| Ovarian carcinoma is the leading cause of death from gynecological cancer. Although advances in treatment with cytoreductive surgery and chemotherapy have improved the survial rate in the last decade, in most patients,the disease is diagnosis at an advanced stage,survial is still poor,with a 5-yr survial rate of only 30%. thus requiring new therapeutic modalities.Since the advent of hybridoma technology, the potential of murine mAbs for therapeutic and diagnostic application in human cancers has been a focus of interest. However, the therapeutic use of monoclonal antibodies in human cancers has emt with limited success, because there are great demands on such applications of antibody fragments. For example, therapeutic antibody fragments require lower immunogenicity, exhibit more rapid blood clearance and better tumor penetration.The high demand for and the increasing number of applications of antibodies require more efficient methods for their high-level production and the availability of molecules with favorable properties for every antigen. As most of McAb are rodent antibodies with relatively large size, The major limitations of monoclonal antibody conjugates as therapeutic agents havebeen inadequate tumor penetration and immunogenicity. Furthermore, until recently, the production of antibodies was limited to very laborious and time-consuming processes involving animal immunization schemes and/or hybridoma generation. Thus single-chain Fv (scFv) fragments became a particularly popular antibody format. The size of these molecules is reduced to the antigen-binding part of the antibody, and they contain the variable domains of the heavy and light chain connected via a flexible linker. Compared to intact IgG or Fab fragments, their relatively small size and absence of Fc-effector domains may allow them to penetrate tumors more rapidly, exhibit more rapid blood clearance and lower immunogenicity and can readily be used to construct chimeric molecules containing drus or cytokines or bivalent and bispecific antibodies, In addition, Murine scFv can be also engineered for improving their performances in vivo in humans by modulating their affinity or by replacing murine by human frameworks and Most scFv fragments can be obtained easily from recombinant expression in Escherichia coll in sufficient amounts. ScFv therefore represent valuable molecules for the targeted delivery of drugs. Toxins or radionuclides to a tumor site and has great potential for the development of therapeutic or diagnostic reagents.One successful approach to recombinant antibody production has been developed ,This approach relies on a phage-display system in which fragments of antibodies are expressed as fusion proteins displayed on the phage surface. Since the displayed antibody retains its antigen-binding capability, it is thus possible to enrich for recombinant phage expressing specific antibodies by affinity selection. With this approach, antibodies of defined specificity and affinity can be selected from a population. Recombinant phage antibody technology has the power and versatility to mimic the features of immune diversity and selection. In time, it may even be possible to replace the current practices of animal immunization and hybridoma development with a bacterial system capable of synthesizing andexpressing virtually unlimited quantities of antibodies to practically any antigen. Phage antibody genes can be easily sequenced, mutated and screened to improve antigen binding. It is even possible to rearrange the genes which code for the various regions of an antibody molecule such that its specificity and affinity for an antigen are altered (3). The aim of the present study was to construct anti-ovarian cancer scFv genes library and obtaine ScFv fragments with binding activities to ovarian cancer antigen By recombinant phage antibody technique,which paves a way for the study of prevention and cure of ovarian cancer.Since epithelial ovarian carcinoma still remains the most lethal of gynecologic cancers, ovarian cancer cel...
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