Browsing by Subject "Sequence Analysis, RNA"

Now showing 1 - 13 of 13
  • Thumbnail Image
    ItemRestricted
    Elucidation of hepatitis C virus transmission and early diversification by single genome sequencing.
    (PLoS Pathog, 2012) Li, Hui; Stoddard, Mark B; Wang, Shuyi; Blair, Lily M; Giorgi, Elena E; Parrish, Erica H; Learn, Gerald H; Hraber, Peter; Goepfert, Paul A; Saag, Michael S; Denny, Thomas N; Haynes, Barton F; Hahn, Beatrice H; Ribeiro, Ruy M; Perelson, Alan S; Korber, Bette T; Bhattacharya, Tanmoy; Shaw, George M
    A precise molecular identification of transmitted hepatitis C virus (HCV) genomes could illuminate key aspects of transmission biology, immunopathogenesis and natural history. We used single genome sequencing of 2,922 half or quarter genomes from plasma viral RNA to identify transmitted/founder (T/F) viruses in 17 subjects with acute community-acquired HCV infection. Sequences from 13 of 17 acute subjects, but none of 14 chronic controls, exhibited one or more discrete low diversity viral lineages. Sequences within each lineage generally revealed a star-like phylogeny of mutations that coalesced to unambiguous T/F viral genomes. Numbers of transmitted viruses leading to productive clinical infection were estimated to range from 1 to 37 or more (median = 4). Four acutely infected subjects showed a distinctly different pattern of virus diversity that deviated from a star-like phylogeny. In these cases, empirical analysis and mathematical modeling suggested high multiplicity virus transmission from individuals who themselves were acutely infected or had experienced a virus population bottleneck due to antiviral drug therapy. These results provide new quantitative and qualitative insights into HCV transmission, revealing for the first time virus-host interactions that successful vaccines or treatment interventions will need to overcome. Our findings further suggest a novel experimental strategy for identifying full-length T/F genomes for proteome-wide analyses of HCV biology and adaptation to antiviral drug or immune pressures.
  • Thumbnail Image
    ItemOpen Access
    Evaluating whole transcriptome amplification for gene profiling experiments using RNA-Seq.
    (BMC Biotechnol, 2015-07-30) Faherty, SL; Campbell, CR; Larsen, PL; Yoder, AD
    BACKGROUND: RNA-Seq has enabled high-throughput gene expression profiling to provide insight into the functional link between genotype and phenotype. Low quantities of starting RNA can be a severe hindrance for studies that aim to utilize RNA-Seq. To mitigate this bottleneck, whole transcriptome amplification (WTA) technologies have been developed to generate sufficient sequencing targets from minute amounts of RNA. Successful WTA requires accurate replication of transcript abundance without the loss or distortion of specific mRNAs. Here, we test the efficacy of NuGEN's Ovation RNA-Seq V2 system, which uses linear isothermal amplification with a unique chimeric primer for amplification, using white adipose tissue from standard laboratory rats (Rattus norvegicus). Our goal was to investigate potential biological artifacts introduced through WTA approaches by establishing comparisons between matched raw and amplified RNA libraries derived from biological replicates. RESULTS: We found that 93% of expressed genes were identical between all unamplified versus matched amplified comparisons, also finding that gene density is similar across all comparisons. Our sequencing experiment and downstream bioinformatic analyses using the Tuxedo analysis pipeline resulted in the assembly of 25,543 high-quality transcripts. Libraries constructed from raw RNA and WTA samples averaged 15,298 and 15,253 expressed genes, respectively. Although significant differentially expressed genes (P < 0.05) were identified in all matched samples, each of these represents less than 0.15% of all shared genes for each comparison. CONCLUSIONS: Transcriptome amplification is efficient at maintaining relative transcript frequencies with no significant bias when using this NuGEN linear isothermal amplification kit under ideal laboratory conditions as presented in this study. This methodology has broad applications, from clinical and diagnostic, to field-based studies when sample acquisition, or sample preservation, methods prove challenging.
  • Thumbnail Image
    ItemOpen Access
    Hybrid error correction and de novo assembly of single-molecule sequencing reads.
