Deletion of interferon-γ delays onset and severity of dacryoadenitis in CD25KO mice

Abstract

Insights

Removing interferon-gamma (IFN-γ) in CD25 knockout mice delays lacrimal gland damage and preserves function in a Sjögren syndrome model. Autoantibodies and T-cell infiltration still increased with age, impacting tear production.

Area of Science:

  • Immunology
  • Ophthalmology
  • Autoimmune Diseases

Background:

  • Sjögren Syndrome (SS) is an autoimmune disorder affecting exocrine glands.
  • Dacryoadenitis, inflammation of the lacrimal gland, is a key feature of SS.
  • The role of interferon-gamma (IFN-γ) in SS-related dacryoadenitis is not fully understood.

Purpose of the Study:

  • To investigate the role of IFN-γ in the onset and severity of dacryoadenitis.
  • To evaluate the impact of IFN-γ deletion on lacrimal gland function and immune cell infiltration in a CD25 knockout (KO) mouse model of SS.

Main Methods:

  • Created CD25/IFN-γ double KO (γDKO) mice by crossbreeding CD25KO and IFN-γKO strains.
  • Analyzed lacrimal gland (LG) infiltrating lymphocytes using flow cytometry at 8, 12, and 16 weeks.
  • Measured tear epidermal growth factor (EGF) via ELISA, T-cell cytokines via PCR, and serum autoantibodies against M3R via Western blot.

Main Results:

  • γDKO mice exhibited lower lymphocytic infiltration at 8 weeks compared to CD25KO mice (20% vs. 60%), which increased with age.
  • γDKO mice showed altered T-cell cytokine profiles, with lower IL-17A, TGF-β1, IL-21, CCL20 and higher IL-1β, IL-13 mRNA.
  • Tear EGF concentration decreased with age in γDKO mice, correlating inversely with M3R autoantibodies and T-cell infiltration.

Conclusions:

  • IFN-γ deletion delays glandular destruction and preserves lacrimal gland function in the CD25KO mouse model.
  • M3R autoantibodies increased with age in both γDKO and CD25KO strains.
  • Reduced lacrimal gland function in γDKO mice correlated with T-cell infiltration and M3R autoantibodies.

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