Lentivirus and Lentiviral Vectors


Download Lentivirus PDF


Characteristics

Morphology

Family: Retroviridae; Genus: Lentiviridae. The Lentiviridae genus includes the primate Human Immunodeficiency Virus (HIV) types 1-2 and the non-human primate Simian Immunodeficiency Virus (SIV). HIV-derived vectors are highly efficient vehicles for in vivo gene delivery. Lentiviruses are approx. 120nm in diameter, enveloped, and contain a nucleocapsid containing two copies of single-stranded positive-sense RNA. Cis and trans-acting factors of the lentivirus are on separate plasmids depending on the Viral Vector generation. Third generation systems are currently the safest to use because the virus production is split across four plasmids.

Growth Conditions

Packaging cells: 293T cells Lentiviral vectors infect dividing and non-dividing cells.


Health Hazards

Host Range

If the HIV envelop is replaced with VesiculoStomatitis Virus (VSV)-G then a broad host-range can be achieved.

Modes of Transmission

Direct exposure to infected bodily fluids, sexual contact, splash or percutaneous injection.

Signs and Symptoms

Fever, fatigue, weight loss, immunological and neurological disease. Insertional mutagenesis is the major risk after exposure to retroviral vectors.

Infectious Dose

Unknown.

Incubation Period

1-6 months


Medical Precautions/Treatment

Prophylaxis

Post exposure prophylaxis for occupational exposure with HIV-based viral vectors includes the use of anti-retroviral drugs.

Vaccines

None available.

Treatment

Anti-retroviral therapy when indicated.

Surveillance

Serological monitoring; Western blot test advised for confirmation.

Emory Requirements

Report all incidents. All work including retroviral vectors must be reviewed by the IBC.


Laboratory Hazards

Laboratory Acquired Infections (LAIs)

Six reported lab infections (splash or puncture wounds)

Sources

Direct contact with skin and mucous membranes, parenteral inoculation and ingestion.


Supplemental References

Canadian MSDS

Pathogen Safety Data Sheets

BMBL: 5th Edition

Biosafety in Microbiological and Biomedical Laboratories (BMBL)

NIH

Biosafety Considerations for Research with Lentiviral Vectors (PDF)


Containment

BSL-2/ABSL-2

Containment Level 2 facilities, equipment, and operational practices. No open-bench work should be performed with retroviral vectors. All work should be performed inside a Biosafety Cabinet. Use of needle-safe sharps is encouraged. Centrifuge rotors must have a lid, samples should be loaded/unloaded inside the BSC and the centrifuge should be decontaminated with appropriate disinfectant after use. If the vector is replication incompetent, animals infected with retroviral vectors will remain at ABSL-2 for 72h, then moved to ABSL1. If the vector is replication competent, animals will be housed at ABSL2 for the length of the experiment


Spill Procedures

Small

Notify others working in the lab. Allow aerosols to settle. Don appropriate PPE. Cover area of the spill with paper towels and apply an EPA registered disinfectant, working from the perimeter towards the center. Allow 30 minutes of contact time before disposal and cleanup of spill materials. Decontaminate before disposal: steam sterilization, incineration, chemical disinfection

Large

Contact Emory’s Biosafety Officer (404-727-8863),
the EHSO Office (404-727-5922), or
The Spill Response Team (404-727-2888).


Exposure Procedures

Mucous membrane

Flush eyes, mouth or nose for 15 minutes at eyewash station.

Other Exposures

Wash area with soap and water for 15 minutes.

Reporting

Immediately report incident to supervisor, complete an employee incident report in PeopleSoft.

Medical Followup 

7am-4pm (OIM): EUH (404-686-7941) EUHM (404-686-7106) WW (404-728-6431)

After Hours: OIM NP On Call 404-686-5500 PIC# 50464

Needle Stick (OIM): EUH (404-686-8587) EUHM (404-686-2352)

Yerkes: Maureen Thompson Office (404-727-8012) Cell (404-275-0963)


Viability

Disinfection

10% freshly prepared bleach solution or 70% ethanol.

Inactivation

Heat at 56˚C for 30+ minutes.

Survival Outside Host

90-99% reduction in several hours.


Personal Protective Equipment (PPE)

Minimum PPE Requirements

At minimum, personnel are required to don gloves, closed toed shoes, lab coat, and appropriate face and eye protection prior to working with Lentivirus. Additional PPE may be required depending on lab specific SOPs.

Additional Precautions

Use respiratory protection if work will be performed outside the biosafety cabinet. Additional precautions should be considered with work involving animals or large scale activities.