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Teh YC, Chooi MY, Liu D, Kwok I, Lai GC, Ayub Ow Yong L, Ng M, Li JLY, Tan Y, Evrard M, Tan L, Liong KH, Leong K, Goh CC, Chan AYJ, Shadan NB, Mantri CK, Hwang YY, Cheng H, Cheng T, Yu W, Tey HL, Larbi A, St John A, Angeli V, Ruedl C, Lee B, Ginhoux F, Chen SL, Ng LG, Ding JL, Chong SZ. Transitional premonocytes emerge in the periphery for host defense against bacterial infections. Sci Adv 2022; 8:eabj4641. [PMID: 35245124 PMCID: PMC8896792 DOI: 10.1126/sciadv.abj4641] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Circulating Ly6Chi monocytes often undergo cellular death upon exhaustion of their antibacterial effector functions, which limits their capacity for subsequent macrophage differentiation. This shrouds the understanding on how the host replaces the tissue-resident macrophage niche effectively during bacterial invasion to avert infection morbidity. Here, we show that proliferating transitional premonocytes (TpMos), an immediate precursor of mature Ly6Chi monocytes (MatMos), were mobilized into the periphery in response to acute bacterial infection and sepsis. TpMos were less susceptible to apoptosis and served as the main source of macrophage replenishment when MatMos were vulnerable toward bacteria-induced cellular death. Furthermore, TpMo and its derived macrophages contributed to host defense by balancing the proinflammatory cytokine response of MatMos. Consequently, adoptive transfer of TpMos improved the survival outcome of lethal sepsis. Our findings hence highlight a protective role for TpMos during bacterial infections and their contribution toward monocyte-derived macrophage heterogeneity in distinct disease outcomes.
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Affiliation(s)
- Ye Chean Teh
- Singapore Immunology Network (SIgN), A*STAR (Agency for Science, Technology and Research), Biopolis, Singapore 138648, Singapore
- Department of Biological Science, National University of Singapore (NUS), Singapore 117543, Singapore
| | - Ming Yao Chooi
- Singapore Immunology Network (SIgN), A*STAR (Agency for Science, Technology and Research), Biopolis, Singapore 138648, Singapore
- Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117545, Singapore
| | - Dehua Liu
- Singapore Immunology Network (SIgN), A*STAR (Agency for Science, Technology and Research), Biopolis, Singapore 138648, Singapore
| | - Immanuel Kwok
- Singapore Immunology Network (SIgN), A*STAR (Agency for Science, Technology and Research), Biopolis, Singapore 138648, Singapore
| | - Ghee Chuan Lai
- Singapore Immunology Network (SIgN), A*STAR (Agency for Science, Technology and Research), Biopolis, Singapore 138648, Singapore
| | - Liyana Ayub Ow Yong
- Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117545, Singapore
- Genome Institute of Singapore, A*STAR (Agency for Science, Technology and Research), Biopolis, Singapore 138672, Singapore
| | - Melissa Ng
- Singapore Immunology Network (SIgN), A*STAR (Agency for Science, Technology and Research), Biopolis, Singapore 138648, Singapore
| | - Jackson L. Y. Li
- Singapore Immunology Network (SIgN), A*STAR (Agency for Science, Technology and Research), Biopolis, Singapore 138648, Singapore
| | - Yingrou Tan
- Singapore Immunology Network (SIgN), A*STAR (Agency for Science, Technology and Research), Biopolis, Singapore 138648, Singapore
- National Skin Centre, 1 Mandalay Road, Singapore 308205, Singapore
| | - Maximilien Evrard
- Singapore Immunology Network (SIgN), A*STAR (Agency for Science, Technology and Research), Biopolis, Singapore 138648, Singapore
| | - Leonard Tan
- Singapore Immunology Network (SIgN), A*STAR (Agency for Science, Technology and Research), Biopolis, Singapore 138648, Singapore
- Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117545, Singapore
| | - Ka Hang Liong
