Application of β-lactamase Reporter Fusions as an Indicator of Effector Protein Secretion During Infections with the Obligate Intracellular Pathogen Chlamydia trachomatis

Authors

Konrad E. Mueller, University of KentuckyFollow
Kenneth A. Fields, University of KentuckyFollow

Abstract

Chlamydia spp. utilize multiple secretion systems, including the type III secretion system (T3SS), to deploy host-interactive effector proteins into infected host cells. Elucidation of secreted proteins has traditionally required ectopic expression in a surrogate T3SS followed by immunolocalization of endogenous candidate effectors to confirm secretion by chlamydiae. The ability to transform Chlamydia and achieve stable expression of recombinant gene products has enabled a more direct assessment of secretion. We adapted TEM-1 β-lactamase as a reporter system for assessment of chlamydial protein secretion. We provide evidence that this system facilitates visualization of secretion in the context of infection. Specifically, our findings provide definitive evidence that C. trachomatis CT695 is secreted during infection. Follow-up indirect immunofluorescence studies confirmed CT695 secretion and indicate that this effector can be secreted at multiple points during the chlamydial developmental cycle. Our results indicate that the BlaM-fusion reporter assay will allow efficacious identification of novel secreted proteins. Moreover, this approach can easily be adapted to enable more sophisticated studies of the secretion process in Chlamydia.

Document Type

Article

Publication Date

8-10-2015

Notes/Citation Information

Published in PLOS One, vol. 10, no. 8, article e0135295, p. 1-18.

© 2015 Mueller, Fields.

This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

Digital Object Identifier (DOI)

http://dx.doi.org/10.1371/journal.pone.0135295

Funding Information

This work is supported by a grant from NIAID: AI065530.

Repository Citation

Mueller, Konrad E. and Fields, Kenneth A., "Application of β-lactamase Reporter Fusions as an Indicator of Effector Protein Secretion During Infections with the Obligate Intracellular Pathogen Chlamydia trachomatis " (2015). Microbiology, Immunology, and Molecular Genetics Faculty Publications. 76.
https://uknowledge.uky.edu/microbio_facpub/76