Definition: In this task, you're given a paragraph from the research paper and your task is to generate a suitable title for the research paper based on the given paper. Under 100 words is a good title length.
Input: A panel of 28 monoclonal antibodies (MAb) against the structural proteins of murine hepatitis virus-4, strain JHM (MHV-4) was used in three antigen binding assays to determine the extent of antigenic homology among six strains of murine coronaviruses. The antigenic determinants studied were highly conserved on the El glycoproteins and nucleocapsid (N) proteins of all strains tested. In contrast, antigenic polymorphism was observed among the E2 glycoproteins. Of three previously described antigenic determinants against which neutralizing antibodies are directed, only one, termed A(E2), was conserved on all strains. Antigenic site.B(E2) was found only on the strongly neurotropic MHV4 and site C(E2) was present on the virulent MHV4 and MHV-3 (hepatotropic) strains, but absent on the weakly pathogenic MHV-A59, MHV-1 and MHV-S strains. Four non-neutralizing antibodies against at least one topographically distinct antigenic determinant, which we previously designated D(E2), gave binding patterns consistent with two distinct sites. One of these was present on all MHV strains tested and the other was present on all strains except MHV-S. These non-neutralizing antigenic sites were redesignated E(E2) and D(E2) respectively. coronavirus, antigen, glycoprotein, monoclonal antibody, epitope, polymorphism

Antigenic variation among murine coronaviruses: Evidence for polymorphism on the peplomer glycoprotein, E2