    (Nat Biotechnol, 2012-07-01) Koren, Sergey; Schatz, Michael C; Walenz, Brian P; Martin, Jeffrey; Howard, Jason T; Ganapathy, Ganeshkumar; Wang, Zhong; Rasko, David A; McCombie, W Richard; Jarvis, Erich D; Adam M Phillippy
    Single-molecule sequencing instruments can generate multikilobase sequences with the potential to greatly improve genome and transcriptome assembly. However, the error rates of single-molecule reads are high, which has limited their use thus far to resequencing bacteria. To address this limitation, we introduce a correction algorithm and assembly strategy that uses short, high-fidelity sequences to correct the error in single-molecule sequences. We demonstrate the utility of this approach on reads generated by a PacBio RS instrument from phage, prokaryotic and eukaryotic whole genomes, including the previously unsequenced genome of the parrot Melopsittacus undulatus, as well as for RNA-Seq reads of the corn (Zea mays) transcriptome. Our long-read correction achieves >99.9% base-call accuracy, leading to substantially better assemblies than current sequencing strategies: in the best example, the median contig size was quintupled relative to high-coverage, second-generation assemblies. Greater gains are predicted if read lengths continue to increase, including the prospect of single-contig bacterial chromosome assembly.
  • Thumbnail Image
    ItemOpen Access
    Identification of microRNAs expressed in two mosquito vectors, Aedes albopictus and Culex quinquefasciatus.
    (BMC Genomics, 2010-02-18) Skalsky, Rebecca L; Vanlandingham, Dana L; Scholle, Frank; Higgs, Stephen; Cullen, Bryan R
    BACKGROUND: MicroRNAs (miRNAs) are small non-coding RNAs that post-transcriptionally regulate gene expression in a variety of organisms, including insects, vertebrates, and plants. miRNAs play important roles in cell development and differentiation as well as in the cellular response to stress and infection. To date, there are limited reports of miRNA identification in mosquitoes, insects that act as essential vectors for the transmission of many human pathogens, including flaviviruses. West Nile virus (WNV) and dengue virus, members of the Flaviviridae family, are primarily transmitted by Aedes and Culex mosquitoes. Using high-throughput deep sequencing, we examined the miRNA repertoire in Ae. albopictus cells and Cx. quinquefasciatus mosquitoes. RESULTS: We identified a total of 65 miRNAs in the Ae. albopictus C7/10 cell line and 77 miRNAs in Cx. quinquefasciatus mosquitoes, the majority of which are conserved in other insects such as Drosophila melanogaster and Anopheles gambiae. The most highly expressed miRNA in both mosquito species was miR-184, a miRNA conserved from insects to vertebrates. Several previously reported Anopheles miRNAs, including miR-1890 and miR-1891, were also found in Culex and Aedes, and appear to be restricted to mosquitoes. We identified seven novel miRNAs, arising from nine different precursors, in C7/10 cells and Cx. quinquefasciatus mosquitoes, two of which have predicted orthologs in An. gambiae. Several of these novel miRNAs reside within a ~350 nt long cluster present in both Aedes and Culex. miRNA expression was confirmed by primer extension analysis. To determine whether flavivirus infection affects miRNA expression, we infected female Culex mosquitoes with WNV. Two miRNAs, miR-92 and miR-989, showed significant changes in expression levels following WNV infection. CONCLUSIONS: Aedes and Culex mosquitoes are important flavivirus vectors. Recent advances in both mosquito genomics and high-throughput sequencing technologies enabled us to interrogate the miRNA profile in these two species. Here, we provide evidence for over 60 conserved and seven novel mosquito miRNAs, expanding upon our current understanding of insect miRNAs. Undoubtedly, some of the miRNAs identified will have roles not only in mosquito development, but also in mediating viral infection in the mosquito host.
  • Thumbnail Image
    ItemOpen Access
    Loss of tumor suppressor IGFBP4 drives epigenetic reprogramming in hepatic carcinogenesis.
