IL-6 During Influenza-Streptococcus pneumoniae Co-Infected Pneumonia—A Protector

Frontiers in Immunology

Yibing Yin¹  Jingyi Chen¹  Xuemei Gou²  Shuang Liu²  Xiaofang Wang²  Jun Yuan²  Jiangming Xiao²  Hong Wang²  Xuemei Zhang² 

[1] Department of Laboratory Medicine, The Children's Hospital of Chongqing Medical University, Chongqing, China;Key Laboratory of Diagnostic Medicine Designated by the Ministry of Education, Chongqing Medical University, Chongqing, China;

关键词: influenza;    Streptococcus pneumoniae;    pneumonia;    IL-6;    co-infection;   

DOI  :  10.3389/fimmu.2019.03102

来源: DOAJ

【 摘 要 】

Understanding of pathogenesis and protection mechanisms underlying influenza-Streptococcus pneumoniae co-infection may provide potential strategies for decreasing its high morbidity and mortality. Interleukin-6 (IL-6) is an important cytokine that acts to limit infection-related inflammation; however, its role in co-infected pneumonia remains unclear. Here we show that the clinically relevant co-infected mice displayed dramatically elevated IL-6 levels; which was also observed in patients with co-infected pneumonia. IL-6−/− mice presented with increased bacterial burden, early dissemination of bacteria to extrapulmonary sites accompanied by aggravated pulmonary lesions and high mortality when co-infection. This protective function of IL-6 is associated with cellular death and macrophage function. Importantly, therapeutic administration of recombinant IL-6 protein reduced cells death in BALF, and enhanced macrophage phagocytosis through increased MARCO expression. This protective immune mechanism furthers our understanding of the potential impact of immune components during infection and provides potential therapeutic avenues for influenza-Streptococcus pneumoniae co-infected pneumonia.

【 授权许可】

Unknown