Disentangling a Holobiont – Recent Advances and Perspectives in Nasonia Wasps

The parasitoid wasp genus Nasonia (Hymenoptera: Chalcidoidea) is a well-established model organism for insect development, evolutionary genetics, speciation, and symbiosis. The host-microbiota assemblage which constitutes the Nasonia holobiont (a host together with all of its associated microbes) consists of viruses, two heritable bacterial symbionts and a bacterial community dominated in abundance by a few taxa in the gut. In the wild, all four Nasonia species are systematically infected with the obligate intracellular bacterium Wolbachia and can additionally be co-infected with Arsenophonus nasoniae. These two reproductive parasites have different transmission modes and host manipulations (cytoplasmic incompatibility vs. male-killing, respectively). Pioneering studies on Wolbachia in Nasonia demonstrated that closely related Nasonia species harbor multiple and mutually incompatible Wolbachia strains, resulting in strong symbiont-mediated reproductive barriers that evolved early in the speciation process. Moreover, research on host-symbiont interactions and speciation has recently broadened from its historical focus on heritable symbionts to the entire microbial community. In this context, each Nasonia species hosts a distinguishable community of gut bacteria that experiences a temporal succession during host development and members of this bacterial community cause strong hybrid lethality during larval development. In this review, we present the Nasonia species complex as a model system to experimentally investigate questions regarding: (i) the impact of different microbes, including (but not limited to) heritable endosymbionts, on the extended phenotype of the holobiont, (ii) the establishment and regulation of a species-specific microbiota, (iii) the role of the microbiota in speciation, and (iv) the resilience and adaptability of the microbiota in wild populations subjected to different environmental pressures. We discuss the potential for easy microbiota manipulations in Nasonia as a promising experimental approach to address these fundamental aspects

Development and Validation of a Risk Score for Chronic Kidney Disease in HIV Infection Using Prospective Cohort Data from the D:A:D Study

Ristola M. on työryhmien DAD Study Grp ; Royal Free Hosp Clin Cohort ; INSIGHT Study Grp ; SMART Study Grp ; ESPRIT Study Grp jäsen.Background Chronic kidney disease (CKD) is a major health issue for HIV-positive individuals, associated with increased morbidity and mortality. Development and implementation of a risk score model for CKD would allow comparison of the risks and benefits of adding potentially nephrotoxic antiretrovirals to a treatment regimen and would identify those at greatest risk of CKD. The aims of this study were to develop a simple, externally validated, and widely applicable long-term risk score model for CKD in HIV-positive individuals that can guide decision making in clinical practice. Methods and Findings A total of 17,954 HIV-positive individuals from the Data Collection on Adverse Events of Anti-HIV Drugs (D:A:D) study with >= 3 estimated glomerular filtration rate (eGFR) values after 1 January 2004 were included. Baseline was defined as the first eGFR > 60 ml/min/1.73 m2 after 1 January 2004; individuals with exposure to tenofovir, atazanavir, atazanavir/ritonavir, lopinavir/ritonavir, other boosted protease inhibitors before baseline were excluded. CKD was defined as confirmed (>3 mo apart) eGFR In the D:A:D study, 641 individuals developed CKD during 103,185 person-years of follow-up (PYFU; incidence 6.2/1,000 PYFU, 95% CI 5.7-6.7; median follow-up 6.1 y, range 0.3-9.1 y). Older age, intravenous drug use, hepatitis C coinfection, lower baseline eGFR, female gender, lower CD4 count nadir, hypertension, diabetes, and cardiovascular disease (CVD) predicted CKD. The adjusted incidence rate ratios of these nine categorical variables were scaled and summed to create the risk score. The median risk score at baseline was -2 (interquartile range -4 to 2). There was a 1: 393 chance of developing CKD in the next 5 y in the low risk group (risk score = 5, 505 events), respectively. Number needed to harm (NNTH) at 5 y when starting unboosted atazanavir or lopinavir/ritonavir among those with a low risk score was 1,702 (95% CI 1,166-3,367); NNTH was 202 (95% CI 159-278) and 21 (95% CI 19-23), respectively, for those with a medium and high risk score. NNTH was 739 (95% CI 506-1462), 88 (95% CI 69-121), and 9 (95% CI 8-10) for those with a low, medium, and high risk score, respectively, starting tenofovir, atazanavir/ritonavir, or another boosted protease inhibitor. The Royal Free Hospital Clinic Cohort included 2,548 individuals, of whom 94 individuals developed CKD (3.7%) during 18,376 PYFU (median follow-up 7.4 y, range 0.3-12.7 y). Of 2,013 individuals included from the SMART/ESPRIT control arms, 32 individuals developed CKD (1.6%) during 8,452 PYFU (median follow-up 4.1 y, range 0.6-8.1 y). External validation showed that the risk score predicted well in these cohorts. Limitations of this study included limited data on race and no information on proteinuria. Conclusions Both traditional and HIV-related risk factors were predictive of CKD. These factors were used to develop a risk score for CKD in HIV infection, externally validated, that has direct clinical relevance for patients and clinicians to weigh the benefits of certain antiretrovirals against the risk of CKD and to identify those at greatest risk of CKD.Peer reviewe

