Timing effects on the inhibition of apoptosis by Toxoplasma gondii infection (MPF6P.655)

Abstract

Abstract Toxoplasma gondii inhibits apoptosis in infected cells. This inhibition requires ongoing protein synthesis. Toxoplasma gondii is a protozoan that exists as an obligate intracellular parasite. Inhibiting apoptosis in infected cells may help preserve the parasite from damage by cytotoxic T lymphocytes during the immune response. Many inducers of apoptosis, such as cytokine withdrawal, have a long lag time and others, such as CTL killing, are cumbersome, so for this study, we focused on apoptosis induced by beauvericin and measured by nuclear morphology of cells observation in a UV microscope. Beauvericin is a toxin produced by certain fungi that is capable of inducing programmed cell death when cells are exposed. To determine the longevity of the inhibitory effect by Toxoplasma, we used cycloheximide to inhibit protein production after infection of the cells and monitored the loss of inhibition over time. We also evaluated how quickly after infection inhibition of apoptosis can be observed. We also share our observation of an in vitro artifact we inadvertently discovered: that mycoplasma infection interferes with infection of some cells by Toxoplasmam, resulting in a reduction in the inhibition of apoptosis.