T cell phenotypes in women with Chlamydia trachomatis infection and influence of treatment on phenotype distributions

T cell phenotypes involved in the immune response to Chlamydia trachomatis (CT) have not been fully elucidated in humans. We evaluated differences in T cell phenotypes between CT-infected women and CT-seronegative controls and investigated changes in T cell phenotype distributions after CT treatment and their association with reinfection. We found a higher expression of T cell activation markers (CD38⁺HLA-DR⁺), T helper type 1 (Th1)- and Th2-associated effector phenotypes (CXCR3⁺CCR5⁺ and CCR4⁺, respectively), and T cell homing marker (CCR7) for both CD4⁺ and CD8⁺ T cells in CT-infected women. At follow-up after treatment of infected women, there were a lower proportion of CD4⁺ and CD8⁺ T cells expressing these markers. These findings suggest a dynamic interplay of CD4⁺ and CD8⁺ T cells in CT infection, and once the infection is treated, these cell markers return to basal expression levels. In women without reinfection, a significantly higher proportion of CD8⁺ T cells co-expressing CXCR3 with CCR5 or CCR4 at follow-up was detected compared to women with reinfection, suggesting they might play some role in adaptive immunity. Our study elucidated changes in T cell phenotypes during CT infection and after treatment, broadening our understanding of adaptive immune mechanisms in human CT infections.     

The habitat and conduit functions of roads in the spread of three invasive plant species

Nonnative plant species commonly occur along roadsides, and populations are often assumed to invade by spread along the road axis. To distinguish between the function of roadsides as movement corridors and as habitat, nonnative plant species were surveyed along roads in deciduous forest sites in southeastern Ohio, USA. The importance of road proximity was tested by comparing nonnative species abundance in 100 m transects along roads with transects in undisturbed forest. Nonnative species were most abundant and most frequently observed in roadside sites in valleys. Three common species were chosen for closer scrutiny. In a seed sowing experiment roads and open sites proved to be better locations for the germination and growth of Microstegium vimineum than non-roadside and closed-canopy sites. Tussilago farfara and Rosa multiflora occurred in a small number of disjunct patches suggesting infrequent arrival in the sampled transects. Both species were strongly clustered at scales consistent with diffusive spread by vegetative growth and short-range seed dispersal. Comparisons of distributions parallel and perpendicular to roads showed no evidence for enhanced dispersal along the road axis. Microstegium distributions were correlated with local light availability implying site saturation. Microstegium micro-distributions suggested that spread along the road axis was facilitated by movement of dormant seeds in road maintenance. Thus, roadsides appear to function as both habitat and a conduit for population expansion, with the rate of spread dependent on the life history of the individual species. These results suggest a hierarchical process of regional invasion, with different dispersal mechanisms functioning at different spatial scales.     

Prion Protein NMR Structure from Tammar Wallaby (Macropus eugenii) Shows that the β2-α2 Loop Is Modulated by Long-Range Sequence Effects

NMR structures are presented for the recombinant construct of residues 121-230 from the tammar wallaby (Macropus eugenii) prion protein (PrP) twPrP(121-230) and for the variant mouse PrPs mPrP[Y225A,Y226A](121-231) and mPrP[V166A](121-231) at 20 °C and pH 4.5. All three proteins exhibit the same global architecture as seen in other recombinant PrP^Cs (cellular isoforms of PrP) and shown to prevail in natural bovine PrP^C. Special interest was focused on a loop that connects the β2-strand with helix α2 in the PrP^C fold, since there are indications from in vivo experiments that this local structural feature affects the susceptibility of transgenic mice to transmissible spongiform encephalopathies. This β2-α2 loop and helix α3 form a solvent-accessible contiguous epitope, which has been proposed to be the recognition area for a hypothetical chaperone, the “protein X”. This hypothetical chaperone would affect the conversion of PrP^C into the disease-related scrapie form (PrP^Sc) by moderating intermolecular interactions related to the transmission barrier of transmissible spongiform encephalopathies between different species. In contrast to mPrP(121-231) and most other mammalian PrP^Cs, the β2-α2 loop is well defined at 20 °C in tammar wallaby PrP and in the two aforementioned variants of mPrP, showing that long-range interactions with helix α3 can have an overriding influence on the structural definition of the β2-α2 loop. Further NMR studies with two variant mPrPs, mPrP[Y225A](121-231) and mPrP[Y226A](121-231), showed that these interactions are dominantly mediated by close contacts between residues 166 and 225. The results of the present study then lead to the intriguing indication that well-defined long-range intramolecular interactions could act as regulators of the functional specificity of PrP^C.     

