Objective To investigate the changes and significance of natural killer (NK)cells and natural killer T (NKT) cells in peripheral blood at different stages in silicotic rat model.
Methods Forty-eight healthy male SD rats were randomly divided into silica exposed group and control group. One miniliter silica suspension (40 mg/mL)was administrated via intratracheal in stillation at one time while equal amount of saline was instilled to the rats of control group. Animals were sacrificed at the day 1, 8, 15, 23, 30 and 37 after instillation, and the peripheral blood samples were collected. The levels of NK(CD3-/CD161+)and NKT (CD3+/CD161+) cells in peripheral blood were detected by flow cytometry.
Results NK cells in peripheral blood of silicotic rats started to increase on the first day after silica instillation (P<0.05). The peak number of NK cells appeared at week 3, then began to decrease, but was still higher than that in the control group. NKT cells decreased (P<0.05)in the early stage obviously. The number of NKT cells increased later on, but was still lower than that in the control group.
Conclusion Silica induces rat in nate immune responses. NK and NKT cells play roles in the development of silicosis.
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