Adoptive Immunotherapy for Multiple Myeloma Using Educated T Cells

自体干细胞移植治疗多发性骨髓瘤(MM)可有效减少细胞，但患者随后复发。一个有希望的研究领域是开发癌症疫苗，这种疫苗可以教育宿主免疫选择性地靶向和消除MM细胞，并可用于根除自体干细胞移植后的残留疾病。我们已经开发出一种癌症疫苗，在这种疫苗中，树突状细胞(DC)与自体肿瘤细胞融合，从而呈现多种肿瘤抗原，并能够引发广泛的抗肿瘤反应。在晚期多发性骨髓瘤患者的临床试验中，用自体DC/MM融合接种疫苗在大多数患者中诱导了抗肿瘤免疫，疾病稳定时间从10周到36个月不等。在对多发性骨髓瘤患者进行的一项正在进行的试验中，我们证明了在接受DC/肿瘤融合疫苗接种和干细胞移植的同时，骨髓瘤反应性T细胞显著扩张，并伴随着接种疫苗后移植后残留疾病的根除。为了克服限制疫苗反应的内在免疫抑制环境和调节性T细胞，我们正在开发将过继免疫疗法与MM反应性T细胞克隆相结合的策略。一种方法是在干细胞采集之前使用疫苗接种，这样受过教育的淋巴细胞在移植时被注入，并通过移植后接种在体内进一步扩大。或者，过继免疫治疗可以通过体外产生具有激活表型的MM特异性T细胞来进一步优化。我们发现，DC/MM融合疫苗在体外刺激后连接CD3/CD28导致激活的肿瘤反应性T细胞急剧扩张，同时最大限度地减少调节性T细胞的存在。我们的假设是，将移植介导的细胞减少和调节性T细胞去除与活化的肿瘤反应性淋巴细胞的输注相结合，并通过DC/MM融合加强疫苗接种，为优化MM的细胞免疫治疗提供了理想的平台。为了解决这一假设，我们的具体目标是：1)评估DC/MM联合接种和体内过继转移的毒性、细胞和体液抗肿瘤免疫以及临床反应。 目的：1)通过DC/MM融合和抗CD3/CD28体外连续刺激，优化骨髓瘤特异性T细胞的体外扩增策略；3)确定体外产生和扩增的骨髓瘤特异性T细胞与DC/MM融合免疫前后联合应用的毒性、免疫应答和临床效果。

Autologous stem cell transplantation for multiple myeloma (MM) results in effective cytoreduction but patients subsequently relapse. A promising area of investigation is the development of cancer vaccines that educate host immunity to selectively target and eliminate MM cells and can be used to eradicate residual disease following autologous stem cell transplantation. We have developed a cancer vaccine in which dendritic cells (DC) are fused to autologous tumor cells resulting in the presentation of multiple tumor antigens with the capacity to elicit a broad anti-tumor response. In a clinical trial of patients with advanced MM, vaccination with autologous DC/MM fusions induced anti-tumor immunity in a majority of patients, and disease stabilization ranging from 10 weeks to 36 months. In an ongoing trial of MM patients undergoing DC/tumor fusion vaccination in conjunction with stem cell transplantation, we have demonstrated a marked expansion of myeloma reactive T cells with the concomitant eradication of post-transplant residual disease following vaccination. To overcome the intrinsic immunosuppressive environment and regulatory T ceils that limit vaccine response, we are developing strategies to incorporate adoptive immunotherapy with MM reactive T cell clones. One approach is the use of vaccination prior to stem cell collection such that educated lymphocytes are infused at the time of transplant and further expanded in vivo by post-transplant vaccination. Alternatively, adoptive immunotherapy may be further optimized by ex-vivo generation of MM specific T cells with an activated phenotype. We have found that ligation of CD3/CD28 following ex vivo stimulation with DC/MM fusion vaccine results in the dramatic expansion of activated tumor reactive T cells while minimizing the presence of regulatory T cells. Our hypothesis is that combining transplant mediated cytoreduction and regulatory T cell depletion with the infusion of activated tumor reactive lymphocytes and boosting vaccination with DC/MM fusions offers the ideal platfomn for optimized cellular immunotherapy in MM. To address this hypothesis the Specific Aims are: 1) To evaluate toxicity, cellular and humoral antitumor immunity, and clinical response of a combined DC/MM vaccination and adoptive transfer of in vivo primed T cells; 2) To optimize strategies for the ex vivo expansion of myeloma specific T cells using sequential stimulation with DC/MM fusions and anti-CD3/CD28 ex vivo; and 3) To define the toxicity, immunologic response and clinical effect of ex vivo generated and expanded myeloma specific T cells administered in conjunction with pre and post-transplant vaccination with DC/MM fusions.