Role of CD8 + T cells in lethal Plasmodium yoelii 17XL infection
10.3760/cma.j.cn112309-20240105-00009
- VernacularTitle:CD8 ＋T细胞在致死型约氏疟原虫17XL感染中的作用研究
- Author:
Tong LYU
1
;
Yuzhi CHANG
;
Feifei LI
;
Chenchen ZHANG
;
Yaming CAO
;
Hui FENG
Author Information
1. 德阳市人民医院检验科，德阳 618000
- Keywords:
Plasmodium yoelii;
CD8 + T cells;
Effector T cell;
Memory T cell
- From:
Chinese Journal of Microbiology and Immunology
2024;44(7):620-628
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To investigate the role of CD8 + T cells in lethal Plasmodium yoelii 17XL ( Py 17XL) infection. Methods:BALB/c mice and C57BL/6 mice were infected with Py 17XL-infected red blood cells (1×10 6 cells/0.1 ml) through intraperitoneal injection to establish the mouse models of Py 17XL infection. Parasitemia (the percentage of erythrocytes infected with Py 17XL) and the survival rates of the mice was observed dynamically. Flow cytometry was used to detect the number of effector T cells (T EFF) and central memory T cells (T CM) of CD8 + T cell subpopulations, the expression of IFN-γ and granzyme B (GB) levels, and the expression of surface chemokine receptors CXCR3, CXCR6 and CX3CR1. FTY720 blocking experiment was conducted on Py 17XL-infected C57BL/6 mice to analyze the impact of CD8 + T cell migration on Py 17XL infection. Results:The parasitemia of BALB/c mice increased rapidly 5 d after infection and reached the peak on 8 d [(79.57±3.82)%]. Besides, the parasitemia was higher in BALB/c mice than in C57BL/6 mice 5-8 d after infection ( P<0.000 1). All BALB/c mice died on 9 d. The parasitemia of C57BL/6 mice reached the peak on 14 d [(48.19±3.19)%] and then decreased to 0 on 26 d. There was statistically significant difference in the survival rate between the two groups ( P<0.000 1). Flow cytometry results showed that compared with the BALB/c mice, the absolute number of CD8 + T cells in spleen and liver tissues and the number of CD8 + T EFF and CD8 + T CM cells in spleen and lymph nodes of C57BL/6 mice increased significantly ( P<0.05). Compared with the BALB/c mice, the levels of GB, IFN-γ and chemokines expressed by CD8 + T cells in spleen and liver tissues of C57BL/6 mice increased significantly ( P<0.05). The FTY720 blocking experiment showed that the survival rate, the absolute number of CD8 + T cells in liver and spleen, and the number of CD8 + CXCR3 + T cells decreased significantly in the experimental group ( P<0.05). Conclusions:CD8 + T EFF and CD8 + T CM cells contribute to resistance against Py 17XL infection by secreting GB and IFN-γ. The chemokine receptor CXCR3 plays an important role in mediating the chemotaxis of CD8 + T cells to spleen and liver.