    (Nucleic acids research, 2018-09) Lee, Ying-Ying; Mok, Myth Ts; Kang, Wei; Yang, Weiqin; Tang, Wenshu; Wu, Feng; Xu, Liangliang; Yan, Mingfei; Yu, Zhuo; Lee, Sau-Dan; Tong, Joanna HM; Cheung, Yue-Sun; Lai, Paul BS; Yu, Dae-Yeul; Wang, Qianben; Wong, Grace LH; Chan, Andrew M; Yip, Kevin Y; To, Ka-Fai; Cheng, Alfred SL
    Genomic sequencing of hepatocellular carcinoma (HCC) uncovers a paucity of actionable mutations, underscoring the necessity to exploit epigenetic vulnerabilities for therapeutics. In HCC, EZH2-mediated H3K27me3 represents a major oncogenic chromatin modification, but how it modulates the therapeutic vulnerability of signaling pathways remains unknown. Here, we show EZH2 acts antagonistically to AKT signaling in maintaining H3K27 methylome through epigenetic silencing of IGFBP4. ChIP-seq revealed enrichment of Ezh2/H3K27me3 at silenced loci in HBx-transgenic mouse-derived HCCs, including Igfbp4 whose down-regulation significantly correlated with EZH2 overexpression and poor survivals of HCC patients. Functional characterizations demonstrated potent growth- and invasion-suppressive functions of IGFBP4, which was associated with transcriptomic alterations leading to deregulation of multiple signaling pathways. Mechanistically, IGFBP4 stimulated AKT/EZH2 phosphorylation to abrogate H3K27me3-mediated silencing, forming a reciprocal feedback loop that suppressed core transcription factor networks (FOXA1/HNF1A/HNF4A/KLF9/NR1H4) for normal liver homeostasis. Consequently, the in vivo tumorigenicity of IGFBP4-silenced HCC cells was vulnerable to pharmacological inhibition of EZH2, but not AKT. Our study unveils chromatin regulation of a novel liver tumor suppressor IGFBP4, which constitutes an AKT-EZH2 reciprocal loop in driving H3K27me3-mediated epigenetic reprogramming. Defining the aberrant chromatin landscape of HCC sheds light into the mechanistic basis of effective EZH2-targeted inhibition.
  • Thumbnail Image
    ItemOpen Access
    Meta-Analysis of COVID-19 BAL Single-Cell RNA Sequencing Reveals Alveolar Epithelial Transitions and Unique Alveolar Epithelial Cell Fates.
    (American journal of respiratory cell and molecular biology, 2023-12) Karmaus, Peer WF; Tata, Aleksandra; Meacham, Julie M; Day, Frank; Thrower, David; Tata, Purushothama Rao; Fessler, Michael B
    Single-cell RNA sequencing (scRNA-seq) of BAL cells has provided insights into coronavirus disease (COVID-19). However, reports have been limited by small patient cohorts. We performed a meta-analysis of BAL scRNA-seq data from healthy control subjects (n = 13) and patients with COVID-19 (n = 20), sourced from six independent studies (167,280 high-quality cells in total). Consistent with the source reports, increases in infiltrating leukocyte subtypes were noted, several with type I IFN signatures and unique gene expression signatures associated with transcellular chemokine signaling. Noting dramatic reductions of inferred NKX2-1 and NR4A1 activity in alveolar epithelial type II (AT-II) cells, we modeled pseudotemporal AT-II-to-AT-I progression. This revealed changes in inferred AT-II cell metabolic activity, increased transitional cells, and a previously undescribed AT-I state. This cell state was conspicuously marked by the induction of genes of the epidermal differentiation complex, including the cornified envelope protein SPRR3 (small proline-rich protein 3), upregulation of multiple KRT (keratin) genes, inferred mitochondrial dysfunction, and cell death signatures including apoptosis and ferroptosis. Immunohistochemistry of lungs from patients with COVID-19 confirmed upregulation and colocalization of KRT13 and SPRR3 in the distal airspaces. Forced overexpression of SPRR3 in human alveolar epithelial cells ex vivo did not activate caspase-3 or upregulate KRT13, suggesting that SPRR3 marks an AT-I cornification program in COVID-19 but is not sufficient for phenotypic changes.
  • No Thumbnail Available
    ItemOpen Access
    Pol II docking and pausing at growth and stress genes in C. elegans.
    (Cell Rep, 2014-02-13) Maxwell, Colin S; Kruesi, William S; Core, Leighton J; Kurhanewicz, Nicole; Waters, Colin T; Lewarch, Caitlin L; Antoshechkin, Igor; Lis, John T; Meyer, Barbara J; Baugh, L Ryan
    Fluctuations in nutrient availability profoundly impact gene expression. Previous work revealed postrecruitment regulation of RNA polymerase II (Pol II) during starvation and recovery in Caenorhabditis elegans, suggesting that promoter-proximal pausing promotes rapid response to feeding. To test this hypothesis, we measured Pol II elongation genome wide by two complementary approaches and analyzed elongation in conjunction with Pol II binding and expression. We confirmed bona fide pausing during starvation and also discovered Pol II docking. Pausing occurs at active stress-response genes that become downregulated in response to feeding. In contrast, "docked" Pol II accumulates without initiating upstream of inactive growth genes that become rapidly upregulated upon feeding. Beyond differences in function and expression, these two sets of genes have different core promoter motifs, suggesting alternative transcriptional machinery. Our work suggests that growth and stress genes are both regulated postrecruitment during starvation but at initiation and elongation, respectively, coordinating gene expression with nutrient availability.
