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Comprehensive analysis of clinical Burkholderia pseudomallei isolates demonstrates conservation of unique lipid A structure and TLR4-dependent innate immune activation.
PLoS Negl Trop Dis. 2018 02; 12(2):e0006287.PN

Abstract

Burkholderia pseudomallei is an environmental bacterium that causes melioidosis, a major community-acquired infection in tropical regions. Melioidosis presents with a range of clinical symptoms, is often characterized by a robust inflammatory response, may relapse after treatment, and results in high mortality rates. Lipopolysaccharide (LPS) of B. pseudomallei is a potent immunostimulatory molecule comprised of lipid A, core, and O-polysaccharide (OPS) components. Four B. pseudomallei LPS types have been described based on SDS-PAGE patterns that represent the difference of OPS-type A, type B, type B2 and rough LPS. The majority of B. pseudomallei isolates are type A. We used matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) followed by electrospray ionization quadrupole time-of-flight mass spectrometry (ESI-QqTOF MS) and gas chromatography to characterize the lipid A of B. pseudomallei within LPS type A isolates. We determined that B. pseudomallei lipid A is represented by penta- and tetra-acylated species modified with 4-amino-4-deoxy-arabinose (Ara4N). The MALDI-TOF profiles from 171 clinical B. pseudomallei isolates, including 68 paired primary and relapse isolates and 35 within-host isolates were similar. We did not observe lipid A structural changes when the bacteria were cultured in different growth conditions. Dose-dependent NF-κB activation in HEK cells expressing TLR4 was observed using multiple heat-killed B. pseudomallei isolates and corresponding purified LPS. We demonstrated that TLR4-dependent NF-κB activation induced by heat-killed bacteria or LPS prepared from OPS deficient mutant was significantly greater than those induced by wild type B. pseudomallei. These findings suggest that the structure of B. pseudomallei lipid A is highly conserved in a wide variety of clinical and environmental circumstances but that the presence of OPS may modulate LPS-driven innate immune responses in melioidosis.

Authors+Show Affiliations

Department of Microbiology and Immunology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.Department of Microbial Pathogenesis, University of Maryland, Baltimore, MD, United States of America.Department of Microbiology and Immunology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.Department of Microbiology and Immunology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand. Department of Tropical Hygiene, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.Division of Pulmonary and Critical Care Medicine, Harborview Medical Center, University of Washington, Seattle, WA, United States of America. International Respiratory and Severe Illness Center, University of Washington, Seattle, WA, United States of America.Department of Microbial Pathogenesis, University of Maryland, Baltimore, MD, United States of America.Department of Microbiology and Immunology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand. Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

29474381

Citation

Sengyee, Sineenart, et al. "Comprehensive Analysis of Clinical Burkholderia Pseudomallei Isolates Demonstrates Conservation of Unique Lipid a Structure and TLR4-dependent Innate Immune Activation." PLoS Neglected Tropical Diseases, vol. 12, no. 2, 2018, pp. e0006287.
Sengyee S, Yoon SH, Paksanont S, et al. Comprehensive analysis of clinical Burkholderia pseudomallei isolates demonstrates conservation of unique lipid A structure and TLR4-dependent innate immune activation. PLoS Negl Trop Dis. 2018;12(2):e0006287.
Sengyee, S., Yoon, S. H., Paksanont, S., Yimthin, T., Wuthiekanun, V., Limmathurotsakul, D., West, T. E., Ernst, R. K., & Chantratita, N. (2018). Comprehensive analysis of clinical Burkholderia pseudomallei isolates demonstrates conservation of unique lipid A structure and TLR4-dependent innate immune activation. PLoS Neglected Tropical Diseases, 12(2), e0006287. https://doi.org/10.1371/journal.pntd.0006287
Sengyee S, et al. Comprehensive Analysis of Clinical Burkholderia Pseudomallei Isolates Demonstrates Conservation of Unique Lipid a Structure and TLR4-dependent Innate Immune Activation. PLoS Negl Trop Dis. 2018;12(2):e0006287. PubMed PMID: 29474381.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Comprehensive analysis of clinical Burkholderia pseudomallei isolates demonstrates conservation of unique lipid A structure and TLR4-dependent innate immune activation. AU - Sengyee,Sineenart, AU - Yoon,Sung Hwan, AU - Paksanont,Suporn, AU - Yimthin,Thatcha, AU - Wuthiekanun,Vanaporn, AU - Limmathurotsakul,Direk, AU - West,T Eoin, AU - Ernst,Robert K, AU - Chantratita,Narisara, Y1 - 2018/02/23/ PY - 2017/10/11/received PY - 2018/01/31/accepted PY - 2018/03/07/revised PY - 2018/2/24/pubmed PY - 2018/6/16/medline PY - 2018/2/24/entrez SP - e0006287 EP - e0006287 JF - PLoS neglected tropical diseases JO - PLoS Negl Trop Dis VL - 12 IS - 2 N2 - Burkholderia pseudomallei is an environmental bacterium that causes melioidosis, a major community-acquired infection in tropical regions. Melioidosis presents with a range of clinical symptoms, is often characterized by a robust inflammatory response, may relapse after treatment, and results in high mortality rates. Lipopolysaccharide (LPS) of B. pseudomallei is a potent immunostimulatory molecule comprised of lipid A, core, and O-polysaccharide (OPS) components. Four B. pseudomallei LPS types have been described based on SDS-PAGE patterns that represent the difference of OPS-type A, type B, type B2 and rough LPS. The majority of B. pseudomallei isolates are type A. We used matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) followed by electrospray ionization quadrupole time-of-flight mass spectrometry (ESI-QqTOF MS) and gas chromatography to characterize the lipid A of B. pseudomallei within LPS type A isolates. We determined that B. pseudomallei lipid A is represented by penta- and tetra-acylated species modified with 4-amino-4-deoxy-arabinose (Ara4N). The MALDI-TOF profiles from 171 clinical B. pseudomallei isolates, including 68 paired primary and relapse isolates and 35 within-host isolates were similar. We did not observe lipid A structural changes when the bacteria were cultured in different growth conditions. Dose-dependent NF-κB activation in HEK cells expressing TLR4 was observed using multiple heat-killed B. pseudomallei isolates and corresponding purified LPS. We demonstrated that TLR4-dependent NF-κB activation induced by heat-killed bacteria or LPS prepared from OPS deficient mutant was significantly greater than those induced by wild type B. pseudomallei. These findings suggest that the structure of B. pseudomallei lipid A is highly conserved in a wide variety of clinical and environmental circumstances but that the presence of OPS may modulate LPS-driven innate immune responses in melioidosis. SN - 1935-2735 UR - https://www.unboundmedicine.com/medline/citation/29474381/Comprehensive_analysis_of_clinical_Burkholderia_pseudomallei_isolates_demonstrates_conservation_of_unique_lipid_A_structure_and_TLR4_dependent_innate_immune_activation_ L2 - https://dx.plos.org/10.1371/journal.pntd.0006287 DB - PRIME DP - Unbound Medicine ER -