Transcriptome network analysis implicates CX3CR1-positive type 3 dendritic cells in non-infectious uveitis.

Area of Science:

• Immunology
• Ophthalmology
• Cell Biology

Background:

• Type I interferons (IFNs) are known to expand CD1c+ conventional dendritic cells (CD1c+ DCs).
• The specific role of CD1c+ DCs in conditions lacking elevated type I IFNs, such as non-infectious uveitis, is not well understood.

Purpose of the Study:

• To investigate the molecular basis of CD1c+ DC involvement in non-infectious uveitis.
• To characterize CD1c+ DC populations in patients with non-infectious uveitis compared to healthy donors.

Main Methods:

• RNA-sequencing and high-dimensional flow cytometry were used to analyze CD1c+ DCs from two patient cohorts and healthy donors.
• Validation was performed in an independent case-control cohort.
• Peripheral blood and inflamed eye samples were analyzed.

Main Results:

• CD1c+ DCs in non-infectious uveitis patients showed a gene expression profile centered around the chemokine receptor CX3CR1.
• This CX3CR1-driven gene module was not associated with type I IFN activity.
• CX3CR1+ DC3s were found to be diminished in peripheral blood, while CX3CR1- DC3s were not.
• Stimulated CX3CR1+ DC3s secreted high levels of inflammatory cytokines like TNF-alpha.
• CX3CR1+ DC3-like cells were detected in the inflamed eyes of patients.

Conclusions:

• CX3CR1+ DC3s are implicated in the pathophysiology of non-infectious uveitis.
• These cells contribute to inflammation by secreting proinflammatory mediators, independent of type I IFNs.