Poster 86 - IL-4 Therapy Mitigates Corneal Damage in Dry Eye Disease

Saturday, October 26, 2024

10:00 AM - 12:00 PM EST

Location: Exhibit Hall E, F & G

Presenting Author(s)

Caroline Praveen

Student at South Fayette High School
UPMC Cancer Center Hillman Academy
Mcdonald, Pennsylvania, United States

Co-Author(s)

AN

Alexis L. Nolfi

Graduate Student
University of Pittsburgh, Pennsylvania, United States
MK

Mangesh Kulkarni

Research Assistant Professor
University of Pittsburgh, United States

Primary Investigator(s)

BB

Bryan Brown

Associate Professor
University of Pittsburgh, United States

Introduction: Dry eye disease (DED) affects 344 million globally, stemming from inadequate corneal lubrication due to lacrimal gland inflammation and tear film instability [Messmer, E.M. PMC 2015 v.112(5)] Current treatments, including artificial tears, cyclosporine, and lifitegrast fail to provide complete symptom relief; the tear drops do not address the underlying mechanisms of DED, and the prescription medications are accompanied by a host of adverse effects that ultimately encourage non-compliance. On a cellular level, reduced tear production has recently been associated with an increase in inflammatory M1-like macrophages that target the lacrimal gland [3]. However, the interleukin 4 (IL-4) is a cytokine that induces the polarization of M1 macrophages into the M2 phenotype, which possesses anti-inflammatory and pro-regenerative properties. Therefore, we hypothesized that IL-4 is a pleiotropic cytokine that can be utilized as a long-term treatment for DED. We are using a pre-clinical rabbit model to test our hypothesis.

Materials and

Methods: To establish a surgical model of DED, the lacrimal gland was removed in 6 New Zealand white rabbits (3.3-3.5 kg), whose corneal dimensions and architecture resemble that of a human [4]. Given that DED takes 3-4 weeks on average to manifest, we began assessing the corneal damage at 3 weeks post-surgery. At the peak of symptoms, the rabbit corneas were randomly assigned to a treatment vs. control group. For the next two weeks, the treatment group received 1ng of IL-4 (30 μl drops) daily, while the control group was treated with PBS. Corneal abrasion was measured using fluorescein staining under fluorescent light as well as lissamine staining under brightfield. Two to three pictures were taken of each eye with both stains at every assessment. At the end of the experimental period, the stained area in each image was quantified with pixel classification tools in QuPath biomage analysis software. Thresholds were set to classify the intensity of the stain as either medium or high in the fluorescein and lissamine images. Ultimately, these intensities were averaged and presented as percentages of their total corneal area with GraphPad Prism. Such methods were designated to trend the abraded area in the DED induced corneas, which would exemplify the capacity for IL-4 to prevent corneal damage.

Results, Conclusions, and Discussions: As shown in Figure 1, the derived data indicates a decrease in stained area for the IL-4 treated groups. The baseline data presented with minimal staining, consistent with that of a normal cornea. At 4.5 weeks post-surgery, the graphs showed the increased corneal damage expected in the surgical model of DED. Corneal staining intensified in the control group treated with only PBS, as revealed in the R5 Left and R6 Left data groups. In contrast, the IL-4 treated groups (R5 Right and R6 Right) revealed significant decrease in corneal damage during the two weeks of treatment.
Analyzing the trends in stained areas between control and experimental eyes demonstrates the efficacy of the IL-4 treatment and aligns with the data from the investigations subjected to the previous four rabbits. The reduction in corneal damage with the IL-4 treatment exemplifies the therapeutic potential of the interleukin in addressing the mechanisms of DED. We are currently testing controlled release systems to deliver IL-4 over an extended period, ultimately with the goal to extend the window of relief for future patients who may utilize the treatment as a coated contact lens or as eye drops once we are able to fully develop an engineered commercial product.
The prevalence of dry eye disease (DED) and the ineptitude of existing treatments prompts investigation into novel therapeutic approaches. Because Interleukin-4 (IL-4) is effective in promoting the expression of pro-regenerative M2 macrophages, we investigated its effect on the cornea to therefore observe its ability to treat dry eye. In a rabbit model, the reduction in dye stained corneal abrasion attests to the potential of IL-4 as a long-term solution.

Acknowledgements (Optional): This research was made possible by my mentor Dr. Mangesh Kulkarni, the Brown Lab, the UPMC Hillman Academy, and the University of Pittsburgh.

References (Optional): Messmer, E. M. (2015). The Pathophysiology, Diagnosis, and Treatment of Dry eye Disease. Deutsches Ärzteblatt International. https://doi.org/10.3238/arztebl.2015.0071

Stapleton, F., Velez, F. G., Lau, C., & Wolffsohn, J. S. (2024). Dry eye disease in the young: A narrative review. the Ocular Surface/the Ocular Surface, 31, 11–20. https://doi.org/10.1016/j.jtos.2023.12.001

Ling, J., Chan, B. C., Tsang, M. S., Gao, X., Leung, P. C., Lam, C. W., Hu, J., & Wong, C. K. (2022). Current Advances in Mechanisms and Treatment of Dry Eye Disease: Toward Anti-inflammatory and Immunomodulatory Therapy and Traditional Chinese Medicine. Frontiers in Medicine, 8. https://doi.org/10.3389/fmed.2021.815075

Centre for Comparative Medicine Research of the University of Hong Kong. (n.d.). https://ccmr.hku.hk/en/Animals/Animals/Animal-Strains/Rabbit/NZW