VH IG PEPTIDE VACCINES FOR HUMAN B CELL MALIGNANCIES

用于人类 B 细胞恶性肿瘤的 VH IG 肽疫苗

• 批准号: 6640684
• 负责人: RICHARD B BANKERT
• 金额: $ 37.23万
• 依托单位: STATE UNIVERSITY OF NEW YORK AT BUFFALO
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-04-01 至 2006-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6640684
• 关键词: B cell lymphoma; SCID mouse; clinical research; complementary DNA; dendritic cells; gene mutation; human subject; immunoglobulin genes; immunoglobulins; molecular cloning; neoplasm /cancer genetics; neoplasm /cancer vaccine; polymerase chain reaction; synthetic peptide; transfection; transfection /expression vector; tumor antigens; vaccine development

Human B-cell malignancies display on their surface, membrane-associated immunoglobulin (Ig). The variable regions at the amino terminal ends of both heavy and light chains (VH and VL) of Ig contain clonal specific epitopes that represent tumor specific antigens. The cloning and sequencing of VH cDNAs from tumor specimens of patients with B-cell lymphomas allow us to generate different synthetic peptides based upon these sequences. This will be exploited to test vaccination strategies in which patients' dendritic cells are pulsed with these peptides and their ability to induce tumor specific immunity will be examined. In Aim 1, peptides corresponding to hypervariable (CDR1-3) regions of B-cell lymphomas that have either germline or somatically mutated sequences are being tested. In Aim 2 peptides corresponding to the more conserved germline and somatically mutated framework VH regions are being tested for immunogenicity. In these first two vaccination strategies (Aims l and 2) we will use synthetic peptides of 11-30 amino acids to pulse DC's which would be expected to take up (by macropinocytosis), process and present small peptides in the context of MHC Class 1 and ll to autologous lymphocytes. In Aim 3, smaller synthetic peptides (9-mers) which are expected to bind directly to Class I on dendritic cells without processing, are selected from the entire tumor-associated VH region based upon optimal MHC Class I binding strengths that are predicted by peptide binding motifs specific for an HLA allele expressed by the patient. In Aim 4, patients' dendritic cells are transfected with mammalian expression vectors encoding either selected VH region peptides or the entire tumor associated VH region and the transfected dendritic cells tested for immunogenicity. In all 4 Aims, the vaccination strategies are evaluated for their ability to induce protective anti-tumor immunity using a human/SCID mouse chimeric model in which patients' peptide-pulsed or transfected dendritic cells, along with patients' lymphocytes, are engrafted in SCID mice and subsequently challenged with autologous tumor cells. Peptide pulsed or transfected D.C. are also evaluated in vitro for their ability to provoke tumor specific cytotoxic T lymphocytes. These results are expected to define immunogenic VH region peptides and to establish an optimal clinical strategy for the vaccination of patients with B cell malignancies. Valuable insights are also anticipated with respect to designing vaccination protocols for other tumors where a tumor specific antigen has been identified.

人类 B 细胞恶性肿瘤在其表面展示膜相关免疫球蛋白 (Ig)。 Ig 重链和轻链（VH 和 VL）氨基末端的可变区含有代表肿瘤特异性抗原的克隆特异性表位。对 B 细胞淋巴瘤患者肿瘤标本中的 VH cDNA 进行克隆和测序使我们能够根据这些序列生成不同的合成肽。这将用于测试疫苗接种策略，其中用这些肽脉冲患者的树突状细胞，并检查它们诱导肿瘤特异性免疫的能力。在目标 1 中，正在测试与具有种系或体细胞突变序列的 B 细胞淋巴瘤高变 (CDR1-3) 区域相对应的肽。在 Aim 2 中，正在测试对应于更保守的种系和体细胞突变框架 VH 区域的肽的免疫原性。在前两种疫苗接种策略（目标 1 和 2）中，我们将使用 11-30 个氨基酸的合成肽来脉冲 DC，预计 DC 会吸收（通过巨胞饮作用）、处理并在 MHC 1 类和 II 类背景下将小肽呈递给自体淋巴细胞。在目标 3 中，根据最佳 MHC I 类结合强度从整个肿瘤相关 VH 区中选择较小的合成肽（9 聚体），预计无需加工即可直接与树突状细胞上的 I 类结合，而最佳 MHC I 类结合强度是通过对患者表达的 HLA 等位基因具有特异性的肽结合基序预测的。在目标4中，用编码选定的VH区肽或整个肿瘤相关VH区的哺乳动物表达载体转染患者的树突细胞，并测试转染的树突细胞的免疫原性。在所有 4 个目标中，使用人/SCID 小鼠嵌合模型评估疫苗接种策略诱导保护性抗肿瘤免疫的能力，在该模型中，将患者的肽脉冲或转染的树突细胞以及患者的淋巴细胞移植到 SCID 小鼠中，然后用自体肿瘤细胞进行攻击。还在体外评估肽脉冲或转染的 DC 激发肿瘤特异性细胞毒性 T 淋巴细胞的能力。这些结果有望定义免疫原性 VH 区肽，并建立 B 细胞恶性肿瘤患者疫苗接种的最佳临床策略。对于已鉴定出肿瘤特异性抗原的其他肿瘤的疫苗接种方案的设计，也有望获得有价值的见解。