Immune Response to Respiratory Syncytial Virus Infection in Ovalbumin Sensitized Mice / 实用儿科临床杂志

ABSTRACT

Objective To observe the lung inflammation and the expression of T - helper cell related cytokines in respiratory syncytial virus(RSV) infected Balb/c mice pre - sensitized with ovalbumin(OVA). Methods Mice were randomly divided into two series nonsen-sitized and sensitized animal model with nebulized OVA once a day for 10 days. Each of the series was divided again into two groups control group,RSV infected group with nasal draping plus nebulizing. All the mice were sacrificed 5 days later of infection. Viral isolation of lung organization was performed in each group. Pulmonary pathological detection and the levels of interleukin - 4(IL-4), interferon-? (IFN- ?) mRNA were evaluated by RT- PCR. Results The RSV were found only in RSV infected groups. The Balb/c mice developed typical interstitial pneumonia after RSV infection. When the mice pre- sensitized were infected with RSV, the pulmonary inflammation, lymphocyte and eosinophils infiltration and cell - collar peribronchiles were more severe in lung organization and bronchiole than those in the single RSV infection group. In the lung organization of control group, there were no mRNA expression of IL - 4 and IFN - ?. The mRNA of IFN -? was expressed in the lung organization of RSV infected groups while had not showed mRNA of IL- 4. In the OVA+ RSV group the mRNA expression of IL - 4 was obvious, while the expresses of IFN -? scarcely. Conclusions Pulmonary inflammation is more severe in the infection after OVA sensitization. RSV infection alone results in a Th1 - like cytokine response, while the infection after OVA sensitization results in Th2 - like response.