- Singapore Immunology Network (SIgN), A*STAR (Agency for Science, Technology and Research), Biopolis, Singapore 138648, Singapore
| | - Keith Leong
- Singapore Immunology Network (SIgN), A*STAR (Agency for Science, Technology and Research), Biopolis, Singapore 138648, Singapore
| | - Chi Ching Goh
- Singapore Immunology Network (SIgN), A*STAR (Agency for Science, Technology and Research), Biopolis, Singapore 138648, Singapore
| | - Andrew Y. J. Chan
- Singapore Immunology Network (SIgN), A*STAR (Agency for Science, Technology and Research), Biopolis, Singapore 138648, Singapore
| | - Nurhidaya Binte Shadan
- Singapore Immunology Network (SIgN), A*STAR (Agency for Science, Technology and Research), Biopolis, Singapore 138648, Singapore
| | - Chinmay Kumar Mantri
- Program in Emerging Infectious Diseases, Duke-NUS Medical School, Singapore 169857, Singapore
| | - You Yi Hwang
- Singapore Immunology Network (SIgN), A*STAR (Agency for Science, Technology and Research), Biopolis, Singapore 138648, Singapore
| | - Hui Cheng
- State Key Laboratory of Experimental Hematology, National Clinical Research Centre for Blood Diseases, Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin 300020, China
| | - Tao Cheng
- State Key Laboratory of Experimental Hematology, National Clinical Research Centre for Blood Diseases, Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin 300020, China
| | - Weimiao Yu
- Institute of Molecular and Cell Biology (IMCB), A*STAR (Agency for Science, Technology and Research), Singapore 138673, Singapore
| | - Hong Liang Tey
- Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117545, Singapore
- National Skin Centre, 1 Mandalay Road, Singapore 308205, Singapore
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore 308232, Singapore
| | - Anis Larbi
- Singapore Immunology Network (SIgN), A*STAR (Agency for Science, Technology and Research), Biopolis, Singapore 138648, Singapore
| | - Ashley St John
- Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117545, Singapore
- Program in Emerging Infectious Diseases, Duke-NUS Medical School, Singapore 169857, Singapore
| | - Veronique Angeli
- Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117545, Singapore
| | - Christiane Ruedl
- School of Biological Sciences, Nanyang Technological University, Singapore 637551, Singapore
| | - Bernett Lee
- Singapore Immunology Network (SIgN), A*STAR (Agency for Science, Technology and Research), Biopolis, Singapore 138648, Singapore
| | - Florent Ginhoux
- Singapore Immunology Network (SIgN), A*STAR (Agency for Science, Technology and Research), Biopolis, Singapore 138648, Singapore
- Shanghai Institute of Immunology, Shanghai JiaoTong University School of Medicine, Shanghai 200025, China
| | - Swaine L. Chen
- Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117545, Singapore
- Genome Institute of Singapore, A*STAR (Agency for Science, Technology and Research), Biopolis, Singapore 138672, Singapore
| | - Lai Guan Ng
- Singapore Immunology Network (SIgN), A*STAR (Agency for Science, Technology and Research), Biopolis, Singapore 138648, Singapore
- Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117545, Singapore
- State Key Laboratory of Experimental Hematology, National Clinical Research Centre for Blood Diseases, Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin 300020, China
- School of Biological Sciences, Nanyang Technological University, Singapore 637551, Singapore
- Corresponding author. (L.G.N.); (J.L.D.); (S.Z.C.)
| | - Jeak Ling Ding
- Department of Biological Science, National University of Singapore (NUS), Singapore 117543, Singapore
- Corresponding author. (L.G.N.); (J.L.D.); (S.Z.C.)
| | - Shu Zhen Chong
- Singapore Immunology Network (SIgN), A*STAR (Agency for Science, Technology and Research), Biopolis, Singapore 138648, Singapore
- Corresponding author. (L.G.N.); (J.L.D.); (S.Z.C.)
