CHARACTERISTIC IN-VITRO EVOLUTION PATTERN OF FOOT-AND-MOUTH-DISEASE VIRUS A81 CASTELLANOS/ARG/87/

The in vitro evolution of Foot and mouth disease virus (FMDV) A/81/Cas tellanos/Arg/87 (A/Castellanos/87) was studied by partial biological a nd biochemical characterization of viral populations selected after 25 passages on secondary fetal bovine kidney cell monolayers. These pass ages were performed in the presence or absence of immune pressure exer ted in the form of antiviral polyclonal serum. While the viral populat ions passaged in the absence of immune pressure acquired characteristi cs such as antigenic heterogeneity, VP1 amino acid modification and pl aque size reduction, the populations selected after immune pressure al so presented both neutralizing resistance and attenuation for suckling mice. The comparison with other previously studied FMDV strains sugge sts that FMDV A/Castellanos/87 adopts a differential response to immun ological pressure and other selective forces. In addition, the sequenc ing analysis of viral selected populations shows a restriction in the number and type of amino acid replacements tolerated by FMDV capsid pr oteins. (C) 1997 Elsevier Science B.V.