Amplification, Cloning And Sequence Analysis Of The Genes Of V_H And V_K Of An Anti-human CD3 Monoclonal Antibody

The vast Majority of monoclonal antibodies (mAbs) available today are rodent. Murine mAbs for human therapy is limited, especially when repeat administration in that they usually elicit an immune response in human as for immunogenicity to human. An obvious alternative would be produce human mAbs to reduce the immune response. However, there are considerable difficulties in the production of human mAbs by hybridoma technology. In the few cases where human hybridomas have produced they have usually proven to be unstable and to secrete Ig at low levels. Additionally, most of the human mAbs currently available are of IgM isotype, which limits their usefulness. Another alternative is to produce genetically engineered antibody molecules.The first step of production of genetically engineered antibody molecules is to isolate the variable region genes of the antibodies. Polymerase chain reaction (PCR) is a simple and rapid method to obtain these genes. Before PCR, a pair of primers should be designed and synthesized. This is of great importance especially when the sequences to be amplified have not been identified.CD3 molecules is present on the surfaces of all mature lymphocytes. Tightly associated with T cell antigen receptors, the CD3 molecules exist as form T cell antigen receptor complexes. When T cell receptors bind and recognize an antigen, the signals are transduced through CD3 molecules. There have been some reports demonstrating that anti-CD3 antibodies could activate T lymphocytes. Recently, bispecific antibodies (BIABs) composed of anti-CD3 and anti-tumor Ab were used to link cytotoxic T lymphocytes (CTL) with tumor cells, rendering the tumor cell more sensitive to attack by CTL. Engineered BIAB might be even more advantageous when used in human being.First, we identified conserved regions at each end of the nucleotide sequ-...