Related Experiment Videos
Mixed hematopoietic chimerism and transplantation tolerance
1BMT Section, Massachusetts General Hospital/Harvard Medical School, Boston 02129, USA.
Immunologic Research
|January 1, 1997
Summary
Achieving durable transplantation tolerance involves hematopoietic stem cell engraftment in T-lymphocyte depleted recipients. This method creates mixed hematopoietic chimeras, inducing tolerance via central clonal deletion without harsh conditioning.
Area of Science:
- Immunology
- Transplantation Biology
- Stem Cell Research
Background:
- Durable transplantation tolerance is crucial for successful organ and cell transplantation.
- Current methods often involve toxic or myeloablative conditioning, limiting their application.
- Inducing mixed hematopoietic chimerism offers a promising avenue for achieving tolerance.
Purpose of the Study:
- To review laboratory approaches for inducing stable mixed hematopoietic chimerism.
- To explore methods for achieving specific central deletional allogeneic and xenogeneic tolerance.
- To present strategies that avoid toxic or myeloablative host conditioning.
Main Methods:
- Depletion of recipient T-lymphocytes prior to transplantation.
- Engraftment of donor pluripotent hematopoietic stem cells (PPHSC).
- Monitoring of mixed hematopoietic chimerism and immune tolerance.
Main Results:
- Stable mixed hematopoietic chimerism was achieved in recipients.
- Both host and donor cells coexisted, demonstrating mutual tolerance.
- Central, intrathymic clonal deletion was identified as the primary tolerance mechanism.
- Tolerance was maintained by the immigration of host and donor marrow-derived cells to the thymus.
Conclusions:
- Stable mixed hematopoietic chimerism can be induced without toxic conditioning.
- Central deletional tolerance is a key mechanism for allogeneic and xenogeneic tolerance.
- This approach offers a less toxic strategy for achieving durable transplantation tolerance.