Bronchiectasis With Chronic Infection With Pseudomonas Aeruginosa

The goal of this study is to determine if viral infection with the common cold leads to an exacerbation in participants with bronchiectasis. The investigators will compare the participants with bronchiectasis to a group of healthy participants. The main questions it aims to answer are: * Does viral infection with the common cold lead to an exacerbation in bronchiectasis? * Does the immune response differ to that of a healthy participant? Participants will attend for a screening visit to see if they are eligible. All participants who are eligible and have consented to take part will have baseline investigations done including blood tests and a bronchoscopy. They will be given a spray of a virus that causes the common cold into their nose. They will then be followed up over the next 6 weeks with some of the following procedures at each study visit; spirometry, nasosorption, nasal lavage, nasal brushing, blood test, sputum collection and a bronchoscopy. Participants will be asked to keep a daily record of their symptoms throughout the study.