Parkman Robertson
Division of Research Immunology/Bone Marrow Transplantation, Childrens Hospital Los Angeles, Los Angeles, CA 90027, USA.
Blood Cells Mol Dis. 2008 Jan-Feb;40(1):91-3. doi: 10.1016/j.bcmd.2007.06.024. Epub 2007 Sep 17.
Most studies evaluating immune reconstitution following hematopoietic stem cell transplantation (HSCT) have focused on immunophenotypic analysis and the capacity of the immune system to respond to mitogenic stimulation. However, protection against infectious pathogens and potentially anti-tumor responses correlate with the presence of antigen-specific immunity, not the immunophenotypic presence of T lymphocytes. Antigen-specific T lymphocytes present after HSCT can be derived from donor antigen-specific T lymphocytes present in the transplantation inoculum if it is not T cell depleted. Furthermore, the naive T lymphocytes contained in the HSCT inoculum have the potential to develop into antigen-specific T lymphocytes. If the transplantation inoculum is T cell depleted, then all antigen-specific T lymphocytes will have to be derived from the newly engrafted hematopoietic stem cells following their differentiation through the recipient thymus. Thus, defects in thymopoiesis will result in delays or the absence of naive T lymphocytes and ultimately defects in antigen-specific immunity.
大多数评估造血干细胞移植（HSCT）后免疫重建的研究都集中在免疫表型分析以及免疫系统对有丝分裂原刺激的反应能力上。然而，对感染性病原体的保护以及潜在的抗肿瘤反应与抗原特异性免疫的存在相关，而非T淋巴细胞的免疫表型存在。如果移植接种物未进行T细胞清除，HSCT后出现的抗原特异性T淋巴细胞可源自移植接种物中存在的供体抗原特异性T淋巴细胞。此外，HSCT接种物中所含的初始T淋巴细胞有发展成为抗原特异性T淋巴细胞的潜力。如果移植接种物进行了T细胞清除，那么所有抗原特异性T淋巴细胞都必须源自新植入的造血干细胞，这些干细胞在通过受体胸腺分化之后产生。因此，胸腺生成缺陷将导致初始T淋巴细胞延迟出现或缺失，并最终导致抗原特异性免疫缺陷。
