Histoenzymatic activities of three KB cell lines latently infected by Myxovirus parainfluenzae, type 3, strain EA-102. I. Aminopeptidase activity

Abstract

Three lines of KB cells (KBEA 1, KBEA 2, and KBEA 3) latently infected by Myxovirus parainfluenzae, type 3, were tested in situ for their leucine aminopeptidase activity (AP). A difference in the activity of this enzyme was demonstrated between the 3 KBEA cell lines and the KB uninfected cell line. Evidence is presented that this activity is related to viral infection. KB cells display a particularly strong AP activity 1 hour after having been infected by the myxovirus. The AP test was found to be reliable in detecting M. parainfluenzae infection in these cells, and other possible applications of the technique are discussed. Also discussed is the role of aminopeptidase activity in the biology of the Paramyxoviruses.