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

项目总结 使用免疫抑制药物预防移植后的干细胞/器官排斥反应强加了几种 严重的副作用，包括机会性感染或病毒重新激活的风险增加，如 Epstein-Barr病毒(EBV)。EBV感染与移植后大量淋巴组织增生性疾病有关 疾病(PTLDS)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，如减少免疫抑制或使用B抗体治疗 细胞抗原CD20。然而，这些治疗方法有相当大的局限性，例如增加移植风险。 抗宿主疾病或免疫系统减弱，由于不分青红皂白地靶向B细胞、癌症或 健康。因此，迫切需要一种新的EBV特异性免疫疗法来中和EBV感染 并以EBV细胞为靶点治疗EBV相关的PTLDS和其他淋巴瘤。EBV使用多个信封 感染宿主细胞的糖蛋白(GP)，包括主要的免疫优势gp350和Gh/gl复合体 分别促进B细胞和上皮细胞的进入。我们在小鼠身上进行的临床前研究表明 同时免疫gp350和Gh/gl疫苗的小鼠血清对EBV感染的预防效果优于单独接种 免疫原。此外，抗gp350(72A1)和抗Gh/g1(E1D1)的单抗在体外可阻断EB病毒的感染。 包括B细胞和上皮细胞。此外，其他研究人员还开发了药物和多肽(例如，L2P4) 在体外和体内特异性靶向EBV细胞。克服现有的治疗面临的挑战 对于EBV PTLDS和其他淋巴瘤，我们建议开发和结合两种治疗方法：(1)抗- 人源化抗EBV糖蛋白gp350和gl/Gh双特异性中和抗体gp350-Gh/Gl 作为预防EBV感染的预防性药物；以及(2)抗CD19-P4，一种新的抗体-- 抗CD19(B细胞抗原)抗体与P4肽偶联的多肽结合物(APC) 一种治疗EBV PTLDS和其他淋巴瘤的免疫治疗剂。在成功完成后 在这项建议中，我们的长期目标是测试双特异性NAB和APC在临床前的联合使用 作为治疗EBV相关PTLDS和淋巴瘤的创新免疫治疗方法的试验 免疫功能受损的病人。

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.