Three-dimensional Culture of Human Airway Epithelium in Matrigel for Evaluation of Human Rhinovirus C and Bocavirus Infections

Objective Newly identified human rhinovirus C （HRV-C） and human bocavirus （HBoV） cannot propagate in vitro in traditional cell culture models; thus obtaining knowledge about these viruses and developing related vaccines are difficult. Therefore, it is necessary to develop a novel platform for the propagation of these types of viruses.Methods A platform for culturing human airway epithelia in a three-dimensional （3D） pattern using Matrigel as scaffold was developed. The features of 3D culture were identified by immunochemical staining and transmission electron microscopy. Nucleic acid levels of HRV-C and HBoV in 3D cells at designated time points were quantitated by real-time polymerase chain reaction {PCR）. Levels of cytokines, whose secretion was induced by the viruses, were measured by ELISA.Results Properties of bronchial-like tissues, such as the expression of biomarkers CK5, ZO-2, and PCK, and the development of cilium-like protuberances indicative of the human respiration tract, were observed in 3D-cultured human airway epithelial （HAE） cultures, but not in monolayer-cultured cells. Nucleic acid levels of HRV-C and HBoV and levels of virus-induced cytokines were also measured using the 3D culture system.Conclusion Our data provide a preliminary indication that the 3D culture model of primary epithelia using a Matrigel scaffold in vitro can be used to propagate HRV-C and HBoV.

Effect of cigarette smoke extraction on the expression of found in inflammatory zone 1 in rat lung epithelial L2 cells

Background Found in inflammatory zone 1 （FIZZ1） protein increased in pulmonary epithelial cells and in limited amounts of other lung cells.FIZZ1 increased in murine model of smoke induced chronic obstructive pulmonary disease.However,the direct role of FIZZ1 produced by pulmonary epithelium stimulated with cigarette smoke extraction has not been determined.We examined the expression and function of FIZZ1 in rat lung epithelial L2 cells.Methods The rat lung epithelial L2 cells （CCL 149） were exposed to cigarette smoke extraction,expression of FIZZ1 mRNA was investigated by RT-PCR.Levels of FIZZ1 protein were detected by Western blotting and laser confocal microscope.CCL 149 cells were treated with different concentrations and for different time of recombinant protein FIZZ1.After treatment,the expression levels of interleukin 8 （IL-8） were detected by enzyme-linked immunosorbent assay （ELISA）.Results When CCL 149 cells were exposed to cigarette smoke extraction,FIZZ1 mRNA and protein levels expressed significantly higher than control group.Recombinant protein FIZZ1 promoted the expression of IL-8 in a dose and time dependent manner in a certain range.Conclusions Cigarette smoke extraction activates FIZZ1 at mRNA and protein levels in CCL 149 cells.Recombinant protein FIZZ1 induces the expression of IL-8 and may thus participate in the process of chronic obstructive pulmonary disease airway inflammation and airflow obstruction.Generally,immune cells such as macrophages,neutrophils and lymphocytes are unavoidably involved in airway inflammatory and immune responses to cigarette smoke,but it is still unclear whether their involvement in the pathogenesis of chronic obstructive pulmonary disease is based on the specific expression in lung epithelial cells of FIZZ1.

Effects of epithelial cell injury of the lower respiratory tract in the pathogenesis of allergic responses in a rat model

Background Asthma is a complex disease involving genetic and environment interactions. Atopy is a strong risk factor for asthma. The airway epithelium not only forms a physical barrier but also provides immune defense against harmful materials. To explore the effects of airway epithelium on asthma, we hypothesized that environmental injuries could act on bronchial epithelial cells and damage the physical barrier, which might facilitate allergens to stimulate immunoreactions and play an important role in the pathogenesis of asthma. Methods Thirty eight-week-old male Wistar rats were randomly divided into five groups with six rats in each group： control group, asthma group, ovalbumin （OVA）＋OVA group, lipopolysaccharide （LPS） group and LPS＋OVA group. In the control group, 0.9% saline was injected intraperitoneally on day 1. Fourteen days later, the rats were exposed to aerosolized 0.9% saline. In the asthma group, the rats were sensitized with an injection of 10 mg of OVA, followed by an aerosolized 2% OVA challenge14 days later. The OVA＋OVA group was sensitized by an inhalation 2% OVA, 20 minutes a day, from day 1 to day 7, and then OVA challenged in the same way as the asthma group. In the LPS group, LPS （200 μl, μg/μl） was given by airway on day 1 and day 3, with a simultaneous aerosol inhalation of 2% OVA for 20 minutes a day from day 1 to day 7. Fourteen days later, the rats were challenged with saline as in the control group. While in the LPS＋OVA group, LPS （200 μl, 1 μg/μl） was given by airway on day 1 and day 3, with a simultaneous aerosol inhalation of 2% OVA for 20 minutes a day from day 1 to day 7. Fourteen days later, the rats were challenged with OVA as in the asthma group. The expression of interleukin （IL）-4, interferon-gamma （IFN-γ） and thymic stromal lymphopoietin （TSLP） in the lungs was detected by reverse transcription polymerase chain reaction （RT-PCR） and the pulmonary pathological changes were also observed. The level of IL-4, IFN-γ and IgE in plasma was detected by enzyme-linked immunosorbent assay （ELISA）. Bronchoalveolar lavage fluid （BALF） was collected to conduct differential cell counts. Flow cytometry analysis was also used to count Thl and Th2 cells. Results The pathological changes in the LPS＋OVA group were similar to the asthma group, while in other groups, the pathological changes were not obvious. The ratio of lymphocytes in BALF, IL-4/IFN-γ in plasma and the expression of the TSLP and IL-4 in the asthma and LPS＋OVA groups were higher than in the control group and the OVA＋OVA group （P 〈0.05）. The level of IgE was higher in the asthma, LPS and LPS＋OVA groups than in the control group and the OVA＋OVA group （P 〈0.05）. By flow cytometry analysis, the Thl/Th2 ratio was lower in the LPS＋OVA and asthma groups than in other groups （P 〈0.05）. Conclusions The experiment results show that the injury to the bronchial epithelial layer may be the initial event of allergic responses. This finding implies that a rational approach to therapeutics would be to increase the resistance of the airways to environmental injuries rather than concentrating on suppressing inflammation.