Monoclonal antibodies as tools to target cell functions

Monoclonal antibody (mAb) technology has enabled the creation of mAb of unique specificities and potential large scale production, allowing the study of cell functions. To achieve this goal mAb can be used either as agonists or as inhibitors of a certain biological activity. In the present report we focus on the utilization of mAb technology in basic sciences in particular in the study of cell functions within intracellular compartments. Antibodies can indeed be used to dissect intracellular processes, but the limiting step for this kind of studies is the delivery of mAb to the intracellular compartment without affecting either cell viability or functionality. To overcome this problem several solutions have been explored using either the biological properties of the cells or artificial means. As described hereafter, several successful examples can be scored but all the strategies have drawbacks. Liposome mediated antibody transfer, electroporation and microinjection efficiently deliver mAb intracellularly, but do not target specific subcellular compartments. Recombinant DNA technology instead has provided means to overcome these limitations. This technique allows an intracellular expression of the antibody which can be inducible and limited to particular cell compartments. Furthermore, if high efficiency transduction with a stable vector into stem cells can be achieved, gene transfer mediated "intracellular immunization" might be a feasible treatment strategy in pathology.