IL-21/IL-21R Regulates the Neutrophil-Mediated Pathologic Immune Response during Chlamydial Respiratory Infection

Figure 4

The pulmonary neutrophil level of WT mice after administration of recombinant murine IL-21 (rIL-21) during Chlamydia muridarum (C. muridarum) lung infection. For rIL-21 treatment, wild-type (WT) mice were inoculated intranasally with 0.5 μg rIL-21 in 20 μl PBS at the day before and days 0, 2, 4, and 6 after C. muridarum infection, and the control group was given 20 μl sterile PBS in the same schedule. The (a) percentages and (b) numbers of pulmonary neutrophils were detected by flow cytometry with pulmonary neutrophils represented as CD45⁺ CD11b⁺ Ly-6G⁺ cells. (c) The percentages of CD62L positive cells in pulmonary neutrophils were analyzed by flow cytometry at indicated times after infection. (d) The myeloperoxidase (MPO) activity in the lung tissues after C. muridarum infection was shown. (e, f) The mRNA level of matrix metalloproteinase 8 (MMP8) and S100A8 was examined by qPCR. Data are represented as from per group, representative one of three independent experiments. Statistical significances of differences are determined by two-way ANOVA followed by Bonferroni’s multiple comparisons test. , , and .

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