Related Experiment Video
Updated: Dec 8, 2025
Multicellular Human Alveolar Model Composed of Epithelial Cells and Primary Immune Cells for Hazard Assessment
Published on: May 6, 2020
Mechanisms of the lipopolysaccharide-induced inflammatory response in alveolar epithelial cell/macrophage co-culture
Jiansheng Li1,2, Yanqin Qin1,2, Yulong Chen1,2
1Henan Key Laboratory of Chinese Medicine for Respiratory Disease, Henan University of Chinese Medicine, Zhengzhou, Henan 450046, P.R. China.
Abstract:
The interaction between alveolar epithelial cells (EpCs) and macrophages (MPs) serves an important role in initiating and maintaining inflammation in chronic pulmonary diseases. The aim of the present study was to investigate the molecular mechanisms of the inflammatory response in co-cultured EpCs and MPs. Briefly, a co-culture system of A549 (EpCs) and THP-1 (monocyte/MPs) cells was established in a filter-separated Transwell plate to evaluate the inflammatory response. Following lipopolysaccharide (LPS) treatment, cytokine levels were measured using ELISAs, NF-κB transcription factor activity was detected using EMSA and protein expression levels were analyzed using Western blot assays subsequently in EpCs and MPs. Co-cultured EpCs/MPs were found to secrete increased levels of interleukin (IL)-6, IL-1β, IL-8 and tumor necrosis factor (TNF)-α following LPS exposure for 6, 12, 24 and 48 h compared with either EpC or MP monocultures. Concurrently, NF-κB was revealed to be activated in MPs at 6 and 12 h, and in EpCs at 24 h. NF-κB DNA binding, Toll-like receptor 4 expression levels and the p65 phosphorylation status were also increased, which may contribute to the inflammatory response in the EpC/MP co-cultures. Notably, cytokine levels decreased following the inhibition of NF-κB expression with pyrrolidinedithiocarbamate. In conclusion, the present study successfully established an EpC/MP co-culture system using LPS, which may be a useful model for studying chronic inflammation in vitro.
Insights
This study developed a co-culture model of lung cells and immune cells to investigate chronic pulmonary inflammation. The model revealed that activating NF-κB signaling drives the release of inflammatory cytokines.
Area of Science:
- Pulmonary Medicine
- Cell Biology
- Immunology
Background:
- Alveolar epithelial cells (EpCs) and macrophages (MPs) interact to drive chronic pulmonary inflammation.
- Understanding the molecular mechanisms of this interaction is crucial for developing new treatments.
Purpose of the Study:
- To investigate the molecular mechanisms of the inflammatory response in co-cultured EpCs and MPs.
- To establish a reliable in vitro model for studying chronic pulmonary inflammation.
Main Methods:
- A co-culture system of A549 (EpCs) and THP-1 (monocyte/MPs) cells was established using Transwell plates.
- Lipopolysaccharide (LPS) was used to induce inflammation, followed by measurements of cytokine levels (ELISA), NF-κB activity (EMSA), and protein expression (Western blot).
Main Results:
- Co-cultured EpCs/MPs secreted significantly higher levels of IL-6, IL-1β, IL-8, and TNF-α compared to monocultures after LPS exposure.
- NF-κB activation was observed in MPs and EpCs at different time points post-LPS.
- Inhibition of NF-κB signaling reduced cytokine secretion, confirming its role in the inflammatory response.
Conclusions:
- The established EpC/MP co-culture system effectively models LPS-induced chronic pulmonary inflammation in vitro.
- NF-κB signaling plays a key role in mediating the inflammatory response in this co-culture model.
- This model provides a valuable tool for further research into chronic inflammatory lung diseases.
