Methods of determining the suitability of cultured thymus tissue for implantation into humans and associated methods of use
Inventors
Markert, Mary Louise • Hale, Laura P. • Kurtzberg, Joanne • Cheatham, Lynn • Sempowski, Gregory D. • MacIntyre, Andrew N. • TRACY, Alex • MARKS, Kristin • PIHEL, Karin
Assignees
Enzyvant Therapeutics GmbH • Duke University
Publication Number
US-12364715-B2
Publication Date
2025-07-22
Expiration Date
2039-02-22
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Abstract
Methods and compositions for promoting donor-specific tolerance and immunocompetence to a recipient of a solid organ transplant, by implanting an allogeneic solid organ in a recipient in need of a solid organ transplant and further comprising surgical implantation of a tissue-engineered allogeneic cultured postnatal thymus tissue product in the recipient of a solid organ from a donor.Methods of producing an allogeneic cultured postnatal thymus tissue-derived product suitable for implantation into a human; methods of culturing allogeneic cultured postnatal thymus tissue-derived product suitable for implantation into a human and methods of using allogeneic cultured postnatal thymus tissue-derived product by implantation in a human subject.
Core Innovation
The invention provides methods and compositions for promoting donor-specific tolerance and immunocompetence to recipients of solid organ transplants by implanting an allogeneic cultured postnatal thymus tissue-derived product (CTT) from the organ donor into the recipient. The process involves surgical implantation of a tissue-engineered, allogeneic cultured postnatal thymus tissue product, which is cultured for a period of about 6 to about 21 days to produce partially T cell-depleted thymus tissue slices retaining thymic epithelial cells (TECs). This cultured thymus tissue enables immune system reconstitution and tolerance to donor antigens while maintaining immunocompetence.
The problem addressed is that transplant rejection remains a major challenge in solid organ transplantation due to recipient T cells rejecting donor organs and development of antibodies by recipient B cells against the donor. Current immunosuppressive therapies have toxicity and do not achieve consistent tolerance. The limited viability window of organs and complications due to immune rejection highlight the need for improved methods to induce tolerance and achieve immune reconstitution post-transplantation, especially to overcome graft rejection and related failures.
Claims Coverage
The patent includes one independent claim focused on the method of producing an allogeneic cultured postnatal thymus tissue-derived product suitable for implantation.
Method of producing a partially T-cell depleted donor thymus tissue product through culturing
The method comprises slicing donor thymus into slices, placing them on a support structure, and culturing them in a thymus organ medium for about 6 to 21 days to produce partially T-cell depleted donor thymus tissue slices.
Monitoring biomarker CCL21 to determine suitability
During culturing, detecting an increased level of CCL21 in the thymus organ medium compared to baseline at day 0 and confirming the cultured tissue slices show areas positive for cytokeratin staining, at least one Hassall body, and intact nuclei of thymic epithelial and stromal cells to confirm suitability for implantation.
Additional biomarker monitoring for quality control
Optionally detecting levels of L-selectin, M-CSF, galectin-7 or IL-16 in the thymus organ medium during culturing, with decreased levels compared to baseline indicating expected thymocyte depletion.
Further biomarker monitoring for TEC function
Optionally detecting increased levels of one or more of CXCL12, CXCL16, or CCL11 in the thymus organ medium during culturing compared to baseline to indicate thymic epithelial cell function and viability.
Flexibility in culturing period
The culturing step may last from any period between about 5 days to 21 days, including specific integer day ranges such as 6-21 days.
Specific cytokeratin staining as indicator of tissue quality
The cultured thymus tissue slices show cytokeratin 14 (CK14) staining scattered throughout in a lacy pattern, which is indicative of viable thymic epithelial cells.
The claims focus on a method for producing cultured, partially T-cell depleted postnatal thymus tissue suitable for implantation, characterized by culturing thymus slices for 6 to 21 days, monitoring biomarker levels such as increase in CCL21 and cytokeratin staining, with optional further biomarker assessments to control tissue quality and function, enabling the manufacture of a thymus tissue product that supports immune reconstitution and tolerance upon implantation.
Stated Advantages
The invention promotes donor-specific tolerance and immunocompetence in recipients of solid organ transplants.
The culturing process depletes donor thymocytes while preserving thymic epithelial cell networks and architecture.
Implantation of the cultured thymus tissue leads to reconstitution of a functional immune system and tolerance to donor and self antigens.
Use of the cultured thymus tissue reduces the need for long-term immunosuppression with associated toxicities.
Biomarkers such as CCL21, L-selectin, and others provide non-destructive means to assess viability and suitability of cultured thymus tissue.
Documented Applications
Treating T cell immunodeficiency resulting from congenital athymia including complete DiGeorge anomaly and mutations such as FOXN1 deficiency.
Promoting donor-specific tolerance to allogeneic solid organ transplants such as heart, kidney, liver, lung, pancreas, intestinal and composite tissue transplants.
Use in recipients who are thymectomized and undergo solid organ transplantation to induce tolerance to donor antigens.
Use of cultured thymus tissue co-transplantation with solid organs in pediatric and adult heart transplant recipients to improve graft survival.
Cryopreservation of cultured thymus tissue for future implantation in the event of solid organ rejection or immunosuppression-associated tissue damage.
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