Safety is our number one priority. To us, this is not only a saying but a full commitment. We value biosafety and biosecurity, and we are dedicated to being responsible scientists. Therefore, we established an elaborate biosafety framework – which we partially turned into reality. Other parts remain theory and are yet to be implemented by future generations of iGEMers.
We hope that our biosafety concept provides a rationale that brings us one step closer to taking advantage of GMOs as therapeutic delivery machines by addressing concerns of policy makers, experts and the general public. To maximally guarantee patient safety, we developed a comprehensive, multi-level biosafety system. It builds on the use of probiotic GRAS lactobacilli with auxotrophies, their mechanical entrapment within a “biocage”, the introduction of an artificial metabolic burden and a theoretical tailored quorum-sensing based kill switch. Altogether these measures harbor the potential to ultimately prevent the propagation of the GMOs within the body and the environment.
Level 2 is the physical entrapment of the GMO. We used a biocompatible polymeric cage to create a mechanical barrier for our lactobacilli and largely prevent their spread in the human body and the environment. By fine-tuning the pore size of the cage, we aim to ensure the flow of small metabolites, therapeutic proteins or enzymes and prevent the escape of the expression host.
Level 3 is the introduction of a negative selection pressure. Safety goes beyond the expected, therefore we are also preparing the GMO for the eventuality of a break-free. The introduced therapeutic genes produce an artificial metabolic burden, which renders the Lactobacillus less fit than other microbes of the human gut microbiome. Thus, we maintain the balance in the human intestinal tract and prevent any overgrowth of the introduced species.
Level 4 is the establishment of a kill switch that we designed on a theoretical level and the genomic integration of our Friendzyme expression cassette. No foreign genetic material or GMO should be distributed and amplified in the human body or in the environment. We can make sure that no such event occurs by introducing a synthetic gene circuit. We conceptualized a kill switch which could be activated on 1. missing quorum sensing upon eventual Lactobacillus escape from the biocontainer in the intestine and 2. environmental conditions outside the intestine after excretion of the therapeutic construct, including atmospheric oxygen levels, decreased temperature and light exposure. The kill switch would activate the local expression of a nuclease that degrades plasmid and genomic DNA. This strategy combined with a permanent genomic integration prevents the spread of GMOs or host DNA including plasmids in the human colon and in the environment.
Our COVID safety concept
The uprise of SARS-CoV2 has changed the way we work, the way we interact and the way we hold our meetings as an iGEM team.
Throughout the year, we had very strict safety measures in order to guarantee the largest possible security for all of our team members as well as for their families and other people.
1. All meetings online (February-June)
During the time when vaccines were not yet available to everyone and the number of COVID-19 cases in Austria was still rather high, we kept all meetings online. Despite the wish to get to know each other and to start forming friendships, we agreed that meetings - especially in a group as large as ours - would be far too risky.
The first in-person meetings took place in mid-June when the majority of our members was vaccinated and the case numbers in Austria were very low.
2. Our lab safety concept
In order to ensure the safe progression of our lab work, we developed an elaborate safety concept that would ensure maximum protection of the individual team members, comply with university regulations and allow us to continue working even if a COVID-19 case should occur in our team.
Personal protection equipment
All people working in the lab were required to wear an FFP2 mask and, wherever possible, maintain a distance of 2 m while working. The masks were kindly provided to us by one of our sponsors, M&B Stricker, and distributed in an amount that every person could change them in the middle of the day.
Organization of the lab space
We were quite lucky to have a big laboratory available for our work. We assigned a workbench to each member, making sure that - depending on the number of people present at the same time on the respective day - the largest possible distance between the members could be maintained while working
Every person at the lab had to have a valid negative PCR test to be allowed to work. Since the majority of our team members was fully vaccinated by the time of the lab start, this allowed us to ensure a maximum of security for everyone.
According to Austrian regulation a PCR test is valid for 72 hours and in Vienna two free PCR tests per week were available for everyone. Since they could be dropped off at nearly every drug store, supermarket, and gas station in the city, this made it quite easy and convenient for every member of the lab team to keep their test status updated.
Throughout the whole summer, our lab team was working in shifts of 4-8 people, that switched every Thursday. This demanded thorough planning since individual availability and levels of lab experience needed to be considered.
For every shift, we appointed a shift leader who was responsible for coordination of the work during the shift and updating the leader of the other shift before the shift switch.
We came up with the two-shift-system for the case that one member tested positive. Even if everyone from their shift had to go into quarantine, the other shift would be able to step in and continue working without losing precious time.
Luckily, we did not have a single case in our team throughout the whole summer, but the most important thing is to be prepared!