ABSTRACT
This chapter discusses chlamydiae and speculations about how this genus of obligate intracellular prokaryotic pathogens has adapted to a very specific ecological niche; and a vacuole within the cytoplasm of a eukaryotic host cell. The true nature of the chlamydiae begins to emerge when their growth and development are put into context with the host cell. If antibodies play a role in controlling chlamydial growth in situ, then the chlamydiae must be continuously accessible to either local or serum antibodies. Localization of chlamydiae to the confines of membrane-bound inclusions within the cytoplasm of infected cells serves to protect these organisms from immune mechanisms restricted to the extracellular milieu. The chapter describes immune responses that are induced in response to chlamydiae and how these responses may influence the interactions between chlamydiae and their host cells and the overall outcome of infection. Cytokine-mediated persistence may help explain the nature of tissue damaging inflammation as a result of chlamydial infection.
