Related Experiment Videos
Modulation of peripheral blood mononuclear cell activation status during Salmonella-triggered reactive arthritis
J Kirveskari1, Q He, T Holmström
1National Public Health Institute, Turku, Finland.
Objective:
To determine the activation status of mononuclear cells in the peripheral circulation during the acute phase and the recovery phase of Salmonella-triggered reactive arthritis (ReA).
Methods:
Peripheral blood mononuclear cells (PBMC) were obtained from 8 patients with Salmonella infection (4 with ReA and 4 without) and were studied by reverse transcription-polymerase chain reaction for messenger RNA (mRNA) of proinflammatory and antiinflammatory cytokines, by flow cytometry (FC) for cell surface activation and adhesion molecules, by immunofluorescence (IF) microscopy for bacterial antigens, and by FC, IF, and DNA fragmentation on gel for signs of apoptosis.
Results:
During the acute phase of the infection, PBMC were activated in all patients, as characterized by high levels of expression of CD14, CD11b, and CD11c on monocytes. In the patients with ReA, PBMC also had the capacity to produce interleukin-1beta (IL-1beta), IL-6, IL-8, IL-10, and tumor necrosis factor alpha. During the amelioration of disease, monocyte activation was decreased in all patients. A complete down-regulation of CD14 was detected only in the patients with ReA, whereas the expression of CD14 in the patients without ReA was positive and was similar to that in healthy controls. In addition, cytokine mRNA levels decreased regardless of the presence of Salmonella antigens in blood cells in all 4 patients with ReA.
Conclusion:
High levels of expression of some activation and adhesion molecules and elevated levels of mRNA for certain cytokines that are predominantly produced by monocytes were found in PBMC from patients with acute Salmonella-triggered ReA, which suggests that these cells are activated. On the other hand, complete down-regulation of CD14 and a marked decrease in the cytokine production capacity during amelioration of the disease suggest that suppression of PBMC activity might be involved in recovery from ReA.
Insights
Peripheral blood mononuclear cells (PBMC) show activation during Salmonella-triggered reactive arthritis (ReA). Monocyte activation decreases during recovery, with CD14 down-regulation specific to ReA patients, suggesting suppressed PBMC activity aids recovery.
Area of Science:
- Immunology
- Rheumatology
- Infectious Diseases
Background:
- Reactive arthritis (ReA) can be triggered by Salmonella infections.
- Understanding the immune cell activation status in ReA is crucial for developing effective treatments.
Purpose of the Study:
- To investigate the activation status of peripheral blood mononuclear cells (PBMC) during the acute and recovery phases of Salmonella-induced ReA.
Main Methods:
- Studied PBMC from 8 patients (4 with ReA, 4 without) with Salmonella infection.
- Utilized reverse transcription-polymerase chain reaction (RT-PCR) for cytokine mRNA.
- Employed flow cytometry (FC) for cell surface markers and immunofluorescence (IF) for bacterial antigens.
Main Results:
- PBMC activation, indicated by CD14, CD11b, and CD11c expression, was observed in all patients during acute infection.
- ReA patients showed higher production of proinflammatory cytokines (IL-1beta, IL-6, IL-8, TNF-alpha) and IL-10.
- Monocyte activation decreased during disease amelioration, with complete CD14 down-regulation unique to ReA patients.
Conclusions:
- Activated PBMC, particularly monocytes expressing specific markers and cytokines, are characteristic of acute Salmonella-triggered ReA.
- Down-regulation of CD14 and reduced cytokine production during disease improvement suggest suppressed PBMC activity is involved in ReA recovery.