TUMOR-NECROSIS-FACTOR-ALPHA, INTERLEUKIN-1-ALPHA, AND INTERLEUKIN-6 MESSENGER-RNA EXPRESSED BY HUMAN ASTROCYTOMA-CELLS AFTER INFECTION BY 3 DIFFERENT STRAINS OF TOXOPLASMA-GONDII

The role of cytokines in the pathogenesis of toxoplasmosis remains unknown to a large extent, especially in the case of reactivation that occurs in immunocompromised patients. To assess the importance of tumor necrosis factor alpha (TNFalpha), interleukin 1 alpha (IL1alpha), and interleukin 6 (IL6), we studied the expression of these three cytokines by human astrocytoma cells after infection by three different strains of Toxoplasma gondii. The virulent RH strain, the intermediate 76K strain, and the cystogenic Prugniaud strain did not induce significantly different levels of expression of the cytokine messenger RNAs when the cytokines were studied at 1, 3, 6, and 24 h after parasitic infection. These results could indicate that infection by T. gondii strains of different virulence do not involve strong differences in TNFalpha, IL1alpha, or IL6 expression by human astrocytoma cells.