  • Thumbnail Image
    ItemOpen Access
    Postnatally-transmitted HIV-1 Envelope variants have similar neutralization-sensitivity and function to that of nontransmitted breast milk variants.
    (Retrovirology, 2013-01-10) Fouda, Genevieve G; Mahlokozera, Tatenda; Salazar-Gonzalez, Jesus F; Salazar, Maria G; Learn, Gerald; Kumar, Surender B; Dennison, S Moses; Russell, Elizabeth; Rizzolo, Katherine; Jaeger, Frederick; Cai, Fangping; Vandergrift, Nathan A; Gao, Feng; Hahn, Beatrice; Shaw, George M; Ochsenbauer, Christina; Swanstrom, Ronald; Meshnick, Steve; Mwapasa, Victor; Kalilani, Linda; Fiscus, Susan; Montefiori, David; Haynes, Barton; Kwiek, Jesse; Alam, S Munir; Permar, Sallie R
    BACKGROUND: Breastfeeding is a leading cause of infant HIV-1 infection in the developing world, yet only a minority of infants exposed to HIV-1 via breastfeeding become infected. As a genetic bottleneck severely restricts the number of postnatally-transmitted variants, genetic or phenotypic properties of the virus Envelope (Env) could be important for the establishment of infant infection. We examined the efficiency of virologic functions required for initiation of infection in the gastrointestinal tract and the neutralization sensitivity of HIV-1 Env variants isolated from milk of three postnatally-transmitting mothers (n = 13 viruses), five clinically-matched nontransmitting mothers (n = 16 viruses), and seven postnatally-infected infants (n = 7 postnatally-transmitted/founder (T/F) viruses). RESULTS: There was no difference in the efficiency of epithelial cell interactions between Env virus variants from the breast milk of transmitting and nontransmitting mothers. Moreover, there was similar efficiency of DC-mediated trans-infection, CCR5-usage, target cell fusion, and infectivity between HIV-1 Env-pseudoviruses from nontransmitting mothers and postnatal T/F viruses. Milk Env-pseudoviruses were generally sensitive to neutralization by autologous maternal plasma and resistant to breast milk neutralization. Infant T/F Env-pseudoviruses were equally sensitive to neutralization by broadly-neutralizing monoclonal and polyclonal antibodies as compared to nontransmitted breast milk Env variants. CONCLUSION: Postnatally-T/F Env variants do not appear to possess a superior ability to interact with and cross a mucosal barrier or an exceptional resistance to neutralization that define their capability to initiate infection across the infant gastrointestinal tract in the setting of preexisting maternal antibodies.
  • Thumbnail Image
    ItemOpen Access
    Protocol for fast scRNA-seq raw data processing using scKB and non-arbitrary quality control with COPILOT.
    (STAR protocols, 2022-12) Hsu, Che-Wei; Shahan, Rachel; Nolan, Trevor M; Benfey, Philip N; Ohler, Uwe
    We describe a protocol to perform fast and non-arbitrary quality control of single-cell RNA sequencing (scRNA-seq) raw data using scKB and COPILOT. scKB is a wrapper script of kallisto and bustools for accelerated alignment and transcript count matrix generation, which runs significantly faster than the popular tool Cell Ranger. COPILOT then offers non-arbitrary background noise removal by comparing distributions of low-quality and high-quality cells. Together, this protocol streamlines the processing workflow and provides an easy entry for new scRNA-seq users. For complete details on the use and execution of this protocol, please refer to Shahan et al. (2022).
  • Thumbnail Image
    ItemOpen Access
    Retinal Ganglion Cells With a Glaucoma OPTN(E50K) Mutation Exhibit Neurodegenerative Phenotypes when Derived from Three-Dimensional Retinal Organoids.
