Interleukin-1 receptor type 1 signaling induces excessive inflammatory responses in H1N1 influenza ;virus infection / 中华微生物学和免疫学杂志

Objective To investigate the role of interleukin-1 receptor type 1 (IL-1R1) signaling in H1N1 influenza virus infection. Methods IL-1R1 knockout ( IL-1R1-/-) mice and wild type ( WT) mice were infected intranasally with 2×104 TCID50(50% tissue culture infective dose) of influenza virus H1N1 PR8. Changes in clinical signs, survivals and bodyweights of those mice were monitored daily for 14 consecutive days. Three mice from each group were sacrificed at 3, 7 and 14 days post infection (d. p. i), from which whole lungs were harvested. A part of the lobes was fixed in 4% paraformaldehyde for histopatho-logical assessment and the rest were split and stored at-80 centigrade for further analysis. Real-time quanti-tative PCR and cytometric bead array ( CBA) were performed to detect viral loads in lungs and inflammatory cytokines in supernatants of lung homogenates. Results The mice in both groups showed severe symptoms after the infection of PR8. The maximum bodyweight loss of IL-1R1-/- mice [(24. 22±0. 80) % at 8 d. p. i] was lower than that of WT mice [(28. 03±1. 51)% at 9 d. p. i] (P<0. 05). The IL-1R1-/- mice with PR8 infection showed a higher survival rate (90%) as compared with that of the control group (40%) (P<0. 05). No statistical differences in virus loads were observed between the two groups at 3, 7 and 14 d. p. i. The lung weight to body weight ratio of IL-1R1-/-mice [(1. 42±0. 03) %] was lower than that of WT mice [(1. 79±0. 08) %] at 3 d. p. i (P<0. 05). Pathological changes in IL-1R1-/- mice were less severe than those in WT mice. CBA detection assay revealed that the proinflammatory cytokines in lungs of IL-1R1-/-mice were less than those in WT mice. Conclusion IL-1R1 signaling plays a pathogenic role in mice infec-ted with 2×104 TCID50 of influenza virus PR8 by promoting inflammatory responses.

Genes Involved in Interleukin-1 Receptor Type II Activities Are Associated With Asthmatic Phenotypes

PURPOSE: Interleukin-1 (IL-1) plays a key role in inflammation and immunity and its decoy receptor, IL-1R2, has been implicated in transcriptomic and genetic studies of asthma. METHODS: Two large asthma family collections, the French-Canadian Saguenay-Lac-St-Jean (SLSJ) study and the French Epidemiological Study on the Genetics and Environment of Asthma (EGEA), were used to investigate the association of SNPs in 10 genes that modulate IL-1R2 activities with asthma, allergic asthma, and atopy. Gene-gene interactions were also tested. RESULTS: One SNP in BACE2 was associated with allergic asthma in the SLSJ study and replicated in the EGEA study before statistical correction for multiple testing. Additionally, two SNPs in the MMP2 gene were replicated in both studies prior to statistical correction and reached significance in the combined analysis. Moreover, three gene-gene interactions also survived statistical correction in the combined analyses (BACE1-IL1RAP in asthma and allergic asthma and IL1R1-IL1RAP in atopy). CONCLUSIONS: Our results highlight the relevance of genes involved in the IL-1R2 activity in the context of asthma and asthma-related traits.

Interleukin-1beta Participates in the Development of Pneumococcal Acute Lung Injury and Death by Promoting Alveolar Microvascular Leakage

Streptococcus pneumoniae (S. pneumoniae, also known as pneumococcus) infections are major causes of death worldwide. Despite the development and use of effective antibiotics, high, early mortality due to pneumococcal infections has not been decreased for the last few decades. Recent study found a deadly hemorrhagic acute lung injury (ALI) as a major cause of death at the early stage of severe pneumococcal infections. Interleukin (IL)-1beta was known to play critical roles not only for the development of ALI but also resolution of it. The role of IL-1beta on the pathogenesis of pneumococcal ALI, however, has not been well understood yet. This study aims to investigate the role of IL-1beta on the development of pneumococcal ALI and subsequent death. IL-1beta expression was upregulated in the lungs of pneumococcal ALI in wild-type (WT) mice, but not in the plasma. Despite an increased expression of pulmonary IL-1beta, no inflammatory cell infiltration into airway has been observed. Upregulation of IL-1beta expression was indeed dependent on pneumococcal cytoplasmic toxin pneumolysin and its cell surface receptor Toll-like receptor 4. Deficiency of IL-1R1, a cell surface receptor of IL-1beta, resulted in a markedly reduced hemorrhagic pulmonary edema and early death in pneumococcal ALI. Finally, IL-1beta neutralization in WT mice protects against pulmonary hemorrhagic edema and death. These data suggest that pulmonary expression of IL-1beta exacerbates pneumolysin-induced ALI and death by promoting alveolar hemorrhagic edema.