Salmonella enterica serovar Typhi plasmid pR ST98 enhances intracellular bacterial growth and S. typhi-induced macrophage cell death by suppressing autophagy
OBJECTIVES: Plasmid pR ST98 is a hybrid resistance-virulence plasmid isolated from Salmonella enterica serovar Typhi (S. typhi). Previous studies demonstrated that pR ST98 could enhance the virulence of its host bacteria. However, the mechanism of pR ST98-increased bacterial virulence is still not f...
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| Format: | Article |
| Sprog: | English |
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Elsevier
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| Serier: | Brazilian Journal of Infectious Diseases |
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| Online adgang: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1413-86702012000300008&lng=en&tlng=en |
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| author | Peiyan He Shuyan Wu Yuanyuan Chu Yanru Yang Yuanyuan Li Rui Huang |
| author_facet | Peiyan He Shuyan Wu Yuanyuan Chu Yanru Yang Yuanyuan Li Rui Huang |
| author_sort | Peiyan He |
| collection | DOAJ |
| description | OBJECTIVES: Plasmid pR ST98 is a hybrid resistance-virulence plasmid isolated from Salmonella enterica serovar Typhi (S. typhi). Previous studies demonstrated that pR ST98 could enhance the virulence of its host bacteria. However, the mechanism of pR ST98-increased bacterial virulence is still not fully elucidated. This study was designed to gain further insight into the roles of pR ST98 in host responses. METHODS: Human-derived macrophage-like cell line THP-1 was infected with wild-type (ST8), pR ST98-deletion (ST8-ΔpR ST98), and complemented (ST8-c-pR ST98) S. typhi strains. Macrophage autophagy was performed by extracting the membrane-unbound LC3-I protein from cells, followed by flow cytometric detection of the membrane-associated fraction of LC3-II. Intracellular bacterial growth was determined by colony-forming units (cfu) assay. Macrophage cell death was measured by flow cytometry after propidium iodide (PI) staining. Autophagy activator rapamycin (RAPA) was added to the medium 2 h before infection to investigate the effect of autophagy on intracellular bacterial growth and macrophage cell death after S. typhi infection. RESULTS: Plasmid pR ST98 suppressed autophagy in infected macrophages and enhanced intracellular bacterial growth and S. typhi-induced macrophage cell death. Pretreatment with RAPA effectively restricted intracellular bacterial growth of ST8 and ST8-c-pR ST98, and alleviated ST8 and ST8-c-pR ST98-induced macrophage cell death, but had no significant effect on ST8-ΔpR ST98. CONCLUSIONS: Plasmid pR ST98 enhances intracellular bacterial growth and S. typhi-induced macrophage cell death by suppressing autophagy. |
| first_indexed | 2024-12-19T21:56:55Z |
| format | Article |
| id | doaj.art-ad768722f5974111a25530e03be901b3 |
| institution | Directory Open Access Journal |
| issn | 1678-4391 |
| language | English |
| last_indexed | 2024-12-19T21:56:55Z |
| publisher | Elsevier |
| record_format | Article |
| series | Brazilian Journal of Infectious Diseases |
| spelling | doaj.art-ad768722f5974111a25530e03be901b32022-12-21T20:04:16ZengElsevierBrazilian Journal of Infectious Diseases1678-439116326226610.1590/S1413-86702012000300008S1413-86702012000300008Salmonella enterica serovar Typhi plasmid pR ST98 enhances intracellular bacterial growth and S. typhi-induced macrophage cell death by suppressing autophagyPeiyan He0Shuyan Wu1Yuanyuan Chu2Yanru Yang3Yuanyuan Li4Rui Huang5Soochow UniversitySoochow UniversitySoochow UniversitySoochow UniversitySoochow UniversitySoochow UniversityOBJECTIVES: Plasmid pR ST98 is a hybrid resistance-virulence plasmid isolated from Salmonella enterica serovar Typhi (S. typhi). Previous studies demonstrated that pR ST98 could enhance the virulence of its host bacteria. However, the mechanism of pR ST98-increased bacterial virulence is still not fully elucidated. This study was designed to gain further insight into the roles of pR ST98 in host responses. METHODS: Human-derived macrophage-like cell line THP-1 was infected with wild-type (ST8), pR ST98-deletion (ST8-ΔpR ST98), and complemented (ST8-c-pR ST98) S. typhi strains. Macrophage autophagy was performed by extracting the membrane-unbound LC3-I protein from cells, followed by flow cytometric detection of the membrane-associated fraction of LC3-II. Intracellular bacterial growth was determined by colony-forming units (cfu) assay. Macrophage cell death was measured by flow cytometry after propidium iodide (PI) staining. Autophagy activator rapamycin (RAPA) was added to the medium 2 h before infection to investigate the effect of autophagy on intracellular bacterial growth and macrophage cell death after S. typhi infection. RESULTS: Plasmid pR ST98 suppressed autophagy in infected macrophages and enhanced intracellular bacterial growth and S. typhi-induced macrophage cell death. Pretreatment with RAPA effectively restricted intracellular bacterial growth of ST8 and ST8-c-pR ST98, and alleviated ST8 and ST8-c-pR ST98-induced macrophage cell death, but had no significant effect on ST8-ΔpR ST98. CONCLUSIONS: Plasmid pR ST98 enhances intracellular bacterial growth and S. typhi-induced macrophage cell death by suppressing autophagy.http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1413-86702012000300008&lng=en&tlng=enplasmid pR ST98macrophageautophagyintracellular bacterial growthcell death |
| spellingShingle | Peiyan He Shuyan Wu Yuanyuan Chu Yanru Yang Yuanyuan Li Rui Huang Salmonella enterica serovar Typhi plasmid pR ST98 enhances intracellular bacterial growth and S. typhi-induced macrophage cell death by suppressing autophagy Brazilian Journal of Infectious Diseases plasmid pR ST98 macrophage autophagy intracellular bacterial growth cell death |
| title | Salmonella enterica serovar Typhi plasmid pR ST98 enhances intracellular bacterial growth and S. typhi-induced macrophage cell death by suppressing autophagy |
| title_full | Salmonella enterica serovar Typhi plasmid pR ST98 enhances intracellular bacterial growth and S. typhi-induced macrophage cell death by suppressing autophagy |
| title_fullStr | Salmonella enterica serovar Typhi plasmid pR ST98 enhances intracellular bacterial growth and S. typhi-induced macrophage cell death by suppressing autophagy |
| title_full_unstemmed | Salmonella enterica serovar Typhi plasmid pR ST98 enhances intracellular bacterial growth and S. typhi-induced macrophage cell death by suppressing autophagy |
| title_short | Salmonella enterica serovar Typhi plasmid pR ST98 enhances intracellular bacterial growth and S. typhi-induced macrophage cell death by suppressing autophagy |
| title_sort | salmonella enterica serovar typhi plasmid pr st98 enhances intracellular bacterial growth and s typhi induced macrophage cell death by suppressing autophagy |
| topic | plasmid pR ST98 macrophage autophagy intracellular bacterial growth cell death |
| url | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1413-86702012000300008&lng=en&tlng=en |
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