    (Stem cell reports, 2020-07) VanderWall, Kirstin B; Huang, Kang-Chieh; Pan, Yanling; Lavekar, Sailee S; Fligor, Clarisse M; Allsop, Anna R; Lentsch, Kelly A; Dang, Pengtao; Zhang, Chi; Tseng, Henry C; Cummins, Theodore R; Meyer, Jason S
    Retinal ganglion cells (RGCs) serve as the connection between the eye and the brain, with this connection disrupted in glaucoma. Numerous cellular mechanisms have been associated with glaucomatous neurodegeneration, and useful cellular models of glaucoma allow for the precise analysis of degenerative phenotypes. Human pluripotent stem cells (hPSCs) serve as powerful tools for studying human disease, particularly cellular mechanisms underlying neurodegeneration. Thus, efforts focused upon hPSCs with an E50K mutation in the Optineurin (OPTN) gene, a leading cause of inherited forms of glaucoma. CRISPR/Cas9 gene editing introduced the OPTN(E50K) mutation into existing lines of hPSCs, as well as generating isogenic controls from patient-derived lines. RGCs differentiated from OPTN(E50K) hPSCs exhibited numerous neurodegenerative deficits, including neurite retraction, autophagy dysfunction, apoptosis, and increased excitability. These results demonstrate the utility of OPTN(E50K) RGCs as an in vitro model of neurodegeneration, with the opportunity to develop novel therapeutic approaches for glaucoma.
  • Thumbnail Image
    ItemOpen Access
    RNA-Seq and ChIP-Seq reveal SQSTM1/p62 as a key mediator of JunB suppression of NF-κB-dependent inflammation.
    (J Invest Dermatol, 2015-04) Zhang, Xiaoling; Jin, Jane Y; Wu, Joseph; Qin, Xiaoxia; Streilein, Robert; Hall, Russell P; Zhang, Jennifer Y
    Mice with epidermal deletion of JunB transcription factor displayed a psoriasis-like inflammation. The relevance of these findings to humans and the mechanisms mediating JunB function are not fully understood. Here we demonstrate that impaired JunB function via gene silencing or overexpression of a dominant negative mutant increased human keratinocyte cell proliferation but decreased cell barrier function. RNA-seq revealed over 500 genes affected by JunB loss of function, which included the upregulation of an array of proinflammatory molecules relevant to psoriasis. Among these were tumor necrosis factor α (TNFα), CCL2, CXCL10, IL6R, and SQSTM1, an adaptor protein involved in nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) activation. Chromatin immunoprecipitation (ChIP)-Seq and gene reporter analyses showed that JunB directly suppressed SQSTM1 by binding to a consensus AP-1 cis element located around 2 kb upstream of SQSTM1-transcription start site. Similar to JunB loss of function, SQSTM1-overexpression induced TNFα, CCL2, and CXCL10. Conversely, NF-κB inhibition genetically with a mutant IκBα or pharmacologically with pyrrolidine dithiocarbamate (PDTC) prevented cytokine, but not IL6R, induction by JunB deficiency. Taken together, our findings indicate that JunB controls epidermal growth, barrier formation, and proinflammatory responses through direct and indirect mechanisms, pinpointing SQSTM1 as a key mediator of JunB suppression of NF-κB-dependent inflammation.
  • Thumbnail Image
    ItemOpen Access
    Simple and inexpensive ribosome profiling analysis of mRNA translation.
    (Methods (San Diego, Calif.), 2015-12) Reid, David W; Shenolikar, Shirish; Nicchitta, Christopher V
    The development and application of ribosome profiling has markedly advanced our understanding of ribosomes and mRNA translation. The experimental approach, which relies on deep sequencing of ribosome-protected mRNA fragments generated by treatment of polyribosomes with exogenous nucleases, provides a transcriptome-wide assessment of translation. The broad application of ribosome profiling has been slowed by the complexity and expense of the protocol. Here, we provide a simplified ribosome profiling method that uses micrococcal nuclease to generate ribosome footprints in crude cellular extracts, which are then purified simply by size selection via polyacrylamide gel electrophoresis. This simplification removes the laborious or expensive purification of ribosomes that has typically been used. This direct extraction method generates gene-level ribosome profiling data that are similar to a method that includes ribosome purification. This protocol should significantly ease the barrier to entry for research groups interested in employing ribosome profiling.
  • Thumbnail Image
    ItemOpen Access
    Single-cell meta-analysis of SARS-CoV-2 entry genes across tissues and demographics.
