Maintenance and targeting of bone marrow derived allo-reactive human plasma cells

摘要抗HLAI类和II类的供体特异性同种异体抗体(DSA)是一种主要的 器官移植中的问题。DSA可引起急性和慢性排斥反应，可能是 移植前存在的主要障碍是找到可接受的供者 病人“。不幸的是，目前还没有有效的治疗方法来耗尽DSA或阻断它们的作用。 我们先前的研究表明，骨髓来源的长寿命浆细胞(LLPC)是 持续血清DSA的主要来源。LLPC很少见，特征不佳，对 目前最新的体内治疗方法。抵抗治疗的机制可能是由于以下事实 LLPC驻留在支持基质细胞的有利于生存的微环境/利基环境中 而白细胞提供了延长LLPC寿命和防止昔日凋亡的因素 信号。由于获取、分离和培养人骨髓LLPC存在困难，许多 人类PC的生物学仍不清楚，这阻碍了有效的开发 治疗。为了克服这个问题，我们建立了一种体外PC/基质细胞共培养模型。 我们现在可以在小鼠骨髓间充质干细胞(SC)系上维持人类PC 重组人IL-6的存在。培养6周后，这些PC保留了典型的PC 表型和旺盛地分泌免疫球蛋白和免疫球蛋白。使用这一新颖的系统，我们现在准备 功能性骨髓来源PC的体外研究及影响其寿命的因素 和抗体的产生。

Abstract Donor-specific alloantibodies (DSA) against HLA Class I and Class II are a major problem in organ transplantation. DSA can cause acute and chronic rejection and can be a major barrier to finding an acceptable donor when present pre-transplant in “sensitized patients”. Unfortunately, no effective therapy exists to either deplete DSAs or block their effect. Our prior studies suggested that bone marrow (BM)-derived long-lived plasma cells (LLPCs) are a major source of persistent serum DSA. LLPCs are rare, poorly characterized and resistant to most current therapy in vivo. The mechanism of resistance to therapy may be due to the fact that LLPCs reside in pro-survival microenvironments/niches in which supporting stromal cells and leukocytes provide factors that enhance LLPCs longevity and prevent erstwhile apoptotic signals. Due to difficulties in procuring, isolating, and culturing human BM LLPCs, much of the biology of human PCs remains unclear and this has hindered the development of effective therapies. To overcome this problem, we developed an in vitro PC/stromal cell co-culture model. We now can maintain human PCs on mouse mesenchymal stromal cell (SC) lines in the presence of recombinant human IL-6. After 6 weeks culture, these PCs retain the typical PC phenotype and robustly secrete IgG and IgA Igs. Using this novel system, we now are poised to study functional BM-derived PCs in vitro and interrogate factors responsible for their longevity and antibody production.