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Mishra A, Lai GC, Yao LJ, Aung TT, Shental N, Rotter-Maskowitz A, Shepherdson E, Singh GSN, Pai R, Shanti A, Wong RMM, Lee A, Khyriem C, Dutertre CA, Chakarov S, Srinivasan KG, Shadan NB, Zhang XM, Khalilnezhad S, Cottier F, Tan ASM, Low G, Chen P, Fan Y, Hor PX, Lee AKM, Choolani M, Vermijlen D, Sharma A, Fuks G, Straussman R, Pavelka N, Malleret B, McGovern N, Albani S, Chan JKY, Ginhoux F. Microbial exposure during early human development primes fetal immune cells. Cell 2021; 184:3394-3409.e20. [PMID: 34077752 PMCID: PMC8240556 DOI: 10.1016/j.cell.2021.04.039] [Citation(s) in RCA: 120] [Impact Index Per Article: 40.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 02/09/2021] [Accepted: 04/23/2021] [Indexed: 02/06/2023]
Abstract
The human fetal immune system begins to develop early during gestation; however, factors responsible for fetal immune-priming remain elusive. We explored potential exposure to microbial agents in utero and their contribution toward activation of memory T cells in fetal tissues. We profiled microbes across fetal organs using 16S rRNA gene sequencing and detected low but consistent microbial signal in fetal gut, skin, placenta, and lungs in the 2nd trimester of gestation. We identified several live bacterial strains including Staphylococcus and Lactobacillus in fetal tissues, which induced in vitro activation of memory T cells in fetal mesenteric lymph node, supporting the role of microbial exposure in fetal immune-priming. Finally, using SEM and RNA-ISH, we visualized discrete localization of bacteria-like structures and eubacterial-RNA within 14th weeks fetal gut lumen. These findings indicate selective presence of live microbes in fetal organs during the 2nd trimester of gestation and have broader implications toward the establishment of immune competency and priming before birth.
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Affiliation(s)
- Archita Mishra
- Singapore Immunology Network (SIgN), A(∗)STAR, 8A Biomedical Grove, Immunos Building, Level 4, Singapore 138648, Singapore
| | - Ghee Chuan Lai
- Singapore Immunology Network (SIgN), A(∗)STAR, 8A Biomedical Grove, Immunos Building, Level 4, Singapore 138648, Singapore
| | - Leong Jing Yao
- Translational Immunology Institute, Singhealth/Duke-NUS Academic Medical Centre, the Academia, 20 College Road, Discovery Tower Level 8, Singapore 169856, Singapore
| | - Thet Tun Aung
- Department of Microbiology and Immunology, Immunology Translational Research Programme, Yong Loo Lin School of Medicine, Immunology Programme, Life Sciences Institute, National University of Singapore, Singapore 117597, Singapore
| | - Noam Shental
- Department of Mathematics and Computer Science, Open University of Israel, Ra'anana 4353701, Israel
| | - Aviva Rotter-Maskowitz
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Edwin Shepherdson
- Department of Reproductive Medicine, KK Women's and Children's Hospital, Singapore 229899, Singapore
| | - Gurmit Singh Naranjan Singh
- Singapore Immunology Network (SIgN), A(∗)STAR, 8A Biomedical Grove, Immunos Building, Level 4, Singapore 138648, Singapore
| | - Rhea Pai
- Genome Institute of Singapore (GIS), A(∗)STAR, 60 Biopolis Street, Singapore 138672, Singapore
| | - Adhika Shanti
- Singapore Immunology Network (SIgN), A(∗)STAR, 8A Biomedical Grove, Immunos Building, Level 4, Singapore 138648, Singapore
| | - Regina Men Men Wong
- Genome Institute of Singapore (GIS), A(∗)STAR, 60 Biopolis Street, Singapore 138672, Singapore
| | - Andrea Lee
- Translational Immunology Institute, Singhealth/Duke-NUS Academic Medical Centre, the Academia, 20 College Road, Discovery Tower Level 8, Singapore 169856, Singapore
| | - Costerwell Khyriem
- Department of Reproductive Medicine, KK Women's and Children's Hospital, Singapore 229899, Singapore
| | - Charles Antoine Dutertre
