IL-9 blockade attenuates inflammation in a murine model of methicillin-resistant Staphylococcus aureus pneumonia.

IL-9 blockade attenuates inflammation in a murine model of methicillin-resistant Staphylococcus aureus pneumonia. Acta Biochim Biophys Sin (Shanghai). 2020 Jan 15;: Authors: Xu W, Tian K, Li X, Zhang S Abstract Methicillin-resistant Staphylococcus aureus (MRSA) is an important etiology of pneumonia. Interleukin (IL)-9 is a T helper 9 (Th9) cytokine and participates in the pathogenesis of infectious diseases. Here, we investigated the role of IL-9 by using an MRSA pneumonia animal model. The BALB/c mice underwent nasal inhalation with an ST239 MRSA strain to establish the mouse model of MRSA pneumonia, and a subset of mice were intravenously injected with IL-9 neutralizing antibody or immunoglobulin (Ig) G. At 3 and 8 days postinfection, the peripheral blood, bronchioalveolar lavage fluid (BALF), and lung tissues were collected. The frequencies of Th9 cells and the levels of cytokines in peripheral blood, BALF, and lung tissues were determined by flow cytometry and enzyme-linked immunosorbent assay (ELISA), respectively. The colony counts of MRSA in BALF and lung tissue were detected. The lung pathological changes were examined using hematoxylin and eosin staining. Data from flow cytometry, qRT-PCR, and ELISA showed that MRSA-infected mice exhibited higher frequency of Th9 cells and higher IL-9 mRNA and protein levels in the peripheral blood, BALF, and lung tissues of mice. In contrast, the neutralization of IL-9 abrogated MRSA inocu...
Source: Acta Biochimica et Biophysica Sinica - Category: Biochemistry Authors: Tags: Acta Biochim Biophys Sin (Shanghai) Source Type: research