CD8⁺ T Cells Promote Pathological Angiogenesis in Ocular Neovascular Disease

Area of Science:

• Immunology
• Ophthalmology
• Vascular Biology

Background:

• Elevated CD4+ and CD8+ T cells are observed in ocular fluids of neovascular retinopathy patients.
• The specific role of these T cells in the disease pathogenesis remains unclear.

Purpose of the Study:

• To elucidate the role of CD8+ T cells in neovascular retinopathy.
• To identify the mechanisms by which CD8+ T cells contribute to retinal neovascularization and vascular leakage.

Main Methods:

• Flow cytometry analysis of T cell populations in blood, lymphoid organs, and retina.
• T cell depletion studies (CD8+ vs. CD4+).
• Reporter mice for T cell localization and adoptive transfer experiments with genetically modified T cells.
• Chemokine receptor blockade (CXCR3).

Main Results:

• CD8+ T cells, but not CD4+ T cells, were significantly increased in the retina during retinopathy development.
• Depletion of CD8+ T cells reduced retinal neovascularization and vascular leakage.
• CD8+ T cells were found near neovascular tufts, and their pathogenic effects were mediated by TNF, IFNγ, and Granzymes.
• CXCR3 was identified as the critical chemokine receptor for CD8+ T cell retinal infiltration, with CXCR3 blockade reducing T cell numbers and disease severity.

Conclusions:

• CD8+ T cells play a significant, previously unappreciated role in neovascular retinopathy pathogenesis.
• CXCR3-mediated migration is central to CD8+ T cell recruitment into the retina.
• Targeting CD8+ T cell recruitment pathways, such as CXCR3, offers a potential therapeutic strategy for neovascular retinopathies.