[Changes of peripheral blood T lymphocytes, IFN-gamma, TNF-alpha and IL-4 in rats infected by Toxoplasma gondii].

Objective: To observe the changes of peripheral blood T lymphocytes, IFN-gamma, TNF-alpha and IL.4 in rats infected by T gondii.

Methods: 48 Sprague-Dawley(SD) rats were intra-abdominally injected with 2 x 10(5)/L of cellulose purified living tachyzoites in 2 ml and randomly divided into 8 groups Six rat was intra-abdominally injected 2 ml of saline as control and 4 rats were remained as normal control. Peripheral blood was collected and the level of IFN-gamma, TNF-alpha, IL-4 was analyzed by ELISA on day 1, 3, 7, 14, 28, 35, 42, 60.

Results: Level of IFN-gamma (6.73 pg/nil) and IL-4 (6.91 pg/ml) increased in experimental rats on day 7 (P < 0.05) and maintained. Level of TNF-alpha (14.37 pg/ml) increased in experimental rats on day 28 (P < 0.05), and that of CD8+ T lymphocytes (14.22%) was signficantly lower than that in control (23.08%) (P < 0.05) and recovered on day 28. No considerable change was observed on the level of CD4 T lymphocytes.

Conclusion: The level of CD8 T lymphocytes, IFN-gamma, TNF-alpha and IL-4 in the rat can be affected by the infection of T. gondii and the level of CD4+ T lymphocytes shows no change.