Endotoxin Induced Chorioamnionitis Prevents Intestinal Development during Gestation in Fetal Sheep

Chorioamnionitis is the most significant source of prenatal inflammation and preterm delivery. Prematurity and prenatal inflammation are associated with compromised postnatal developmental outcomes, of the intestinal immune defence, gut barrier function and the vascular system. We developed a sheep model to study how the antenatal development of the gut was affected by gestation and/or by endotoxin induced chorioamnionitis.Chorioamnionitis was induced at different gestational ages (GA). Animals were sacrificed at low GA after 2d or 14d exposure to chorioamnionitis. Long term effects of 30d exposure to chorioamnionitis were studied in near term animals after induction of chorioamnionitis. The cellular distribution of tight junction protein ZO-1 was shown to be underdeveloped at low GA whereas endotoxin induced chorioamnionitis prevented the maturation of tight junctions during later gestation. Endotoxin induced chorioamnionitis did not induce an early (2d) inflammatory response in the gut in preterm animals. However, 14d after endotoxin administration preterm animals had increased numbers of T-lymphocytes, myeloperoxidase-positive cells and gammadelta T-cells which lasted till 30d after induction of chorioamnionitis in then near term animals. At early GA, low intestinal TLR-4 and MD-2 mRNA levels were detected which were further down regulated during endotoxin-induced chorioamnionitis. Predisposition to organ injury by ischemia was assessed by the vascular function of third-generation mesenteric arteries. Endotoxin-exposed animals of low GA had increased contractile response to the thromboxane A2 mimetic U46619 and reduced endothelium-dependent relaxation in responses to acetylcholine. The administration of a nitric oxide (NO) donor completely restored endothelial dysfunction suggesting reduced NO bioavailability which was not due to low expression of endothelial nitric oxide synthase.Our results indicate that the distribution of the tight junctional protein ZO-1, the immune defence and vascular function are immature at low GA and are further compromised by endotoxin-induced chorioamnionitis. This study suggests that both prematurity and inflammation in utero disturb fetal gut development, potentially predisposing to postnatal intestinal pathology.     

Solar Drinking Water Disinfection (SODIS) to Reduce Childhood Diarrhoea in Rural Bolivia: A Cluster-Randomized,Controlled Trial

Background

Solar drinking water disinfection (SODIS) is a low-cost, point-of-use water purification method that has been disseminated globally. Laboratory studies suggest that SODIS is highly efficacious in inactivating waterborne pathogens. Previous field studies provided limited evidence for its effectiveness in reducing diarrhoea.

Methods and Findings

We conducted a cluster-randomized controlled trial in 22 rural communities in Bolivia to evaluate the effect of SODIS in reducing diarrhoea among children under the age of 5 y. A local nongovernmental organisation conducted a standardised interactive SODIS-promotion campaign in 11 communities targeting households, communities, and primary schools. Mothers completed a daily child health diary for 1 y. Within the intervention arm 225 households (376 children) were trained to expose water-filled polyethyleneteraphtalate bottles to sunlight. Eleven communities (200 households, 349 children) served as a control. We recorded 166,971 person-days of observation during the trial representing 79.9% and 78.9% of the total possible person-days of child observation in intervention and control arms, respectively. Mean compliance with SODIS was 32.1%. The reported incidence rate of gastrointestinal illness in children in the intervention arm was 3.6 compared to 4.3 episodes/year at risk in the control arm. The relative rate of diarrhoea adjusted for intracluster correlation was 0.81 (95% confidence interval 0.59–1.12). The median length of diarrhoea was 3 d in both groups.

