants and their potential seeding into the population in a clinical setting.

microbiology↗

REGN-COV2 antibody cocktail prevents and treats SARS-CoV-2 infection in rhesus macaques and hamsters

An urgent global quest for effective therapies to prevent and treat COVID-19 disease is ongoing. We previously described REGN-COV2, a cocktail of two potent neutralizing antibodies (REGN10987+REGN10933) targeting non-overlapping epitopes on the SARS-CoV-2 spike protein. In this report, we evaluate the in vivo efficacy of this antibody cocktail in both rhesus macaques and golden hamsters and demonstrate that REGN-COV-2 can greatly reduce virus load in lower and upper airway and decrease virus induced pathological sequalae when administered prophylactically or therapeutically. Our results provide evidence of the therapeutic potential of this antibody cocktail.

microbiology↗

Molecular taxonomy of human ocular outflow tissues defined by single cell transcriptomics

The conventional outflow pathway is a complex tissue responsible for maintaining intraocular pressure (IOP) homeostasis. The coordinated effort of multiple cells with differing responsibilities ensure healthy outflow function and IOP maintenance. Dysfunction of one or more resident cell type results in ocular hypertension and risk for glaucoma, a leading cause of blindness. In this study, single cell RNA sequencing was performed to generate a comprehensive cell atlas of human conventional outflow tissues. We obtained 17757 genes expression profiles from 8758 cells from eight eyes of four donors representing the outflow cell transcriptome. Upon clustering analysis, 12 distinct cell types were identified, and region-specific expression of candidate genes were mapped in human tissues. Significantly, we identified two distinct expression patterns (myofibroblast and fibroblast) from cells located in the trabecular meshwork (TM), the primary structural component of the conventional outflow pathway. We also located neuron and macrophage signatures in the TM. The second primary component structure, Schlemms canal displayed a unique combination of lymphatic/blood vascular gene expression. Other expression clusters corresponded to cells from neighboring tissues, predominantly in the ciliary muscle/scleral spur, which together correspond to the uveoscleral outflow path. Importantly, the utility of our atlas was demonstrated by mapping glaucoma-relevant genes to outflow cell clusters. Our study provides a comprehensive molecular and cellular classification of conventional and unconventional outflow pathway structures responsible for IOP homeostasis. Significance statementOcular hypertension is the primary, and only modifiable risk factor for glaucoma, the leading cause of irreversible blindness. Intraocular pressure is regulated homeostatically by resistance to aqueous humor outflow through an architecturally complex tissue, the conventional/trabecular pathway. In this study, we generated a comprehensive cell atlas of the human trabecular meshwork and neighboring tissues using single cell, RNA sequencing. We identified 12 distinct cell types, and mapped region-specific expression of candidate genes. The utility of our atlas was demonstrated by mapping glaucoma-relevant genes to conventional outflow cell clusters. Our study provides a comprehensive molecular and cellular classification of tissue structures responsible for intraocular pressure homeostasis in health, and dysregulation in disease.

cell biology↗

Whole exome sequencing and characterization of coding variation in 49,960 individuals in the UK Biobank

The UK Biobank is a prospective study of 502,543 individuals, combining extensive phenotypic and genotypic data with streamlined access for researchers around the world. Here we describe the first tranche of large-scale exome sequence data for 49,960 study participants, revealing approximately 4 million coding variants (of which ~98.4% have frequency < 1%). The data includes 231,631 predicted loss of function variants, a >10-fold increase compared to imputed sequence for the same participants. Nearly all genes (>97%) had [&ge;]1 predicted loss of function carrier, and most genes (>69%) had [&ge;]10 loss of function carriers. We illustrate the power of characterizing loss of function variation in this large population through association analyses across 1,741 phenotypes. In addition to replicating a range of established associations, we discover novel loss of function variants with large effects on disease traits, including PIEZO1 on varicose veins, COL6A1 on corneal resistance, MEPE on bone density, and IQGAP2 and GMPR on blood cell traits. We further demonstrate the value of exome sequencing by surveying the prevalence of pathogenic variants of clinical significance in this population, finding that 2% of the population has a medically actionable variant. Additionally, we leverage the phenotypic data to characterize the relationship between rare BRCA1 and BRCA2 pathogenic variants and cancer risk. Exomes from the first 49,960 participants are now made accessible to the scientific community and highlight the promise offered by genomic sequencing in large-scale population-based studies.

genomics↗

Profiling copy number variation and disease associations from 50,726 DiscovEHR Study exomes

Copy number variants (CNVs) are a substantial source of genomic variation and contribute to a wide range of human disorders. Gene-disrupting exonic CNVs have important clinical implications as they can underlie variability in disease presentation and susceptibility. The relationship between exonic CNVs and clinical traits has not been broadly explored at the population level, primarily due to technical challenges. We surveyed common and rare CNVs in the exome sequences of 50,726 adult DiscovEHR study participants with linked electronic health records (EHRs). We evaluated the diagnostic yield and clinical expressivity of known pathogenic CNVs, and performed tests of association with EHR-derived serum lipids, thereby evaluating the relationship between CNVs and complex traits and phenotypes in an unbiased, real-world clinical context. We identified CNVs from megabase to exon-level resolution, demonstrating reliable, high-throughput detection of clinically relevant exonic CNVs. In doing so, we created a catalog of high-confidence common and rare CNVs and refined population frequency estimates of known and novel gene-disrupting CNVs. Our survey among an unselected clinical population provides further evidence that neuropathy-associated duplications and deletions in 17p12 have similar population prevalence but are clinically under-diagnosed. Similarly, adults who harbor 22q11.2 deletions frequently had EHR documentation of neurodevelopmental/neuropsychiatric disorders and congenital anomalies, but not a formal genetic diagnosis (i.e., deletion). In an exome-wide association study of lipid levels, we identified a novel five-exon duplication within LDLR segregating in a large kindred with features of familial hypercholesterolemia. Exonic CNVs provide new opportunities to understand and diagnose human disease.

genomics↗