Briscoe D M, Dharnidharka V R, Isaacs C, Downing G, Prosky S, Shaw P, Parenteau N L, Hardin-Young J
Department of Medicine, Children's Hospital, and Harvard Medical School, Boston, Massachusetts 02115, USA.
Transplantation. 1999 Jun 27;67(12):1590-9. doi: 10.1097/00007890-199906270-00014.
Engineered tissues have been proposed for the treatment of a variety of conditions including the partial or complete replacement of human organs. To determine the basis for the rejection of these tissues, we analyzed the immune response to allogeneic human skin equivalent (HSE, also called Apligraf) in the humanized SCID mouse (hu-PBL-SCID).
Two models of hu-PBL-SCID were used for these studies. In one model, human skin or HSE was transplanted onto humanized mice so that graft survival could be analyzed. In the other model, skin grafts were allowed to heal on naive mice before humanization. This model was used to analyze the immunologic response to the vascularized skin allograft. Humanization was performed by adoptive transfer of human PBL into SCID mice by i.p. injection.
Both human foreskin and HSE successfully engrafted onto naive SCID mice and remained stable for more than 6 months. In contrast, human foreskin was rejected by 21 days posttransplant in hu-PBL-SCID, whereas HSE consistently engrafted for more than 28 days. Treatment of HSE grafts with interferon-y for 5 days to induce maximal MHC class II molecule expression before grafting failed to induce rejection. HSE also engrafted onto hu-PBL-SCID mice that were exposed to alloantigen by prior injection with interferon-gamma-treated keratinocytes identical to those used to generate the HSE. In addition, we determined that humanization of SCID mice following engraftment and vascularization of human foreskin resulted in marked CD3+ T cell infiltrates and a lymphocyte-induced vasculitis. In contrast, the response in vascularized HSE was associated with minimal CD3+ T cell infiltration in the absence of vasculitis or morphological features of rejection.
These results support the use of HSE and other allogeneic engineered tissues in humans provided that such tissues are limited in their antigen presenting capabilities. In addition, our findings suggest a critical function for the donor endothelial cell in rejection.
工程组织已被提议用于治疗多种病症，包括部分或完全替代人体器官。为了确定这些组织被排斥的基础，我们分析了人源化SCID小鼠（hu-PBL-SCID）对同种异体人皮肤替代物（HSE，也称为Apligraf）的免疫反应。
两种hu-PBL-SCID模型用于这些研究。在一种模型中，将人皮肤或HSE移植到人性化小鼠上，以便分析移植物存活情况。在另一种模型中，皮肤移植物在人源化之前先在未处理的小鼠上愈合。该模型用于分析对血管化皮肤同种异体移植物的免疫反应。通过腹腔注射将人外周血淋巴细胞过继转移到SCID小鼠中来实现人源化。
人包皮和HSE均成功移植到未处理的SCID小鼠上，并在6个月以上保持稳定。相比之下，人包皮在hu-PBL-SCID中移植后21天被排斥，而HSE始终能成功移植超过28天。在移植前用干扰素-γ处理HSE移植物5天以诱导最大程度的MHC II类分子表达，未能诱导排斥反应。HSE也能移植到通过预先注射与用于生成HSE的角质形成细胞相同的经干扰素-γ处理的角质形成细胞而接触过同种异体抗原的hu-PBL-SCID小鼠上。此外，我们确定在人包皮植入和血管化后对SCID小鼠进行人源化会导致明显的CD3 + T细胞浸润和淋巴细胞诱导的血管炎。相比之下，血管化HSE中的反应与最小程度的CD3 + T细胞浸润相关，不存在血管炎或排斥的形态学特征。
这些结果支持在人体中使用HSE和其他同种异体工程组织，前提是这些组织的抗原呈递能力有限。此外，我们的研究结果表明供体内皮细胞在排斥反应中起关键作用。
