Survey of interferon production and sensitivity human cell lines.

Seven presumed diploid and 11 established cell lines were studied for their ability to produce free interferon in response to a standardized Newcastle disease virus challenge. Interferon production was evaluated in both serum-containing and serum-free medium. The ability of these cell lines to respond to the application of a standard interferon preparation by becoming resistant to virus was also examined. The diploid lines were distinctly more efficient producers of interferon than were the established lines. They also evidenced a greater requirement for serum to produce their maximum titers, but some were able to produce good titers in serum-free medium. The diploid lines were uniformly more sensitive to the application of exogenous interferon than were the established cell lines and attained greater degrees of virus resistance, but all lines tested displayed measurable sensitivity to interferon.