Conclusions

Despite an extensive SODIS promotion campaign we found only moderate compliance with the intervention and no strong evidence for a substantive reduction in diarrhoea among children. These results suggest that there is a need for better evidence of how the well-established laboratory efficacy of this home-based water treatment method translates into field effectiveness under various cultural settings and intervention intensities. Further global promotion of SODIS for general use should be undertaken with care until such evidence is available.

Trial Registration

www.ClinicalTrials.gov {"type":"clinical-trial","attrs":{"text":"NCT00731497","term_id":"NCT00731497"}}NCT00731497 Please see later in the article for Editors'' Summary     

Multidrug resistance-associated protein-1 (MRP1) genetic variants,MRP1 protein levels and severity of COPD

Background

Multidrug resistance-associated protein-1 (MRP1) protects against oxidative stress and toxic compounds generated by cigarette smoking, which is the main risk factor for chronic obstructive pulmonary disease (COPD). We have previously shown that single nucleotide polymorphisms (SNPs) in MRP1 significantly associate with level of FEV₁ in two independent population based cohorts. The aim of our study was to assess the associations of MRP1 SNPs with FEV₁ level, MRP1 protein levels and inflammatory markers in bronchial biopsies and sputum of COPD patients.

Methods

Five SNPs (rs212093, rs4148382, rs504348, rs4781699, rs35621) in MRP1 were genotyped in 110 COPD patients. The effects of MRP1 SNPs were analyzed using linear regression models.

Results

One SNP, rs212093 was significantly associated with a higher FEV₁ level and less airway wall inflammation. Another SNP, rs4148382 was significantly associated with a lower FEV₁ level, higher number of inflammatory cells in induced sputum and with a higher MRP1 protein level in bronchial biopsies.

Conclusions

This is the first study linking MRP1 SNPs with lung function and inflammatory markers in COPD patients, suggesting a role of MRP1 SNPs in the severity of COPD in addition to their association with MRP1 protein level in bronchial biopsies.     

Comparing the Cervista HPV HR Test and Hybrid Capture 2 Assay in a Dutch Screening Population: Improved Specificity of the Cervista HPV HR Test by Changing the Cut-Off

The diagnostic performance of the widely-used Cervista HPV HR test was compared to the Hybrid Capture 2 (HC2) test in a Dutch population-based cervical cancer screening program. In 900 scrapings of women with normal cytomorphology, specificity was 90% (95%CI: 87.84–91.87) for the Cervista HPV HR test and 96% (95%CI: 94.76–97.37) for the HC2 test with 93% agreement between both tests (κ = 0.5, p<0.001). The sensitivity for CIN2+ using 65 scrapings of women with histological-confirmed CIN2+ was 91% (95%CI: 80.97–96.51) for the Cervista HPV HR test and 92% (95%CI: 82.94–97.43) for the HC2 test with 95% agreement between both tests (κ = 0.7, p<0.001). Fifty-seven of 60 HC2 negative/Cervista positive cases tested HPV-negative with PCR-based HPV assays; of these cases 56% were defined as Cervista triple-positive with FOZ values in all 3 mixes higher than the second cut-off of 1.93 (as set by manufacturer). By setting this cut-off at 5.0, specificity improved significantly without affecting sensitivity. External validation of this new cut-off at 5.0 in triple-positive scrapings of women selected from the SHENCCASTII database revealed that 22/24 histological normal cases now tested HPV-negative in the Cervista HPV HR test, while CIN2+ lesions remained HPV-positive. The intra-laboratory reproducibility of the Cervista HPV HR test (n = 510) showed a concordance of 92% and 93% for cut-off 1.93 and 5.0 (κ = 0.83 and κ = 0.84, p<0.001) and inter-laboratory agreement of the Cervista HPV HR test was 90% and 93% for cut-off 1.93 and 5.0 (κ = 0.80 and κ = 0.85, p<0.001). In conclusion, the specificity of the Cervista HPV HR test could be improved significantly by increasing the second cut-off from 1.93 to 5.0, without affecting the sensitivity of the test in a population-based screening setting.     

