Related Experiment Videos
Identification of a 2-Md plasmid from Shigella flexneri associated with reactive arthritis
H Stieglitz1, S Fosmire, P Lipsky
1Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas 75235.
Abstract:
The development of reactive arthritis, a sterile inflammatory polyarthropathy that primarily affects HLA-B27 positive individuals, has been associated with previous enteric infections caused by various gram-negative bacteria. The possibility that a common bacterial epitope triggers the disease was investigated by screening a panel of documented arthritogenic Shigella strains as well as 2 epidemic-associated nonarthritogenic Shigella controls. A 2-Md plasmid specific to the arthritogenic strains was identified and sequenced. The plasmid encodes a number of small peptides that could be related to the development of reactive arthritis. Within 1 of these is a stretch of 5 consecutive amino acids, inferred from the DNA sequence and contained within an open reading frame, that is homologous to amino acid residues 71-75 of the polymorphic region of the alpha 1 domain of HLA-B27. The data indicate that there is a bacterial plasmid common to arthritogenic Shigella strains that may play a role in triggering reactive arthritis. The finding that this plasmid encodes an epitope shared with HLA-B27 suggests that molecular mimicry may play a role in the induction of this disease.
Insights
A common bacterial plasmid in arthritogenic Shigella strains may trigger reactive arthritis. This plasmid contains an epitope that mimics HLA-B27, suggesting molecular mimicry in disease development.
Area of Science:
- Immunology
- Microbiology
- Genetics
Background:
- Reactive arthritis is a sterile inflammatory polyarthropathy primarily affecting HLA-B27 positive individuals.
- The condition is often preceded by enteric infections from gram-negative bacteria.
Purpose of the Study:
- To investigate if a common bacterial epitope triggers reactive arthritis.
- To identify specific bacterial factors associated with arthritogenic Shigella strains.
Main Methods:
- Screening of documented arthritogenic Shigella strains and nonarthritogenic controls.
- Identification and sequencing of a 2-Md plasmid specific to arthritogenic strains.
- Analysis of plasmid-encoded peptides for homology with HLA-B27.
Main Results:
- A 2-Md plasmid was identified and sequenced in arthritogenic Shigella strains.
- The plasmid encodes small peptides, one with a 5-amino acid sequence homologous to HLA-B27.
- This shared epitope suggests a potential role for molecular mimicry.
Conclusions:
- A common bacterial plasmid in arthritogenic Shigella strains may contribute to reactive arthritis development.
- The plasmid's shared epitope with HLA-B27 provides evidence for molecular mimicry in disease induction.