Characterization of Epstein-Barr virus monoclonal antibodies as tools for diagnosing and prevention of EBV infection in transplant settings

项目摘要 使用免疫抑制药物来预防移植后的干细胞/器官排斥， 严重的副作用，包括增加机会性感染或病毒重新激活的风险，如 EB病毒（EBV）。EB病毒感染与许多移植后淋巴增生性淋巴结转移有关。 疾病（PTLD）和其他淋巴瘤。各种非标准化、非特异性的治疗方法被用来 治疗EBV+ PTLD病例，如减少免疫抑制或用抗B抗体治疗 细胞抗原CD 20。然而，这些治疗有相当大的局限性，如增加移植的风险， 抗宿主疾病或免疫系统减弱，由于不加选择地靶向B细胞，癌性或 健康.因此，迫切需要一种新的EBV特异性免疫疗法，中和EBV感染 并靶向EBV+细胞以治疗EBV相关的PTLD和其它淋巴瘤。EBV使用多个包膜 糖蛋白（gps）感染宿主细胞，包括主要的免疫显性gp 350和gH/gL复合物 分别促进进入B细胞和上皮细胞。我们对小鼠的临床前研究表明， 用gp 350和gH/gL疫苗免疫的小鼠血清比单独免疫的小鼠血清更好地预防EBV感染。 免疫原此外，抗gp 350（72 A1）和抗gH/gL（E1 D1）的mAb在体外阻断EBV感染。 B细胞和上皮细胞。此外，其他研究人员已经开发了药物和肽（例如，L2P4） 在体外和体内特异性靶向EBV+细胞。为了克服治疗艾滋病所面临的现有挑战， 针对EBV+ PTLDs和其他淋巴瘤，我们建议开发并联合收割机两种治疗方法：（1）抗- gp 350-gH/gL，抗EBV糖蛋白gp 350和gL/gH的人源化双特异性中和抗体 复合物，用作预防EBV感染的预防剂;和（2）抗-CD 19-P4，一种新的抗体， 由与P4肽缀合的抗-CD 19（B细胞抗原）抗体组成的肽缀合物（APC）， 治疗EBV+ PTLD和其它淋巴瘤的免疫抑制剂。在圆满完成 我们的长期目标是在临床前试验中测试双特异性nAb和APC的组合使用。 试验作为一种创新的免疫疗法，针对EBV相关的PTLD和淋巴瘤， 免疫功能低下的患者。

PROJECT SUMMARY The use of immunosuppressive drugs to prevent stem cell/organ rejection post-transplant imposes several serious side effects, including increased risk of opportunistic infections or reactivation of viruses such as Epstein-Barr virus (EBV). Infection with EBV is associated with numerous post-transplant lymphoproliferative diseases (PTLDs) and other lymphomas. A variety of non-standardized, non-specific treatments are used to treat EBV+ PTLD cases, such as reduction of immunosuppression or treatment with antibodies against the B cell antigen CD20. However, these treatments have considerable limitations, such as increased risk of graft- versus-host disease or weakened immune system, due to indiscriminate targeting of B cells, cancerous or healthy. Thus, there is an urgent need for a novel EBV-specific immunotherapy that neutralizes EBV infection and targets EBV+ cells to treat EBV-related PTLDs and other lymphomas. EBV uses multiple envelope glycoproteins (gps) to infect host cells, including the major immunodominant gp350 and the gH/gL complex that facilitate entry into B cells and epithelial cells, respectively. Our pre-clinical studies in mice showed that sera from mice immunized with both gp350 and gH/gL vaccines prevented EBV infection better than individual immunogens. Furthermore, mAbs against gp350 (72A1) and anti-gH/gL (E1D1) block in vitro EBV infection of both B cells and epithelial cells. In addition, other researchers have developed drugs and peptides (e.g., L2P4) that specifically target EBV+ cells in vitro and in vivo. To overcome the existing challenges facing treatment of EBV+ PTLDs and other lymphomas, we propose to develop and combine two lines of treatment: (1) anti- gp350-gH/gL, a humanized bispecific neutralizing antibody against EBV glycoproteins gp350 and gL/gH complex for use as a prophylactic agent to prevent EBV infection; and (2) anti-CD19–P4, a novel antibody- peptide conjugate (APC) comprised of anti-CD19 (B cell antigen) antibody conjugated to P4 peptide for use as an immunotherapeutic agent to treat EBV+ PTLDs and other lymphomas. Following the successful completion of this proposal, our long-term goal is to test combinatorial use of the bispecific nAb and APC in pre-clinical trials as an innovative immunotherapeutic treatment against EBV-associated PTLDs and lymphomas for immunocompromised patients.