Human Practices

Where did we start?

This year, CU Boulder’s iGEM team decided to tackle the problem of hyperimmune attacks as a response to monoclonal antibody therapeutics by attempting to design an on/off switch for antibodies that can be implemented while the antibody is circulating in the blood of a patient.

We knew our track was therapeutics and wanted to execute a project where if it was successful, it would have a big impact on a major problem experienced clinically. We brainstormed up and coming clinical treatments because we knew that novel treatment options would probably still have less than optimal side effects which we could center our project around fixing.

Our Initial Project and Inspiration

After going through many options, we landed on MAb, or Monoclonal Antibody Therapy. This kind of treatment involves giving patients injections of curated antibodies that will specifically target one system or pathway in the body and have a certain effect. We decided to go with MAb therapy because it is currently working to help many patients across the country and across the world cope with various illnesses, including rheumatoid arthritis, cancer, and various autoimmune diseases.

We also liked the idea of focusing on MAb therapy because one of the side effects is an intense hyperimmune reaction where the body recognizes the antibody treatment as a foreign entity and attacks it, causing intense physiological symptoms leading to possible hospitalization and death. This was our decided purpose for our project: design a version of antibody therapy where a hyperimmune reaction can be averted if it arises.

When focusing on our human practice efforts in the lab, we realized the best authority figure to ask about the public good our project could do would be clinicians. Clinicians are educated in the molecular processes of how these treatments work, and they see the real-life results of patients who are recipients, when the results are amazing, and when they go terribly wrong.

Dr. Roxana Naderi

We got in contact with an internal medicine physician, Dr. Roxana Naderi; she works at the University of Colorado Teaching Hospital at Anschutz. She is a hospitalist, meaning that she sees patients who have become hospitalized due to acute illness.

We discussed our project inspiration and implementation with Dr. Naderi and first asked for her general feedback. She said she thinks there would definitely be a place in the clinical market for a product like ours. Based on the treatment opportunities of MAb therapy, she thinks that there is a need for a technology that would be able to turn an antibody on or off in the patient’s blood.

More specifically, we wanted to know from a clinical perspective how often hyperimmune attacks occur, and how bad they can get. From her perspective as a hospitalist, she only sees the cases where something goes wrong, but she said that from her estimates, MAb therapies are highly effective in a majority of cases. However, she did describe certain symptoms that she sees in her patients who come in suffering from the side effects on MAb therapy. Some symptoms included: colitis, rash, chemical pneumonitis (inflammation of lung tissue) autoimmune encephalitis, and neurologic issues.

All of this information confirmed our initial assumption that hyperimmune attacks were a prominent and relevant side effect for MAb therapy, and a solution for this treatment would be relevant in a clinical setting. However, she then mentioned some considerations which caused us to seriously rethink our goal for the project.

She explained that although she is not an expert in immunology or oncology, she believes there could be a chance that the hyperimmune attacks are simply due to the presence of the foreign antibody in the blood, not due to the antibody being active and binding antigen in the blood. This disrupted our whole project because the foundational assumption we made was that by deactivating the binding domain of the antibody, we could avert hyperimmune attacks.

She also discussed the fact that some MAb therapies are given as a cocktail of multiple different antibodies, and in this case, you would have no idea which antibody is causing the reaction, and therefore it would be hard to turn off the right antibody.

Given this additional information, we had to talk to an expert in MAb therapy to consult further about the actual molecular mechanisms of antibodies and hyperimmune attacks to get more information about the validity of our project.

Dr. Jose Mayordomo

We consulted Dr. Jose Mayordomo, who is specialized in hematology and immune-oncology. He is well versed in MAb therapies and has cared for many patients who have received these therapies, which means he has seen both the successful treatments and the adverse side effects. He sat down to discuss our project with us, and we told him both what our idea was, and the concerns we had from speaking with Dr. Naderi.

Regarding the question of whether or not deactivating the antibody would resolve a hyperimmune attack, Dr. Mayordomo indicated that it would depend on the kind of deactivation that was occurring. He explained that when MAb therapy was first invented, they used murine antibodies that were isolated from mice. This caused a high rate of rejection when injected into human patients because of course, the mouse antibody was detected as foreign and caused a hyperimmune attack. Since then, scientists have found a way to “humanize” antibodies by replacing most or all of the sequences with sequences from human antibodies, and this has drastically reduced the incidence of hyperimmune attacks in patients because it is less likely to recognize that protein as foreign. Based on this information, he inferred that in MAb therapies which are not fully humanized, the efficacy of our construct would be based on whether the conformational change hid the murine sequences in the antibody from being exposed to our own immune system.

Dr. Mayordomo also discussed that he saw other uses for our project that do not involve hyperimmune attack reduction. The main purpose he saw for our product was to truncate the functionality of antibodies in the blood after some set amount of time. For example, one MAb therapy treats rheumatoid arthritis by targeting B-cells and essentially inactivating them, thereby not allowing them to attack the body’s own tissue and joints. This also has the side effect of completely weakening the immune system, and those effects can take years and years to recover, so the patient would live in an immunodeficient state for up to years. This could be at least partially resolved if we could inject the patient with the antibody switch so that the therapy would be active until it has resolved the original illness, but could be turned off before it produced long-lasting side effects.

This would be most viable to implement in MAb therapies that target autoimmune disorders, and also MAb therapies that ramp up the body’s immune system (such as PD-L1 and PD-1 antibodies). In these cases, it would be extremely useful to have a way of pumping the brakes on the antibody therapy to avoid extreme side effects.

How did we Integrate Human Practices

We started off doing our project with the goal of applying it to hyperimmune attacks that happen while a patient receives an injection of MAb therapy. However, through our interactions with both Dr. Naderi and Dr. Mayordomo, we realized some of the problems with achieving that goal through our system, and what our system could actually help mitigate in clinical settings.

Dr. Naderi broadly indicated to us that there could be a problem with our assumption that deactivating an antibody would mitigate the immune response to the foreign protein. Dr. Mayordomo more specifically explained to us why our system would not surely mitigate a hyperimmune response, because this response is due to our own antibodies recognizing the murine sequences as foreign. Since our protein construct would not hide the murine sequences from the immune system, this would probably not be the best way to mitigate that type of reaction. Therefore, we shifted our purpose away from hyperimmune attack prevention.

We refocused our purpose again, based on the advice and consultation of both physicians we spoke to. Dr. Mayordomo especially suggested that our system would be particularly useful in preventing long-term adverse side effects from MAb therapy that either stunt or overstimulate the immune system.