Abstract
Interferon has been a potential chemotherpeutic agent for the prevention of respiratory infection for the past 20 years. However, the only significant antiviral effect was reported to occur in volunteers treated with large doses of human leukocyte interferon administered before and after viral challenge.
This report describes damage to the cilialy system of mouse nasal epithelia resulting from the challenge of mouse adapted influenza A virus PR8 (PR8) and the sensitivity of mouse nasal epithelia to exogenously applied mouse brain interferon (MBIF). Organ culture of mouse nasal epithelia was used to measure responses.
The nasal epithelia taken from the C3H strain mouse (female, 6 wks old) were cultured in RPMI 1640 supplemented with 10% heat inactvated fetal calf serum and 10% chicken embryo extracts. The culture discs were incubated in a humidified atmosphere of 5% CO2 and 95% air at 37°C. The cilialy movement of the epithlia was quantitatively analyzed by an inverted binocular microscope (phase contrast).
Without any treatment, the cilialy movement was observed for longer than 2 wks and the residual cilialy rate was more than 50% on the 7th day. However, with PR8 challenge, the residual cilialy was almost 0% on the 7th day. And MBIF (100 Iu) or L-cell IF (100 Iu) added to the medium before PR8 challenge reduced the viral damage to the cilialy epithelium. (p<0.001). Such an antiviral effect was not observed after the pretreatment of heat-inactivated MBIF, mock MBIF or human leukocyte interferon. In summary, the nasal epithelial cells obtained antiviral resistance by IF treatment.
