Fluorescence-Reported Allelic Exchange Mutagenesis Reveals a Role for Chlamydia trachomatis TmeA in Invasion That Is Independent of Host AHNAK

• Published in: Infection and immunity 2017-12, Vol.85 (12)
• Main Authors: McKuen, M J, Mueller, K E, Bae, Y S, Fields, K A
• Format: Article
• Language: English
• Subjects: Animals; Bacterial Proteins - genetics; Bacterial Proteins - metabolism; Cells, Cultured; Cellular Microbiology: Pathogen-Host Cell Molecular Interactions; Chlamydia Infections - pathology; Chlamydia trachomatis - genetics; Chlamydia trachomatis - pathogenicity; Disease Models, Animal; Fluorescence; Gene Targeting - methods; Humans; Membrane Proteins - metabolism; Mice; Mutagenesis; Neoplasm Proteins - metabolism; Recombination, Genetic; Survival Analysis; Virulence Factors - genetics; Virulence Factors - metabolism
• ISSN: 0019-9567; 1098-5522
• DOI: 10.1128/IAI.00640-17

Development of approaches to genetically manipulate is fostering important advances in understanding pathogenesis. luorescence- eported llelic xchange utagenesis (FRAEM) now enables the complete deletion of specific genes in L2. We have leveraged this technology to delete the coding sequences for a known type III effector. The evidence provided here indicates that CT694/CTL0063 is a virulence protein involved in chlamydial invasion. Based on our findings, we designate the gene product corresponding to ranslocated embrane-associated ffector A (TmeA). Deletion of did not impact development of intracellular chlamydiae. However, the absence of TmeA manifested as a decrease in infectivity in both tissue culture and murine infection models. The defect was reflected by impaired invasion of host cells. TmeA binds human AHNAK, and we demonstrate here that AHNAK is transiently recruited by invading chlamydiae. TmeA, however, is not required for endogenous AHNAK recruitment. TmeA also impairs AHNAK-dependent actin bundling activity. This TmeA-mediated effect likely does not explain impaired invasion displayed by the strain of , since AHNAK-deficient cells revealed no invasion phenotype. Overall, our data indicate the efficacy of FRAEM and reveal a role of TmeA during chlamydial invasion that manifests independently of effects on AHNAK.