Identification and production of monoclonal antibodies against a discriminating protein molecule between B and D variants of encephalomyocarditis virus

Abstract

The protein profiles of two EMC virus variants B and D in the infected L929 fibroblast lysates were examined using one- and two-dimensional gel electrophoresis. Both variants yielded a protein molecule of similar molecular weight but differing in its isoelectric point (pI). The B variant lysate yielded a molecule with pI ⋍ 7.5 whereas the same molecule from the D lysate focused at pI ⋍ 5.2 . A monoclonal antibody (MCA) produced against pI ⋍ 5.2 fraction of the D variant successfully detected viral antigens in the D variant infected fibroblasts with only background cross reactivity with the B variant infected cells. This MCA also detected D viral antigen(s) in organ sections obtained from D but not from B variant infected mice. This study therefore suggests a clear shift in the pI of a 23 kD protein molecule serving as a possible discriminating antigen between the B and D variants of EMC virus.