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1.
Nature ; 623(7989): 1026-1033, 2023 Nov.
Article in English | MEDLINE | ID: mdl-37993716

ABSTRACT

Human immunodeficiency virus 1 (HIV-1) infection is initiated by binding of the viral envelope glycoprotein (Env) to the cell-surface receptor CD41-4. Although high-resolution structures of Env in a complex with the soluble domains of CD4 have been determined, the binding process is less understood in native membranes5-13. Here we used cryo-electron tomography to monitor Env-CD4 interactions at the membrane-membrane interfaces formed between HIV-1 and CD4-presenting virus-like particles. Env-CD4 complexes organized into clusters and rings, bringing the opposing membranes closer together. Env-CD4 clustering was dependent on capsid maturation. Subtomogram averaging and classification revealed that Env bound to one, two and finally three CD4 molecules, after which Env adopted an open state. Our data indicate that asymmetric HIV-1 Env trimers bound to one and two CD4 molecules are detectable intermediates during virus binding to host cell membranes, which probably has consequences for antibody-mediated immune responses and vaccine immunogen design.


Subject(s)
CD4 Antigens , Cell Membrane , HIV Envelope Protein gp120 , HIV-1 , Protein Multimerization , Humans , AIDS Vaccines/chemistry , AIDS Vaccines/immunology , Capsid/chemistry , Capsid/metabolism , Capsid/ultrastructure , CD4 Antigens/chemistry , CD4 Antigens/metabolism , CD4 Antigens/ultrastructure , Cell Membrane/chemistry , Cell Membrane/metabolism , Cell Membrane/ultrastructure , Cryoelectron Microscopy , Electron Microscope Tomography , HIV Antibodies/immunology , HIV Envelope Protein gp120/chemistry , HIV Envelope Protein gp120/metabolism , HIV Envelope Protein gp120/ultrastructure , HIV Infections/virology , HIV-1/chemistry , HIV-1/ultrastructure , Virion/chemistry , Virion/metabolism , Virion/ultrastructure
2.
Genome Med ; 15(1): 35, 2023 05 10.
Article in English | MEDLINE | ID: mdl-37165454

ABSTRACT

BACKGROUND: High sequence identity between segmental duplications (SDs) can facilitate copy number variants (CNVs) via non-allelic homologous recombination (NAHR). These CNVs are one of the fundamental causes of genomic disorders such as the 3q29 deletion syndrome (del3q29S). There are 21 protein-coding genes lost or gained as a result of such recurrent 1.6-Mbp deletions or duplications, respectively, in the 3q29 locus. While NAHR plays a role in CNV occurrence, the factors that increase the risk of NAHR at this particular locus are not well understood. METHODS: We employed an optical genome mapping technique to characterize the 3q29 locus in 161 unaffected individuals, 16 probands with del3q29S and their parents, and 2 probands with the 3q29 duplication syndrome (dup3q29S). Long-read sequencing-based haplotype resolved de novo assemblies from 44 unaffected individuals, and 1 trio was used for orthogonal validation of haplotypes and deletion breakpoints. RESULTS: In total, we discovered 34 haplotypes, of which 19 were novel haplotypes. Among these 19 novel haplotypes, 18 were detected in unaffected individuals, while 1 novel haplotype was detected on the parent-of-origin chromosome of a proband with the del3q29S. Phased assemblies from 44 unaffected individuals enabled the orthogonal validation of 20 haplotypes. In 89% (16/18) of the probands, breakpoints were confined to paralogous copies of a 20-kbp segment within the 3q29 SDs. In one del3q29S proband, the breakpoint was confined to a 374-bp region using long-read sequencing. Furthermore, we categorized del3q29S cases into three classes and dup3q29S cases into two classes based on breakpoints. Finally, we found no evidence of inversions in parent-of-origin chromosomes. CONCLUSIONS: We have generated the most comprehensive haplotype map for the 3q29 locus using unaffected individuals, probands with del3q29S or dup3q29S, and available parents, and also determined the deletion breakpoint to be within a 374-bp region in one proband with del3q29S. These results should provide a better understanding of the underlying genetic architecture that contributes to the etiology of del3q29S and dup3q29S.


