The contribution and regulation of various CD4+ T cell lineages that occur with remitting vs progressive courses in sarcoidosis are poorly understood. We developed a multiparameter flow cytometry ...panel to sort these CD4+ T cell lineages followed by measurement of their functional potential using RNA-sequencing analysis at six-month intervals across multiple study sites. To obtain good quality RNA for sequencing, we relied on chemokine receptor expression to identify and sort lineages. To minimize gene expression changes induced by perturbations of T cells and avoid protein denaturation caused by freeze/thaw cycles, we optimized our protocols using freshly isolated samples at each study site. To accomplish this study, we had to overcome significant standardization challenges across multiple sites. Here, we detail standardization considerations for cell processing, flow staining, data acquisition, sorting parameters, and RNA quality control analysis that were performed as part of the NIH-sponsored, multi-center study, BRonchoscopy at Initial sarcoidosis diagnosis Targeting longitudinal Endpoints (BRITE). After several rounds of iterative optimization, we identified the following aspects as critical for successful standardization: 1) alignment of PMT voltages across sites using CS&T/rainbow bead technology; 2) a single template created in the cytometer program that was used by all sites to gate cell populations during data acquisition and cell sorting; 3) use of standardized lyophilized flow cytometry staining cocktails to reduce technical error during processing; 4) development and implementation of a standardized Manual of Procedures. After standardization of cell sorting, we were able to determine the minimum number of sorted cells necessary for next generation sequencing through analysis of RNA quality and quantity from sorted T cell populations. Overall, we found that implementing a multi-parameter cell sorting with RNA-seq analysis clinical study across multiple study sites requires iteratively tested standardized procedures to ensure comparable and high-quality results.
Autoreactive B cells have a major function in autoimmunity. A small subset of B cells expressing two distinct B-cell-antigen-receptors (B
cells) is elevated in many patients with systematic lupus ...erythematosus (SLE) and in the MRL(/lpr) mouse model of lupus, and is often autoreactive. Here we show, using RNAseq and in vitro and in vivo analyses, signals that are required for promoting B
cell numbers and effector function in autoimmune mice. Compared with conventional B cells, B
cells are more responsive to Toll-like receptor 7/9 and type I/II interferon treatment, display higher levels of MHCII and co-receptors, and depend on IL-21 for their homeostasis; moreover they expand better upon T cell-dependent antigen stimulation, and mount a more robust memory response, which are characteristics essential for enhanced (auto)immune responses. Our findings thus provide insights on the stimuli for the expansion of an autoreactive B cell subset that may contribute to the etiology of SLE.
Abstract
Sarcoidosis is a complex systemic disease. Our study aimed to (1) identify novel alleles associated with sarcoidosis susceptibility; (2) provide an in-depth evaluation of HLA alleles and ...sarcoidosis susceptibility and (3) integrate genetic and transcription data to identify risk loci that may more directly impact disease pathogenesis. We report a genome-wide association study of 1335 sarcoidosis cases and 1264 controls of European descent (EA) and investigate associated alleles in a study of African Americans (AA: 1487 cases and 1504 controls). The EA and AA cohort was recruited from multiple United States sites. HLA alleles were imputed and tested for association with sarcoidosis susceptibility. Expression quantitative locus and colocalization analysis were performed using a subset of subjects with transcriptome data. Forty-nine SNPs in the HLA region in HLA-DRA, -DRB9, -DRB5, -DQA1 and BRD2 genes were significantly associated with sarcoidosis susceptibility in EA, rs3129888 was also a risk variant for sarcoidosis in AA. Classical HLA alleles DRB1*0101, DQA1*0101 and DQB1*0501, which are highly correlated, were also associated with sarcoidosis. rs3135287 near HLA-DRA was associated with HLA-DRA expression in peripheral blood mononuclear cells and bronchoalveolar lavage from subjects and lung tissue and whole blood from GTEx. We identified six novel SNPs (out of the seven SNPs representing the 49 significant SNPs) and nine HLA alleles associated with sarcoidosis susceptibility in the largest EA population. We also replicated our findings in an AA population. Our study reiterates the potential role of antigen recognition and/or presentation HLA class II genes in sarcoidosis pathogenesis.
Orofacial malformations resulting from genetic and/or environmental causes are frequent human birth defects yet their etiology is often unclear because of insufficient information concerning the ...molecular, cellular and morphogenetic processes responsible for normal facial development. We have, therefore, derived a comprehensive expression dataset for mouse orofacial development, interrogating three distinct regions - the mandibular, maxillary and frontonasal prominences. To capture the dynamic changes in the transcriptome during face formation, we sampled five time points between E10.5-E12.5, spanning the developmental period from establishment of the prominences to their fusion to form the mature facial platform. Seven independent biological replicates were used for each sample ensuring robustness and quality of the dataset. Here, we provide a general overview of the dataset, characterizing aspects of gene expression changes at both the spatial and temporal level. Considerable coordinate regulation occurs across the three prominences during this period of facial growth and morphogenesis, with a switch from expression of genes involved in cell proliferation to those associated with differentiation. An accompanying shift in the expression of polycomb and trithorax genes presumably maintains appropriate patterns of gene expression in precursor or differentiated cells, respectively. Superimposed on the many coordinated changes are prominence-specific differences in the expression of genes encoding transcription factors, extracellular matrix components, and signaling molecules. Thus, the elaboration of each prominence will be driven by particular combinations of transcription factors coupled with specific cell:cell and cell:matrix interactions. The dataset also reveals several prominence-specific genes not previously associated with orofacial development, a subset of which we externally validate. Several of these latter genes are components of bidirectional transcription units that likely share cis-acting sequences with well-characterized genes. Overall, our studies provide a valuable resource for probing orofacial development and a robust dataset for bioinformatic analysis of spatial and temporal gene expression changes during embryogenesis.
