The mechanisms by which RNA arboviruses, including chikungunya virus (CHIKV), evolve and maintain the ability to infect vertebrate and invertebrate hosts are poorly understood. To understand how host specificity shapes arbovirus populations, we studied CHIKV populations passaged alternately between invertebrate and vertebrate cells (invertebrate ↔ vertebrate) to simulate natural alternation and...

Cell culture Cell culture techniques have been described previously. C1 hiPSCs and the hESC lines WIBR#3 were maintained on mitomycin C inactivated mouse embryonic fibroblast (MEF) feeder layers in hESC medium [DMEM/F12 (Invitrogen) supplemented with 15% fetal bovine serum (FBS) (Hyclone), 5% KnockOutTM Serum Replacement (Invitrogen), 1 mM glutamine (Invitrogen), 1% nonessential amino acids (In...

Malaria parasites vary in virulence, but the effects of mosquito transmission on virulence phenotypes have not been systematically analysed. Using six lines of malaria parasite that varied widely in virulence, three of which had been serially blood-stage passaged many times, we found that mosquito transmission led to a general reduction in malaria virulence. Despite that, the between-line varia...

Enzymes used for passaging human pluripotent stem cells (hPSCs) digest cell surface proteins, resulting in cell damage. Moreover, cell dissociation using divalent cation-free solutions causes apoptosis. Here we report that Mg(2+) and Ca(2+) control cell-fibronectin and cell-cell binding of hPSCs, respectively, under feeder- and serum-free culture conditions without enzyme. The hPSCs were detach...

Human ectocervical explant cultures were grown in medium with D-valine substituted for L-valine. Pure epithelial cell monolayers were obtained with both dialyzed and undialyzed fetal calf serum. Epithelial cell explant colonies grown in D-valine medium supplemented with undialyzed serum could routinely be subcultured if plated at a density of 1.5 x 10(4) cells/sq cm or higher. Such cultures cou...

Vaccination is an efficient approach to preventing influenza virus infections. Recently, we developed A and B vaccine backbones that increased the yield of several viruses in Madin–Darby canine kidney (MDCK) African green monkey (Vero) cells. These also viral replication embryonated chicken eggs, which are most frequently used platform for manufacturing. In this study, further increase titers i...