Mechanisms of Bunyavirus Virulence: A Genetic Approach.

The construction and characterization of hybridomas making monoclonal antibodies against La Crosse and Tahyna viruses is described. These antibodies have been characterized by the following tests 1 ELISA, 2 neutralization, 3 hemagglutination inhibition HI, 4 cross reactivity against California serogroup viruses, 5 immunoprecipitation of viral protein. These antibodies have been shown to be useful tools for the classification of new viral isolates and for the phenotyping of reassortant viruses. They have been used to select variant viruses, which can escape neutralization. The virulence of California serogroup viruses is being studied by genetic analysis. a Two parent viruses, have been selected to represent a virulent prototype La Crosse original and an avirulent prototype Tahyna 18157. b The pathogenesis of these two viruses has been studied by infections of suckling mice, and it has been found that the neuroinvasive virulent virus replicates well in striated muscle with subsequent viremia, while the avirulent virus does not. c Reassortants have been constructed from these two parents and partially phenotyped. d Variant viruses, selected with neutralizing monoclones, are under study for reduced virulence.