Discovery of a vaccine antigen that protects mice from Chlamydia pneumoniae infection.

Chlamydiae are atypical intracellular bacteria that infect via mucosal surfaces causing, for example, trachoma, pneumonia, cervicitis, urethritis and infertility. Existing antibiotics are only partially effective and no vaccines are available. Using surface expressed or secreted proteins previously identified by genomics and proteomics we tested five as vaccines against intranasal challenge with Chlamydia pneumoniae. One antigen, LcrE, induced CD4+ and CD8+ T cell activation, type 1 cytokine secretion and neutralising antibodies and was completely effective in eliminating infection. Such antigens are highly conserved and essential to all Chlamydial species. The discovery of an effective vaccine for Chlamydiae pneumoniae has potential wide benefits for human health.

Manipulation of immunity to and pathology of respiratory infections.

Respiratory infections are the third leading cause of death worldwide and are a priority for vaccine development. Immune defence mechanisms are critical in recovery from most respiratory infections but the role of the immune system in causing bystander lung injury is not as well understood, and will be the focus of this review. Immune-mediated injury results from physical occlusion of the airways or the ensuing 'cytokine storm', which may spill over into the systemic circulation and cause devastating consequences. Respiratory pathogens employ numerous strategies to avoid detection by the immune system. One of these, the alteration of key surface determinants, makes the design of rational vaccines problematic. In the following review the immune compartments responsible for clinical lung disease are discussed, and current and novel strategies to reduce their potency are overviewed.