Immune Profiling of T Cells Infiltrating Vitreous Humor in Tubercular Uveitis

ABSTRACT

Purpose: To assess cellular composition and local cytokine response in vitreous humor of tubercular uveitis.

Methods: Cells were collected from vitreous cassettes and peripheral blood of 8 tubercular uveitis and 5 control subjects, undergoing vitrectomy and analyzed by flow cytometry for cellular composition, activation status, proinflammatory cytokine expression, and uptake of TLR9 ligand, CpG ODN 2216.

Results: CD3 + T cells with equal proportion of CD4+ and CD8 + T cells formed major fraction of infiltrating cells. The vitreous humor showed higher expression of recent activation marker, CD69, and proinflammatory cytokines, IFN-γ and IL-17A, in CD4 + T cells as compared to peripheral blood. Lastly, intraocular CD4 + T cells showed reduced uptake of ODN 2216 than peripheral blood.

Conclusions: Our results indicate that local antigenic stimuli trigger T cell infiltration and activation of CD4 + T cells that are hyporesponsive to TLR9 stimulation. These infiltrating T cells might be responsible in further aggravating ocular inflammation.

KEYWORDS:

• Activated T cell
• T cells
• Th1 response
• Th17 response
• TLR9
• Tubercular uveitis
• Vitreous humor

Acknowledgments

Authors wish to acknowledge the helping hand offered by Aradhana Sonik from the Advanced Eye Centre, PGIMER.

Declaration of interest

The authors declare no conflict of interests.

Additional information

Funding

Centre of Excellence, Advance Eye Centre, PGIMER funded by Department of Biotechnology (DBT), Government of India, New Delhi for support [Grant No. BT/01/CEIB/11/02] (awarded to AG and NS) and Indian Council of Medical Research for providing fellowship to RS [3/1/3/JRF-2012/HRD-87].