ImmunoCellin : Antibody Intracellular Delivery Technology
“Antibodies are proteins that circulate in the blood, remaining outside the cells. In the case of cancers, though, over 90% of the deregulated targets that lead to the disease are inside the cells, Therapeutic antibody internalization offers huge potential by allowing to reach many new targets.”
Dr. Laurent Meunier, founder of BioCellChallenge
Without an appropriate transport mechanism, the antibodies are unable to cross the plasma membrane of living cells and reach their intracellular targets.
ImmunoCellin is a lipid based technology that allow antibodies to be delivered directly in the cytosol of a living cell. Antibodies are integrated within lipidic structures through hydrophobic and electrostatic interactions. No chemical coupling occurs guaranteeing that the antibody is not denatured. It is delivered directly in the cytosol with no endosome trapping. The antibody keeps its full activity and can reach the intracellular target.
Reproducible and universal
The delivery has shown efficiency with a number of adherent cell lines.
The antibody keeps its full activity
A fluorescent antibody recognizing the NFkb protein, factor of transcription localized in the cytosol, has been internalized with the technology ImmunoCellin.
A signal was inducted (with PMA) at the level of the plasmic membrane in order to relocate the protein from the cytosol towards the nucleus. The protein was well located in the nucleus showing that the antibody was not denatured by IC and keeps it full activity.
The antibody can fix its target
A fluorescent antibody directed against a nucleoporin (protein located on the nuclear envelope) was internalized with ImmunoCellin. An intracellular marking has been clearly observed on the nuclear envelope. The antibody is not hindered inside the cell, it remains functional and keeps its ability to fix its target
Internalization pathway : A direct delivery in the cytosol
In order to study the internalization,the complexe ImmunoCellin / Antiboby was compared with the transferrin, known for its endocytosis pathway.
An IgG , marked with green fluorescent labeling has been internalized with ImmunoCellin together with transferrin, labeling with red marker.
After 16 hours of incubation, we did not observe (colocalization) of the transferrin and the antibody internalized with IC . Both ways of internalization are different, what indicates that the endocytosis pathway of the antibody is not the one of the transferrin.
Biological activity of the internalized antibody in oncology
RAS, is an intracellular protein involved in the transduction of the signal. It comes to mute in numerous cancers occurring a constant and continuous cellular division.
An anti-RAS able to block this activity has been used and compared with an antibody control, able to recognize and fix the protein but devoided of RAS inhibitive activity.
The AC control had no effect and did not allow to inhibit the cellular proliferation. On the other hand, we clearly observed a reduction of the cellular proliferation on the tumoral cell lines 3T6 treated with the anti RAS IgG and internalized with ImmunoCellin.