New Chimeric Antigen Receptors for Treating Hematologic Malignancies

“新型嵌合抗原受体”项目由两部分组成。在这个项目的第一部分，我们试图鉴定具有不同抗原特异性的嵌合抗原受体(CAR)，而不是我们有丰富经验的抗CD19嵌合抗原受体。寻找具有新特异性的嵌合抗原受体的第一步是找到合适的靶点。我们对寻找多发性骨髓瘤或霍奇金淋巴瘤的抗原靶向感兴趣，这些靶点可以安全有效地被CARS靶向。在过去的一年里，我们花费了相当多的时间和资源来筛选正常人体组织中候选抗原的表达。这是开发新靶点的关键第一步，因为如果一个靶点在正常人体组织上表达，用表达嵌合抗原受体的T细胞靶向它可能会造成显著的毒性。我们用定量聚合酶链式反应和免疫组织化学方法对正常组织进行了筛选。我们已经确定了一种在正常组织中表达非常有限的抗原。这种抗原由多发性骨髓瘤细胞和一些霍奇金淋巴瘤细胞表达。我们已经构建了3个新的CAR基因，旨在针对这种抗原。我们很快就会在体外测试这些新车。“新嵌合抗原受体”项目的第二个方面是探索慢病毒载体在CARS中转导T细胞的应用。我们与理查德·摩根在NCI的外科部门进行了合作，并从摩根博士那里获得了名为pRRLSIN.cPPT.MSCV.coDMF5.oPRE的慢病毒载体。在去除载体中的coDMF5组分后，我们将多个CAR基因克隆到该慢病毒载体中。我们正在体外测试新的慢病毒CAR载体，希望为未来的临床试验开发新的CAR载体。

The "New Chimeric Antigen Receptors" project consists of 2 parts. In the first part of this project we are attemping to identify chimeric antigen receptors (CARs) with different antigen specificities than the anti-CD19 chimeric antigen receptors that we have extensive experience with. The first step to finding chimeric antigen receptors with new specificities is to find appropriate targets. We are interested in finding antigenic targets on multiple myeloma or hodgkins lymphoma that could be safely and effectively targeted by CARs. We have spent considerable time and resources in the past year screening normal human tissues for expression of candidate antigens. This is a critical first step in developing new targets because if a target is expressed on normal human tissues, targeting it with chimeric-antigen-receptor-expressing T cells could cause significant toxicity. We have been screening normal tissues by quantitative PCR and by immunohistochemistry. We have identified one antigen with very restricted expression on normal tissues. This antigen is expressed by multiple myeloma cells and some hodgkins lymphoma cells. We have constructed 3 new CAR genes that are designed to target this antigen. We will soon test these new CARs in vitro. The second aspect of the "New Chimeric Antigen Receptor" project is to explore the use of lentiviral vectors for transducing T cells with CARs. We have a collaboration with Richard Morgan in the Surgery Branch of the NCI and we have obtained a lentiviral vector called pRRLSIN.cPPT.MSCV.coDMF5.oPRE from Dr. Morgan. We have cloned multipe CAR genes into this lentiviral vector after removing the coDMF5 component from the vector. We are testing the new lentiviral CAR vectors in vitro in hopes of developing a new CAR vector for future clinical trials.