Subject(s)
Genomics , Segmental Duplications, Genomic , Humans , Chromosome Mapping , Syndrome , Haplotypes , DNA Copy Number Variations
3.
Mol Ther Methods Clin Dev ; 28: 366-384, 2023 Mar 09.
Article in English | MEDLINE | ID: mdl-36879849

ABSTRACT

Barriers to effective gene therapy for many diseases include the number of modified target cells required to achieve therapeutic outcomes and host immune responses to expressed therapeutic proteins. As long-lived cells specialized for protein secretion, antibody-secreting B cells are an attractive target for foreign protein expression in blood and tissue. To neutralize HIV-1, we developed a lentiviral vector (LV) gene therapy platform for delivery of the anti-HIV-1 immunoadhesin, eCD4-Ig, to B cells. The EµB29 enhancer/promoter in the LV limited gene expression in non-B cell lineages. By engineering a knob-in-hole-reversed (KiHR) modification in the CH3-Fc eCD4-Ig domain, we reduced interactions between eCD4-Ig and endogenous B cell immunoglobulin G proteins, which improved HIV-1 neutralization potency. Unlike previous approaches in non-lymphoid cells, eCD4-Ig-KiHR produced in B cells promoted HIV-1 neutralizing protection without requiring exogenous TPST2, a tyrosine sulfation enzyme required for eCD4-Ig-KiHR function. This finding indicated that B cell machinery is well suited to produce therapeutic proteins. Lastly, to overcome the inefficient transduction efficiency associated with VSV-G LV delivery to primary B cells, an optimized measles pseudotyped LV packaging methodology achieved up to 75% transduction efficiency. Overall, our findings support the utility of B cell gene therapy platforms for therapeutic protein delivery.

4.
Micromachines (Basel) ; 14(2)2023 Feb 13.
Article in English | MEDLINE | ID: mdl-36838142

ABSTRACT

In the past few years, object detection has attracted a lot of attention in the context of human-robot collaboration and Industry 5.0 due to enormous quality improvements in deep learning technologies. In many applications, object detection models have to be able to quickly adapt to a changing environment, i.e., to learn new objects. A crucial but challenging prerequisite for this is the automatic generation of new training data which currently still limits the broad application of object detection methods in industrial manufacturing. In this work, we discuss how to adapt state-of-the-art object detection methods for the task of automatic bounding box annotation in a use case where the background is homogeneous and the object's label is provided by a human. We compare an adapted version of Faster R-CNN and the Scaled-YOLOv4-p5 architecture and show that both can be trained to distinguish unknown objects from a complex but homogeneous background using only a small amount of training data. In contrast to most other state-of-the-art methods for bounding box labeling, our proposed method neither requires human verification, a predefined set of classes, nor a very large manually annotated dataset. Our method outperforms the state-of-the-art, transformer-based object discovery method LOST on our simple fruits dataset by large margins.

5.
Front Neurol ; 13: 918022, 2022.
Article in English | MEDLINE | ID: mdl-35911904

ABSTRACT

We report the genetic analysis of two consanguineous pedigrees of Pakistani ancestry in which two siblings in each family exhibited developmental delay, epilepsy, intellectual disability and aggressive behavior. Whole-genome sequencing was performed in Family 1, and we identified ~80,000 variants located in regions of homozygosity. Of these, 615 variants had a minor allele frequency ≤ 0.001, and 21 variants had CADD scores ≥ 15. Four homozygous exonic variants were identified in both affected siblings: PDZD7 (c.1348_1350delGAG, p.Glu450del), ALG6 (c.1033G>C, p.Glu345Gln), RBM20 (c.1587C>G, p.Ser529Arg), and CNTNAP2 (c.785G>A, p.Gly228Arg). Sanger sequencing revealed co-segregation of the PDZD7, RBM20, and CNTNAP2 variants with disease in Family 1. Pathogenic variants in PDZD7 and RBM20 are associated with autosomal recessive non-syndromic hearing loss and autosomal dominant dilated cardiomyopathy, respectively, suggesting that these variants are unlikely likely to contribute to the clinical presentation. Gene panel analysis was performed on the two affected siblings in Family 2, and they were found to also be homozygous for the p.Gly228Arg CNTNAP2 variant. Together these families provide a LOD score 2.9 toward p.Gly228Arg CNTNAP2 being a completely penetrant recessive cause of this disease. The clinical presentation of the affected siblings in both families is also consistent with previous reports from individuals with homozygous CNTNAP2 variants where at least one allele was a nonsense variant, frameshift or small deletion. Our data suggests that homozygous CNTNAP2 missense variants can also contribute to disease, thereby expanding the genetic landscape of CNTNAP2 dysfunction.

