Abstract
Abstract: :
Purpose: Integrity of blood:aqueous barrier is important to maintain immune privilege in the eye and is essential to prevent leakage of large amount of plasma proteins into the anterior chamber (AC). Most of the TGF–beta inside the eye is in its latent form and requires a conversion to the active form to have an immunosuppressive activity. We wished to determine effects of ocular trauma on immune privilege in the eye, specifically, on integrity of blood:aqueous barrier and on activation of TGF–beta in the aqueous humor (AqH). Methods: BALB/c mouse eyes received one of the following treatments. 1, A scratch on the surface of the central cornea with tip of a 30 G syringe needle. 2. A puncture at the central cornea with the needle. 3. Injection of 2 ul HBSS (vehicle) into the AC, 4. Injection of 50 ug ovalbumin (OVA) in 2 ul HBSS into AC. AqH was collected at different time points after the surgery. Total protein contents and active TGF–beta activity in the AqH were analyzed. Results: Scratching, puncture of the cornea, and injection of HBSS into the AC caused a mono–phasic increase of total AqH protein content with a peak at 1–2 hr, Injection of OVA into the AC induced a bi–phasic increase of AqH total proteins with first peak at 1–2 hr and the second peak at 6 hr. All of the above treatments to the eyes caused an increased production of active TGF–beta in the AqH. Conclusions: Trauma to the cornea and injection into the AC are sufficient to cause breakdown of blood:aqueous barrier and activation of TGF–beta in the AqH.
Keywords: immune tolerance/privilege • anterior chamber • trauma