Establishment of producing immunologic tolerance by intrathymic antigen inoculation

2006 Fiscal Year Final Research Report Summary

• Project/Area Number: 17580281
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Clinical veterinary science
• Research Institution: Yamaguchi University
• Principal Investigator: UNE Satoshi Yamaguchi University, Agriculture, Associate Professor, 農学部, 助教授 (60294659)
• Co-Investigator(Kenkyū-buntansha): TAURA Yasuho Yamaguchi University, Agriculture, Professor, 農学部, 教授 (80163153) ; NAKAICHI Munekazu Yamaguchi University, Agriculture, Professor, 農学部, 教授 (60243630)
• Project Period (FY): 2005 – 2006
• Keywords: immunology / transplantation・regenerative medicine / immune tolerance / thymus / diabetes mellitus

Research Abstract

We have focused on the dog and pig immune responses toward the pig as the donor source. Furthermore, we try to examined the potentialities of the producing tolerance by intrathymic injection.
Unmodified canine serum caused approximate 100% PK15 cell. 5 carbohydrates (N-acetyl-β-D-Mannosamine, a -D-Galactose-1-phosphate, Arabinogalactan, Galactal(ICN) and N-acetyl-β-D-Glucosamine) were inhibited the cell damage against canine serum (47.4, 45.2, 34.8, 25.0, 23.1% respectively). And they were mixed, it was showed the protective effect (76.5%). The combine with PK15 cells and WGA lectin was obtained inhibition of PK15 cell damage. This study provides the evidence that (1) there are some carbohydrates on PK15 cells that may be the target against canine anti pig antibodies, (2) there may be useful role for inhibition to binding between carbohydrates as antigen and canine anti pig antibodies in order to prevent hyperacute rejection.
NIH minipigs were injected into either the thymus (Thymus grou p) or the spleen (Spleen group) with islets. In the Thymus group: 1) Anti-donor stimulation indices (SI) of mixed lymphocyte reactions (MLR) decreased, and remained low; 2) Peripheral blood lymphocytes (PBL) showed minimal cytotoxic activities in cell mediated lymphocytotoxicity (CML) assays; 3) Anti-donor cytotoxic T lymphocyte (CTL) activities in MLR-CML became undetectable; 4) Precursors of proliferating T lymphocytes (PTL-p) against donor LC decreased to an undetectable level; 5) Anti-donor cytotoxic antibodies were not detected; In contrast, in the Spleen group at 1 month: 1) Anti-donor SI of MLR increased; 2) Anti-donor cytotoxic activities increased in both CML and MLC-CML; 3) The PTL-p against donor LC increased; 4)Anti-donor antibodies were detectable starting from 1 week. These results demonstrated that intrathymic inoculation of islets induces unresponsiveness of PBL as well as suppression of systemic anti-donor cytotoxic antibody, and maintenances stable unresponsiveness directed against donor, but not third-party antigens.