Enhancing TB Case Detection: Experience in Offering Upfront Xpert MTB/RIF Testing to Pediatric Presumptive TB and DR TB Cases for Early Rapid Diagnosis of Drug Sensitive and Drug Resistant TB

Background

Diagnosis of pulmonary tuberculosis (PTB) in children is challenging due to difficulties in obtaining good quality sputum specimens as well as the paucibacillary nature of disease. Globally a large proportion of pediatric tuberculosis (TB) cases are diagnosed based only on clinical findings. Xpert MTB/RIF, a highly sensitive and specific rapid tool, offers a promising solution in addressing these challenges. This study presents the results from pediatric groups taking part in a large demonstration study wherein Xpert MTB/RIF testing replaced smear microscopy for all presumptive PTB cases in public health facilities across India.

Methods

The study covered a population of 8.8 million across 18 programmatic sub-district level tuberculosis units (TU), with one Xpert MTB/RIF platform established at each study TU. Pediatric presumptive PTB cases (both TB and Drug Resistant TB (DR-TB)) accessing any public health facilities in study area were prospectively enrolled and tested on Xpert MTB/RIF following a standardized diagnostic algorithm.

Results

4,600 pediatric presumptive pulmonary TB cases were enrolled. 590 (12.8%, CI 11.8–13.8) pediatric PTB were diagnosed. Overall 10.4% (CI 9.5–11.2) of presumptive PTB cases had positive results by Xpert MTB/RIF, compared with 4.8% (CI 4.2–5.4) who had smear-positive results. Upfront Xpert MTB/RIF testing of presumptive PTB and presumptive DR-TB cases resulted in diagnosis of 79 and 12 rifampicin resistance cases, respectively. Positive predictive value (PPV) for rifampicin resistance detection was high (98%, CI 90.1–99.9), with no statistically significant variation with respect to past history of treatment.

Conclusion

Upfront access to Xpert MTB/RIF testing in pediatric presumptive PTB cases was associated with a two-fold increase in bacteriologically-confirmed PTB, and increased detection of rifampicin-resistant TB cases under routine operational conditions across India. These results suggest that routine Xpert MTB/RIF testing is a promising solution to present-day challenges in the diagnosis of PTB in pediatric patients.     

The Homeostatic Chemokine CCL21 Predicts Mortality in Aortic Stenosis Patients and Modulates Left Ventricular Remodeling

Background

CCL21 acting through CCR7, is termed a homeostatic chemokine. Based on its role in concerting immunological responses and its proposed involvement in tissue remodeling, we hypothesized that this chemokine could play a role in myocardial remodeling during left ventricular (LV) pressure overload.

Methods and Results

Our main findings were: (i) Serum levels of CCL21 were markedly raised in patients with symptomatic aortic stenosis (AS, n = 136) as compared with healthy controls (n = 20). (ii) A CCL21 level in the highest tertile was independently associated with all-cause mortality in these patients. (iii) Immunostaining suggested the presence of CCR7 on macrophages, endothelial cells and fibroblasts within calcified human aortic valves. (iv). Mice exposed to LV pressure overload showed enhanced myocardial expression of CCL21 and CCR7 mRNA, and increased CCL21 protein levels. (v) CCR7^−/− mice subjected to three weeks of LV pressure overload had similar heart weights compared to wild type mice, but increased LV dilatation and reduced wall thickness.

Conclusions

Our studies, combining experiments in clinical and experimental LV pressure overload, suggest that CCL21/CCR7 interactions might be involved in the response to pressure overload secondary to AS.