6.
Am J Hum Genet ; 109(8): 1500-1519, 2022 08 04.
Article in English | MEDLINE | ID: mdl-35931052

ABSTRACT

Identifying causative gene(s) within disease-associated large genomic regions of copy-number variants (CNVs) is challenging. Here, by targeted sequencing of genes within schizophrenia (SZ)-associated CNVs in 1,779 SZ cases and 1,418 controls, we identified three rare putative loss-of-function (LoF) mutations in OTU deubiquitinase 7A (OTUD7A) within the 15q13.3 deletion in cases but none in controls. To tie OTUD7A LoF with any SZ-relevant cellular phenotypes, we modeled the OTUD7A LoF mutation, rs757148409, in human induced pluripotent stem cell (hiPSC)-derived induced excitatory neurons (iNs) by CRISPR-Cas9 engineering. The mutant iNs showed a ∼50% decrease in OTUD7A expression without undergoing nonsense-mediated mRNA decay. The mutant iNs also exhibited marked reduction of dendritic complexity, density of synaptic proteins GluA1 and PSD-95, and neuronal network activity. Congruent with the neuronal phenotypes in mutant iNs, our transcriptomic analysis showed that the set of OTUD7A LoF-downregulated genes was enriched for those relating to synapse development and function and was associated with SZ and other neuropsychiatric disorders. These results suggest that OTUD7A LoF impairs synapse development and neuronal function in human neurons, providing mechanistic insight into the possible role of OTUD7A in driving neuropsychiatric phenotypes associated with the 15q13.3 deletion.


Subject(s)
Induced Pluripotent Stem Cells , Schizophrenia , DNA Copy Number Variations , Humans , Neurons , Schizophrenia/metabolism , Synapses/metabolism
7.
Proc Natl Acad Sci U S A ; 119(22): e2118124119, 2022 05 31.
Article in English | MEDLINE | ID: mdl-35617426

ABSTRACT

Fragile X­associated tremor/ataxia syndrome (FXTAS) is a debilitating late-onset neurodegenerative disease in premutation carriers of the expanded CGG repeat in FMR1 that presents with a spectrum of neurological manifestations, such as gait ataxia, intention tremor, and parkinsonism [P. J. Hagerman, R. J. Hagerman, Ann. N. Y. Acad. Sci. 1338, 58­70 (2015); S. Jacquemont et al., JAMA 291, 460­469 (2004)]. Here, we performed whole-genome sequencing (WGS) on male premutation carriers (CGG55­200) and prioritized candidate variants to screen for candidate genetic modifiers using a Drosophila model of FXTAS. We found 18 genes that genetically modulate CGG-associated neurotoxicity in Drosophila, such as Prosbeta5 (PSMB5), pAbp (PABPC1L), e(y)1 (TAF9), and CG14231 (OSGEPL1). Among them, knockdown of Prosbeta5 (PSMB5) suppressed CGG-associated neurodegeneration in the fly as well as in N2A cells. Interestingly, an expression quantitative trait locus variant in PSMB5, PSMB5rs11543947-A, was found to be associated with decreased expression of PSMB5 and delayed onset of FXTAS in human FMR1 premutation carriers. Finally, we demonstrate evidence that PSMB5 knockdown results in suppression of CGG neurotoxicity via both the RAN translation and RNA-mediated toxicity mechanisms, thereby presenting a therapeutic strategy for FXTAS.


