FIG. 7.

CVB3/TD strains are neutralized by anti-CVB3 polyclonal serum and infect cells to produce viral proteins. (A) Cultures of 10⁵ HeLa cells were inoculated with 10³ TCID₅₀ units of CVB3/28 (lane 28), 10⁷ rTCID₅₀ TD8 (lane 8), 10⁴ rTCID₅₀ TD13 (lane 13), 10⁵ rTCID₅₀ TD18 (lane 18), 10⁵ rTCID₅₀ TD31 (lane 31), 10⁶ rTCID₅₀ TD50 (lane 50), or 0.1 ml of heart homogenate taken 18 days p.i. (lane AJ). Total RNA was prepared after 72 h for RT-PCRs with primers KS1 and KS2 (amplimer size, 390 bp). Lane M, 100-bp marker; lane +, CVB3/28 viral RNA RT-PCR; lane -, negative control RT-PCR; lane CC, uninfected cell control. The arrow indicates a 400-bp marker. (B) Same as in panel A, except CVB3 antiserum (1:500) was added to virus stocks in infections, washes, and medium. (C) Cultures of 10⁵ HeLa cells were inoculated with 10⁶ TCID₅₀ units of CVB3/28 (lane 28), 10⁷ rTCID₅₀ TD8 (lane 8), 10⁷ rTCID₅₀ TD50 (lane 50), or uninfected cell control (lane CC). Cells were harvested at 7 h, resuspended in Laemmli buffer, electrophoresed, and analyzed by Western blotting, and viral proteins were detected as described in Materials and Methods. Mobility of molecular weight markers of 150, 75, 50, and 37 is noted. (D) Same as in panel C, but cells were harvested at 26 h p.i.