S-Space College of Medicine/School of Medicine (의과대학/대학원) Parasitology and Tropical Medicine (기생충학전공) Journal Papers (저널논문_기생충학전공)
Suppression of CD4(+) T-Cells in the Spleen of Mice Infected with Toxoplasma gondii KI-1 Tachyzoites
- Kim, Won-Hee; Shin, Eun-Hee; Yu, Seung-Young; Kim, Jae-Lip; Chai, Jong-Yil; Jung, Bong-Kwang
- Issue Date
- KOREAN JOURNAL OF PARASITOLOGY; Vol.48 4; 325-329
- Toxopalsma gondii; host immunity; IFN-gamma; Korean isolate-1; splenocyte; intraperitoneal infection
- Toxoplasma gondii KI-1, a recent new isolate from Korea, shows similar pathogenicity and infectivity to mice compared to the virulent RH strain. To understand characteristics of host immunity, including immune enhancement or suppression, we investigated proliferative responses and phenotypes of spleen cells. In addition, kinetics of IFN-gamma, a Th1 cytokine, was examined in BALB/c mice up to day 6 post-infection (PI). Intraperitoneal injection of mice with 10(3) KI-1 tachyzoites induced significant decreases (P < 0.05) in proliferative responses of spleen cells. This occurred at days 2-6 PI even when concanavalin A (con A) was added and when stimulated with KI-1 antigen, suggesting suppression of the immunity. CD4(+) T-cells decreased markedly at day 2 PI (P < 0.05), whereas CD8(+) T-cells, NK cells, and macrophages did not show significant changes, except a slight, but significant, increase of CD8(+) T-cells at day 6 PI. The capacity of splenocytes to produce IFN-gamma by con A stimulation dropped significantly at days 2-6 PI. These results demonstrate that intraperitoneal injection of KI-1 tachyzoites can induce immunosuppression during the early stage of infection, as revealed by the decrease of CD4(+) T-cells and IFN-gamma.