- Singapore Immunology Network (SIgN), A(∗)STAR, 8A Biomedical Grove, Immunos Building, Level 4, Singapore 138648, Singapore; Translational Immunology Institute, Singhealth/Duke-NUS Academic Medical Centre, the Academia, 20 College Road, Discovery Tower Level 8, Singapore 169856, Singapore; Program in Emerging Infectious Disease, Duke-NUS Medical School, 8 College Road, Singapore 169857, Singapore
| | - Svetoslav Chakarov
- Singapore Immunology Network (SIgN), A(∗)STAR, 8A Biomedical Grove, Immunos Building, Level 4, Singapore 138648, Singapore
| | - K G Srinivasan
- Singapore Immunology Network (SIgN), A(∗)STAR, 8A Biomedical Grove, Immunos Building, Level 4, Singapore 138648, Singapore
| | - Nurhidaya Binte Shadan
- Singapore Immunology Network (SIgN), A(∗)STAR, 8A Biomedical Grove, Immunos Building, Level 4, Singapore 138648, Singapore
| | - Xiao-Meng Zhang
- Singapore Immunology Network (SIgN), A(∗)STAR, 8A Biomedical Grove, Immunos Building, Level 4, Singapore 138648, Singapore
| | - Shabnam Khalilnezhad
- Singapore Immunology Network (SIgN), A(∗)STAR, 8A Biomedical Grove, Immunos Building, Level 4, Singapore 138648, Singapore
| | - Fabien Cottier
- Singapore Immunology Network (SIgN), A(∗)STAR, 8A Biomedical Grove, Immunos Building, Level 4, Singapore 138648, Singapore
| | - Alrina Shin Min Tan
- Singapore Immunology Network (SIgN), A(∗)STAR, 8A Biomedical Grove, Immunos Building, Level 4, Singapore 138648, Singapore
| | - Gillian Low
- Singapore Immunology Network (SIgN), A(∗)STAR, 8A Biomedical Grove, Immunos Building, Level 4, Singapore 138648, Singapore
| | - Phyllis Chen
- Translational Immunology Institute, Singhealth/Duke-NUS Academic Medical Centre, the Academia, 20 College Road, Discovery Tower Level 8, Singapore 169856, Singapore
| | - Yiping Fan
- Department of Reproductive Medicine, KK Women's and Children's Hospital, Singapore 229899, Singapore; Experimental Fetal Medicine Group, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117597, Singapore
| | - Pei Xiang Hor
- Singapore Immunology Network (SIgN), A(∗)STAR, 8A Biomedical Grove, Immunos Building, Level 4, Singapore 138648, Singapore
| | - Avery Khoo May Lee
- Singapore Immunology Network (SIgN), A(∗)STAR, 8A Biomedical Grove, Immunos Building, Level 4, Singapore 138648, Singapore
| | - Mahesh Choolani
- Department of Obstetrics & Gynaecology, Yong Loo Lin School of Medicine, National University of Singapore, NUHS Tower Block, 1E Kent Ridge Road, Singapore 119228, Singpore
| | - David Vermijlen
- Department of Pharmacotherapy and Pharmaceutics, Institute for Medical Immunology, ULB Center for Research in Immunology (U-CRI), Université Libre de Bruxelles (ULB), Brussels 1050, Belgium
| | - Ankur Sharma
- Genome Institute of Singapore (GIS), A(∗)STAR, 60 Biopolis Street, Singapore 138672, Singapore; Harry Perkins Institute of Medical Research, QEII Medical Centre and Centre for Medical Research, the University of Western Australia, PO Box 7214, 6 Verdun Street, Nedlands, Perth, WA 6009, Australia; Curtin Medical School, Curtin Health Innovation Research Institute, Curtin University, Perth, WA 6102, Australia
| | - Garold Fuks
- Department of Physics of Complex Systems, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Ravid Straussman
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Norman Pavelka
- Singapore Immunology Network (SIgN), A(∗)STAR, 8A Biomedical Grove, Immunos Building, Level 4, Singapore 138648, Singapore
| | - Benoit Malleret
- Singapore Immunology Network (SIgN), A(∗)STAR, 8A Biomedical Grove, Immunos Building, Level 4, Singapore 138648, Singapore; Department of Microbiology and Immunology, Immunology Translational Research Programme, Yong Loo Lin School of Medicine, Immunology Programme, Life Sciences Institute, National University of Singapore, Singapore 117597, Singapore
| | - Naomi McGovern
- Department of Pathology and Centre for Trophoblast Research, Tennis Court Road, Cambridge CB2 1QP, UK.
