The Effect of Betamethasone and IFN-gamma on Replication of Toxoplasma gondii (RH Strain) and Nitric Oxide Production in HeLa Cell Culture

Toxoplasmosis is a protozoal infection caused by toxoplasma gondii. toxoplasmosis produce severe damage in patients who are immunosuppresed. in those who are immunosupressed,latent infection can be reactivated resulting in acute disseminating disease. betamethasone is asynthetic glycocorticoid, used as an anti-inflamatory and immunosuppressant in a wide varietyof disorders.the aim of this study was evaluation of betamethasone as an immunosuppressordrug on infected cells by toxoplasma gondii. in this study, at first hela cells were grown in 24well culture plates in culture medium .when confluent monolayer was obtained, we compared 6groups to evaluate the effect of betamethasone as a corticosteroid drug (two concentrations 4and 40μg/ml) and the effect of ifn-γ (100 iu/ml ) on growth, replication and nitric oxide(no) production. the results showed, that high number of plaques were seen in group with 40μg/ml of betamethasone and the lowest number of plaques were seen in group with 100 iu ofifn-γ. the difference between plaque number in control and groups treated with ifn-γ andbetamethasone was significant (p<0.05). the groups with betamethasone or ifn-γ withouttachyzoites did not show any effect on cell structures. replication rates in the wells treated withifn-γ were decreased significantly 72h post inoculation in comparison with control group (p<0.05). there was no significant difference among different groups in no production. theresults indicated that betamethasone increase the invasion of tachyzoites to host cells in vitro.