Treatment of human peripheral blood leukocytes with proteases does not affect Sendai virus-induced interferon production.

Trypsinization of human peripheral blood leukocytes was found to have no effect on Sendai virus adsorption or on interferon induction by the virus. alpha-Chymotrypsin and papain also did not affect interferon induction, although the three proteases did remove part of the leukocyte surface material. In contrast, treatment of leukocytes with neuraminidase reduced virus adsorption and thoroughly abolished interferon induction. We conclude that protease-resistant structures on leukocyte surfaces serve as the receptor of Sendai virus for the induction of interferon.