| | - Salvatore Albani
- Translational Immunology Institute, Singhealth/Duke-NUS Academic Medical Centre, the Academia, 20 College Road, Discovery Tower Level 8, Singapore 169856, Singapore.
| | - Jerry Kok Yen Chan
- Department of Reproductive Medicine, KK Women's and Children's Hospital, Singapore 229899, Singapore; Experimental Fetal Medicine Group, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117597, Singapore; OBGYN-Academic Clinical Program, Duke-NUS, Duke-NUS Medical School, 8 College Road, Singapore 169857, Singapore; Cancer and Stem Cell Biology Program, Duke-NUS Graduate Medical School, Singapore 119077, Singapore.
| | - Florent Ginhoux
- Singapore Immunology Network (SIgN), A(∗)STAR, 8A Biomedical Grove, Immunos Building, Level 4, Singapore 138648, Singapore; Translational Immunology Institute, Singhealth/Duke-NUS Academic Medical Centre, the Academia, 20 College Road, Discovery Tower Level 8, Singapore 169856, Singapore; Shanghai Institute of Immunology, Shanghai JiaoTong University School of Medicine, 280 South Chongqing Road, Shanghai 200025, China.
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Tso GHW, Reales-Calderon JA, Tan ASM, Sem X, Le GTT, Tan TG, Lai GC, Srinivasan KG, Yurieva M, Liao W, Poidinger M, Zolezzi F, Rancati G, Pavelka N. Experimental evolution of a fungal pathogen into a gut symbiont. Science 2018; 362:589-595. [DOI: 10.1126/science.aat0537] [Citation(s) in RCA: 134] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Accepted: 09/12/2018] [Indexed: 12/21/2022]
Abstract
Gut microbes live in symbiosis with their hosts, but how mutualistic animal-microbe interactions emerge is not understood. By adaptively evolving the opportunistic fungal pathogenCandida albicansin the mouse gastrointestinal tract, we selected strains that not only had lost their main virulence program but also protected their new hosts against a variety of systemic infections. This protection was independent of adaptive immunity, arose as early as a single day postpriming, was dependent on increased innate cytokine responses, and was thus reminiscent of “trained immunity.” Because both the microbe and its new host gain some advantages from their interaction, this experimental system might allow direct study of the evolutionary forces that govern the emergence of mutualism between a mammal and a fungus.
