Nasal LPS Challenge in Healthy Volunteers

The purpose of this study is to develop a nasal challenge model that causes a mild degree of inflammation, without causing any pain or symptoms, but that allows us to measure a variety of proteins in nasal secretions which causes inflammation in the nose. The nasal challenge model involves spraying the nostrils in the form of a fine mist with 4 different doses (1, 10, 30 and 100µg per nostril) of lipopolysaccharide (LPS) including a placebo. LPS is a type of protein which has been carefully purified from the outer cell wall of certain bacteria, is sterile and does not contain live bacteria, and will not cause infection. The investigators will measure any inflammation in the nose by looking at cells collected by washing the inside of the nose (nasal lavage) and placing small strips of paper in the nasal cavity. The paper absorbs the nasal fluid and the chemicals produced during inflammation and can be extracted from the paper and analysed in the laboratory. The investigators will also be collecting a small amount of nasal epithelium taken by way of a nasal scrape; this is done by using a Rhinoprobe, a small plastic curette which is used to scrape a small piece of lining of the nose. The investigators hope that information obtained from this study will be used in future studies that will test new study drugs designed to treat diseases of the airways and lungs ( like asthma and chronic obstructive pulmonary disease (COPD) and hay fever.