Zou Yi, Xu Jun, Zhong Nanshan
Guangzhou Institute of Respiratory Disease, Guangzhou 510120, China.
Zhonghua Jie He He Hu Xi Za Zhi. 2002 Aug;25(8):470-4.
To determine the effects of RSV infection on the development of lung inflammation and the expressions of T-helper cell related cytokines in Balb/c mice pre-sensitized with ovalbumin.
Forty mice were randomly divided into four groups: (1) the control group: nonsensitized, noninfected; (2) the RSV group: nonsensitized, infected; (3) the OVA group: sensitized, noninfected; and (4) the OVA + RSV group: sensitized, infected (RSV 6.5 x 10(6) PFU nasal drip). Bronchoalveolar lavage (BAL) was performed in six mice from each group five days after RSV nasal inoculation. Cells in the BAL were counted and classified and the supernatants of the BALF were used for detection of IL-4 and IFN-gamma. Four mice in each group were sacrificed for lung RNA extraction, and IL-4, IL-5 and IFN-gamma mRNA levels were determined by RT-PCR.
(1) Total BAL cells from the RSV group [(14.5 +/- 5.4) x 10(6)/ml] and the OVA + RSV group [(16.8 +/- 4.9) x 10(6)/ml] were significantly higher than those in the control group [(7.7 +/- 2.4) x 10(6)/ml] and the OVA group [(9.0 +/- 2.5) x 10(6)/ml] (all P < 0.05), with more lymphocytes in the RSV group (0.63 +/- 0.05) and the OVA + RSV group (0.77 +/- 0.09) than the control group (0.28 +/- 0.05) (P < 0.05) and the OVA group (0.36 +/- 0.03) (P < 0.05). More eosinophils were found in the OVA + RSV group (0.0690 +/- 0.0100) than in the RSV group (0.0090 +/- 0.0050), the OVA group (0.0100 +/- 0.0040) and the control (0.0030 +/- 0.0010) (all P < 0.05). (2) Pulmonary inflammation in the OVA + RSV group and the RSV group was more severe than that in the OVA group and the control group. More lymphocyte infiltration was found in the OVA + RSV and the RSV groups. More eosinophils were found in the OVA + RSV group, but not in the other groups. (3) Expression of IL-4, IL-5, and IFN-gamma mRNA: IFN-gamma mRNA expression (1.05 +/- 0.12) was higher in the RSV group, than in the control (0.00 +/- 0.00). There were only minimal expression of IL-5 mRNA and no expression of IL-4 mRNA, indicating a Th1-like cytokine response. Expressions of IL-4 mRNA and IL-5 mRNA were significantly higher in the OVA + RSV group than in the other groups, but the IFN-gamma mRNA expression was less than that in the RSV group, indicating a Th2-like cytokine response. (4) IFN-gamma activation in BALF from the RSV group [(33.8 +/- 1.1) pg/ml] was significantly higher than that in the other groups (P < 0.05), while IL-4 showed no significant change as compared to the control group. The level of IL-4 in the OVA + RSV group [(24.0 +/- 1.5) pg/ml] was significantly higher than that in all the other groups (P < 0.05).
RSV infection in OVA-sensitized Balb/c mice caused a different immune response from that caused by RSV infection in nonsensitized mice. RSV infection alone resulted in a Th1-like cytokine response, while infection after OVA sensitization resulted in a Th2-like response.
确定呼吸道合胞病毒（RSV）感染对卵清蛋白预致敏的Balb/c小鼠肺部炎症发展及辅助性T细胞相关细胞因子表达的影响。
40只小鼠随机分为四组：（1）对照组：未致敏、未感染；（2）RSV组：未致敏、感染；（3）OVA组：致敏、未感染；（4）OVA + RSV组：致敏、感染（经鼻滴注6.5×10⁶ PFU的RSV）。RSV经鼻接种5天后，对每组6只小鼠进行支气管肺泡灌洗（BAL）。对BAL中的细胞进行计数和分类，并将BALF的上清液用于检测白细胞介素-4（IL-4）和干扰素-γ（IFN-γ）。每组处死4只小鼠用于提取肺RNA，通过逆转录聚合酶链反应（RT-PCR）测定IL-4、IL-5和IFN-γ mRNA水平。
（1）RSV组[（14.5±5.4）×10⁶/ml]和OVA + RSV组[（16.8±4.9）×10⁶/ml]的BAL细胞总数显著高于对照组[（7.7±2.4）×10⁶/ml]和OVA组[（9.0±2.5）×10⁶/ml]（均P<0.05），RSV组（0.63±0.05）和OVA + RSV组（0.77±0.09）的淋巴细胞多于对照组（0.28±0.05）（P<0.05）和OVA组（0.36±0.03）（P<0.05）。OVA + RSV组（0.0690±0.0100）的嗜酸性粒细胞多于RSV组（0.0090±0.0050）、OVA组（0.0100±0.0040）和对照组（0.0030±0.0010）（均P<0.05）。（2）OVA + RSV组和RSV组的肺部炎症比OVA组和对照组更严重。OVA + RSV组和RSV组有更多的淋巴细胞浸润。OVA + RSV组有更多的嗜酸性粒细胞，而其他组没有。（3）IL-4、IL-5和IFN-γ mRNA的表达：RSV组的IFN-γ mRNA表达（1.05±0.12）高于对照组（0.00±0.00）。IL-5 mRNA仅有微量表达，IL-4 mRNA无表达，表明为Th1样细胞因子反应。OVA + RSV组的IL-4 mRNA和IL-5 mRNA表达显著高于其他组，但IFN-γ mRNA表达低于RSV组，表明为Th2样细胞因子反应。（4）RSV组BALF中的IFN-γ活性[（33.8±1.1）pg/ml]显著高于其他组（P<0.05），而IL-4与对照组相比无显著变化。OVA + RSV组的IL-4水平[（
