CLONING OF IMMUNOGLOBULIN GENES

我们最近启动了一项计划， 确定特异性的抗体。 这种免疫球蛋白分子 这可能是理想的放射治疗和放射成像将 包括具有鼠可变区嵌合抗体， 人恒定区。 此外，我们计划生成同种型 特异性单克隆抗体基因转换变体。 我们将 还试图操纵抗体基因， 抗体分子的Fc片段的变化导致 生物效应器功能的期望变化。 我们的计划 还包括产生下调的抗体分子（Fab ′ 2， Fab和FV）。 这样的分子可用于抗原清除 没有补体激活。 在其他可取的变体中， 我们将尝试通过基因 操作将包括，a）具有改善的亲和力的抗体， 目标，B）具有改变的碳水化合物含量的分子，和c） 能特异性结合某些酶的抗体分子 或有毒物质。 为了实现我们的目标，我们最初将尝试克隆 轻链和重链基因信使的cDNA拷贝 杂交瘤合成抗肿瘤免疫球蛋白 相关抗原。 我们将描述这些克隆人的特征， 尝试通过将它们插入到 合适的载体并将构建体转染入骨髓瘤 细胞 随后，我们将尝试克隆重新排列的 基因组DNA片段，其编码以下重链和轻链基因： 杂交瘤

We have recently initiated a program to develop chimeric antibodies of defined specificity. Such immunoglobin molecules which could be ideal for radiotherapy and radioimaging will include chimeric antibodies with murine variable region and human constant region. Additionally, we plan to generate isotype switch variant of specific monoclonal antibody genes. We will also attempt to manipulate antibody genes that may lead to a change in Fc fragment of the antibody molecule resulting in a desirable change in the biological effector function. Our plans also include generation of pared down antibody molecules (Fab' 2, Fab and FV). Such molecules can be used for antigen clearance without complement activation. Among other desirable variants of antibody molecules that we will attempt to generate by gene manipulation will include, a) antibodies with improved affinity for the target, b) molecules with altered carbohydrate content, and c) antibody molecules that can specifically bind to certain enzymes or toxic substances. To attain our objectives we will initially attempt to clone the cDNA copies of messages for light and heavy chain genes of immunoglobulin synthesized by hybridomas against tumor associated antigens. We will characterize these clones and will attempt expression of the cDNA constructs by inserting them in appropriate vectors and transfecting the construct into myeloma cells. Subsequently, we will attempt to clone the rearranged genomic DNA segments encoding heavy and light chain genes of hybridomas.