PROTEINASE-LIKE ACTIVITY IN THE CYTO-TOXIC FACTOR PRODUCED BY T-CELLS DURING DENGUE VIRUS-INFECTION

  • 1 May 1989
    • journal article
    • research article
    • Vol. 67  (1) , 32-37
Abstract
Dengue type 2 virus (DV)-induced cytotoxic factor (CF) or the virus-primed spleen cells capable of secreting CF were treated with various proteinase inhibitors and their activity was assayed. It was observed that the cytotoxic activity of CF was inhibited significantly, in a dose-dependent manner, by pretreatment with bovine pancreatic trypsin inhibitor (BPTI) and phenylmethylsulphonyl fluoride (PMSF), to a lesser extent by a soya-bean trypsin inhibitor (SVTI) and leupeptin and not at all by 1,10-phenanthroline (OP). Similar effects were observed by pretreatment of DV-primed spleen cells. Amidolytic activity of CF or its purified fractions was assayed using twelve chromogenic peptide substrates and all the substrates were hydrolysed to the varying extent. The amidolytic activity of CF was also inhibited by pretreatment with proteinase inhibitors. Thus, CF could be a proteinase with the distinction of having a broad spectrum of activity.