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Delivery of Proteins, Peptides or Cell-impermeable Small Molecules into Live Cells by Incubation with the Endosomolytic Reagent dfTAT
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Intracellular delivery of antibodies using TAT fusion protein A

Masayasu Mie1, Fumio Takahashi, Hisakage Funabashi

  • 1Department of Biological Information, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Yokohama, Japan.

Biochemical and Biophysical Research Communications
|October 11, 2003
PubMed

Internalization of antibodies into mammalian cells is a useful method for analyzing and regulating cellular function. In this study, we developed a novel method for the delivery of antibodies into cells using the TAT-fused protein. This fusion protein consists of two functional domains, the protein transduction domain of HIV-1 TAT and the B domain of staphylococcal protein A (SpA), which has an ability to bind to the IgG. The TAT-SpA fusion protein was mixed with fluorescence-labeled rabbit IgG and added to cells. The internalization of antibody was analyzed using confocal microscopy and flow cytometry in living cells. As a result, fluorescence-labeled IgG with the TAT-SpA fusion protein was observed intracellularly. Flow cytometry results demonstrated time course and dose dependence relationships of antibody internalization. These results suggest that the TAT-SpA fusion protein can be a useful reagent for the delivery of antibody into cells.

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