Team:UFMG Brazil/Safety

Project

Overview

Problem and
Solution

Chassis

Devices and
kill switch

Lab Work

Safety

Notebook

Protocols

Results

Modeling

Practices

Overview

Integrated Human
Practices

Public
Engagement

Synenergene

Overview

Application
Scenarios

Techno-moral

Team

Our Team

Attributions

Collaborations

Sponsors

Safety

The main issue related with safety is that the wild type of our chassis is pathogenic, responsible for causing leishmaniasis. However, we are using an attenuated Leishmania donovani strain, the L. donovani Cen1^-/-, which is deficient for the gene of Centrin-1 and was described by Selvapandiyan et al. (2004). Moreover, the virulence reduction of this Leishmania strain has been evaluated and confirmed with different animal models, such as mice (Selvapandiyan et al., 2006), hamsters (Selvapandiyan et al., 2009) and dogs (Fiuza et al., 2014). Besides, human macrophage infection by this strain has also been proved to be reduced in vitro (Selvapandiyan et al., 2004).

Our goal is to use this Leishmania chassis as an in situ drug delivery system to macrophages. Although they should be safe to human, environmental damage could still happen if these GMOs were to leak into the wilderness after a sandfly took a blood meal on an undergoing treatment patient. To prevent that, we designed a kill switch to eliminate promastigote modified Leishmania outside the lab. The execution of the project is of low risk to our team during lab phase. Besides the fact that the strain is attenuated, our lab is equipped with level 2 biosafety requirements, containing all the proper security equipments. Even if an accidental infection occurs, the medicine recommended for Leishmania infection, named Glucantime (Aventis), is also available in our lab and can cure leishmaniasis in 20 days.

We foresee some problems with using a parasite to treat inflammation-related diseases, such as that the host-parasite interaction could increase the inflammatory process in high responsive people, and also the possibility of the strain to reacquire virulence factors. On this last topic, however, the probability should be very low, since this attenuated strain has remained stable for several years. Another case would be if the modified Leishmania were lose the ability to express IFN-β, which would lead to treatment failure. To solve theses problems, exhaustive analysis of a model should be performed, stability analysis of IFN-β production should be tested in laboratory and high-quality control protocols for confirmation of non-pathogenicity potential should be developed and validated.

References

Selvapandiyan A, Debrabant A, Duncan R, Muller J, Salotra P, Sreenivas G, Salisbury JL, Nakhasi HL. Centrin gene disruption impairs stage-specific basal body duplication and cell cycle progression in Leishmania. J Biol Chem. 2004 Jun 11;279(24):25703-10.

Selvapandiyan A, Duncan R, Debrabant A, Lee N, Sreenivas G, Salotra P, Nakhasi HL. Genetically modified live attenuated parasites as vaccines for leishmaniasis. Indian J Med Res. 2006 Mar;123(3):455-66.

Selvapandiyan A, Dey R, Nylen S, Duncan R, Sacks D, Nakhasi HL. Intracellular replication-deficient Leishmania donovani induces long lasting protective immunity against visceral leishmaniasis. J Immunol. 2009 Aug 1;183(3):1813-20.

Fiuza JA, Gannavaram S, Santiago Hda C, Selvapandiyan A, Souza DM, Passos LS, de Mendonça LZ, Lemos-Giunchetti Dda S, Ricci ND, Bartholomeu DC, Giunchetti RC, Bueno LL, Correa-Oliveira R, Nakhasi HL, Fujiwara RT. Vaccination using live attenuated Leishmania donovani centrin deleted parasites induces protection in dogs against Leishmania infantum. Vaccine. 2015 Jan 3;33(2):280-8.