NRSA Fellowship for Gabrielle Keb: Chlamydia Trachomatis Secreted Effector Proteins: Infection Properties and Identification of Host Targets

Intracellular Chlamydia lacking both TmeA and TmeB, type III secreted anti-host proteins, generate fewer chlamydial progeny in tissue culture and have significantly decreased infectivity in mice. Previous attempts to identify their functions utilized fluorescence-reported allelic exchange mutagenesis (FRAEM), but resulted in unclear phenotypes due to cassette-induced polar effects. Recently, I have developed floxed-cassette allelic exchange mutagenesis (FLAEM), to reverse cassette-induced polar effects and generate the first ever markerless C. trachomatis deletion mutant. I hypothesize that TmeA and TmeB are functionally related and important for establishing the inclusion, because they are co-transcribed, share a common chaperone, and are secreted into the host cell at the same time. The proposed work will utilize the marker-less C. trachomatis deletion mutant to determine when during chlamydial development TmeA and TmeB are important, and identify their eukaryotic host cell targets. The outcomes of this research will directly contribute to understanding of chlamydial biology and will identify potential drug targets to prevent the spread of infection to millions world-wide.