Nanotechnology Targeting Novel CD154:CD11b Interactions for Transplant Tolerance

摘要/摘要 已知阻断CD40-CD154相互作用是一种高效抑制同种异体反应性T细胞的方法 诱导小鼠和非人移植耐受的反应及某些条件下的反应 灵长类模型。然而，这一治疗策略的潜力对 移植的结果还没有实现。CD154阻滞剂与不良反应相关 早期临床试验中的高凝状态，促使CD40作为替代疗法的治疗靶点。 然而，由于疗效不足，CD40阻滞剂在最近的临床试验中失败了。因此，我们试图 确定阻断CD40的观察到的劣势是否有生物学解释 到阻断CD154，以便随后设计出克服它的方法。在2020年的一项研究中，我们报告了CD11b是 同种异体免疫过程中CD154的第二个受体，通过它的信号被抗CD154阻断 但不是抗CD40试剂。我们证明了CD154：CD11b相互作用在局部发挥作用 同种异体移植可增强供者反应性CD8 T细胞的浸润，加速同种异体移植排斥反应。此外，新的 初步数据显示，CD154而不是CD40阻断会导致移植物特异性Foxp3的产生 ITreg，提示CD154：CD11b阻断的增加可能会促进iTreg在 抗CD40抗体。在这项提案中，我们将把这些发现转化为NHP同种异体肾移植模型，以 阐明CD154：CD11b阻断在移植耐受中的作用，并测试一种新的纳米治疗方法 更好地靶向CD154：CD11b相互作用并与抗CD40协同促进移植的策略 体内耐受性。在第一个目的中，我们将阐明CD154：CD11b阻断的机制 有助于抑制同种异体免疫和诱导Foxp3 Treg，使用新技术识别 并追踪NHP中的同种异体反应效应和调节性T细胞，并将使用MIBI-TOF和转录 研究阻断CD154：CD11b相互作用对免疫结构和免疫功能影响的方法 同种异体移植物中T细胞、树突状细胞和巨噬细胞/单核细胞的转录图谱。在第二个目标中，我们有 开发了一种新的纳米颗粒，该纳米颗粒包裹着一种特定的多肽抑制物，可以阻止CD154：CD11b 有约束力的。利用尖端的纳米技术来阻止这种相互作用，而不是单抗，提供了 通过单独的免疫调节剂对纳米颗粒进行生物工程的能力的明显优势 “有效载荷”，进一步发扬包容。鉴于CD154阻断已被证明有能力诱导长期， 在NHP中持久耐受，我们的总体假设是结合新的CD154：CD11b阻断 含有抗CD40的纳米粒将导致移植耐受的建立。

Abstract/ Summary Blockade of CD40-CD154 interactions is known to be a highly effective means of inhibiting alloreactive T cell responses and under some conditions inducing transplantation tolerance in both murine and non-human primate models. However, the potential of this therapeutic strategy to have a transformative impact on transplantation outcomes has yet to be realized. CD154 blockers were associated with adverse hypercoagulability in early clinical trials, instigating the therapeutic targeting of CD40 as an alternative therapy. However, CD40 blockers have failed in recent clinical trials due to insufficient efficacy. We therefore sought to determine if there is a biological explanation underlying the observed inferiority of blocking CD40 as compared to blocking CD154, in order to then devise ways to overcome it. In a 2020 study, we reported that CD11b is a second receptor for CD154 during alloimmunity, signaling through which is blocked by anti-CD154 reagents but not anti-CD40 reagents. We showed that CD154:CD11b interactions function locally within the allograft to enhance donor-reactive CD8+ T cell infiltration and accelerate allograft rejection. In addition, new preliminary data show that CD154 but not CD40 blockade results in the generation of graft-specific Foxp3+ iTreg, suggesting that the addition of CD154:CD11b blockade may boost iTreg generation in the context of anti-CD40. In this proposal, we will translate these findings into an NHP allogeneic renal transplant model to elucidate the role of CD154:CD11b blockade in transplantation tolerance, and to test a novel nanotherapeutic strategy to better target CD154:CD11b interactions and synergize with anti-CD40 in promoting transplantation tolerance in vivo. In the first Aim, we will elucidate the mechanisms by which CD154:CD11b blockade contributes to the inhibition of alloimmunity and the induction of Foxp3+ Treg, using novel techniques to identify and track alloreactive effector and regulatory T cells in NHP, and will use MIBI-TOF and transcriptomic approaches to interrogate the effects of blocking CD154:CD11b interactions on the immune architecture and transcriptomic profile of T cells, DC, and macrophage/monocytes within allografts. In the second Aim, we have developed a novel nanoparticle that is coated with a specific peptide inhibitor that prevents CD154:CD11b binding. Utilizing cutting edge nanotechnology to block this interaction, instead of a monoclonal antibody, offers the distinct advantage of the ability to bioengineer the nanoparticle with a separate immunomodulatory “payload” to further promote tolerance. Given the demonstrated ability of CD154 blockade to induce long-term, durable tolerance in NHP, our overall hypothesis is that combining the novel CD154:CD11b blocking nanoparticle with anti-CD40 will result in the establishment of transplantation tolerance.