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Lai GC, Tan TG, Pavelka N. The mammalian mycobiome: A complex system in a dynamic relationship with the host. Wiley Interdiscip Rev Syst Biol Med 2018; 11:e1438. [PMID: 30255552 PMCID: PMC6586165 DOI: 10.1002/wsbm.1438] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/04/2018] [Revised: 08/26/2018] [Accepted: 08/28/2018] [Indexed: 12/21/2022]
Abstract
Mammalian barrier surfaces are densely populated by symbiont fungi in much the same way the former are colonized by symbiont bacteria. The fungal microbiota, otherwise known as the mycobiota, is increasingly recognized as a critical player in the maintenance of health and homeostasis of the host. Here we discuss the impact of the mycobiota on host physiology and disease, the factors influencing mycobiota composition, and the current technologies used for identifying symbiont fungal species. Understanding the tripartite interactions among the host, mycobiota, and other members of the microbiota, will help to guide the development of novel prevention and therapeutic strategies for a variety of human diseases. This article is categorized under:
Physiology > Mammalian Physiology in Health and Disease Laboratory Methods and Technologies > Genetic/Genomic Methods Models of Systems Properties and Processes > Organismal Models
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Lai GC, Cho H, Bernhardt TG. The mecillinam resistome reveals a role for peptidoglycan endopeptidases in stimulating cell wall synthesis in Escherichia coli. PLoS Genet 2017; 13:e1006934. [PMID: 28749938 PMCID: PMC5549755 DOI: 10.1371/journal.pgen.1006934] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Revised: 08/08/2017] [Accepted: 07/19/2017] [Indexed: 12/01/2022] Open
Abstract
Bacterial cells are typically surrounded by an net-like macromolecule called the cell wall constructed from the heteropolymer peptidoglycan (PG). Biogenesis of this matrix is the target of penicillin and related beta-lactams. These drugs inhibit the transpeptidase activity of PG synthases called penicillin-binding proteins (PBPs), preventing the crosslinking of nascent wall material into the existing network. The beta-lactam mecillinam specifically targets the PBP2 enzyme in the cell elongation machinery of Escherichia coli. Low-throughput selections for mecillinam resistance have historically been useful in defining mechanisms involved in cell wall biogenesis and the killing activity of beta-lactam antibiotics. Here, we used transposon-sequencing (Tn-Seq) as a high-throughput method to identify nearly all mecillinam resistance loci in the E. coli genome, providing a comprehensive resource for uncovering new mechanisms underlying PG assembly and drug resistance. Induction of the stringent response or the Rcs envelope stress response has been previously implicated in mecillinam resistance. We therefore also performed the Tn-Seq analysis in mutants defective for these responses in addition to wild-type cells. Thus, the utility of the dataset was greatly enhanced by determining the stress response dependence of each resistance locus in the resistome. Reasoning that stress response-independent resistance loci are those most likely to identify direct modulators of cell wall biogenesis, we focused our downstream analysis on this subset of the resistome. Characterization of one of these alleles led to the surprising discovery that the overproduction of endopeptidase enzymes that cleave crosslinks in the cell wall promotes mecillinam resistance by stimulating PG synthesis by a subset of PBPs. Our analysis of this activation mechanism suggests that, contrary to the prevailing view in the field, PG synthases and PG cleaving enzymes need not function in multi-enzyme complexes to expand the cell wall matrix. Penicillin and related beta-lactams are one of our oldest and most effective classes of antibiotics. These drugs target enzymes called penicillin-binding proteins (PBPs) that build the essential cell wall that surrounds bacterial cells. Beta-lactams have long been used as chemical and genetic probes to uncover the mechanisms required for proper bacterial cell wall biogenesis. In this report, we use a high-throughput genetic approach to comprehensively identify nearly all genetic loci that promote resistance to the beta-lactam mecillinam in the model organism Escherichia coli. Moreover, by performing our analysis in several different genetic backgrounds we were able to generate a rich resource that defines those alleles that promote resistance by inducing a stress response and those that are more likely to do so by directly modulating cell wall synthesis. Further characterization of one of the stress response-independent resistance loci helped us discover that enzymes that cleave crosslinks in the cell wall are capable of activating cell wall synthesis by a subset of PBPs. Our analysis of the activation mechanism challenges the prevailing view in the field that cell wall synthases and cell wall cleaving enzymes must work in multi-enzyme complexes to assemble the cell wall.
