New substances: risk assessment summary 22153, 22154 and 22155

Overview

Notified organisms:

• A genetically modified Drosophila melanogaster strain with a single insert of a construct containing a gene expressing human erythropoietin and a marker gene balanced over a chromosome balancer (NSN 22153, hereafter referred to as strain 15)
• A genetically modified Drosophila melanogaster strain with a single insert of a construct containing a gene expressing human interleukin-12 and a marker gene balanced over a chromosome balancer (NSN 22154, hereafter referred to as strain 16)
• A genetically modified Drosophila melanogaster strain with a single insert of a construct containing a gene expressing human transforming growth factor-beta3 and a marker gene balanced over a chromosome balancer (NSN 22155, hereafter referred to as strain 17)

Schedule of the New Substances Notification Regulations (Organisms) [NSNR(Organisms)]: Schedule 5 - Information Required in Respect of Organisms Other than Micro-organisms

Organism type: Insect

Use: Fruit flies modified to produce recombinant human erythropoietin (EPO), human interleukin (IL)-12 and human transforming growth factor (TGF)-beta3

Anticipated quantity: confidential and not for disclosure

Assessment level of concern:

• Human health hazard: Low
• Human exposure: Low
• Environmental hazard: Low
• Environmental exposure: Low

Assessment conclusion under section 64 of the Canadian Environmental Protection Act, 1999 (CEPA): Low risk, not suspected to be toxic

Category: Eligible for addition to the Domestic Substances List

Recommended action: None

Waiver: Requested for information on data from a test conducted to determine its pathogenicity, toxicity or invasiveness (paragraph 5(a) of Schedule 5 of the NSNR(Organisms)) under paragraph 106(8)(a) of CEPA

Synopsis

D. melanogaster strains 15, 16 and 17 are genetically modified fruit flies that were notified for use in the production of recombinant human EPO, IL-12 and TGF-beta3 proteins which will be used for research and development only.

A waiver requested for information element 5(a) of Schedule 5 of the NSNR(Organisms) for the data from a test to determine the pathogenicity, toxicity, or invasiveness of the notified strain was granted. Information is gathered from such tests to determine whether the living organisms are toxic or capable of becoming toxic is not necessary. D. melanogaster is a well characterized species that has a long history of safe use in research and laboratory settings. Given the long history of safe use of the parental strain, the lack of any identified toxin or virulence genes in the notified organisms and their specific genetic modifications, the notified D. melanogaster strains are not expected to have adverse effects towards invertebrate, vertebrate or plant species.

Based on the evaluation of information submitted by the notifier and information from literature reviews, the risk assessment concluded that the hazard potential and the exposure potential to human health and the environment from the manufacture of the notified organism is low.

The ecological and human health portions of this assessment have undergone written peer review. Comments were received on the technical portions of this assessment and were taken into consideration when the evaluation was written. The final content and outcome of this assessment remain the responsibility of Health Canada and Environment and Climate Change Canada.

Background information

D. melanogaster strains 15, 16 and 17 are genetically modified common fruit flies to be used to produce human EPO, IL-12 and TGF-beta3. Strains 15, 16 and 17 are derived from a commercially available laboratory strain of D. melanogaster and will be manufactured by Future Fields under controlled conditions in a single contained facility in Edmonton, Alberta. The produced recombinant proteins will be used for research and development purposes only.

Hazard assessment

The environmental and human hazard potential of D. melanogaster strains 15, 16 and 17 is determined to be low because:

• as a species, D. melanogaster has an extensive history of safe use in research and development
  • D. melanogaster is not known to have adverse effects on other species present in the natural environment nor is it known to be a vector of disease
  • there are several genetically modified strains of D. melanogaster that are on the DSL with no reports of adverse effects in any non-human species
• D. melanogaster strains 15, 16 and 17 are derived from a commonly used inbred laboratory strain
  • the parental strain is not known to be associated with any health hazards to humans
  • although a gene marker partially rescues some of the drawbacks associated with the parental strain (retinal degeneration and male copulation success), it may not be enough to offset the genetic disadvantages this line exhibits due to inbreeding depression, including progressive loss of mobility, reduced reproductive fitness, as well as impaired resistance to various forms of stress
  • therefore, the notified strains are not expected to propagate effectively in the natural environment in the event of accidental release
• D. melanogaster strains 15, 16 and 17 express human EPO, IL-12 and TGF-beta3 proteins, respectively
  • the inserted genetic material (transgene, promoters and terminators used to control gene expression, antibiotic resistance gene marker) do not code for toxins and are not associated with any adverse effects in humans
  • the expressed recombinant proteins are not expected to be toxic or allergenic as they are not structurally similar to any known allergens or toxins
  • the inserted genetic material and the expressed proteins are not known to have pathogenic or toxic adverse effects on other species in the natural environment
• while wild D. melanogaster has been reported to harbour opportunistic human pathogens, there are no reported cases of zoonotic infections attributed to the species
• the notified strains retain the antibiotic resistance gene for ampicillin, which is inserted into a chromosome that doesn’t contain genetic elements known to facilitate the horizontal transfer of a transgene
• in the unlikely event of its release from the facility, no adverse human health effects are expected

Hazards related to micro-organisms used in the workplace should be classified accordingly under the Workplace Hazardous Materials Information System (WHMIS)^{Footnote 1}  .

Exposure assessment

The environmental and indirect human exposure potential of D. melanogaster strains 15, 16 and 17 is determined to be low because:

• D. melanogaster strains 15, 16 and 17 are intended for use as living insect bioreactors in a contained facility and are not expected to be released into the environment
  • there are no other foreseeable potential uses for the notified organisms other than the production of the protein for use in specific commercial products to be sold for use in research and development
• the main source of human exposure to the notified strains is expected from the manufacture in a plant pest containment level 1 facility located in Edmonton, Alberta
• the facility design and standard operating procedures (SOPs) used by Future Fields ensure containment of all life stages of the notified line of D. melanogaster
  • strains 15, 16 and 17 are not expected to be released into the environment
  • containment measures in place are expected to prevent releases of adult flies, and larvae will be harvested and euthanized to extract the proteins from the notified strains
  • the general population is therefore not expected to be exposed to live strain 15, 16 or 17 flies
  • any escape and release incidents will be documented and reviewed by the notifier, and protocols will be revised to prevent re-occurrence
• the genetic mutations of the parent strain and modifications to the notified organisms result in poor stress responses, less effective reproductive behaviour, and impacted locomotion
  • in the unlikely event of escape to the environment, the notified organisms and their genes are unlikely to propagate within wild type D. melanogaster populations
• proteins are harvested only from the larval life stage, which are flightless and have limited mobility
  • all larvae will be euthanized before extracting the proteins of interest
  • adult flies represent 1-2% of the total population and are used only for line maintenance and propagation
• in the unlikely event of an inadvertent release of adult flies of strain 15, 16 or 17, human-controlled environments could provide warm refuges during cooler weather and aid the survival of potential escapees
  • it is noted that wild type fruit flies already live in close association with humans and, thus the general population are routinely exposed to the species without reported cases of adverse effects
  • the notified strains expressing the human proteins are not expected to cause any adverse effects to human health

Risk characterization

Owing to the low potential hazard and the low potential exposure, the environmental risk associated with the manufacture and use of D. melanogaster strains 15, 16 and 17 to produce human EPO, IL-12 and TGF-beta3, respectively, is determined to be low.

Owing to the low potential hazard and the low potential exposure the human health risk associated with the manufacture and use of D. melanogaster strains 15, 16 and 17 to produce human EPO, IL-12 and TGF-beta3, respectively, is determined to be low.

Risk assessment conclusion

There is no evidence to suggest a potential risk of adverse environmental effects at the exposure levels predicted to the environment from the production D. melanogaster strains 15, 16 and 17 and human EPO, IL-12 and TGF-beta3. The risk to the environment associated with D. melanogaster strains 15, 16 and 17 are not suspected to meet criteria in paragraphs 64(a) or (b) of CEPA. No further action is recommended.

Similarly, there is no evidence to suggest a risk of adverse human health effects at the exposure levels predicted to the general population in Canada from the production of human EPO, IL-12 and TGF-beta3. This risk to human health associated with D. melanogaster strains 15, 16 and 17 are not suspected to meet criteria in paragraph 64(c) of CEPA. No further action is recommended.