Differential invasiveness & expression of antimicrobial peptides in Shigella serotypes
Background & objectives: The study of Shigella pathogenesis at present is severely hampered by the lack of a relevant animal model that replicates human bacillary dysentery. Different Shigella serogroups cause varying severity of clinical illness. Ex vivo colonization of Shigella flexneri, S. dy...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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Wolters Kluwer Medknow Publications
2023-01-01
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| Series: | Indian Journal of Medical Research |
| Subjects: | |
| Online Access: | http://www.ijmr.org.in/article.asp?issn=0971-5916;year=2023;volume=158;issue=3;spage=303;epage=310;aulast=Narayan |
| _version_ | 1797351984242622464 |
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| author | Chandradeo Narayan Vishal Kant Jai Kumar Mahajan Balvinder Mohan Neelam Taneja |
| author_facet | Chandradeo Narayan Vishal Kant Jai Kumar Mahajan Balvinder Mohan Neelam Taneja |
| author_sort | Chandradeo Narayan |
| collection | DOAJ |
| description | Background & objectives: The study of Shigella pathogenesis at present is severely hampered by the lack of a relevant animal model that replicates human bacillary dysentery. Different Shigella serogroups cause varying severity of clinical illness. Ex vivo colonization of Shigella flexneri, S. dysenteriae and S. sonnei were characterized in human paediatric colonic pinch biopsies in the in vitro organ culture (IVOC) model to study the invasiveness of Shigella by gentamicin protection assay (GPA). Furthermore, the expression of antimicrobial peptides (AMPs) in response to different serotypes of Shigella was also studied in IVOC model.
Methods: IVOC explants were inoculated with 109 colony forming units of different serotypes of Shigella and recovery of bacteria studied. Histopathological analysis was carried out to study inflammatory immune responses. GPA was done to elucidate the invasiveness of different serotypes of Shigella. Secretions of AMPs were measured by enzyme-linked immunosorbent assay (ELISA). Western blotting was performed to check the expression of AMPs and nuclear factor kappa B in IVOC explants.
Results: After 24 h post-infection, the colon biopsies showed intense inflammatory reaction. In both IVOC and GPA, S. dysenteriae 1 was the most invasive as compared to S. flexneri and S. sonnei. S. sonnei was the least invasive. ELISA demonstrated that S. sonnei dampened the HBD (human β-defensin)-2 responses whereas there was augmentation by S. dysenteriae and there was a modest but non-significant increase by S. flexneri. A modest increase in HBD-3 by S. sonnei and S. flexneri was observed but was not found to be significant. However, western blotting data showed upregulation of all AMPs by all serotypes. Western blotting is more sensitive than ELISA.
Interpretation & conclusions: In the present study, differences in invasiveness and AMP production induced by different serotypes of Shigella were found. Human intestinal IVOC represents a model system to investigate early interaction between pathogenic bacteria and the human gut. |
| first_indexed | 2024-03-08T13:08:39Z |
| format | Article |
| id | doaj.art-b9a94ef14e5848f5bb608188e5b35109 |
| institution | Directory Open Access Journal |
| issn | 0971-5916 |
| language | English |
| last_indexed | 2024-03-08T13:08:39Z |
| publishDate | 2023-01-01 |
| publisher | Wolters Kluwer Medknow Publications |
| record_format | Article |
| series | Indian Journal of Medical Research |
| spelling | doaj.art-b9a94ef14e5848f5bb608188e5b351092024-01-18T15:52:27ZengWolters Kluwer Medknow PublicationsIndian Journal of Medical Research0971-59162023-01-01158330331010.4103/ijmr.IJMR_4864_20Differential invasiveness & expression of antimicrobial peptides in Shigella serotypesChandradeo NarayanVishal KantJai Kumar MahajanBalvinder MohanNeelam TanejaBackground & objectives: The study of Shigella pathogenesis at present is severely hampered by the lack of a relevant animal model that replicates human bacillary dysentery. Different Shigella serogroups cause varying severity of clinical illness. Ex vivo colonization of Shigella flexneri, S. dysenteriae and S. sonnei were characterized in human paediatric colonic pinch biopsies in the in vitro organ culture (IVOC) model to study the invasiveness of Shigella by gentamicin protection assay (GPA). Furthermore, the expression of antimicrobial peptides (AMPs) in response to different serotypes of Shigella was also studied in IVOC model. Methods: IVOC explants were inoculated with 109 colony forming units of different serotypes of Shigella and recovery of bacteria studied. Histopathological analysis was carried out to study inflammatory immune responses. GPA was done to elucidate the invasiveness of different serotypes of Shigella. Secretions of AMPs were measured by enzyme-linked immunosorbent assay (ELISA). Western blotting was performed to check the expression of AMPs and nuclear factor kappa B in IVOC explants. Results: After 24 h post-infection, the colon biopsies showed intense inflammatory reaction. In both IVOC and GPA, S. dysenteriae 1 was the most invasive as compared to S. flexneri and S. sonnei. S. sonnei was the least invasive. ELISA demonstrated that S. sonnei dampened the HBD (human β-defensin)-2 responses whereas there was augmentation by S. dysenteriae and there was a modest but non-significant increase by S. flexneri. A modest increase in HBD-3 by S. sonnei and S. flexneri was observed but was not found to be significant. However, western blotting data showed upregulation of all AMPs by all serotypes. Western blotting is more sensitive than ELISA. Interpretation & conclusions: In the present study, differences in invasiveness and AMP production induced by different serotypes of Shigella were found. Human intestinal IVOC represents a model system to investigate early interaction between pathogenic bacteria and the human gut.http://www.ijmr.org.in/article.asp?issn=0971-5916;year=2023;volume=158;issue=3;spage=303;epage=310;aulast=Narayanantimicrobial peptides - cathelicidins - shigella - α-defensins - β-defensins |
| spellingShingle | Chandradeo Narayan Vishal Kant Jai Kumar Mahajan Balvinder Mohan Neelam Taneja Differential invasiveness & expression of antimicrobial peptides in Shigella serotypes Indian Journal of Medical Research antimicrobial peptides - cathelicidins - shigella - α-defensins - β-defensins |
| title | Differential invasiveness & expression of antimicrobial peptides in Shigella serotypes |
| title_full | Differential invasiveness & expression of antimicrobial peptides in Shigella serotypes |
| title_fullStr | Differential invasiveness & expression of antimicrobial peptides in Shigella serotypes |
| title_full_unstemmed | Differential invasiveness & expression of antimicrobial peptides in Shigella serotypes |
| title_short | Differential invasiveness & expression of antimicrobial peptides in Shigella serotypes |
| title_sort | differential invasiveness expression of antimicrobial peptides in shigella serotypes |
| topic | antimicrobial peptides - cathelicidins - shigella - α-defensins - β-defensins |
| url | http://www.ijmr.org.in/article.asp?issn=0971-5916;year=2023;volume=158;issue=3;spage=303;epage=310;aulast=Narayan |
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