RADIOACTIVE LABELING OF BLOOD CELLS AND THEIR PRODUCTS

这个项目的总体目标是改进收获方法 和放射性标记血液细胞成分，以研究动力学和 标记细胞的组织分布及其诊断意义 重新注入后的实用程序。到目前为止，最大的临床影响是 放射性标记白细胞的成像已被检测到病灶 标记的中性粒细胞感染和标记的肿瘤定位 淋巴细胞。然而，目前的方法存在严重的技术问题。 困难包括放射性从标记细胞中泄漏出来，以及 由于细胞核的自辐射分解而造成的细胞损伤。 我们将继续开发高比活度放射性标记 (氨基苯乙烯基)吡啶(ASP)膜作为染料的试剂 标记混合白细胞以显示炎症部位(131I、129I、 ~(111)In或~(99m)Tc)和体内放射敏感淋巴细胞的标记 跟踪研究(131I或111英寸)。我们已经准备并使用了 标记淋巴细胞和混合淋巴细胞的放射性碘膜染料 白细胞产量高。对后者的初步研究已经 在狗的炎症诱导部位表现出高度的定位。 由于放射性核素被限制在细胞膜上，标记的染料 对淋巴细胞的放射毒性比使用的放射性药物要小 目前。通过测量大鼠T细胞迁移模式的变化。 用剂量增加的放射性标记染料标记的淋巴细胞，我们将 确定与111In-oxine相比，放射性毒性是否降低。这个 外周血淋巴细胞功能与肿瘤侵袭能力的关系 用新染料标记的淋巴细胞(TIL)将定位于肿瘤 在Balb/c小鼠EMT6乳腺癌肉瘤中进行试验。这个 标记染料的辐射毒性降低应该允许更高剂量的 管理的活动，从而增加信息的内容 过继免疫治疗前的图像。 一种现在经典的负载荧光钙结合配体的方法 将适合于用99mTc络合物标记白细胞。 我们将合成几个同时含有二胺二硫化物的配体 (N2S2)可在细胞内水解的部分和基团。这个 这些新的中性99mTcvO(N2S2)配合物的总体亲脂性将 让它们扩散到白细胞中。然后细胞内酯酶就会 从而将络合物转化为新的带电99mTcV(N2S2)络合物 将极地复合体困在细胞内。白血球标记 新药物将在含有尿酸钠的麻醉动物身上进行测试 诱导痛风和大肠埃希菌。通过诊断成像技术诊断脓肿。 用这些试剂标记的白细胞应该能提供更好的图像 ~(99m)Tc-HMPAO标记~(99m)Tc的体内渗漏部位 白血球模糊了图像。 我们将检测粒细胞集落刺激因子(G-CSF)的作用。 脑脊液)对放射性标记白细胞在诱导部位摄取的影响 发炎。如果G-CSF增加中性粒细胞的摄取 炎症，该程序最终可能被用来检测 白细胞减少症患者的感染情况。

The overall goal of this project is to improve the methods of harvesting and radiolabeling blood cellular components, to study the kinetics and tissue distribution of the labeled cells, and to explore their diagnostic utility after reinjection. To date, the greatest clinical impact of imaging radiolabeled leukocytes has been the detection of foci of infection by labeled neutrophils, and in tumor localization by labeled lymphocytes. However, current methods suffer from serious technical difficulties including radioactivity leaking out of labeled cells, and cell damage from autoradiolysis of cell nuclei. We will continue the development of high specific activity radiolabeled (aminostyryl)pyridinium (ASP) membrane permeant dyes as agents with which to label mixed leukocytes for imaging sites of inflammation (131I, 129I, 111In, or 99mTc) and for labeling radiosensitive lymphocytes for in vivo tracking studies (131I or 111In). We have prepared and used radioiodinated membrane permeant dyes to label both lymphocytes and mixed leukocytes in high yield. Preliminary studies with the latter have demonstrated high localization in induced sites of inflammation in dogs. Since radionuclides are restricted to the cell membrane, labeled dyes will be less radiotoxic to lymphocytes than the radiopharmaceuticals used currently. By measuring changes in the migration pattern of rat T- lymphocytes labeled with increasing doses of radiolabeled dyes, we will determine the reduction in radiotoxicity compared to 111In-oxine. The ability of peripheral blood lymphocytes (PBLs) and tumor infiltrating lymphocytes (TILs) labeled with the new dyes to localize in tumors will be tested in EMT6 mammary carcinosarcoma tumors in Balb/c mice. The decreased radiotoxicity of the labeled dyes should allow higher doses of administered activity and thereby increase the information content of the images prior to adoptive immunotherapy. A now classic approach for loading fluorescent calcium-binding ligands into cells will be adapted for labeling leukocytes with 99mTc complexes. We will synthesize several ligands containing both a diaminedisulfide (N2S2) moiety and groups which can be hydrolyzed intracellularly. The overall lipophilicity of these new neutral 99mTcvO(N2S2) complexes will allow them to diffuse into leukocytes. Intracellular esterases will then convert the complex to a new charged 99mTcV(N2S2) complex thereby trapping the polar complex within the cell. Leukocytes labeled with the new agents will be tested in anesthetized animals bearing sodium urate induced gout and E coli. abscesses by diagnostic imaging techniques. Leukocytes labeled with these agents should provide improved images in regions of the body where leakage of 99mTc from 99mTc-HMPAO labeled leukocytes obscures the image. We will measure the effect of granulocyte colony-stimulating factor (G- CSF) on the uptake of radiolabeled leukocytes in induced sites of inflammation. If G-CSF increases neutrophil uptake in sites of inflammation, the procedure could ultimately be used to detect sites of infection in patients with leukopenia.