Immunomodulation of cucumber mosaic virus infection by intrabodies selected in vitro from a stable single-framework phage display library.

Immunomodulation by the ectopic expression of intracellular antibodies ('intrabodies') has a great potential for interfering with physiological or pathological functions in vivo in a highly specific manner. One of the major obstacles of this technology is the inability of most antibodies to properly fold and function in the reducing environment of the cytoplasm, which prevents the formation of essential disulfide bonds. We wished to assess the intracellular performance of antibodies derived from a semi-synthetic single-chain variable fragment (scFv) phage display library ('F8 library') built on a thermodynamically stable single-framework scaffold.