Formation of Human Thymus Organoids in Three-Dimensional Fibrin Hydrogels
October 4th, 2024
Here, we describe a protocol for the formation of human iPSC-derived thymus organoids grown in 3D fibrin hydrogels aiming to support thymic epithelial cell (TEC) maturation and prolonged maintenance, as well as thymopoiesis in vitro.
We are trying to study the mechanisms responsible for self-tolerance, autoimmunity, especially the role played by air in the expression of self antigens presented by thymic epithelial cells to developing thymocytes. Our research has applications for cell therapy in the context of autoimmune diseases, organ transplants, and cancer. Our system produces thymic organoids, which are formed and seeded in a way that reproduces crucial biological and mechanical cues, which are essential for the maintenance and maturation of thymic epithelial cells.
The which in turn are essential to support thymobiosis, can be maintained for up to six weeks in the system. Our findings contribute to developing better techniques for in vitro t-lymphocyte production with many potential applications for research and cell therapy. As our research progresses, we hope to contribute to a better understanding of the mechanisms underlying self-tolerance and autoimmunity.
We are currently focusing on characterizing our organoids further in terms of cellular composition and organization, and our goal is to explore the role played by the r-gene in regulating cell antigen expression in the thymus and to establish a study model for the autoimmune disease episode. To begin thaw of thrombin and aprotinin on ice, and place a fibrinogen vial in a 37 degree Celsius water bath. Using a pipette, homogenize them under the hood.
Then using sterile pliers, place the inserts into the culture wells, leaving at least one column or row empty on the plate. To a 0.25 milliliter tube first add the required volumes of fibrinogen and aprotinin. Next, add the thrombin into the tube and quickly flush two times without creating bubbles.
Draw the entire content of the tube. Position the pipette vertically above the center of the insert and gently flush a reagent mix without generating bubbles. Incubate for at least one hour at 37 degrees Celsius for solidification until the mix turns opaque white.
For organoid seeding, confirm under a microscope that the micro masses forms spheric cell masses with a compact chorus surrounded by a lower density halo of early thymic progenitors. Cut the tip of a P 200 cone and wash it with an anti-adherent solution. Tilt the plate to a nearly vertical position and aspirate the cell masses from the bottom of the well.
Delicately deposit the mass at the top of the hydrogels without touching the gel. Check under the microscope that no organoid is left in the plate wells. Then slowly add a quarter of the volume of culture medium at the top of the hydrogel without touching it, and add the remaining 3/4s at the bottom of the well.
Add one milliliter of PBS to the empty culture wells to maintain humidity in the plate and incubate it at 37 degrees Celsius with 5%carbon dioxide. The organoids form spheric to oblong structures and occasionally merge to form larger structures in the hydrogels.
Overview
This study presents a protocol for creating human iPSC-derived thymus organoids within 3D fibrin hydrogels. The aim is to support the maturation of thymic epithelial cells and facilitate thymopoiesis in vitro.
Key Study Components
Area of Science
- Neuroscience
- Cell Biology
- Immunology
Background
- Understanding self-tolerance and autoimmunity is crucial for therapeutic advancements.
- Thymic epithelial cells play a key role in presenting self-antigens to developing thymocytes.
- Thymic organoids can mimic the thymic environment for research purposes.
- Current methods for in vitro T-lymphocyte production require improvement.
Purpose of Study
- To develop a reliable system for producing thymic organoids.
- To investigate the mechanisms of self-tolerance and autoimmunity.
- To explore the role of r-gene in regulating antigen expression in the thymus.
Methods Used
- Preparation of fibrin hydrogels for organoid culture.
- Seeding of thymic progenitor cells into the hydrogels.
- Incubation under controlled conditions to promote organoid formation.
- Microscopic analysis to confirm organoid development.
Main Results
- Thymic organoids maintained for up to six weeks showed structural integrity.
- Organoids formed spherical to oblong structures, indicating successful maturation.
- Research findings contribute to better techniques for T-lymphocyte production.
- Characterization of organoids revealed insights into cellular composition.
Conclusions
- The developed protocol enhances the understanding of thymic biology.
- Thymic organoids represent a valuable tool for studying autoimmunity.
- Future research will focus on further characterizing organoid functionality.
Frequently Asked Questions
Executive Industry Relevance
Reconstituting the human thymic microenvironment in vitro addresses a critical bottleneck in modeling T cell development and self-tolerance for immunology-driven drug discovery. The 3D fibrin hydrogel-based thymus organoid system enables scalable, functional recapitulation of thymic epithelial cell (TEC) biology, supporting predictive confidence in early-stage immune modulation and cell therapy research. This platform advances portfolio strategies targeting autoimmunity, transplantation tolerance, and T cell engineering by providing a physiologically relevant, reproducible model for mechanistic de-risking.
Strategic Applications in Biopharma R&D
Early Discovery & Target Validation
- Enables interrogation of self-tolerance mechanisms and antigen presentation in a controlled, human-relevant system.
- Supports functional validation of TEC-driven T cell selection and maturation pathways.
- Facilitates mechanistic de-risking for targets implicated in autoimmunity and immune tolerance.
- Provides a platform for hypothesis-driven exploration of gene function in thymic biology.
Screening & Assay Development
- Establishes a reproducible, scalable 3D culture system for TEC and thymocyte co-culture.
- Delivers quantitative outputs on organoid formation, cellular composition, and T cell generation.
- Enables standardization of immune cell differentiation assays for compound or genetic screening.
- Supports downstream evaluation of immune-modulating agents in a physiologically relevant context.
Translational & Preclinical Research
- Aligns with disease-relevant modeling of autoimmunity and transplantation tolerance.
- Provides continuity from discovery-stage mechanistic studies to preclinical validation of immune interventions.
- Enables risk-adjusted advancement of cell therapy and immunomodulatory candidates.
- Supports translational biomarker exploration in human-derived organoid systems.
Pipeline & Workflow Integration
This 3D thymus organoid model integrates into the discovery-to-preclinical continuum, bridging early mechanistic studies with translational immune research.
- Discovery Biology: Facilitates hypothesis testing on self-tolerance, antigen presentation, and TEC function.
- Screening: Provides a standardized, scalable assay system for immune cell differentiation and function.
- Analytics: Enables quantitative assessment of organoid structure, cellular composition, and T cell output.
- Translational Research: Connects in vitro findings to disease-relevant immune modulation and biomarker strategies.
- Enterprise Reuse: Offers a reusable platform for diverse immune research and cell therapy development programs.
Operational & Enterprise Impact
- Scientific Value: Increases predictive confidence in immune target validation and mechanistic de-risking.
- Operational Value: Delivers standardized, reproducible, and scalable 3D culture workflows.
- Strategic Value: Improves go/no-go decisions for immune modulation and cell therapy portfolios.
- Portfolio Impact: Enables risk-adjusted prioritization of immune and regenerative medicine assets.
Implementation Considerations
- Requires expertise in stem cell differentiation, 3D culture, and immune cell biology.
- Needs access to specialized cell culture infrastructure and analytical microscopy.
- Demands cross-team standardization for reproducibility and data comparability.
- May require adaptation for different donor sources or disease models.
- Practical limitations include TEC rarity and sensitivity to microenvironmental cues.
