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Problem Chlamydia trachomatis genital tract infections are easily treated with antibiotics; however, the majority of infections are asymptomatic and therefore untreated, highlighting the need for a vaccine. Because most infections are asymptomatic, vaccination could potentially be administered to individuals who may have an acute infection at that time. In such individuals, the effect of vaccination on the existing infection is unknown; however, one potential outcome could be the development of a persistent infection. In vitro chlamydial persistence has been well characterized in various strains; however, there have been no reported studies in C. muridarum. Method of Study We performed ultrastructural characterization and transcriptome analysis of selected genes. We then used the transcriptional profiles of the selected genes to examine whether intranasal immunization of mice during an active genital infection would induce persistence in the upper reproductive tract of female mice. Results and Conclusions We found that persistence developed in the oviducts of mice as a result of immunization. This is a significant finding, not only because it is the first time that C. muridarum persistence has been characterized in vitro, but also due to the fact that there is a minimal characterization of in vivo persistence of any chlamydial species. This highlights the importance of the timing of vaccination in individuals. [ABSTRACT FROM AUTHOR]

Huston WM, Gloeckl S, de Boer L, Beagley KW, Timms P. Apoptosis is induced in Chlamydia trachomatis-infected HEp-2 cells by the addition of a combination innate immune activation compounds and the inhibitor wedelolactone. Am J Reprod Immunol 2011; 65: 460-465 Innate immune activation of human cells, for some intracellular pathogens, is advantageous for vacuole morphology and pathogenic viability. It is unknown whether innate immune activation is advantageous to Chlamydia trachomatis viability. Innate immune activation of HEp-2 cells during Chlamydia infection was conducted using lipopolysaccharide (LPS), polyI:C, and wedelolactone (innate immune inhibitor) to investigate the impact of these conditions on viability of Chlamydia. The addition of LPS and polyI:C to stimulate activation of the two distinct innate immune pathways (nuclear factor kappa beta and interferon regulatory factor) had no impact on the viability of Chlamydia. However, when compounds targeting either pathway were added in combination with the specific innate immune inhibitor (wedelolactone) a major impact on Chlamydia viability was observed. This impact was found to be due to the induction of apoptosis of the HEp-2 cells under these conditions. This is the first time that induction of apoptosis has been reported in C. trachomatis-infected cells when treated with a combination of innate immune activators and wedelolactone. [ABSTRACT FROM AUTHOR]