Safety

Jiangnan iGEM team is devoted to construct an original cell line feasible for the rapid production of a broad spectrum of vaccines. We strictly follow the safe regulations in the project design, lab work and shipment. Please see details as below.

Safe project design

(1) For materials

We use three cell lines, i.e., MDBK(NBL-1), BHK-21, CHO, and two viruses, i.e., IBRV, CDV in our project. We have submitted the check-in form for each one of them and got the permission from HQ in using them in our experiment. All of these aforementioned organisms are only used for scientific research purposes, and Jiangnan team has strict specifications to ensure that they do not affect the environment and society.

Cell lines
1) MDBK cells were used as our chassis cells. Through genomic modification, we enabled this cell line with three features, i.e., broad spectrum, high titer and suspension.
2) CHO and BHK cells were used to explore genes responsible for the suspension feature of cells. High throughput sequencing was applied to the suspension and non-suspension cells of these lines to determine genes differentially expressed between suspended and non-suspended cells. These genes were used in the network construction, where the top one was selected for in vitro experimental validation.

Virus
1) IBRV was used to construct the "High Titer" feature of the chassis cells. We used the ‘infection of IBRV on MDBK cells’ as the infection model to measure changes in titer after genetic modulation and/or plasma treatment, as MDBK is a natural host of IBRV. For efficient test of virus titer, we developed a method that can easily and fast test the titer of DNA viruses including IBRV.
2) CDV was used to construct the "Broad Spectrum" feature of the chassis cells. We expressed Nectin 4 and TfR on MDBK cells, and tested whether the sensitivity spectrum of MDBK cells could be expanded using CDV which does not naturally infect MDBK. We may use CPV and other viruses in the future to more comprehensively test the ‘Broad Spectrum’ feature of the established cell line which, however, is not part of this competition due to time restriction.

(2) For potential risk

Following the advice from The Safety and Security Committee of iGEM, we contacted Fangzhong Wang from the Center for Biosafety Research and Strategy at Tianjin University. Through a series of correspondences, Prof. Wang kindly suggested us to reinforce the safety training on students who conduct the experiments which we have strictly followed. Prof. Wang also warranted us on the potential misuse and nefarious use, which we think are rather low with the following reasons:
1) The misuse risk is low:
The misuse risk is low because we didn't modify the virus but the chassis cell. The receptors selected for modulation to create effective infection are determined by the receptors already existed on the chassis cell, and differ among cell lines. Thus, modifying the chassis cells does not extensively expand the infection spectrum of a given virus.
2) The nefarious use risk is low:
The nefarious use risk is low because the current technology we used for chassis cell modulation cannot be directly transferred to another cell line, as new technological issues, such as functional expression of the receptor will arise which cannot be solved by the established the current technology.

Also important is that the benefits of this project significantly outweigh the potential risks.
Our project offers a solution that can considerably reduce the cost of vaccine production. Despite the high demand on vaccine, there is a lack of cell lines suitable for rapid virus production with reduced cost and independent intellectual property. Specifically, the stocks and slaughter of major livestocks such as pigs, cattle and sheep have maintained a steady growth rate of 5-10%, but the productivity level of domestic vaccines is difficult to meet the increasing supply demand in China, especially in the supply of high-quality and low-cost vaccines. Our project can effectively solve or release such problems. Take IBRV vaccine as an example, our modified chassis cells can triple IBRV titer, i.e., reducing the production cost by three times. Thus, compared with the enormous industrial benefits, the potential risks are negligible.

Safe lab work

Before conducting wet lab experiments, each team member has received the strict safety training given by our PI, lab technician and the university biosafety office. During these trainings, lab rules, staff responsible for biosafety issues, biosafety equipment and rules were comprehensively covered. Through these trainings, we are more acquainted with the experimental procedures, operation approaches on these equipments, and all safety issues and solutions.

Safe shipment