In lung tissues of patients without COPD we did not detect NTHI using both PCR and ISH. Modulation 17-DMAG IC50 of TGF B signalling by infection with NTHI To characterize regulation of TGF B signaling molecules by NTHI a transcriptome array of in vitro infected COPD lung tissue was performed. Data of the array showed no significant changes of TGF B receptors and Smad 3 expression. Regarding TGF B expression we found a moderate increase, whereas a strong expression of BAMBI with 3 fold increase after in vitro infection of COPD lung tissue was demonstrated. NTHI induced host response Measurement of cytokine concentrations from superna tants of in vitro infected lung tissue revealed a strong proinflammatory response with increased expression of CXCL 8 and TNF.

Furthermore infection led to increased expres sion of the MAP kinase p38, which is demonstrated in figure 4c and 4d. Inhibition of p38 significantly inhibited CXCL 8 and TNF expression. NTHI infec tion of lung tissues and A549 cells generated a significant decrease of TGF B release in the supernatant. A reduction of TGF B expression in infected lung tissue was also observed using IHC. BAMBI is strongly upregulated in lung tissue in response to NTHI infection in vivo and in vitro BAMBI was expressed ubiquitously on AM and to a lesser degree on AEC. This was demonstrated using IHC and ISH and was confirmed by RT PCR and sequencing. Using IHC on isolated AMs a typical membrane bound pattern is demonstrated. In vitro infection revealed that NTHI induces a strong upregulation of BAMBI in the lung tissue on AM and AEC as well as on isolated AM and A549 cells.

This was demonstrated on RNA and protein level. This induction was observed uniformly among the different lung tissues, cells and cell lines tested. In vivo NTHI infected lung tissue of COPD patients showed also a stronger expression of BAMBI on AM and AEC compared to lung tissue without NTHI infection and control tissue. However, there was no correlation with the different GOLD classes. Figure 7 demonstrates the increased expression of BAMBI on the RNA level in in vitro infected lung tis sue. Discussion In the present study we demonstrate for the first time the expression of the TGF pseudoreceptor BAMBI in the human lung. COPD patients with NTHI infection showed increased expression of BAMBI in the lung tis sues when compared to non infected patients. Further more we show the upregulation of the pseudoreceptor by in vitro infection using two Carfilzomib different NTHI strains in combination with a strong proinflammatory response and decreased expression of TGF B. The characterization of BAMBI adds a new mechanism to the complex regulation of TGF B in the human lung.