Immunology of CLL I--Active immunotherapy & autologous stem cell transplantation

该建议的中心假设是存在白血病相关抗原，可以诱导宿主抗白血病免疫，从而导致白血病细胞清除。此外，我们假设，由于白血病细胞的表型，这种白血病特异性T细胞存在于一种能量状态，从而排除了有效的免疫介导的白血病克隆清除。最后，我们假设改变这种表型的方法，或者诱导对白血病相关抗原的免疫，将为这种疾病的患者提供新的有效的治疗策略。为了检验这一点，我们有以下具体目标：(1)评估使用已被：(A)基因修饰以表达重组CD40-配体（CD154）的自体白血病细胞进行免疫治疗的潜力；或(B)通过体外cd40结扎诱导表达免疫共刺激分子；(2)通过克隆和表达白血病特异性Ig，确定专业抗原提呈细胞（APCs）在体外和体内提呈B-CLL Ig特异性抗原诱导抗B-CLL特异性免疫的能力；(B)从B- cll特异性Ig重排中鉴定推定的肽序列；(C)含有B-CLL特异性Ig和Ig肽的脉冲APCs；(D)尝试使用专业APCs脉冲B-CLL特异性Ig和Ig肽产生Ig特异性细胞毒性T细胞（CTL）；(3)体外检测血液T细胞、T细胞亚群、抗白血病CTL细胞系、CD4+ T细胞或CD4+ T细胞亚群通过CD3/CD28结扎扩增的表达的T细胞受体V β谱；(4)进行自体干细胞移植（SCT），以解决对临床结果的影响：(A)清除；(B)高剂量清髓治疗；(5)确定常规治疗和自体SCT后治疗微小残留疾病的可行性、安全性和有效性：(A)表达重组CD154的转基因CLL细胞；(B)体外经CDE40活化的CLL细胞；或(C)用B-CLL特异性Ig和/或肽脉冲的专业APC。通过这些研究，我们将验证CLL患者可以对其白血病细胞产生细胞免疫识别的假设，这可能对治疗这种疾病有效。

The central hypothesis of this proposal is that there exist leukemia- associated antigens that can induce host anti-leukemia immunity resulting in leukemia-cell clearance. Furthermore, we hypothesize that because of the leukemia cell phenotype, such leukemia-specific T cells exist in a state o f anergy, thereby precluding effective immune-mediated clearance of the leukemic clone. Finally, we hypothesize that methods that alter this phenotype, or that induce immunity against leukemia-associated antigens, will provide novel and effective therapeutic strategies for patients with this disease. To examine this, we have the following specific aims: (1) Evaluate the potential for immunotherapy using autologous leukemia cells that have been: (A) genetically-modified to express recombinant CD40- ligand (CD154); or (B) induced to express immune co-stimulatory molecules through CD40-ligation ex vivo; (2) Determine the capacity of professional antigen presenting cells (APCs) to present B-CLL Ig specific antigens to induce anti-B-CLL specific immunity in vitro and in vivo by: (A) cloning and expressing the leukemia specific Ig; (B) identifying the putative peptide sequences from the B-CLL specific Ig rearrangements; (C) pulsing APCs with B-CLL specific Ig and Ig peptides; and (D) attempting to generate Ig specific cytotoxic T cells (CTL) using professional APCs pulsed with B-CLL specific Ig and Ig peptides; (3) examine the expressed T cell receptor V beta repertoires of blood T cells, T cell subsets, anti-leukemia CTL cell lines, and CD4+ T cells, or CD4+ T cell subsets expanded via CD3/CD28 ligation in vitro; (4) Undertake autologous stem cell transplantation (SCT) to address the impact on clinical outcome of : (A) purging; or (B) high dose myeloablative therapy; and (5) Determine the feasibility, safety, and efficacy of treating minimal residual disease following conventional therapy and autologous SCT using: (A) genetically modified CLL cells to express recombinant CD154; (B) CLL cells activated via CDE40 ex vivo; or (C) professional APC pulsed with B-CLL specific Ig and/or peptides. Through these studies we will test the hypothesis that patients with CLL can develop cellular immune recognition of their leukemia cells that potentially may be effective in the treatment of this disease.