Patient-derived Retinal Organoids for Modeling Uveitis: Developing a Humanized In Vitro Model in Ocular Inflammation Research

Uveitis, an immune-mediated inflammatory disease of the eye, represents a significant cause of visual impairment worldwide, accounting for 10-20% of blindness cases in developed nations and up to 25% in developing countries (1). Despite its prevalence, current research models for uveitis, primarily animal-based, often fail to fully recapitulate human disease characteristics (2).

Our preliminary work has shown promising results in developing patient-specific models for uveitis. We generated induced pluripotent stem cells (iPSCs) from three patients with birdshot chorioretinopathy (BCR), a specific form of uveitis strongly associated with the HLA-A29 allele. These patient-derived iPSCs were successfully differentiated into retinal organoids and retinal pigment epithelium (RPE) cultures.

Flow cytometry analysis revealed that RPE cultures from BCR patients exhibited differential surface HLA-Class I molecule expression compared to controls. Furthermore, multiplex immunoassay and proteomic analysis showed elevated secretion of pro-inflammatory cytokines, including IL-8 in BCR patient-derived cells.

These findings suggest that patient-derived retinal organoids can recapitulate key inflammatory characteristics of uveitis, offering a promising platform for studying disease mechanisms and potentially bridging the gap between animal models and human disease.

Aims & Objectives

Aim: To develop and validate patient-derived retinal organoids as a novel in vitro model for studying uveitis.

Objectives:

• Generate iPSCs from patients with genetically-associated uveitis conditions and differentiate them into retinal organoids.
• Characterize the immune profiles of patient-specific retinal organoids through:

1. Immunofluorescence and flow cytometry to identify disease-related alterations
2. Cytokine profiling using multiplex immunoassay and high-throughput proteomic analysis
3. Co-culture experiments with patient-derived T cells to examine responses to pathogenic and tolerogenic T cell populations

• Evaluate the response of patient-derived organoids to anti-inflammatory treatments, particularly TNF inhibitors.
• Correlate in vitro findings with clinical outcomes in patients to validate the model’s predictive potential.

Key Hypothesis: Patient-derived retinal organoids will recapitulate key inflammatory characteristics of uveitis, providing a more relevant platform for studying disease mechanisms and treatment responses than current models.

Methods

Patient-derived iPSCs will be generated from a collaborator, allowing the PhD student to focus on organoid development and characterisation. Retinal organoids will be differentiated using a stepwise protocol involving neural induction, retinal specification, and photoreceptor maturation over 24 weeks.

Organoid characterization will employ multi-parameter flow cytometry using a panel of retinal cell-specific markers. Immunohistochemistry will be performed to assess the spatial organization of retinal layers and localise key cell types. Immune profiling will utilise multiplex cytokine assays. Co-culture experiments with patient-derived T cells will be conducted to further explore the immune response. Treatment response will be evaluated by exposing organoids to TNF-α inhibitors (e.g., adalimumab) and assessing changes in inflammatory markers. Iterative bleaching extends multiplexity (IBEX) (a technique recently established in the lab) will be employed for high-resolution, multi-parameter imaging of immune cell interactions within organoids.

The student will develop skills in organoid culture and differentiation, immunohistochemistry, advanced microscopy techniques including IBEX, flow cytometry, and biostatistics. They will also gain experience in experimental design, data interpretation, and scientific communication.

Training Plan

The student will receive comprehensive training in:

• Organoid culture and differentiation techniques
• Immunohistochemistry and flow cytometry
• Advanced microscopy, including IBEX
• Biostatistics

They will attend courses on:

• Research ethics and integrity
• Scientific writing and presentation skills
• Experimental design in biomedical research

Conferences:

• International Society for Stem Cell Research (ISSCR) annual meeting
• Association for Research in Vision and Ophthalmology (ARVO) annual meeting

The student will also participate in:

• Weekly lab meetings and journal clubs
• Quarterly presentations at the University’s Uveitis research meeting

Additionally, they will have opportunities for interaction and collaboration with clinical researchers forstering their long-term growth

Deadline: 16:00 GMT Friday 13^th December 2024

Supervisors: Dr Panayiotis Maghsoudlou & Prof Andrew Dick  

Key words: Uveitis, Retinal Organoids, iPSCs, In Vitro Models, Inflammation

University of Bristol Scholarship – How to apply

Submit your application via the University of Bristol portal: Start your application Study at Bristol University of Bristol. Search for then select ‘Translational Health Sciences (PhD)’. Click ‘Apply’ next to the September 2025 start.

Before applying, please check the entry requirements for the programme.

You must provide the following in your application:

• A curriculum vitae
• Two references
• A personal statement (maximum of two sides of A4, font size 11)

Incomplete applications will not be considered.

A research statement is not needed for this studentship. Please upload a document to the research statement section, stating ‘I am applying for the Bristol Medical School Scholarships. No research statement is required.’

In the funding section of the application form, please choose ‘University of Bristol Scholarship’.

In the research section, please enter the project title and the supervisors’ names as written on this advert.

We are keen to support applicants from minority and under-represented backgrounds (based on protected characteristics) and those who have experienced other challenges or disadvantages. We encourage you to use your personal statement to ensure we can take these factors into account.

The anticipated start date is Autumn 2025. Applications will be reviewed in January and interviews are scheduled for February.

Application enquiries

For project-related queries, please contact the project supervisor: Dr Panayiotis Maghsoudlou (p.maghsoudlou@bristol.ac.uk). For application queries, please contact fohs-pgadmissions@bristol.ac.uk.