Intracellular antibodies (intrabodies) versus RNA interference for therapeutic applications.

Currently there are two technology platforms for the ablation of protein function: (a) RNAi-mediated gene-silencing at the post-transcriptional level, and (b) intrabody knockout of protein function at the post-translational level. Both approaches hold much promise for therapeutic applications. The pertinent question is how to choose between these alternative approaches. This commentary examines the advantages and disadvantages of these newly-emerging technology platforms. The RNAi approach is much less technically challenging than the intrabody-mediated knockout of protein function, but its major limitation is non-specificity. Although it is time-consuming and labor-intensive to generate intrabodies for specific intracellular protein targets, a much higher level of specificity can be attained. Ultimately, the choice between these strategies depend on the specific application in question, as well as on further technical advances in both technology platforms.