New method for thyroid transplantation across major histocompatibility complex barriers using allogeneic bone marrow...

Area of Science:

• Immunology
• Transplantation Biology
• Regenerative Medicine

Background:

• Allogeneic bone marrow transplantation (BMT) can induce donor-specific tolerance for organ transplants across major histocompatibility complex (MHC) barriers.
• Previous research showed portal venous administration of donor bone marrow cells (BMCs) with immunosuppressants induces tolerance.
• A novel, human-applicable method for thyroid transplantation combined with BMT was developed using central and intrahepatic tolerance induction.

Purpose of the Study:

• To establish a new, efficient method for thyroid allograft transplantation using bone marrow transplantation (BMT).
• To induce donor-specific tolerance across MHC barriers for enhanced graft survival.
• To develop a protocol applicable to humans for transplantation tolerance.

Main Methods:

• Recipient mice received busulfan (BU) and sublethal irradiation (6-5 Gy) to create space for donor hematopoietic cells.
• Donor BMCs were treated with neuraminidase (Neu) to enhance liver trapping for intrahepatic tolerance induction.
• Neu-treated BMCs were injected intravenously, followed by engraftment of donor thyroid organs under the renal capsule.

Main Results:

• A combination of BU, 6 Gy irradiation, and i.v. injection of Neu-treated BMCs achieved a 90% thyroid graft survival rate over 100 days.
• A 70% graft survival rate was observed with 5 Gy irradiation under the same conditions.
• Omission of either BU or Neu treatment significantly decreased graft survival rates, indicating their critical roles.

Conclusions:

• A single-day protocol combining busulfan (BU) and neuraminidase (Neu) treatments successfully induced long-term tolerance.
• This method effectively prevented the rejection of thyroid allografts in a mouse model.
• The developed protocol shows promise for clinical application in transplantation tolerance.