Tumor matrix remodeling in anti-myeloma immunity and immunotherapy

项目摘要/摘要 多发性骨髓瘤(MM)是第二种最常见的血癌，目前仍无法治愈。自体 干细胞移植(ASCT)仍然是符合条件的患者的主要治疗方法。尽管常规使用 新型药物作为ASCT后的“维持剂”延缓或防止复发，多数患者会在术后死亡 移植。有大量证据表明，免疫调节机制已经建立 在ASCT后，骨髓微环境有利于复发，是有吸引力的治疗靶点。 ASCT后复发依赖于产生耐受性IL10的髓系细胞(树突状细胞(DC)和巨噬细胞， 统称为TOL-DC)和IL17建议以细胞自主的方式作用于MM细胞。然而， 引发这些过程的上游信号或微环境触发因素尚不清楚。 Toll样受体(TLR)-2信号通路促进ToL-DC极化和Th17分化。我们 先前报道MM-辅助细胞分泌TLR2-配体基质蛋白多糖(VCAN)。 Vcan在癌症中促进tol-dc极化，因此，它构成了触发的首要怀疑因素。 MM中复发促进、TLR2依赖的过程。 在MM微环境中，尤其是在ASCT后，Vcan经历了ADAMTS介导的细胞外 蛋白分解释放N-末端片段，versikine。Versikine充当Matrikine(一种细胞外基质- 调节细胞活动的衍生片段，通常以不同于其母大分子的方式)。 Versikine是一个弱的IL6/IL10触发器，因此不太可能是一个有效的ToL-DC/Th17诱导剂。取而代之的是Versikine 刺激依赖IRF8的转录本，并在体外和体内促进依赖IRF8的BATF3-DC亚集。 我们假设Versikine-IRF8-BATF3-DC轴可能与强大的(或许是主导的) 动态串扰中的耐受性VCAN-TLR2通路。 我们制定了两个特定的目标来研究VCAN和versikine调节抗-HBs的机制。 ASCT后MM免疫：在目标1中，我们将剖析VCAN-TLR2信号在抗MM免疫中的作用并设计 基于靶向耐受性VCAN-TLR2信号的ASCT后治疗新策略。在目标2中，我们将 深入研究Matrikine、versikine在抗MM免疫中的作用。 我们的目标的成功将优化MM的治疗(维持)策略，以延长ASCT后的生存时间。这个 这里提出的实验是由我们最新一代的第一个RAS驱动的MM模型VQ推动的。RAS 途径是人类MM中最常见的突变途径。与目前最先进的MM模型相比， 在C57BL/6J受体中，VQ很容易通过慢病毒载体和植入进行转导(促进机制 活体研究)。这里提出的几项研究使用现有的MM是不可能的或不切实际的 模特们。

PROJECT SUMMARY/ ABSTRACT Multiple myeloma (MM) ranks as the second most common blood cancer and it remains incurable. Autologous stem cell transplantation (ASCT) remains a mainstay of therapy for eligible patients. Despite the routine use of novel agents as post-ASCT “maintenance” to delay or prevent relapse, most patients will succumb after transplant. There is considerable body of evidence to suggest that immunoregulatory mechanisms established in post-ASCT bone marrow (BM) microenvironment favor relapse and constitute attractive therapeutic targets. Post-ASCT relapses depend on tolerogenic IL10-producing myeloid cells (dendritic cells (DC) and macrophages, collectively referred to as tol-DC) and IL17 proposed to act on MM cells in a cell-autonomous manner. However, the upstream signals or microenvironmental triggers that elicit these processes are unclear. Tol-DC polarization and Th17 differentiation are promoted through Toll-like receptor (TLR)-2 signaling. We previously reported that MM-accessory cells secrete the TLR2-ligand matrix proteoglycan, versican (VCAN). VCAN promotes tol-DC polarization in carcinomas and therefore, it constitutes a prime suspect for triggering relapse-promoting, TLR2-dependent processes in MM. In the MM microenvironment, specifically post-ASCT, VCAN undergoes ADAMTS-mediated extracellular proteolysis to release an N-terminal fragment, versikine. Versikine acts as a matrikine (an extracellular matrix- derived fragment that regulates cell activity, often in a manner distinct from that of its parent macromolecule). Versikine is a weak IL6/IL10 trigger, therefore it is unlikely to be a potent tol-DC/Th17 inducer. Instead, versikine stimulates IRF8-dependent transcripts and promotes the IRF8-dependent Batf3-DC subset in vitro and in vivo. We hypothesize that the versikine-IRF8-Batf3-DC axis may engage the potent (and perhaps dominant) tolerogenic VCAN-TLR2 pathway in a dynamic crosstalk. We have delineated 2 specific Aims to investigate the mechanisms by which VCAN and versikine regulate anti- MM immunity post-ASCT: In Aim 1, we shall dissect VCAN-TLR2 signaling in anti-MM immunity and design novel post-ASCT treatment strategies based on targeting tolerogenic VCAN-TLR2 signaling. In Aim 2, we shall study in-depth the role of the matrikine, versikine, in anti-MM immunity. Success of our Aims will optimize MM treatment (maintenance) strategies to prolong post-ASCT survival. The experiments proposed here are facilitated by our recent generation of the first Ras-driven MM model, VQ. RAS pathway is the most commonly mutated pathway in human MM. In contrast to current state-of-art MM models, VQ is readily transducible by lentiviral vectors and engrafts in C57BL/6J recipients (facilitating mechanistic in vivo studies). Several of the studies proposed here have been impossible or impractical using existing MM models.