Infectin

- A cutting-edge technology in virology research

InfectinTM is a viral infection enhancer designed to facilitate viral penetration of the cortical actin barrier, thereby greatly enhancing productive viral infection. Infectin can be used to facilitate the infection of a variety of host cells by different viruses and viral vectors. Infectin can enhance viral infection rates by 5 to 20 fold. Virongy developed Infectin based on the scientific theory that the actin cytoskeleton is a natural barrier for viral entry and post-entry intracellular migration (Yoder et al., Cell, 2008, 134:782).

 

 

Important

  • Once thawed, InfectinTM should be stored at 4oC, and is stable for 3 months.
  • Do not re-freeze and do not leave Infectin at room temperature.
  • Infectin viral infection enhancer works with most cell lines to enhance viral infection. On average, Infectin enhances productive viral infection by 5- to 30-fold*.
  • Infectin is formulated at 10X concentration. For best results, when using Infectin for the first time, start with a higher concentration (final Infectin concentration may be 2X or 3X). The lowest effective dosage can be determined through a titration experiment (final Infectin concentration may be as low as 1X).

(*The degree of enhancement is affected by the type of virus and cells. Enhancement is strongest for enveloped viruses entering cells via membrane fusion.)

 

Applications

  • Enhancing lenti- or retroviral transduction of target cells
  • Enhancing infection rates of other enveloped viruses
  • Facilitating recovery of infectious viruses from cell or tissue cultures
  • Facilitating anti-viral drug screening efficiency

 

 

Protocol

Example 1 - Infectin used to enhance lentiviral infection of suspension CEM-SS cells:

(See Table 2 for scale-up recommendations)

1. Count cells to be infected, and pellet cells by centrifugation at 300 x g for 5 minutes.

Note: Cell viability should be ≥ 80%.

2. Resuspend cells in complete media at a concentration of ~2 x 106 cells mL-1.
3. Use 100 μl of cells (~2 x 105) per infection.
4. Pre-treat cells by adding 10 μl of Infectin so that Infectin concentration is ~1X. Mix and incubate for 30–60 minutes.

For best results, when using Infectin for the first time, start with a higher concentration (final Infectin concentration may be 2X or 3X). The lowest effective dosage can be determined through a titration experiment (final Infectin concentration may be as low as 1X).

5. Add virus to the cells and mix. Note volume of virus used.
6. Add Infectin in an amount equal to 1/10 of the virus volume used, e.g., if 100 μl of virus is used, add 10 μl of Infectin. Incubate at 37°C for 2-4 hours.
7. Add 1 ml fresh complete media to wash cells. Pellet cells as above and remove supernatant. Optional: Repeat once for a total of 2 washes.
8. After washing, resuspend cells in 1 ml complete medium.
9. Culture infected cells as usual to quantify viral replication.

 

Example 2 - Infectin enhances lentiviral transduction of adherent HDFn cells:

1. Count HDFn (Human Dermal Fibroblast, neonatal) cells to be infected and seed ~5 x 105 cells per well into 6-well plates (2 ml per well).
2. Culture cells until cells stably adhere to the plates (4–12 hours).

Note: Cell viability should be ≥ 80%.

3. Before infection, wash cells with 2 ml medium, and leave 0.5 ml medium in each well.
4. Pre-treat cells by adding 50 μl of Infectin so that Infectin concentration is ~1X. Mix and incubate for 30–60 minutes.

For best results, when using Infectin for the first time, start with a higher concentration (final Infectin concentration may be 2X or 3X). The lowest effective dosage can be determined through a titration experiment (final Infectin concentration may be as low as 1X).

5. Add virus to cells and mix. Note volume of virus used.
6. Add Infectin in an amount equal to 1/10 of the virus volume used, e.g., if 100 μl of virus is used, add 10 μl of Infectin. Incubate at 37°C for 2–4 hours.
7. Add 2 ml fresh media to wash cells.
8. After washing, add 2 ml fresh complete medium.
9. Culture infected cells as usual.

 

Viral Enhancement Results:

InfectinTM enhances lentiviral transduction of Hep G2 cells:

    • Hep G2 cells were transduced with lenti-GFP vector in the presence or absence of Infectin

 

References

Yoder et al., Cell, 2008, 134:782

 

Infectin is intended for Research Use Only and is not for diagnostic or therapeutic purposes or uses in humans or animals.