    (Nature medicine, 2021-03) Muus, Christoph; Luecken, Malte D; Eraslan, Gökcen; Sikkema, Lisa; Waghray, Avinash; Heimberg, Graham; Kobayashi, Yoshihiko; Vaishnav, Eeshit Dhaval; Subramanian, Ayshwarya; Smillie, Christopher; Jagadeesh, Karthik A; Duong, Elizabeth Thu; Fiskin, Evgenij; Torlai Triglia, Elena; Ansari, Meshal; Cai, Peiwen; Lin, Brian; Buchanan, Justin; Chen, Sijia; Shu, Jian; Haber, Adam L; Chung, Hattie; Montoro, Daniel T; Adams, Taylor; Aliee, Hananeh; Allon, Samuel J; Andrusivova, Zaneta; Angelidis, Ilias; Ashenberg, Orr; Bassler, Kevin; Bécavin, Christophe; Benhar, Inbal; Bergenstråhle, Joseph; Bergenstråhle, Ludvig; Bolt, Liam; Braun, Emelie; Bui, Linh T; Callori, Steven; Chaffin, Mark; Chichelnitskiy, Evgeny; Chiou, Joshua; Conlon, Thomas M; Cuoco, Michael S; Cuomo, Anna SE; Deprez, Marie; Duclos, Grant; Fine, Denise; Fischer, David S; Ghazanfar, Shila; Gillich, Astrid; Giotti, Bruno; Gould, Joshua; Guo, Minzhe; Gutierrez, Austin J; Habermann, Arun C; Harvey, Tyler; He, Peng; Hou, Xiaomeng; Hu, Lijuan; Hu, Yan; Jaiswal, Alok; Ji, Lu; Jiang, Peiyong; Kapellos, Theodoros S; Kuo, Christin S; Larsson, Ludvig; Leney-Greene, Michael A; Lim, Kyungtae; Litviňuková, Monika; Ludwig, Leif S; Lukassen, Soeren; Luo, Wendy; Maatz, Henrike; Madissoon, Elo; Mamanova, Lira; Manakongtreecheep, Kasidet; Leroy, Sylvie; Mayr, Christoph H; Mbano, Ian M; McAdams, Alexi M; Nabhan, Ahmad N; Nyquist, Sarah K; Penland, Lolita; Poirion, Olivier B; Poli, Sergio; Qi, CanCan; Queen, Rachel; Reichart, Daniel; Rosas, Ivan; Schupp, Jonas C; Shea, Conor V; Shi, Xingyi; Sinha, Rahul; Sit, Rene V; Slowikowski, Kamil; Slyper, Michal; Smith, Neal P; Sountoulidis, Alex; Strunz, Maximilian; Sullivan, Travis B; Sun, Dawei; Talavera-López, Carlos; Tan, Peng; Tantivit, Jessica; Travaglini, Kyle J; Tucker, Nathan R; Vernon, Katherine A; Wadsworth, Marc H; Waldman, Julia; Wang, Xiuting; Xu, Ke; Yan, Wenjun; Zhao, William; Ziegler, Carly GK; NHLBI LungMap Consortium; Human Cell Atlas Lung Biological Network
    Angiotensin-converting enzyme 2 (ACE2) and accessory proteases (TMPRSS2 and CTSL) are needed for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) cellular entry, and their expression may shed light on viral tropism and impact across the body. We assessed the cell-type-specific expression of ACE2, TMPRSS2 and CTSL across 107 single-cell RNA-sequencing studies from different tissues. ACE2, TMPRSS2 and CTSL are coexpressed in specific subsets of respiratory epithelial cells in the nasal passages, airways and alveoli, and in cells from other organs associated with coronavirus disease 2019 (COVID-19) transmission or pathology. We performed a meta-analysis of 31 lung single-cell RNA-sequencing studies with 1,320,896 cells from 377 nasal, airway and lung parenchyma samples from 228 individuals. This revealed cell-type-specific associations of age, sex and smoking with expression levels of ACE2, TMPRSS2 and CTSL. Expression of entry factors increased with age and in males, including in airway secretory cells and alveolar type 2 cells. Expression programs shared by ACE2+TMPRSS2+ cells in nasal, lung and gut tissues included genes that may mediate viral entry, key immune functions and epithelial-macrophage cross-talk, such as genes involved in the interleukin-6, interleukin-1, tumor necrosis factor and complement pathways. Cell-type-specific expression patterns may contribute to the pathogenesis of COVID-19, and our work highlights putative molecular pathways for therapeutic intervention.