Subject(s)
Ataxia , Fragile X Syndrome , Proteasome Endopeptidase Complex , Tremor , Animals , Ataxia/genetics , Disease Models, Animal , Drosophila melanogaster , Fragile X Mental Retardation Protein/genetics , Fragile X Syndrome/genetics , Humans , Male , Proteasome Endopeptidase Complex/genetics , Tremor/genetics
8.
Cell ; 185(4): 641-653.e17, 2022 02 17.
Article in English | MEDLINE | ID: mdl-35123651

ABSTRACT

HIV-1 Env mediates viral entry into host cells and is the sole target for neutralizing antibodies. However, Env structure and organization in its native virion context has eluded detailed characterization. Here, we used cryo-electron tomography to analyze Env in mature and immature HIV-1 particles. Immature particles showed distinct Env positioning relative to the underlying Gag lattice, providing insights into long-standing questions about Env incorporation. A 9.1-Å sub-tomogram-averaged reconstruction of virion-bound Env in conjunction with structural mass spectrometry revealed unexpected features, including a variable central core of the gp41 subunit, heterogeneous glycosylation between protomers, and a flexible stalk that allows Env tilting and variable exposure of neutralizing epitopes. Together, our results provide an integrative understanding of HIV assembly and structural variation in Env antigen presentation.


Subject(s)
Cryoelectron Microscopy , Electron Microscope Tomography , Virion/ultrastructure , env Gene Products, Human Immunodeficiency Virus/ultrastructure , gag Gene Products, Human Immunodeficiency Virus/ultrastructure , 2,2'-Dipyridyl/analogs & derivatives , 2,2'-Dipyridyl/pharmacology , Amino Acid Sequence , Disulfides/pharmacology , Epitopes/chemistry , HEK293 Cells , HIV Envelope Protein gp41/chemistry , Humans , Hydrogen Deuterium Exchange-Mass Spectrometry , Models, Molecular , Neutralization Tests , Peptides/chemistry , Polysaccharides/chemistry , Protein Domains , Protein Structure, Secondary , Protein Subunits/chemistry , env Gene Products, Human Immunodeficiency Virus/chemistry
9.
Transl Psychiatry ; 12(1): 66, 2022 02 17.
Article in English | MEDLINE | ID: mdl-35177588

ABSTRACT

The 1.6 Mb 3q29 deletion is associated with developmental and psychiatric phenotypes, including a 40-fold increased risk for schizophrenia. Reduced birth weight and a high prevalence of feeding disorders in patients suggest underlying metabolic dysregulation. We investigated 3q29 deletion-induced metabolic changes using our previously generated heterozygous B6.Del16+/Bdh1-Tfrc mouse model. Animals were provided either standard chow (STD) or high-fat diet (HFD). Growth curves were performed on HFD mice to assess weight change (n = 30-50/group). Indirect calorimetry and untargeted metabolomics were performed on STD and HFD mice to evaluate metabolic phenotypes (n = 8-14/group). A behavioral battery was performed on STD and HFD mice to assess behavior change after the HFD challenge (n = 5-13/group). We found that B6.Del16+/Bdh1-Tfrc animals preferentially use dietary lipids as an energy source. Untargeted metabolomics of liver tissue showed a strong sex-dependent effect of the 3q29 deletion on fat metabolism. A HFD partially rescued the 3q29 deletion-associated weight deficit in females, but not males. Untargeted metabolomics of liver tissue after HFD revealed persistent fat metabolism alterations in females. The HFD did not affect B6.Del16+/Bdh1-Tfrc behavioral phenotypes, suggesting that 3q29 deletion-associated metabolic and behavioral outcomes are uncoupled. Our data suggest that dietary interventions to improve weight phenotypes in 3q29 deletion syndrome patients are unlikely to exacerbate behavioral manifestations. Our study also highlights the importance of assessing sex in metabolic studies and suggests that mechanisms underlying 3q29 deletion-associated metabolic phenotypes are sex-specific.


Subject(s)
Intellectual Disability , Schizophrenia , Animals , Child , Chromosome Deletion , Developmental Disabilities/genetics , Diet, High-Fat , Female , Humans , Intellectual Disability/genetics , Male , Mice , Mice, Inbred C57BL , Phenotype , Schizophrenia/complications , Schizophrenia/genetics
10.
iScience ; 24(9): 102987, 2021 Sep 24.
Article in English | MEDLINE | ID: mdl-34505005

