Clonal populations of foot-and-mouth disease virus have been serially passaged in cell culture to analyse variation in the absence of immune selection at different antigenic sites of the virus. Mutant frequencies at the RNA regions encoding two independent antigenic sites (sites C and D) were more than twentyfold lower than for antigenic site A (the G-H loop of VP1). Correspondingly, fixation of amino acid substitutions was very restricted in sites C and D. In spite of such a restriction, neutralization assays using fractionated anti-virus polyclonal antibodies has provided direct evidence of significant antigenic variation in the absence of immune selection at sites unrelated to site A. It is proposed that the degree of tolerance to acceptance of amino acid replacements may modulate the variation at different antigenic epitopes of the same virus.


Article metrics loading...

Loading full text...

Full text loading...


Most cited this month Most Cited RSS feed

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error