Toxoplasma gondii: effect of infection on expression of 14-3-3 proteins in human epithelial cells.

14-3-3 Proteins are expressed in most eukaryotes organisms and play varied and crucial roles in a wide range of regulatory processes. In mammalian cells, seven 14-3-3 isoforms have been identified. However, it is not known what effect infection has on 14-3-3 isoform expression. In this study human colonic carcinoma cell lines were infected with Toxoplasma gondii for 24h and expression of 14-3-3 proteins was determined by RT-PCR. HT-29 cells only expressed 3 out of the 7 isoforms while 5 and all 7 isoforms were found in HCT-116 and Caco-2 cells, respectively. Infection had little or no effect in the expression of 14-3-3gamma, epsilon, sigma, and xi; but in HCT-116 cells induced expression of 14-3-3eta and sigma, while 14-3-3beta, eta, and xi were induced in HT-29 cells. If 14-3-3 proteins are involved in cell survival and/or prevention of parasite replication, longer incubation times may be required as no differences in percentage of infection were found among the cell lines at 24h post-infection.