Suitability of a Low Dose Lipopolysaccharide (LPS) Inhalation as a Challenge Model

Inclusion Criteria: * Able and willing to give written informed consent * Healthy male and female nonsmokers, aged 18 to 55 years, with a history of less than 1 pack year having been nonsmokers for at least the last five years * FEV1 ≥ 80 % of predicted, FEV1/FVC ≥ 70 %. * Available to complete all study measurements * Subjects must be able to produce adequate sputum (≥ 1× 106 total cells, ≥ 50 % cell viability, ≤ 20 % squamous epithelial cells) * Negative methacholine challenge (\> 8 mg/mL) * Women will be considered for inclusion if they are: Not pregnant, as confirmed by pregnancy test (see flow chart), and not nursing. Of non-child bearing potential (i.e. physiologically incapable of becoming pregnant, including any female who is pre-menarchial or post-menopausal, with documented proof of hysterectomy or tubal ligation, or meets clinical criteria for menopause and has been amenorrhoeic for more than 1 year prior to the screening visit). Of childbearing potential and using a highly effective method of contraception during the entire study (vasectomised partner, sexual abstinence - the lifestyle of the female should be such that there is complete abstinence from intercourse from two weeks prior to the first dose of study medication until at least 72 hours after treatment -, implants, injectables, combined oral contraceptives, hormonal IUDs or double-barrier methods, i.e. any double combination of IUD, condom with spermicidal gel, diaphragm, sponge, and cervical cap). Exclusion Criteria: * Upper or lower respiratory tract infection in the last four weeks prior to screening * Past or present disease, which as judged by the investigator, may affect the outcome of the study. These diseases include, but are not limited to, cardiovascular disease, malignancy, hepatic disease, renal disease, hematological disease, neurological disease, psychiatric disease, endocrine disease, infectious disease, inflammatory disease or pulmonary disease (including but not confined to asthma, tuberculosis, bronchiectasis or cystic fibrosis) * Regular intake of any prescribed or over the counter medication. Exceptions include paracetamol for pain relief, oral contraceptive medication, hormonal replacement therapy, dietary and vitamin supplements * Any clinically relevant abnormal findings in physical examination, clinical chemistry, hematology, urinalysis, vital signs or ECG at Visit 1, which, in the opinion of the investigator, may either put the subject at risk because of participation in the study, or may influence the results of the study, or the subject's ability to participate in the study. * Administration of corticosteroids within the last 2 weeks prior to screening. Administration of topical corticosteroids within the last 2 weeks prior to screening is permitted at the discretion of the investigator. * History of drug or alcohol abuse * Risk of non-compliance with study procedures * Suspected inability to understand the protocol requirements, instructions and study-related restrictions, the nature, scope, and possible consequences of the study.