基于细胞的噬菌体抗体库筛选技术

肿瘤细胞表面抗原的表达量低，免疫原性弱，因抗原构象改变的原因，用传统的固定化抗原方法很难获得有价值的噬菌体抗体。这类抗原大多具有复杂的结构，且其转运、定位与细胞类型及所处的微环境有关。在基于细胞的筛选中，靶抗原以天然状态存在，不需纯化，甚至可以对未知抗原进行筛选，因此广泛用于对内化抗体和血管内皮抗原表位抗体的筛选。基于细胞的抗体筛选中的主要问题是因非特异结合造成的选择背景过高，迄今，已有许多旨在改善选择灵敏度和特异性的研究开展起来。随高通量流式细胞术、组合化学及蛋白质组学研究技术在细胞筛选中的运用，必将使其日趋实用和成熟。我们拟以细胞和组织筛选的技术做一概括，为了解基于细胞的筛选和优化设计提供参考。

Cell-based Screening of Phage Antibody Library

The limited number and low immunogenicity of tumor antigen make it difficult to screen out valuable phage antibody by panning on purified immobilized antigen because of the alternation of protein conformation. Most of these antigens have complex structure and the transporting and localization are depended on the cell types and microenvironment. Cell panning is applicable to complex antigen in its natural state without an additional purification procedure, or the exact antigen is not even known. So it is widely used in selection of tumor specific antibody, especially internalizing antibody and antibody specific targeting to vascular endothelial antigen. The major problem encountered in cell panning is related to the high background binding of non-specific antibody. Many efforts had been made to improve the specificity and sensitivity of cell panning. The combination of high throughout flow cytometry, combinatorial chemistry and proteome research will make this strategy more practical and fruitful. Here we outlined the progress of panning on intact cells and tissue sections to provide beneficial reference for understand and design of cell based panning.