Project Inspiration and Description

What are monoclonal antibodies and why do we care?

Monoclonal antibody (MAb) therapies are a new wave of pharmaceuticals that are becoming increasingly popular for treating illnesses such as rheumatoid arthritis, asthma, and even certain types of cancer. The process of making these antibodies involves injecting an antigen into an animal, extracting cells which produce the right antibody for that antigen, and fusing those cells with tumor cells so that they divide and replicate very quickly, producing a large amount of the target antibody. They are especially useful because they have specific loops at the tips which can bind antigens very tightly and specifically, reducing the risk that they would bind to some other antigen in the body and cause unintended consequences.

Are there risks associated with MAb therapy?

The administration of MAb’s has been shown to be associated with severe immunogenic side effects such as acute anaphylaxis, serum sickness, and generation of antibodies to combat the foreign entity. These side effects are extremely dangerous and can lead to many physiological symptoms, sometimes even death. In addition, antibodies have a very long half-life in the body, which can last up to months, so it is not easy to reverse side effects once they are experienced as it would be with other drugs that wash out of the system within days.

What is the solution and what inspired us?

We were inspired by this big problem with MAb treatments because there is currently no efficient way to mitigate these potentially deadly side effects other than to mediate the symptoms while waiting for the antibody to wash out of the system. We thought if there could be a way to wash antibodies out of the system faster, or turn them off completely, we could solve this problem. We agreed the best solution would bean antibody switch, in which we could use a small molecule to mediate whether an antibody is essentially “on” or “off” in the body. (insert gif from last year presentation here) Small molecules have a very short half-life in the body, ranging on the order of hours or days, so this would be a quick way to mediate whether the antibody is active in the body. With this solution, patients experiencing anaphylactic shock, or other deadly side effects from MAb treatment could take the small molecule orally, and this would mitigate their symptoms by stopping the reaction altogether quickly.

So what are we doing exactly?

We are engineering antibody based therapeutic with a small molecule that triggers a safety off-switch. Currently, antibody therapeutics have a slew of harmful side effects and can even lead to death as there is no way to shut them off once they are in the body. Our system would solve this immense problem by effectively turning off the antibodies that were intended to help a patient and stop any drastic side effects. Through using computer modeling and molecular biology techniques, we plan to make our designs a reality.

How are we designing our therapeutic?

The protein we engineered consists of two main domains. The first domain consists of the top two regions of an antibody which actually interact with and bind the antigen. We attached these to a protein system called AraC in which a homodimer interacts in one orientation without arabinose, and a different orientation with arabinose. When arabinose is not bound, the orientation of AraC will be such that the antibody domains will be together and functional. However, when arabinose binds the AraC homodimer, the orientation will twist, which will physically twist apart the two antibody domains, rendering it nonfunctional.

What's our plan?

During the course of the project, we plan to model the protein using computer software (PyMOL and PyRosetta), construct the DNA, assemble it via Golden Gate synthesis, and transform it into E. coli to produce the protein. After this, we will perform an assay with fluorescein in order to test the efficacy of our engineered system.