New Human Intestinal Immuno-Organoids Reveal Insights into Immune Cell Dynamics and Cancer Immunotherapy

By Dr. Chinta SidharthanReviewed by Lily Ramsey, LLMAug 26 2024

Organoids developed from adult pluripotent stem cells have greatly furthered our understanding of human physiology and disease and helped improve drug discovery and regenerative medicine research.

However, they lack the organ-specific immune cells and compartments that are essential to capture the specific roles of the organ in various pathologies.

In a recent study published in Nature, Swiss researchers created intestinal immuno-organoids that contain the epithelial organoid and autologous immune compartments containing memory T cells specific to the tissue to understand intestinal disease pathophysiology better.

​​​​​​​Study: Human organoids with an autologous tissue-resident immune compartment. Image Credit: Gorodenkoff/Shutterstock.com

Human Organoids

The development of various human organoids from human pluripotent stem cells has been monumental in improving our understanding of infectious and genetic diseases and advanced drug discovery and regenerative medicine.

However, organoids differ from native organs in the absence of tissue-specific compartments, such as immune compartments that are involved in tissue homeostasis and disease.

The disruption of immune function in various organs, such as the intestines, can cause autoimmune disorders, persistent infections, and even cancers.

Although intestinal organoids can replicate the differentiation of the various epithelial cell types and model the function of these cells accurately, the lack of tissue-specific immune cells prevents them from accurately modeling the pathophysiology of intestinal diseases.

Furthermore, the co-culturing of organoids in adaptive and innate immune cells derived from blood has been unsuccessful in incorporating lymphocyte compartments in the mucosa.

Additionally, while some studies have reported using murine models to generate gut-associated lymphoid tissue, the addition of in vivo development negates the advantages of organoids being an in vitro model.

About the Study

In the present study, the researchers used human tissue samples to create an intestinal immuno-organoid that contains autologous, tissue-resident immune compartments containing resident memory T cells.

These resident memory T cells have previous exposure to antigens and reside in the intestinal mucosa, acting as the frontline defense against various pathogens. Since resident memory T cells do not circulate like other immune cells, they are the ideal type of immune cells to be incorporated into organoids. The previous antigen exposure also ensures that these T cells can function without other immune structures and cells, such as antigen-presenting cells.

The researchers developed a scaffold-based, enzyme-free protocol to isolate immune cells from the intestinal tissue as enzymatic removal reduces the viability of these cells and presents challenges in incorporating them into in vitro systems.

Intestinal tissue samples were obtained from 27 patients who underwent cancer-related surgeries, and tissue sections and immune cells were isolated from these samples.

The immune cells were combined with the organoids derived from the tissue sections, and further interactions between the cells were studied using various methods.

Controlled environments were used to culture the organoids, and antibody treatments were then applied to study the immune reactions of these organoids containing isolated resident memory T cells.

Time-lapse imaging, flow cytometry, and numerous other advanced methods were employed to observe the temporal changes in the cells.

Additionally, dendritic cells derived from blood were also used with intestinal organoids to understand immune responses. These experiments helped the researchers understand the interactions between different immune cells and intestinal organoids in vitro.

Major Findings

The study showed that the non-enzymatic scaffold-based separation method was successful in isolating numerous viable resident memory T cells from the intestinal tissue samples.

These resident memory T cells retained their tissue-specific markers and, in association with intestinal organoids, expressed markers that were specific for the intestinal environment, indicating that these cells were suitable for in vitro integration with organoids.

The co-culturing of these resident memory T cells with intestinal organoids showed successful integration of the T cells with the epithelial barrier of the intestinal organoid, with behavior similar to that shown by intraepithelial lymphocytes in the human intestine.

Furthermore, these immune-integrated organoids could be maintained for close to two weeks, highlighting their value as a stable and functional model of the intestinal immune environment.

Single-cell ribonucleic acid (RNA) sequencing also showed that the genes related to migration and tissue integration were expressed differently in the resident memory T cells within the intestinal immuno-organoids as compared to the gene expression in peripheral blood mononuclear cells (PMBCs).

Furthermore, compared to the static PMBCs, the resident memory T cells within the intestinal organoids were more dynamic in their roles in intestinal immunity.

The intestinal immuno-organoids were also found to be good models of intestinal pathologies, such as the severe intestinal inflammation observed in patients undergoing cancer-related immunotherapy.

Conclusions

Overall, the researchers showed that the intestinal immuno-organoids developed using intestinal tissue and integrated resident memory T cells were an excellent in vitro model of the human intestinal immune environment and were valuable in studying various intestinal pathologies and immune responses involving resident memory T cells.