ABSTRACT

Broadly neutralizing antibodies (bnAbs) against HIV-1 are frequently associated with the presence of autoreactivity/polyreactivity, a property that can limit their use as therapeutic agents. The bnAb 4E10, targeting the conserved Membrane proximal external region (MPER) of HIV-1, displays almost pan-neutralizing activity across globally circulating HIV-1 strains but exhibits nonspecific off-target interactions with lipid membranes. The hydrophobic apex of the third complementarity-determining region of the heavy chain (CDRH3) loop, which is essential for viral neutralization, critically contributes to this detrimental effect. Here, we have replaced the aromatic/hydrophobic residues from the apex of the CDRH3 of 4E10 with a single aromatic molecule through chemical modification to generate a variant that preserves the neutralization potency and breadth of 4E10 but with reduced autoreactivity. Collectively, our study suggests that the localized accumulation of aromaticity by chemical modification provides a pathway to ameliorate the adverse effects triggered by the CDRH3 of anti-HIV-1 MPER bnAbs.

12.
BMC Med Genomics ; 14(1): 154, 2021 06 09.
Article in English | MEDLINE | ID: mdl-34107974

ABSTRACT

BACKGROUND: Structural rearrangements of the genome, which generally occur during meiosis and result in large-scale (> 1 kb) copy number variants (CNV; deletions or duplications ≥ 1 kb), underlie genomic disorders. Recurrent pathogenic CNVs harbor similar breakpoints in multiple unrelated individuals and are primarily formed via non-allelic homologous recombination (NAHR). Several pathogenic NAHR-mediated recurrent CNV loci demonstrate biases for parental origin of de novo CNVs. However, the mechanism underlying these biases is not well understood. METHODS: We performed a systematic, comprehensive literature search to curate parent of origin data for multiple pathogenic CNV loci. Using a regression framework, we assessed the relationship between parental CNV origin and the male to female recombination rate ratio. RESULTS: We demonstrate significant association between sex-specific differences in meiotic recombination and parental origin biases at these loci (p = 1.07 × 10-14). CONCLUSIONS: Our results suggest that parental origin of CNVs is largely influenced by sex-specific recombination rates and highlight the need to consider these differences when investigating mechanisms that cause structural variation.


Subject(s)
Genomics
13.
J Biomol Tech ; 32(2): 74-82, 2021 07.
Article in English | MEDLINE | ID: mdl-34121934

ABSTRACT

Across the United States, the number of staff scientists (master's- or doctoral-level professionals working in nonfaculty roles) has grown by 35% since 2010, and they play an increasingly important role in research efforts. However, few targeted resources are available, which potentially limits the effectiveness of this group. Launched in 2016, the staff scientist path at Emory has tripled in size over 4 y to 138 staff. The present case study evaluated the perceptions of staff scientists related to onboarding experiences and professional development needs, including those needs arising from coronavirus disease 2019 (COVID-19) impacts in the workplace. A survey of Emory staff scientists was conducted from May to June 2019 as part of a program evaluation initiative to assess perceptions of onboarding and professional development opportunities. Interviews with a subset of scientists informed the survey development and identified COVID-19-related impacts on daily work. Results indicated the need for targeted orientation resources specific to staff scientists, accurate and timely information and resources to support scientists' supervisors, and professional development for scientists in leadership and management-related skills. Remote work associated with COVID-19 accentuated the need for managerial skills, including team development in digital work environments. Findings from this case study can inform policies and practices at Emory and other institutions that employ a similar staff scientist model.


Subject(s)
COVID-19/epidemiology , Physicians/statistics & numerical data , SARS-CoV-2/genetics , Workplace , COVID-19/genetics , COVID-19/virology , Career Mobility , Female , Health Personnel , Humans , Male , Physicians/psychology , SARS-CoV-2/pathogenicity
14.
Inflamm Bowel Dis ; 27(12): 1889-1900, 2021 11 15.
Article in English | MEDLINE | ID: mdl-34002220