The rapid increase in gene-centric biological knowledge coupled with analytic approaches for genomewide data integration provides an opportunity to develop systems-level understanding of facial ...development. Experimental analyses have demonstrated the importance of signaling between the surface ectoderm and the underlying mesenchyme are coordinating facial patterning. However, current transcriptome data from the developing vertebrate face is dominated by the mesenchymal component, and the contributions of the ectoderm are not easily identified. We have generated transcriptome datasets from critical periods of mouse face formation that enable gene expression to be analyzed with respect to time, prominence, and tissue layer. Notably, by separating the ectoderm and mesenchyme we considerably improved the sensitivity compared to data obtained from whole prominences, with more genes detected over a wider dynamic range. From these data we generated a detailed description of ectoderm-specific developmental programs, including pan-ectodermal programs, prominence- specific programs and their temporal dynamics. The genes and pathways represented in these programs provide mechanistic insights into several aspects of ectodermal development. We also used these data to identify co-expression modules specific to facial development. We then used 14 co-expression modules enriched for genes involved in orofacial clefts to make specific mechanistic predictions about genes involved in tongue specification, in nasal process patterning and in jaw development. Our multidimensional gene expression dataset is a unique resource for systems analysis of the developing face; our co-expression modules are a resource for predicting functions of poorly annotated genes, or for predicting roles for genes that have yet to be studied in the context of facial development; and our analytic approaches provide a paradigm for analysis of other complex developmental programs.
•A statistically robust and extensively verified multidimensional gene expression resource for mouse facial development.•Data derived from separated ectoderm and mesenchyme from each facial prominence at E10.5 through E12.5.•A facial ectoderm developmental program highlights cell-cell signaling, epithelial diversification and maturation.•Facial development co-expression modules identify sub-programs relevant to patterning, morphogenesis and pathogenesis.•A resource for interpreting clinical genetic data pertaining to facial development, morphology and orofacial clefting.
The extent of the innate immune response is regulated by many positively and negatively acting signaling proteins. This allows for proper activation of innate immunity to fight infection while ...ensuring that the response is limited to prevent unwanted complications. Thus mutations in innate immune regulators can lead to immune dysfunction or to inflammatory diseases such as arthritis or atherosclerosis. To identify novel innate immune regulators that could affect infectious or inflammatory disease, we have taken a comparative genomics RNAi screening approach in which we inhibit orthologous genes in the nematode Caenorhabditis elegans and murine macrophages, expecting that genes with evolutionarily conserved function also will regulate innate immunity in humans. Here we report the results of an RNAi screen of approximately half of the C. elegans genome, which led to the identification of many candidate genes that regulate innate immunity in C. elegans and mouse macrophages. One of these novel conserved regulators of innate immunity is the mRNA splicing regulator Eftud2, which we show controls the alternate splicing of the MyD88 innate immunity signaling adaptor to modulate the extent of the innate immune response.
Mechanisms of self-tolerance often result in CD8(+) tumor-infiltrating lymphocytes (TIL) with a hypofunctional phenotype incapable of tumor clearance. Using a transplantable colon carcinoma model, we ...found that CD8(+) T cells became tolerized in <24 h in an established tumor environment. To define the collective impact of pathways suppressing TIL function, we compared genome-wide mRNA expression of tumor-specific CD8(+) T cells from the tumor and periphery. Notably, gene expression induced during TIL hypofunction more closely resembled self-tolerance than viral exhaustion. Differential gene expression was refined to identify a core set of genes that defined hypofunctional TIL; these data comprise the first molecular profile of tumor-specific TIL that are naturally responding and represent a polyclonal repertoire. The molecular profile of TIL was further dissected to determine the extent of overlap and distinction between pathways that collectively restrict T cell functions. As suggested by the molecular profile of TIL, protein expression of inhibitory receptor LAG-3 was differentially regulated throughout prolonged late-G1/early-S phase of the cell cycle. Our data may accelerate efficient identification of combination therapies to boost anti-tumor function of TIL specifically against tumor cells.
