FIG 2.

Cathepsin L and B expression and activity in HeLa and Vero cells. (A) Cathepsin L mRNA from mock-treated or rgRSV-infected HeLa and Vero cells was reverse transcribed and amplified by reverse transcription-PCR (RT-PCR), and the specific 294-bp product was displayed by agarose gel electrophoresis. (B) Immunoblot detection of cathepsin L protein species in mock- or rgRSV-infected cell lysates. (C and D) Enzymatic activity of cathepsin L (C) and cathepsin B (D) in lysates. (A and B) Data are representative of those from three independent experiments. (C and D) Data from four independent experiments were combined. *, P < 0.05 (unpaired, 2-tailed t test, unequal variance); **, P < 10⁻⁷ (unpaired, 2-tailed t test, unequal variance).