ABSTRACT

BACKGROUND: The gut and oral microbiome have independently been shown to be associated with inflammatory bowel disease (IBD). However, it is not known to what extent gut and oral microbial disease markers converge in terms of their composition in IBD. Further, the spatial and temporal variation within the oral microenvironments of IBD remain to be elucidated. PATIENTS AND METHODS: We used a prospectively recruited cohort of patients with IBD (n = 47) and unrelated healthy control patients (n = 18) to examine the spatial and temporal distribution of microbiota within the various oral microenvironments, represented by saliva, tongue, buccal mucosa, and plaque, and compared them with stool. Microbiome characterization was performed using 16S rRNA gene sequencing. RESULTS: The oral microbiome displayed IBD-associated dysbiosis, in a site- and taxa-specific manner. Plaque samples depicted a relatively severe degree of dysbiosis, and the disease-associated dysbiotic bacterial groups were predominantly the members of the phylum Firmicutes. Our 16S rRNA gene analyses show that oral microbiota can distinguish patients with IBD from healthy control patients, with salivary microbiota performing the best, closely matched by stool and other oral sites. Longitudinal profiles of microbial composition suggest that some taxa are more consistently perturbed than others, preferentially in a site-dependent fashion. CONCLUSIONS: Collectively, these data indicate the potential of using oral microbial profiles in screening and monitoring patients with IBD. Furthermore, these results support the importance of spatial and longitudinal microbiome sampling to interpret disease-associated dysbiotic states and eventually to gain insights into disease pathogenesis.


Subject(s)
Inflammatory Bowel Diseases , Microbiota , Mouth/microbiology , Dysbiosis/diagnosis , Feces/microbiology , Humans , Inflammatory Bowel Diseases/classification , Inflammatory Bowel Diseases/microbiology , RNA, Ribosomal, 16S/genetics
15.
Fertil Steril ; 116(3): 843-854, 2021 09.
Article in English | MEDLINE | ID: mdl-34016428

ABSTRACT

OBJECTIVE: To identify modifying genes that explains the risk of fragile X-associated primary ovarian insufficiency (FXPOI). DESIGN: Gene-based, case/control association study, followed by a functional screen of highly ranked genes using a Drosophila model. SETTING: Participants were recruited from academic and clinical settings. PATIENT(S): Women with a premutation (PM) who experienced FXPOI at the age of 35 years or younger (n = 63) and women with a PM who experienced menopause at the age of 50 years or older (n = 51) provided clinical information and a deoxyribonucleic acid sample for whole genome sequencing. The functional screen was on the basis of Drosophila TRiP lines. INTERVENTION(S): Clinical information and a DNA sample were collected for whole genome sequencing. MAIN OUTCOME MEASURES: A polygenic risk score derived from common variants associated with natural age at menopause was calculated and associated with the risk of FXPOI. Genes associated with the risk of FXPOI were identified on the basis of the P-value from gene-based association test and an altered level of fecundity when knocked down in the Drosophila PM model. RESULTS: The polygenic risk score on the basis of common variants associated with natural age at menopause explained approximately 8% of the variance in the risk of FXPOI. Further, SUMO1 and KRR1 were identified as possible modifying genes associated with the risk of FXPOI on the basis of an untargeted gene analysis of rare variants. CONCLUSIONS: In addition to the large genetic effect of a PM on ovarian function, the additive effects of common variants associated with natural age at menopause and the effect of rare modifying variants appear to play a role in FXPOI risk.


Subject(s)
Fragile X Mental Retardation Protein/genetics , Menopause/genetics , Mutation , Ovary/physiopathology , Primary Ovarian Insufficiency/genetics , Adult , Age Factors , Animals , Animals, Genetically Modified , Case-Control Studies , Drosophila melanogaster/genetics , Female , Fertility/genetics , Genetic Background , Genetic Predisposition to Disease , Genome-Wide Association Study , Humans , Middle Aged , Phenotype , Primary Ovarian Insufficiency/diagnosis , Primary Ovarian Insufficiency/physiopathology , Risk Assessment , Risk Factors
16.
J Biomol Tech ; 32(1): 36-41, 2021 04.
Article in English | MEDLINE | ID: mdl-34025222

ABSTRACT

Force multipliers are attributes of an organization that enable the successful completion of multiple essential missions. Core facilities play a critical role in the research enterprise and can be organized as force multipliers. Conceiving of cores in this way influences their organization, funding, and research impact. To function as a force multiplier for the research enterprise, core facilities need to do more than efficiently provide services for investigators and generate revenue to recover their service costs: they must be aligned with the strategic objectives of a research university. When core facilities are organized in this way, they can facilitate recruitment of faculty and trainees; serve to retain talented faculty; drive, acquire, and maintain cutting-edge research platforms; and promote interaction and collaboration across the institution. Most importantly, cores accelerate the discovery and sharing of knowledge that are the foundation of a modern research university. This idea has been systematically implemented through the Emory Integrated Core Facilities (cores.emory.edu), which include 16 distinct core facilities and the Division of Animal Resources. Force multiplier core facilities can significantly contribute to the many essential missions necessary for the success of the research enterprise at research universities.


