FIG 7.

Effect of prolonged low-pH exposure on HSV-1 infectivity and gB conformation. (A) Extracellular KOS virions were incubated for 10 min or 3 h at pH 7.4 or pH 5. Virions were neutralized for 10 min, and infectivity was determined by plaque assay on Vero cells. Infectivity of the sample treated with pH 7.4 was set to 100%. Data are the means from four replicates with standard errors. The P value was determined using Student's t test. (B) Virions were treated with pH 7.4 or 5.0 for 10 min or 3 h, and virions were neutralized for 10 min if reversibility was being tested, treated with 1% SDS, and analyzed as described for Fig. 5. Number at left is molecular mass in kilodaltons. (C) Virions were treated with pH 7.4 or 5.0 for 10 min or 3 h and then neutralized for 10 min if reversibility was being tested, and antigenic reactivity was determined as described for Fig. 6. Results are representative of three independent experiments.