Chlamydia and Innate Immunity
Uma M. Nagarajan, Breanna J. Turman, Michael R. Knittler and Andreas Klos
from: Chlamydia Biology: From Genome to Disease (Edited by: Ming Tan, Johannes H. Hegemann and Christine Sütterlin). Caister Academic Press, U.K. (2020) Pages: 287-312.
As an obligate intracellular bacterium, Chlamydia is detected by intracellular and extracellular host proteins to mount an innate immune response. The extracellular innate detectors in body fluids include complement and antimicrobial peptides, while the intracellular detectors are the pathogen recognition receptors. Engagement of these receptors with Chlamydia lead to intracellular signalling resulting in cytokine/chemokine secretion. Innate immune cells, such as neutrophils, NK cells, and macrophages, come to the site of infection in response to the chemokine gradients and also produce cytokines such as IFN-g, which can reduce bacterial burden by activation of interferon-response genes and GTPases. The innate immune response to Chlamydia is ineffective at clearing the infection, a finding which has long suggested that the pathogen has evolved means, at the humoral, extra-cellular and cytosolic levels, to subvert this host response. However, the innate response during Chlamydia infection is also associated with tissue pathology. Therefore, a better understanding of the key mediators of chlamydial recognition and early host responses can provide us with potential targets to mitigate host pathology read more ...