Plasmid-Cured Chlamydia caviae Activates TLR2-Dependent Signaling and Retains Virulence in the Guinea Pig Model of Genital Tract Infection

Loss of the conserved “cryptic” plasmid from C. trachomatis and C. muridarum is pleiotropic, resulting in reduced innate inflammatory activation via TLR2, glycogen accumulation and infectivity. The more genetically distant C. caviae GPIC is a natural pathogen of guinea pigs and induces upper genital tract pathology when inoculated intravaginally, modeling human disease. To examine the contribution of pCpGP1 to C. caviae pathogenesis, a cured derivative of GPIC, strain CC13, was derived and evaluated in vitro and in vivo. Transcriptional profiling of CC13 revealed only partial conservation of previously identified plasmid-responsive chromosomal loci (PRCL) in C. caviae. However, 2-deoxyglucose (2DG) treatment of GPIC and CC13 resulted in reduced transcription of all identified PRCL, including glgA, indicating the presence of a plasmid-independent glucose response in this species. In contrast to plasmid-cured C. muridarum and C. trachomatis, plasmid-cured C. caviae strain CC13 signaled via TLR2 in vitro and elicited cytokine production in vivo similar to wild-type C. caviae. Furthermore, inflammatory pathology induced by infection of guinea pigs with CC13 was similar to that induced by GPIC, although we observed more rapid resolution of CC13 infection in estrogen-treated guinea pigs. These data indicate that either the plasmid is not involved in expression or regulation of virulence in C. caviae or that redundant effectors prevent these phenotypic changes from being observed in C. caviae plasmid-cured strains

NACA Research Memorandums

Report presenting testing of the subsonic and transonic handling qualities of the Douglas D-558-II research airplane using several configurations of mid-semispan external stores in the altitude region of 20,000 to 40,000 feet. The configurations had an underslung pylon on each wing, pylons plus simulated 1000-pound bombs, and pylons with 150-gallon fuel tanks. Results regarding longitudinal stability and control characteristics, low-speed characteristics, and lateral stability and control characteristics are provided

NACA Research Memorandums

Report presenting the lateral stability and control characteristics of the Convair YF-102 airplane during flights for the NACA research program. The investigation included gradually increasing sideslips, rudder-fixed aileron rolls, rudder pulses, and trim runs at two different altitudes over the test Mach number range. The lateral handling characteristics appeared satisfactory when viewed in terms of gradually increasing sideslips

NACA Research Memorandums

Report presenting an analysis of the longitudinal stability characteristics of the cambered-wing version of the Convair YF-102 airplane at a range of Mach numbers and altitudes. Results regarding longitudinal trim, stall maneuvers, dynamic longitudinal stability, maneuvering stability, stability and control effectiveness parameters, and artificial-feel system are provided

Relationship between Intracranial Granulomas and Cerebrospinal Fluid Levels of Gamma Interferon and Interleukin-10 in Patients with Tuberculous Meningitis

Cerebrospinal fluid gamma interferon (IFN-γ) and interleukin-10 levels in 39 patients with tuberculous meningitis were serially measured. Cytokine levels did not predict intracranial granuloma (IG) development, but IFN-γ levels in the top quartile after 1 month of therapy were highly associated (odds ratio = 18) with detection of an IG by computed tomography scanning

Cellular infiltrates are similar early during infection in estradiol-treated guinea pigs infected with GPIC or CC13.

<p>Groups of 5 estradiol-treated female guinea pigs infected with GPIC or CC13 were sacrificed on day 9. Pathology scores for inflammatory cells in the (A) uterine horns, and (B) oviducts were similar for GPIC- and CC13-infected animals. Boxes extend from the 25-75 percentiles and whiskers indicate the 5^th–95^th percentiles. (C, E) Representative oviduct histologic sections at 40X and 200X magnification from a guinea pig infected with GPIC. (D, F) Representative oviduct histologic sections at 40X and 200X magnification from a guinea pig infected with CC13. Data are from one experiment with 5 guinea pigs per group.</p

Effect of 2DG treatment on inclusion formation and transcription by <i>C. caviae</i>.

<p>(A) GPIC inclusions in L929 cells 40 hours post infection (A–C). Inclusions formed by GPIC in cells treated with 10 mM 2DG are smaller (B) and may contain aberrant forms (C). Cells were fixed with methanol then stained with an anti-LPS monoclonal antibody and anti-mouse Alexa488 (secondary) to detect chlamydiae and cytoplasm was counterstained with Evans Blue. All inclusions were imaged at 400x magnification. (D) GPIC differentially regulates candidate PRCL transcription in response to 2DG treatment. Total RNA was isolated 24 hours after infection from infected cells treated with 10 mM 2DG and transcripts were quantified as for <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0030747#pone-0030747-g002" target="_blank">Fig. 2D</a>. (E) Reduced PRCL transcription is plasmid-independent in <i>C. caviae</i>. L929 cells infected with CC13 were treated with 2DG as for ‘C’ and transcription of plasmid-insensitive loci 24 hours after infection was examined as before. The transcriptional differences are presented as fold change in expression for each gene in a single representative experiment although each experiment was performed independently at least twice and samples were assayed in triplicate. <i>p</i> values for transcripts indicated with * were <0.05.</p