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Affiliation(s)
- Ghee Chuan Lai
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA, United States of America
| | - Hongbaek Cho
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA, United States of America
| | - Thomas G Bernhardt
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA, United States of America
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Okumus B, Landgraf D, Lai GC, Bakshi S, Arias-Castro JC, Yildiz S, Huh D, Fernandez-Lopez R, Peterson CN, Toprak E, El Karoui M, Paulsson J. Mechanical slowing-down of cytoplasmic diffusion allows in vivo counting of proteins in individual cells. Nat Commun 2016; 7:11641. [PMID: 27189321 PMCID: PMC4873973 DOI: 10.1038/ncomms11641] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Accepted: 04/15/2016] [Indexed: 11/18/2022] Open
Abstract
Many key regulatory proteins in bacteria are present in too low numbers to be detected with conventional methods, which poses a particular challenge for single-cell analyses because such proteins can contribute greatly to phenotypic heterogeneity. Here we develop a microfluidics-based platform that enables single-molecule counting of low-abundance proteins by mechanically slowing-down their diffusion within the cytoplasm of live Escherichia coli (E. coli) cells. Our technique also allows for automated microscopy at high throughput with minimal perturbation to native physiology, as well as viable enrichment/retrieval. We illustrate the method by analysing the control of the master regulator of the E. coli stress response, RpoS, by its adapter protein, SprE (RssB). Quantification of SprE numbers shows that though SprE is necessary for RpoS degradation, it is expressed at levels as low as 3–4 molecules per average cell cycle, and fluctuations in SprE are approximately Poisson distributed during exponential phase with no sign of bursting. Several proteins are expressed at too low abundance in the Escherichia coli (E. coli) proteome to be detected by standard methods. Here, the authors create a microfluidics-based platform enabling single-molecule counting of low-abundance proteins by mechanically slowing-down their diffusion in live E. coli.
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Affiliation(s)
- Burak Okumus
- Department of Systems Biology, Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Dirk Landgraf
- Department of Systems Biology, Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Ghee Chuan Lai
- Department of Systems Biology, Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Somenath Bakshi
- Department of Systems Biology, Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Juan Carlos Arias-Castro
- Department of Systems Biology, Harvard Medical School, Boston, Massachusetts 02115, USA.,Department of Physics, Universidad de los Andes, Bogota 4976-12340, Colombia
| | - Sadik Yildiz
- Department of Systems Biology, Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Dann Huh
- Department of Systems Biology, Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Raul Fernandez-Lopez
- Department of Systems Biology, Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Celeste N Peterson
- Department of Biology, Suffolk University, Boston, Massachusetts 02108, USA
| | - Erdal Toprak
- Department of Systems Biology, Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Meriem El Karoui
- Department of Systems Biology, Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Johan Paulsson
- Department of Systems Biology, Harvard Medical School, Boston, Massachusetts 02115, USA
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Lai GC, Wu CC, Tzeng JE, Liu TJ, P'eng FK. Sarcomatoid carcinoma of the small intestine: a case report. Zhonghua Yi Xue Za Zhi (Taipei) 1997; 59:377-81. [PMID: 9294919] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Sarcomatoid carcinoma of the small intestine is a very rare tumor. Only limited cases have been reported in the literature. The tumor is more malignant than the usual adenocarcinoma of the small intestine. Here we report a 59-year-old female patient who was referred from a local hospital after suffering persistent hematochezia, abdominal pain and distention for three months. Because of persistent intestinal obstruction and bleeding, reoperation at our hospital was performed. A huge tumor, originating from the ileum and with multiple liver and bone metastasis, was found. Palliative resection of the tumor with two segments of the small intestine and sigmoid colon was carried out. Pathology confirmed the diagnosis of sarcomatoid carcinoma. She died two months after operation.
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Affiliation(s)
- G C Lai
- Department of Surgery, Taichung Veterans General Hospital, Taiwan, R.O.C
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