Development of Stem Cell-based Therapies for Limbal Stem Cell Deficiency

Project Summary Limbal stem cell deficiency (LSCD), a blinding corneal disease, is caused by damage to the limbal stem cells or their niche microenvironment. The clinical presentation of LSCD varies greatly based on the severity of the condition, determined by the quantity of functional limbal stem cells (LSCs) remaining in the eye. Therefore, accurately diagnosing and staging LSCD through clinical examination alone is challenging and subjective. The lack of standardized diagnostic methods and disease severity staging has hindered therapy advancements, as uniform criteria are needed to establish standardized outcome measures for comparing the efficacy of different treatments. Moreover, treating LSCD should be tailored according to the severity and laterality of the disease. Transplanting cultivated LSCs may be a safer approach than limbal tissue grafting for severe to total LSCD, as it requires less donor tissue. However, no medical treatment exists for partial LSCD, and standardized quality controls and potency assays are lacking, preventing the quantification of stem cell content without sacrificing the cultivated stem cells for transplantation. Addressing these unmet medical needs, during our last funded period, we characterized several in vivo parameters of LSCD using a non-invasive diagnostic protocol employing multimodal in vivo imaging. This protocol has shown higher accuracy in diagnosing and staging the disease than clinical examination alone Additionally, we developed a robust xenobiotic- and feeder-free LSC manufacturing process and a new LSC therapy, currently under investigation in a Phase I clinical trial. Building upon this progress, the current proposal aims to develop a "liquid biopsy" of the conditioned media of cultivated LSCs for quality control and stem cell content quantification. This will be complemented by a deep machine learning approach to evaluate cultured cell morphology. In parallel, we will identify prognostic biomarkers of in vivo LSC function from serial in vivo multimodal images. Furthermore, to comprehend the ocular surface microenvironment and develop tear biomarker(s) for LSCD, differential profiling of tear components in eyes with LSCD, normal eyes and eyes with comorbidities in LSCD will be investigated using a multi-omic approach.