权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Developing a new type of medicine that suppresses allograft rejection without any side effects in a tailor-made manner

以量身定制的方式开发一种抑制同种异体移植排斥反应且无任何副作用的新型药物

基本信息

批准号：
20591538
负责人：
YOSHIDA Riyoutarou
金额：
$ 2.91万
依托单位：
Osaka Medical College
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2008
资助国家：
日本
起止时间：
2008 至 2010
项目状态：
已结题

项目摘要

Transplantation is one of the optimal treatments for patients possessing non-functional cells, tissues, and organs. However, a variety of host immune cells infiltrating into the transplantation site recognize the allografts as non-self to kill them (allograft rejection). Human MHC class I genes (human leukocyte antigen : HLA) are contained in the A, B, and C regions ; and there are 30, 60, and 10 haplotypes, respectively, assuming that 1 of 20000 donors might have MHC class I molecules identical to those of a recipient. Right now, the recipient continues to take nonspecific immunosuppressive medicine. Sometimes, it causes recipient death by infection as a side effect. The dream on transplantation therapy is to inhibit the allograft rejection, a physiological immune response, without any side effects. There are 2 ways to achieve it : one is isolation of cDNAs encoding receptors for MHC class I molecules and identification of their ligands. The other one is specific inhibition of the int … More eraction between an MHC class I molecule and its receptor without any side effects in a tailor-made manner. In 2006, we isolated 2 cDNA clones encoding novel MHC receptors on allograft-induced macrophages (AIM) for allogeneic MHCs (i.e., H-2D^d and H-2K^d) by using anti-AIM monoclonal antibodies (R15 and R12) and allogeneic MHC tetramers (H-2D^d and H-2K^d). We called these 2 receptors macrophage MHC receptor 1 (MMR1) and MMR2, respectively. In 2010, we isolated a cDNA encoding a human homologue (83.6% amino acid identity) of mouse MMR2 from a human cDNA library, the donors of which had never been allografted, and identified HLA-B62 as a possible ligand for human MMR2 on monocytes. Recently, we also isolated a cDNA encoding a human homologue of mouse MMR1 from a human cDNA library, and identified a possible ligand for human MMR2 on monocytes. Furthermore, in order to know the physiological significance of these MHC class I molecules and their receptors, we established D^d, K^d or D^d,K^d transgenic mice or tumor cells, and transplanted the transgenic skin onto or transgened tumor cells into C57BL/6 mice. The results clearly showed transgene number-dependent, gene expression rate-independent rejection of D^d-, K^d-, or D^dK^d-transgened mouse skin or tumor cells from C57BL/6 (D^bK^b) mice. Using MMR KO mice, finally, we will know the physiological significance of MMRs. On the other hand, in order to develop a new type of medicine that inhibits the interaction between an MHC class I molecule and its receptor, we asked Protein Science Institute Co. to identify the peptide sequences which might suppress the interaction, asked a company to synthesize those peptides, and established MMR-transgened cells by our selves. The binding assay of H-2K^d pentamer to MMR2-transgened EL-4 cells and the effects of 4 kinds of peptides on the interaction are under investigation. Meantime, we realized that an MMR is very specific for an MHC class I molecule and that human or mouse might have several 10 kinds of MMRs for all non-self MHC class I molecules. Therefore, if we could isolate cDNAs for 8 kinds of HLA-A and 9 kinds of HLA-B and if we could develop a new type of medicine to inhibit the interaction of MMRs with MHC class I molecules, we might be able to regulate allograft rejection without any side effects in a tailor-made manner. Less

对于拥有无功能细胞、组织和器官的患者，移植是最理想的治疗方法之一。然而，渗透到移植部位的各种宿主免疫细胞识别异体移植物以杀死它们(同种异体排斥反应)。人类MHC I类基因(人类白细胞抗原：HL A)包含在A、B和C区；假设20000名捐赠者中有1名可能具有与受者相同的MHC I类分子，则分别有30、60和10种单倍型。目前，接受者继续服用非特异性免疫抑制药物。有时，作为副作用，它会通过感染导致受体死亡。移植治疗的梦想是抑制同种异体移植排斥反应，这是一种生理免疫反应，没有任何副作用。有两种方法可以达到这一目的：一是分离编码MHC-I类分子受体的cDNA，并鉴定其配体。另一种是对INT…的特异性抑制MHC I类分子与其受体之间有更多相互作用，量身定做，没有任何副作用。2006年，我们利用抗同种异体MHC受体的单抗(R15和R12)和同种异体MHC四聚体(H-2D^d和H-2K^d)，分离了2个编码同种异体MHC受体的cDNA克隆(H-2D^d和H-2K^d)。我们将这两种受体分别命名为巨噬细胞MHC受体1(MMR1)和MMR2。2010年，我们从一个从未进行过同种异体移植的人的cDNA文库中分离到一个编码小鼠MMR2的人类同源物(氨基酸同源性为83.6%)的cDNA，并鉴定了人类单核细胞上可能的人类MMR2的配基。最近，我们还从一个人的cDNA文库中分离到了一个编码小鼠MMR1的人同源物的cDNA，并在单核细胞上鉴定了一个可能的人MMR2的配体。此外，为了了解这些MHC I类分子及其受体的生理意义，我们建立了D^d，K^d或D^d，K^d转基因小鼠或肿瘤细胞，并将转基因皮肤移植到C57BL/6小鼠的肿瘤细胞上。结果表明，转基因C57BL/6(D^BK^b)小鼠皮肤或肿瘤细胞对D^d、K^d或D^dk^d转基因小鼠皮肤或肿瘤细胞的排斥反应与转基因数量相关，与基因表达速率无关。使用MMR KO小鼠，最终我们将了解MMR的生理意义。另一方面，为了开发一种新型的药物来抑制MHC I类分子与其受体之间的相互作用，我们请蛋白质科学研究所公司鉴定了可能抑制这种相互作用的多肽序列，并请一家公司合成了这些多肽，并自行建立了MMR转基因细胞。H-2K^d五聚体与MMR2转基因EL-4细胞的结合实验及4种多肽对相互作用的影响正在研究中。同时，我们意识到MMR对MHC I类分子是非常特异的，而人类或小鼠可能对所有非自身MHC I类分子都有几十种MMR。因此，如果我们能够分离出8种人类白细胞抗原-A和9种人类白细胞抗原-B的DNA，如果我们能够开发一种新型的药物来抑制MMR与MHC-I类分子的相互作用，我们就有可能以一种量身定制的方式来调节同种异体移植排斥反应，而不会产生任何副作用。较少