Induced aggregation of culture cells by measles virus and its possible link to viral dissemination

Abstract

Measles Virus (MV) Enders and MV Edmonston-Zagreb (EZ) were grown in both U937 cells and PBLs to study their dissemination. The > presence of aggregation and formation of giant cells was observed in those cultures infected with MV EZ, while it was notably absent from cultures infected with the MV Enders. Believing this difference to be a possible link in the understanding of measles virus dissemination, further studies were conducted to test the idea that MV EZ may disseminate intracellularly, while MV Enders disseminates extracellularly. Gamma Gard was added to cultures to study its effects on the dissemination of the two viral strains. Results of this experiment indicated the spread of MV Enders can be completely inhibited by antibody to measles virus, while the spread of MV EZ cannot be. Also, the two vaccine strains were grown in PBLs to ensure that results of studies in U937s could be applied to the animal model. Differences (as compared to growth in U937s) resulted for MV Enders, but not MV EZ. Apparently, the MV Enders could not infect all cells in the cultures and was dying off. So, experiments were conducted whereby aggregation was artificially induced in PBLs infected with MV Enders to see if it could facilitate the dissemination of the virus to normal lymphocytes previously unavailable to infection. While the viral quantification plates were contaminated, the aggregation and giant cell assays showed that MV Enders may disseminated intracellularly if given the opportunity.