SCAN:Secretion and function of virulence proteins of Chlamydia trachomatis

ITQB Scan Seminar

Title: Secretion and function of virulence proteins of Chlamydia trachomatis

Speaker: Jaime Mota

From: Head of Infection Biology Laboratory

Abstract:

Chlamydiae are a large family of obligate intracellular bacteria of eukaryotes, which includes human and animal pathogens as well as endosymbionts of free-living amoebae. These bacteria reside and multiply in host cells within a membranous vacuolar compartment, known as an inclusion. Of particular relevance, Chlamydia trachomatis causes ocular and genital infections in humans that are a significant concern. C. trachomatis strains can be divided into i) epitheliotropic strains (showing tropism for ocular and urogenital epithelial cells) and ii) invasive strains (showing tropism for macrophages and lymph nodes).
C. trachomatis interfere with various host cell processes such as cytoskeleton dynamics, apoptosis, or expression and release of cytokines. Our knowledge of the underlying molecular and cellular mechanisms is relatively scarce, mainly because there are no straightforward genetic tools to manipulate Chlamydiae. However, C. trachomatis uses a type III secretion (T3S) system to inject bacterial virulence (effector) proteins into host cells. More than 10% of the C. trachomatis genes might encode T3S substrates, suggesting that these proteins have a critical role during the bacteria-host cell interaction.
In this SCAN seminar, I will present our studies aiming to: 1) analyse the role of chlamydial type III secreted proteins that localise to the inclusion membrane (Inc proteins) in the different cellular tropisms associated with C. trachomatis infections; 2) identify novel C. trachomatis T3S effectors proteins and study their function; 3) understand how secretion of the > 100 C. trachomatis T3S substrates might be coordinated during host cell infection.