HGS-2 Assessing an actin-binding protein, Thymosin Beta-4, for the treatment of Acanthamoeba keratitis
Start Date
12-4-2024 9:30 AM
End Date
12-4-2024 11:30 AM
Location
University Readiness Center Greatroom
Document Type
Poster
Abstract
Acanthamoeba castellanii is an amoeba that causes eye (Acanthamoeba keratitis (AK)) and CNS (granulomatous amebic encephalitis (GAE)) infections. AK, the majority of which occurs in contact lens wearers, is characterized by severe pain and corneal and retinal damage, which can lead to vision loss. Treatment requires hourly administration of broad-spectrum antimicrobial eye-drops for two days, followed by daytime-only hourly eye-drops for five days. Since amoebae can transform into drug-resistant cysts, this challenging treatment regimen is necessary to kill the amoebae before they transform. Thus, novel treatments are desperately needed. Thymosin Beta-4 (Tβ4) is an actin binding protein that regulates wound healing and inflammation. It has been clinically evaluated for wound healing in patients with epidermolysis bullosa, pressure or venous stasis ulcers, and in patients who have undergone eye surgery or with dry eye syndrome. We hypothesize that Tβ4 may be used in AK to mitigate eye damage. To test this, we developed an in vitro epithelial damage assay. Human retinal epithelial-1 cells were cultured to confluent monolayers and “infected” with Acanthamoeba ± Tβ4 for 18-24 hours. The monolayers were fixed and stained with crystal violet. Damage was assessed by image analysis using NIH ImageJ software. Addition of Tβ4 prior to or during infection prevented monolayer destruction by up to 46%. Treatment of Acanthamoeba alone with Tβ4 did not kill the parasite, suggesting that protection occurred by altering parasite virulence and/or the epithelium. These are promising results that support our hypothesis that Tβ4 may be used in the treatment of AK.
Keywords
Acanthamoeba keratitis, Thymosin beta-4
HGS-2 Assessing an actin-binding protein, Thymosin Beta-4, for the treatment of Acanthamoeba keratitis
University Readiness Center Greatroom
Acanthamoeba castellanii is an amoeba that causes eye (Acanthamoeba keratitis (AK)) and CNS (granulomatous amebic encephalitis (GAE)) infections. AK, the majority of which occurs in contact lens wearers, is characterized by severe pain and corneal and retinal damage, which can lead to vision loss. Treatment requires hourly administration of broad-spectrum antimicrobial eye-drops for two days, followed by daytime-only hourly eye-drops for five days. Since amoebae can transform into drug-resistant cysts, this challenging treatment regimen is necessary to kill the amoebae before they transform. Thus, novel treatments are desperately needed. Thymosin Beta-4 (Tβ4) is an actin binding protein that regulates wound healing and inflammation. It has been clinically evaluated for wound healing in patients with epidermolysis bullosa, pressure or venous stasis ulcers, and in patients who have undergone eye surgery or with dry eye syndrome. We hypothesize that Tβ4 may be used in AK to mitigate eye damage. To test this, we developed an in vitro epithelial damage assay. Human retinal epithelial-1 cells were cultured to confluent monolayers and “infected” with Acanthamoeba ± Tβ4 for 18-24 hours. The monolayers were fixed and stained with crystal violet. Damage was assessed by image analysis using NIH ImageJ software. Addition of Tβ4 prior to or during infection prevented monolayer destruction by up to 46%. Treatment of Acanthamoeba alone with Tβ4 did not kill the parasite, suggesting that protection occurred by altering parasite virulence and/or the epithelium. These are promising results that support our hypothesis that Tβ4 may be used in the treatment of AK.