Subject(s)
Research Personnel , Universities , Humans
17.
J Virol ; 95(13): e0000521, 2021 06 10.
Article in English | MEDLINE | ID: mdl-33883221

ABSTRACT

A major goal of HIV vaccine design is to elicit broadly neutralizing antibodies (bNAbs). Such bNAbs target HIV's trimeric, membrane-embedded envelope glycoprotein spikes (mEnv). Soluble Env (sEnv) trimers have been used as vaccines, but engineering sEnvs for stability, multivalency, and desired antigenicity is problematic and deletes key neutralizing epitopes on glycoprotein 41 (gp41) while creating neoepitopes that elicit unwanted antibodies. Meanwhile, multivalent mEnv vaccines are challenging to develop due to trimer instability and low mEnv copy number amid other extraneous proteins on virus-like particles. Here, we describe a multivalent mEnv vaccine platform that does not require protein engineering or extraneous proteins. mEnv trimers were fixed, purified, and combined with naked liposomes in mild detergent. On removal of detergent, mEnv spikes were observed embedded in liposome particles (mean diameter, 133 nm) in correct orientation. These particles were recognized by HIV bNAbs and not non-NAbs and are designated mEnv liposomes (MELs). Following a sequential immunization scheme in rabbits, MELs elicited antibodies that neutralized tier 2 HIV isolates. Analysis of serum antibody specificities, including those to epitopes involving a missing conserved N-glycosylation site at position 197 near the CD4 binding site on two of the immunogens, provides clues on how NAb responses can be improved with modified immunogens. In sum, MELs are a biochemically defined platform that enables rational immunization strategies to elicit HIV bNAbs using multimerized mEnv. IMPORTANCE A vaccine that induced broadly neutralizing antibodies against HIV would likely end the AIDS pandemic. Such antibodies target membrane-embedded envelope glycoprotein spikes (mEnv) that HIV uses to enter cells. Due to HIV Env's low expression and instability, soluble stabilized Env trimers have been used as vaccine candidates, but these have an altered base that disrupts targets of HIV broadly neutralizing antibodies that bind near the membrane and are not available for all HIV isolates. Here, we describe membrane Env liposomes (MELs) that display a multivalent array of stable mEnvs on liposome particles. MELs showed the expected antibody recognition properties, including targeting parts of mEnv missing on soluble Envs. Immunization with MELs elicited antibodies that neutralized diverse HIV isolates. The MEL platform facilitates vaccine development with potentially any HIV Env at high valency, and a similar approach may be useful for eliciting antibodies to membrane-embedded targets of therapeutic interest.


Subject(s)
AIDS Vaccines/immunology , Broadly Neutralizing Antibodies/immunology , HIV Envelope Protein gp120/immunology , HIV Envelope Protein gp41/immunology , HIV-1/immunology , Antibodies, Viral/immunology , Antigens, Viral/immunology , Epitopes/immunology , HEK293 Cells , HIV Antibodies/immunology , HIV Infections/immunology , HIV Infections/prevention & control , HeLa Cells , Humans , Liposomes/immunology , Protein Engineering/methods , Vaccination
18.
Sci Rep ; 11(1): 8523, 2021 04 19.
Article in English | MEDLINE | ID: mdl-33875724

