Two monoclonal antibodies against La Crosse virus show host-dependent neutralizing activity

Mammalian and arthropod cell cultures were used to assess the neutralizing activity of six monoclonal antibodies specific for the G1 glycoprotein of La Crosse virus. Four antibodies, two neutralizing and two non-neutralizing, showed no host-dependent differences, giving similar results when post-treatment infectivity was determined using either Aedes albopictus cells or BHK-21 cells. For two other antibodies, however, dissimilar activities were observed between the vertebrate and invertebrate cell lines. One of these antibodies was positive when BHK-21 cells were employed as the post-treatment host and negative when mosquito cells were used; the other antibody was the converse. The epitope for this last antibody was present on all California serogroup viruses examined, which suggests that it may have a special significance in the natural life-cycle of the virus.