The Ratio of Treg/Th17 Cells from Mice Infected with Plasmodium yoelii in the Early Stage of Infection
Author(s): CHEN Guang, LIU Lei, BI Sheng, LUO Lan, WANG Fang-fang, CAI Lian-shun, SU Ju-xiang, DAI Yue, College of Basic Medical Sciences, Jiamusi University, The First Affiliated Hospital of Jiamusi University
Pages: 425-429
Year: 2014 Issue: 6
Journal: Chinese Journal of Parasitology and Parasitic Diseases
Keyword: Plasmodium yoelii; Ratio of Treg/Th17 cells; Early infection;
Abstract: Objective To investigate the change of Treg/Th17 cell ratio in mice infected with Plasmodium yoelii17 XL in the early stage of infection. Methods Forty 6-8 week-old female BALB/c mice were randomly divided into infection group and Treg blockade group. All the mice were infected by intraperitoneal injection with 1 ×106P. yoelii17XL-parasitized erythrocytes. Mice in Treg blockade group were intraperitoneally injected with 1 mg CD25 m Ab before infection and on day 1 post-infection, respectively. Three healthy mice served as control. Tail vein blood samples were collected in two groups each with 10 mice during day 1-7 post-infection. The parasitemia was monitored daily by examining Giemsa-stained thin film. The survival rate of infected mice was calculated. Before infection, on day 3 and 5post-infection, the spleen was aseptically removed from each mouse in infection group(n=3) and Treg blockade group(n =3), and splenocyte suspensions were prepared. The proportion of Treg and Th17 cells were analyzed by flow cytometry. The ratio of Treg/Th17 cells was calculated and the relative analysis of the percentage of Treg and Th17 cells was conducted. Results Parasitemia appeared on day 2 post-infection in infection group. On day 5, the infection rate of P. yoelii in erythrocytes increased to(49.8 ±4.7)% with a survival rate of 60.0%. All mice died on day 6 post-infection. In Treg blockade group, P. yoelii 17XL-parasitized erythrocytes appeared on day 2 post-infection; the parasitemia was(10.0 ±3.5)% on day 5, and increased rapidly to 60.0% on day 7; all mice died on day 8. The percentages of Treg and Th17 cells reached(11.1 ±1.3)% and(16.7 ±3.3) % respectively on day 3 post-infection in infection group, and increased to(26.1±4.5)% and(19.6±2.6) % on day 5, considerably higher than that of the control(P <0.01). The ratio of Treg/Th17 cells was 0.7 ±0.1, 1.3 ±0.4 on day 3 and 5 post-infection in infection group,respectively, which was much lower than that of normal control(2.1 ±0.5)(P <0.01, P <0.05). On day 3 and 5 postinfection, the percentages of Treg cells in CD4+T cells was(2.4±1.3)% and(4.3±2.9)%, respectively, and that of Th17 cells reached(26.1±2.2)% and(6.5±2.1)% in Treg blockade group. The ratio of Treg/Th17 cells in Treg blockade group was 0.1±0.1 and 0.7 ±0.4, respectively, which was considerably lower than that of the control(3.6 ±0.4)(P <0.01). The proportion of Treg cells in CD4+T cells was positively correlated with that of Th17 cells(r =0.8166, P <0.01).Conclusion The ratio of Treg/Th17 cells significantly decreases in the early stage of P. yoelii 17 XL infection.
Pages: 425-429
Year: 2014 Issue: 6
Journal: Chinese Journal of Parasitology and Parasitic Diseases
Keyword: Plasmodium yoelii; Ratio of Treg/Th17 cells; Early infection;
Abstract: Objective To investigate the change of Treg/Th17 cell ratio in mice infected with Plasmodium yoelii17 XL in the early stage of infection. Methods Forty 6-8 week-old female BALB/c mice were randomly divided into infection group and Treg blockade group. All the mice were infected by intraperitoneal injection with 1 ×106P. yoelii17XL-parasitized erythrocytes. Mice in Treg blockade group were intraperitoneally injected with 1 mg CD25 m Ab before infection and on day 1 post-infection, respectively. Three healthy mice served as control. Tail vein blood samples were collected in two groups each with 10 mice during day 1-7 post-infection. The parasitemia was monitored daily by examining Giemsa-stained thin film. The survival rate of infected mice was calculated. Before infection, on day 3 and 5post-infection, the spleen was aseptically removed from each mouse in infection group(n=3) and Treg blockade group(n =3), and splenocyte suspensions were prepared. The proportion of Treg and Th17 cells were analyzed by flow cytometry. The ratio of Treg/Th17 cells was calculated and the relative analysis of the percentage of Treg and Th17 cells was conducted. Results Parasitemia appeared on day 2 post-infection in infection group. On day 5, the infection rate of P. yoelii in erythrocytes increased to(49.8 ±4.7)% with a survival rate of 60.0%. All mice died on day 6 post-infection. In Treg blockade group, P. yoelii 17XL-parasitized erythrocytes appeared on day 2 post-infection; the parasitemia was(10.0 ±3.5)% on day 5, and increased rapidly to 60.0% on day 7; all mice died on day 8. The percentages of Treg and Th17 cells reached(11.1 ±1.3)% and(16.7 ±3.3) % respectively on day 3 post-infection in infection group, and increased to(26.1±4.5)% and(19.6±2.6) % on day 5, considerably higher than that of the control(P <0.01). The ratio of Treg/Th17 cells was 0.7 ±0.1, 1.3 ±0.4 on day 3 and 5 post-infection in infection group,respectively, which was much lower than that of normal control(2.1 ±0.5)(P <0.01, P <0.05). On day 3 and 5 postinfection, the percentages of Treg cells in CD4+T cells was(2.4±1.3)% and(4.3±2.9)%, respectively, and that of Th17 cells reached(26.1±2.2)% and(6.5±2.1)% in Treg blockade group. The ratio of Treg/Th17 cells in Treg blockade group was 0.1±0.1 and 0.7 ±0.4, respectively, which was considerably lower than that of the control(3.6 ±0.4)(P <0.01). The proportion of Treg cells in CD4+T cells was positively correlated with that of Th17 cells(r =0.8166, P <0.01).Conclusion The ratio of Treg/Th17 cells significantly decreases in the early stage of P. yoelii 17 XL infection.
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