The study conducted here was to investigate the gene and protein expression of Toll like receptor 9 when human bronchial epithelial cells were induced by lipopolysaccharide. TLRs are pattern recognition receptor (PRR) which plays a key role in innate immunity. They recognise the molecules that are shared by pathogens but distinguishes from the host which is referred to as pathogen associated molecular patterns (PAMPs). The HBECs were first cultured and once it becomes confluent they were induced with 10ng/ml of LPS. In order to find out whether the gene was expressed in the cells, the RNA was isolated and RT-PCR was carried out. Before carrying out the RT-PCR, RNA gel electrophoresis was carried out to show the 28S and 18S bands. Once the gene expression was analysed protein expression was carried out by extracting the protein using RIPA buffer and running the SDS-PAGE followed by staining. Silver staining and western blotting results revealed clear bands at 116kDa illustrating that the TLR9 protein had been expressed. RT-PCR results showed that a smear of bands for TLR9 and the in protein expression bands were seen in TLR9 protein region which indicates that TLR9 was expressed in the HBEC by LPS
