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Jiang M, Chen XH, Li H, Peng XX, Peng B. Exogenous L-Alanine promotes phagocytosis of multidrug-resistant bacterial pathogens. EMBO Rep 2023; 24:e49561. [PMID: 37943703 DOI: 10.15252/embr.201949561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Revised: 10/22/2023] [Accepted: 10/24/2023] [Indexed: 11/12/2023] Open
Abstract
Multidrug-resistant bacteria present a major threat to public health that urgently requires new drugs or treatment approaches. Here, we conduct integrated proteomic and metabolomics analyses to screen for molecular candidates improving survival of mice infected with Vibrio parahaemolyticus, which indicate that L-Alanine metabolism and phagocytosis are strongly correlated with mouse survival. We also assess the role of L-Alanine in improving mouse survival by in vivo bacterial challenge experiments using various bacteria species, including V. parahaemolyticus, Escherichia coli, Pseudomonas aeruginosa, and Klebsiella pneumoniae. Functional studies demonstrate that exogenous L-Alanine promotes phagocytosis of these multidrug-resistant pathogen species. We reveal that the underlying mechanism involves two events boosted by L-Alanine: TLR4 expression and L-Alanine-enhanced TLR4 signaling via increased biosynthesis and secretion of fatty acids, including palmitate. Palmitate enhances binding of lipopolysaccharide to TLR4, thereby promoting TLR4 dimer formation and endocytosis for subsequent activation of the PI3K/Akt and NF-κB pathways and bacteria phagocytosis. Our data suggest that modulation of the metabolic environment is a plausible approach for combating multidrug-resistant bacteria infection.
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Affiliation(s)
- Ming Jiang
- State Key Laboratory of Bio-Control, Guangdong Key Laboratory of Pharmaceutical Functional Genes, School of Life Sciences, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-sen University, Guangzhou, China
- Laboratory for Marine Biology and Biotechnology and Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
- Institute of Animal Science, Guangdong Academy of Agricultural Sciences, Guangzhou, China
| | - Xin-Hai Chen
- State Key Laboratory of Bio-Control, Guangdong Key Laboratory of Pharmaceutical Functional Genes, School of Life Sciences, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-sen University, Guangzhou, China
| | - Hui Li
- State Key Laboratory of Bio-Control, Guangdong Key Laboratory of Pharmaceutical Functional Genes, School of Life Sciences, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-sen University, Guangzhou, China
- Laboratory for Marine Biology and Biotechnology and Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
| | - Xuan-Xian Peng
- State Key Laboratory of Bio-Control, Guangdong Key Laboratory of Pharmaceutical Functional Genes, School of Life Sciences, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-sen University, Guangzhou, China
- Laboratory for Marine Biology and Biotechnology and Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
| | - Bo Peng
- State Key Laboratory of Bio-Control, Guangdong Key Laboratory of Pharmaceutical Functional Genes, School of Life Sciences, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-sen University, Guangzhou, China
- Laboratory for Marine Biology and Biotechnology and Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
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Dyke JS, Huertas-Diaz MC, Michel F, Holladay NE, Hogan RJ, He B, Lafontaine ER. The Peptidoglycan-associated lipoprotein Pal contributes to the virulence of Burkholderia mallei and provides protection against lethal aerosol challenge. Virulence 2021; 11:1024-1040. [PMID: 32799724 PMCID: PMC7567441 DOI: 10.1080/21505594.2020.1804275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Burkholderia mallei is a highly pathogenic bacterium that causes the fatal zoonosis glanders. The organism specifies multiple membrane proteins, which represent prime targets for the development of countermeasures given their location at the host-pathogen interface. We investigated one of these proteins, Pal, and discovered that it is involved in the ability of B. mallei to resist complement-mediated killing and replicate inside host cells in vitro, is expressed in vivo and induces antibodies during the course of infection, and contributes to virulence in a mouse model of aerosol infection. A mutant in the pal gene of the B. mallei wild-type strain ATCC 23344 was found to be especially attenuated, as BALB/c mice challenged with the equivalent of 5,350 LD50 completely cleared infection. Based on these findings, we tested the hypothesis that a vaccine containing the Pal protein elicits protective immunity against aerosol challenge. To achieve this, the pal gene was cloned in the vaccine vector Parainfluenza Virus 5 (PIV5) and mice immunized with the virus were infected with a lethal dose of B. mallei. These experiments revealed that a single dose of PIV5 expressing Pal provided 80% survival over a period of 40 days post-challenge. In contrast, only 10% of mice vaccinated with a PIV5 control virus construct survived infection. Taken together, our data establish that the Peptidoglycan-associated lipoprotein Pal is a critical virulence determinant of B. mallei and effective target for developing a glanders vaccine.
