CONICET | Buscador de Institutos y Recursos Humanos

As insect cells lack the capability to synthesize sterols, the lipid profile of plasma membrane in cultured insect cells is dependent on the culture medium composition. Cultures of the lepidopteran cell line UFL-AG-286 adapted to grow in a cholesterol-free culture medium are refractory to baculovirus infection. Moreover, infection kinetics appeared to be influenced by the type of sterol used to feed them. The aim of this work is to correlate the dynamical properties of the plasma membrane of UFL-AG-286 cells, with the incorporation of different sterols, and their response to baculovirus infection. Cells were treated with methyl-beta-cyclodextrin that reduced 80% of the cellular sterol content. Then, aliquots of treated cells were fed with either cholesterol or sitosterol emulsion, while other aliquot was not fed with sterols. The membrane fluidity in each group of cells was estimated through EPR measurements with spin labels, while the susceptibility to viral infection was determined following the kinetics of AgMNPV virus adsorption. The results indicate that fluidity was increased in sterol depleted cells, but similar values were found in the aliquots fed with sterol and in untreated cells. The cells fed with sitosterol showed a quick virus adsorption at short times, while those fed with cholesterol had a slower initial kinetics but resulted more efficient in the infection