Engineered Protein Nanocarriers for Intracellular Antibody Delivery There is a long list of ?undruggable? targets, disease related protein-protein interactions inside cells that small molecule drugs cannot block. Antibodies, in particular, can be engineered to bind almost any protein and inhibit protein function but have not yet been used against these targets. This is primarily due to the significant, unmet challenge in delivering sufficient amounts of folded, functional antibodies inside cells. The goal of this proposal is to build an intracellular antibody carrier using protein self-assembly and assess the therapeutic activity of delivered antibodies. By utilizing a hexameric protein bundle (HEX) and generic antibody-binding peptides (SPABs), nanoscale complexes containing only protein can be formed with antibodies. Our hypothesis is that the HEX antibody nanocarrier will significantly increase intracellular antibody uptake compared to soluble antibodies, and will enable therapeutic antibody binding to cytosolic targets. Our preliminary data suggests that Hex-SPAB protein nanocarriers do deliver functional antibody into the cytosol and, therefore, could be broadly applicable to future intracellular antibody therapeutics.
Three aims have been set to meet the objective and test the hypothesis. (1) Fabricate and characterize the size, stability and antibody loading of HEX antibody nanocarriers. (2) Measure cellular uptake, cytosolic localization, and therapeutic function of model anti-cancer antibodies delivered by HEX nanocarriers. (3) Determine the therapeutic potential of HEX nanocarriers by adding anti-HER2 targeting antibodies to direct carriers to breast cancer cells, and evaluate the blood circulation time and immunogenicity of HEX nanocarriers in vivo. Two main outcomes are expected. First, an innovative protein nanocarrier will be created that facilitates cytosolic delivery of functional therapeutic antibodies. It will provide proof of concept for intracellular antibody therapeutics to inhibit proteins, including combinations with targeting antibodies. Second, this work will measure key properties necessary for translation, blood circulation time and immunogenicity. This will open the door for intracellular antibody engineering comparable to current extracellular antibodies that are successfully treating human disease.

Public Health Relevance

This research directly addresses human health by creating small protein structures that can deliver therapeutic antibodies inside cells. These antibodies could be new drugs for the many diseases that traditional small molecule drugs cannot treat. Though our proof of concept will target breast cancer, this antibody delivery strategy will be applicable to a wide range of antibodies and diseases.

Agency
National Institute of Health (NIH)
Institute
National Institute of Biomedical Imaging and Bioengineering (NIBIB)
Type
Exploratory/Developmental Grants (R21)
Project #
1R21EB022794-01A1
Application #
9387821
Study Section
Nanotechnology Study Section (NANO)
Program Officer
Rampulla, David
Project Start
2017-09-05
Project End
2019-06-30
Budget Start
2017-09-05
Budget End
2018-06-30
Support Year
1
Fiscal Year
2017
Total Cost
Indirect Cost
Name
Georgia Institute of Technology
Department
Engineering (All Types)
Type
Biomed Engr/Col Engr/Engr Sta
DUNS #
097394084
City
Atlanta
State
GA
Country
United States
Zip Code
30318