Journal Article

Extracellular Hsp70 modulates 16HBE cells' inflammatory responses to cigarette smoke and bacterial components lipopolysaccharide and lipoteichoic acid

Heijink, Irene H., Somborac-Bačura, Anita, Hulina-Tomaškovic, Andrea, Jonker, Marnix R., Rumora, Lada, Rajković, Marija Grdić, Hlapčić, Iva

2022

Overview

Cigarette smoke is a major risk factor for chronic obstructive pulmonary disease (COPD), leading to chronic inflammation, while bacterial components lipopolysaccharide (LPS) and lipoteichoic acid (LTA) are often present in airways of COPD patients, especially during exacerbations. We hypothesised that extracellular heat shock protein 70 (eHsp70), a damage-associated molecular pattern elevated in serum of COPD patients, induces inflammation and alters cigarette smoke and LPS/LTA-induced inflammatory effects in the airway epithelium. We used 16HBE cells exposed to recombinant human (rh) Hsp70 and its combinations with cigarette smoke extract (CSE), LPS or LTA to investigate those assumptions, and we determined pro-inflammatory cytokines’ secretion as well as TLR2 and TLR4 gene expression. rhHsp70 and CSE alone stimulated IL-6, IL-8 and TNF-α secretion. CSE and rhHsp70 had antagonistic effect on IL-6 secretion, while combinations of LPS or LTA with rhHsp70 showed antagonistic effect on TNF-α release. By using specific inhibitors, we demonstrated that effects of rhHsp70 on cytokines’ secretion were mediated via NF-κB and/or MAPK signalling pathways. rhHsp70 increased, and CSE decreased TLR2 gene expression compared to untreated cells, but their combinations increased it compared to CSE alone. LPS and rhHsp70 combinations decreased TLR2 gene expression compared to untreated cells. TLR4 expression was not induced by any of the treatments. In conclusion, we demonstrated that extracellular Hsp70 modulates pro-inflammatory responses of human airway epithelial cells to cigarette smoke and bacterial components LPS and LTA. Simultaneous presence of those compounds and their interactions might lead to inappropriate immune responses and adverse consequences in COPD.

• Publisher: Springer Science + Business Media,Springer Netherlands,Springer Nature B.V
• Subject: Bacteria / Biochemistry / Biomedical and Life Sciences / Biomedicine / Cancer Research / Cell Biology / Chronic obstructive pulmonary disease / Cigarette smoke / Cigarette Smoking / Cigarettes / Cytokines / Damage patterns / Epithelial cells / Epithelium / Gene expression / Heat shock proteins / HSP70 Heat-Shock Proteins - genetics / HSP70 Heat-Shock Proteins - metabolism / Hsp70 protein / Humans / Immune response / Immunology / Inflammation / Inflammation - metabolism / Interleukin 6 / Interleukin 8 / Lipopolysaccharides / Lipopolysaccharides - pharmacology / Lipoteichoic acid / Lung diseases / MAP kinase / Neurosciences / NF-kappa B - metabolism / NF-κB protein / Nicotiana - adverse effects / Nicotiana - metabolism / Obstructive lung disease / Original / Original Article / Pulmonary Disease, Chronic Obstructive - metabolism / Respiratory tract / Risk analysis / Risk factors / Signal transduction / Smoke / Teichoic Acids / TLR2 protein / TLR4 protein / Toll-Like Receptor 2 - genetics / Toll-Like Receptor 2 - metabolism / Toll-Like Receptor 4 - genetics / Toll-Like Receptor 4 - metabolism / Toll-like receptors / Tumor Necrosis Factor-alpha / Tumor necrosis factor-α