Cell lineage specification is a tightly regulated process that is dependent on appropriate expression of lineage and developmental stage-specific transcriptional programs. Here, we show that ...Chromodomain Helicase DNA-binding protein 4 (CHD4), a major ATPase/helicase subunit of Nucleosome Remodeling and Deacetylase Complexes (NuRD) in lymphocytes, is essential for specification of the early B cell lineage transcriptional program. In the absence of CHD4 in B cell progenitors in vivo, development of these cells is arrested at an early pro-B-like stage that is unresponsive to IL-7 receptor signaling and unable to efficiently complete V(D)J rearrangements at Igh loci. Our studies confirm that chromatin accessibility and transcription of thousands of gene loci are controlled dynamically by CHD4 during early B cell development. Strikingly, CHD4-deficient pro-B cells express transcripts of many non-B cell lineage genes, including genes that are characteristic of other hematopoietic lineages, neuronal cells, and the CNS, lung, pancreas, and other cell types. We conclude that CHD4 inhibits inappropriate transcription in pro-B cells. Together, our data demonstrate the importance of CHD4 in establishing and maintaining an appropriate transcriptome in early B lymphopoiesis via chromatin accessibility.
Background
The prevalence of atopic diseases has increased with atopic dermatitis (AD) as the earliest manifestation. We assessed if molecular risk factors in atopic mothers influence their infants' ...susceptibility to an atopic disease.
Methods
Pregnant women and their infants with (n = 174, high‐risk) or without (n = 126, low‐risk) parental atopy were enrolled in a prospective birth cohort. Global differentially methylated regions (DMRs) were determined in atopic (n = 92) and non‐atopic (n = 82) mothers. Principal component analysis was used to predict atopy risk in children dependent on maternal atopy. Genome‐wide transcriptomic analyses were performed in paired atopic (n = 20) and non‐atopic (n = 15) mothers and cord blood. Integrative genomic analyses were conducted to define methylation–gene expression relationships.
Results
Atopic dermatitis was more prevalent in high‐risk compared to low‐risk children by age 2. Differential methylation analyses identified 165 DMRs distinguishing atopic from non‐atopic mothers. Inclusion of DMRs in addition to maternal atopy significantly increased the odds ratio to develop AD in children from 2.56 to 4.26. In atopic compared to non‐atopic mothers, 139 differentially expressed genes (DEGs) were identified significantly enriched of genes within the interferon signaling pathway. Expression quantitative trait methylation analyses dependent on maternal atopy identified 29 DEGs controlled by 136 trans‐acting methylation marks, some located near transcription factors. Differential expression for the same nine genes, including MX1 and IFI6 within the interferon pathway, was identified in atopic and non‐atopic mothers and high‐risk and low‐risk children.
Conclusion
These data suggest that in utero epigenetic and transcriptomic mechanisms predominantly involving the interferon pathway may impact and predict the development of infant atopy.
This study assessed the influence of molecular risk factors in atopic mothers influence on their infants' susceptibility to an atopic disease. DMRs distinguished atopic from non‐atopic mothers. Inclusion of maternal DMRs further increased the risk in the offspring to develop AD conferred by maternal atopy alone. Transcriptomic analyses identified DEGs in atopic compared with non‐atopic mothers with shared DEGs in high‐risk relative to low‐risk children.Abbreviations: DEG, differentially expressed gene; DMR, differentially methylated region; HELZ2, helicase with zinc finger 2; HERC5, HECT and RLD domain containing E3 ubiquitin protein ligase 5; IFI6, interferon α inducible protein 6; IFI44L, interferon induced protein 44 like; IFIT3, interferon‐induced protein with tetratricopeptide repeats 3; IMPAC, Impact of Parental risk factors on Atopy in Children; MX1, MX dynamin like GTPase 1; REC8, REC8 meiotic recombination protein; SIGLEC1, sialic acid binding Ig like lectin 1; XAF1, XIAP associated factor 1
Alveolar macrophages serve as central orchestrators of inflammatory responses in the lungs, both initiating their onset and promoting their resolution. However, the mechanisms that program ...macrophages for these dynamic responses are not fully understood. Over 95% of all mammalian genes undergo alternative pre-mRNA splicing. While alternative splicing has been shown to regulate inflammatory responses in macrophages
, it has not been investigated on a genome-wide scale
Here we used RNAseq to investigate alternative pre-mRNA splicing in alveolar macrophages isolated from lipopolysaccharide (LPS)-treated mice during the peak of inflammation and during its resolution. We found that lung inflammation induced substantial alternative pre-mRNA splicing in alveolar macrophages. The number of changes in isoform usage was greatest at the peak of inflammation and involved multiple classes of alternative pre-mRNA splicing events. Comparative pathway analysis of inflammation-induced changes in alternative pre-mRNA splicing and differential gene expression revealed overlap of pathways enriched for immune responses such as chemokine signaling and cellular metabolism. Moreover, alternative pre-mRNA splicing of genes in metabolic pathways differed in tissue resident
recruited (blood monocyte-derived) alveolar macrophages and corresponded to changes in core metabolism, including a switch to Warburg-like metabolism in recruited macrophages with increased glycolysis and decreased flux through the tricarboxylic acid cycle.
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