ABSTRACT

Lesch-Nyhan disease (LND) is an inherited disorder caused by pathogenic variants in the HPRT1 gene, which encodes the purine recycling enzyme hypoxanthine-guanine phosphoribosyltransferase (HGprt). We generated 6 induced pluripotent stem cell (iPSC) lines from 3 individuals with LND, along with 6 control lines from 3 normal individuals. All 12 lines had the characteristics of pluripotent stem cells, as assessed by immunostaining for pluripotency markers, expression of pluripotency genes, and differentiation into the 3 primary germ cell layers. Gene expression profiling with RNAseq demonstrated significant heterogeneity among the lines. Despite this heterogeneity, several anticipated abnormalities were readily detectable across all LND lines, including reduced HPRT1 mRNA. Several unexpected abnormalities were also consistently detectable across the LND lines, including decreases in FAR2P1 and increases in RNF39. Shotgun proteomics also demonstrated several expected abnormalities in the LND lines, such as absence of HGprt protein. The proteomics study also revealed several unexpected abnormalities across the LND lines, including increases in GNAO1 decreases in NSE4A. There was a good but partial correlation between abnormalities revealed by the RNAseq and proteomics methods. Finally, functional studies demonstrated LND lines had no HGprt enzyme activity and resistance to the toxic pro-drug 6-thioguanine. Intracellular purines in the LND lines were normal, but they did not recycle hypoxanthine. These cells provide a novel resource to reveal insights into the relevance of heterogeneity among iPSC lines and applications for modeling LND.


Subject(s)
Induced Pluripotent Stem Cells/cytology , Lesch-Nyhan Syndrome/pathology , Adolescent , Adult , Cell Differentiation/genetics , Cell Differentiation/physiology , Child , Gene Expression Profiling/methods , Humans , Hypoxanthine Phosphoribosyltransferase/genetics , Lesch-Nyhan Syndrome/genetics , Male , Purines/metabolism , RNA, Messenger/genetics , Young Adult
19.
J Biomol Tech ; 2021 Jan 15.
Article in English | MEDLINE | ID: mdl-33584149

ABSTRACT

Force multipliers are attributes of an organization that enable the successful completion of multiple essential missions. Core facilities play a critical role in the research enterprise and can be organized as force multipliers. Conceiving of cores in this way influences their organization, funding, and research impact. To function as a force multiplier for the research enterprise, core facilities need to do more than efficiently provide services for investigators and generate revenue to recover their service costs: they must be aligned with the strategic objectives of a research university. When core facilities are organized in this way, they can facilitate recruitment of faculty and trainees; serve to retain talented faculty; drive, acquire, and maintain cutting-edge research platforms; and promote interaction and collaboration across the institution. Most importantly, cores accelerate the discovery and sharing of knowledge that are the foundation of a modern research university. This idea has been systematically implemented through the Emory Integrated Core Facilities (cores.emory.edu), which include 16 distinct core facilities and the Division of Animal Resources. Force multiplier core facilities can significantly contribute to the many essential missions necessary for the success of the research enterprise at research universities.

20.
Mol Psychiatry ; 26(8): 4496-4510, 2021 08.
Article in English | MEDLINE | ID: mdl-32015465

ABSTRACT

Schizophrenia occurs in about one in four individuals with 22q11.2 deletion syndrome (22q11.2DS). The aim of this International Brain and Behavior 22q11.2DS Consortium (IBBC) study was to identify genetic factors that contribute to schizophrenia, in addition to the ~20-fold increased risk conveyed by the 22q11.2 deletion. Using whole-genome sequencing data from 519 unrelated individuals with 22q11.2DS, we conducted genome-wide comparisons of common and rare variants between those with schizophrenia and those with no psychotic disorder at age ≥25 years. Available microarray data enabled direct comparison of polygenic risk for schizophrenia between 22q11.2DS and independent population samples with no 22q11.2 deletion, with and without schizophrenia (total n = 35,182). Polygenic risk for schizophrenia within 22q11.2DS was significantly greater for those with schizophrenia (padj = 6.73 × 10-6). Novel reciprocal case-control comparisons between the 22q11.2DS and population-based cohorts showed that polygenic risk score was significantly greater in individuals with psychotic illness, regardless of the presence of the 22q11.2 deletion. Within the 22q11.2DS cohort, results of gene-set analyses showed some support for rare variants affecting synaptic genes. No common or rare variants within the 22q11.2 deletion region were significantly associated with schizophrenia. These findings suggest that in addition to the deletion conferring a greatly increased risk to schizophrenia, the risk is higher when the 22q11.2 deletion and common polygenic risk factors that contribute to schizophrenia in the general population are both present.


Subject(s)
DiGeorge Syndrome , Psychotic Disorders , Schizophrenia , Adult , Case-Control Studies , Cohort Studies , DiGeorge Syndrome/genetics , Humans , Schizophrenia/genetics
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