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Affiliation(s)
- Jeremy S Dyke
- Department of Infectious Diseases, University of Georgia College of Veterinary Medicine , Athens, GA, USA
| | | | - Frank Michel
- Department of Veterinary Biosciences and Diagnostic Imaging, University of Georgia College of Veterinary Medicine , Athens, GA, USA
| | - Nathan E Holladay
- Department of Veterinary Biosciences and Diagnostic Imaging, University of Georgia College of Veterinary Medicine , Athens, GA, USA
| | - Robert J Hogan
- Department of Infectious Diseases, University of Georgia College of Veterinary Medicine , Athens, GA, USA.,Department of Veterinary Biosciences and Diagnostic Imaging, University of Georgia College of Veterinary Medicine , Athens, GA, USA
| | - Biao He
- Department of Infectious Diseases, University of Georgia College of Veterinary Medicine , Athens, GA, USA
| | - Eric R Lafontaine
- Department of Infectious Diseases, University of Georgia College of Veterinary Medicine , Athens, GA, USA
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Rao C, Mao C, Xia Y, Zhang M, Hu Z, Yuan S, Yang W, Yan J, Deng L, Cai X, Mao X, Li Q, Liao Y. Transcriptome Analysis Reveals Unfolded Protein Response Was Induced During the Early Stage of Burkholderia pseudomallei Infection in A549 Cells. Front Genet 2020; 11:585203. [PMID: 33363569 PMCID: PMC7753206 DOI: 10.3389/fgene.2020.585203] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Accepted: 11/09/2020] [Indexed: 12/17/2022] Open
Abstract
Burkholderia pseudomallei is a zoonotic pathogen that usually affects patients' lungs and causes serious melioidosis. The interaction of B. pseudomallei with its hosts is complex, and cellular response to B. pseudomallei infection in humans still remains to be elucidated. In this study, transcriptomic profiling of B. pseudomallei-infected human lung epithelial A549 cells was performed to characterize the cellular response dynamics during the early infection (EI) stage. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were performed by using the online databases DAVID 6.8 and KOBAS 3.0. Real-time quantitative PCR and western blot were used for validation experiments. Compared with the negative control group (NC), a set of 36 common genes varied over time with a cut-off level of 1.5-fold change, and a P-value < 0.05 was identified. Bioinformatics analysis indicated that the PERK-mediated unfolded protein response (UPR) was enriched as the most noteworthy biological process category, which was enriched as a branch of UPR in the signaling pathway of protein processing in the endoplasmic reticulum. Other categories, such as inflammatory responses, cell migration, and apoptosis, were also focused. The molecular chaperone Bip (GRP78), PERK, and PERK sensor-dependent phosphorylation of eIF2α (p-eIF2α) and ATF4 were verified to be increasing over time during the EI stage, suggesting that B. pseudomallei infection activated the PERK-mediated UPR in A549 cells. Collectively, these results provide important initial insights into the intimate interaction between B. pseudomallei and lung epithelial cells, which can be further explored toward the elucidation of the cellular mechanisms of B. pseudomallei infections in humans.
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Affiliation(s)
- Chenglong Rao
- Department of Clinical Microbiology and Immunology, College of Pharmacy and Medical Laboratory, Army Medical University (Third Military Medical University), Chongqing, China
| | - Chan Mao
- Department of Pharmacy, Second Affiliated Hospital, Army Medical University (Third Military Medical University), Chongqing, China
| | - Yupei Xia
- Department of Clinical Microbiology and Immunology, College of Pharmacy and Medical Laboratory, Army Medical University (Third Military Medical University), Chongqing, China
| | - Meijuan Zhang
- Department of Clinical Microbiology and Immunology, College of Pharmacy and Medical Laboratory, Army Medical University (Third Military Medical University), Chongqing, China
| | - Zhiqiang Hu
- Department of Clinical Microbiology and Immunology, College of Pharmacy and Medical Laboratory, Army Medical University (Third Military Medical University), Chongqing, China
| | - Siqi Yuan
- Department of Clinical Microbiology and Immunology, College of Pharmacy and Medical Laboratory, Army Medical University (Third Military Medical University), Chongqing, China
| | - Wenbo Yang
- Department of Clinical Microbiology and Immunology, College of Pharmacy and Medical Laboratory, Army Medical University (Third Military Medical University), Chongqing, China
| | - Jingmin Yan
- Department of Clinical Microbiology and Immunology, College of Pharmacy and Medical Laboratory, Army Medical University (Third Military Medical University), Chongqing, China
| | - Ling Deng
- Department of Clinical Microbiology and Immunology, College of Pharmacy and Medical Laboratory, Army Medical University (Third Military Medical University), Chongqing, China
| | - Xiaolian Cai
- Department of Cardiology, First Affiliated Hospital, Army Medical University (Third Military Medical University), Chongqing, China
| | - Xuhu Mao
- Department of Clinical Microbiology and Immunology, College of Pharmacy and Medical Laboratory, Army Medical University (Third Military Medical University), Chongqing, China
| | - Qian Li
- Department of Clinical Microbiology and Immunology, College of Pharmacy and Medical Laboratory, Army Medical University (Third Military Medical University), Chongqing, China
| | - Yaling Liao
- Department of Clinical Microbiology and Immunology, College of Pharmacy and Medical Laboratory, Army Medical University (Third Military Medical University), Chongqing, China
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