Computer-Assisted Inflammation Analysis Of Kidney-Graft Biopsy To Improve Risk Stratification In Allograft Rejection

Introduction/ Background Kidney graft biopsy plays a key role in diagnosis of antibody-mediated rejection (AMR), the major cause of renal graft failure. The diagnosis of AMR requires the presence of i) donor specific antibodies (DSA), and ii) microvascular inflammatory lesions on kidney graft biopsy. Aims Histological assessment relies onBanffclassification [1] that has quantitative and qualitative limitations and faces in terms of diagnostic accuracy and risk prediction: 1)   this grading is categorical with risks of threshold effect; 2)      the nature of inflammatory cells is not considered. Hence we propose a new method of computerized image analysis in order to finely characterize the quality and intensity of graft inflammation. Methods Data 57 kidney recipients fulfilled theBanffcriteria for AMR between 2004 and 2012 at the Lyon Hospitals. Double immunohistological stainings were performed with CD31 (capillaries) and respectively CD68 (macrophages), CD3 (T lymphocytes), CD66b (granulocytes), CD20 (B lymphocytes). 288 glass slides were scanned  (MiraxScan, 20x, NA=0.8). Algorithms The goal is to quantify the number of immune cells in the different parts of the kidney cortex. Due to the biopsy preparation such as biopsy slicing and image quality staining many variations within the observed object could happen and result to incorrect image segmentation. Hence we combine color component images to extract Regions of Interest (ROI) based on the use of their contextual data information in order to correctly extract the capillaries and immune cells. The algorithms are implemented in the Icy software (http://icy.bioimageanalysis.org) [2]. In the workflow: 1) color deconvolution [3], 2) pre-processing step to segment the pixel staining, 3) extraction of stained objects by combined information. The color deconvolution separates the initial image into 3 component-staining images: blue component for nuclei, brown component for capillaries and the purple one for immune cells. These component images are first preprocessed, by gaussian filtering and then by the k-means classification to segment the images. We combine the segmented ROI and their spatial relation to extract the objects of interest. Results 34 patients had C3d+ DSA and 23 had C3d- DSA. Al- though allograft survival was lower in the C3d+ group (p<0,001 by log-rank),Banffscores for AMR were similar in the 2 groups (3.4±1.1 vs 3.5±1.2, p=0.65). In contrast, our approach revealed notable differences in graft inflammation between the two groups. The number of CD68 cells in the capillaries and in the interstitium allows identifying patients with a risk of graft loss (HR=3.18, p<0.01 et HR=2.62, p=0.01 respectively). The combining C3d test and quantification of monocytes in interstitium allow clustering patients into 3 groups of renal prognosis: C3d-, C3d+/CD68 low and C3d+/CD68 high (p<0.0001 by log rank; C3d+/CD68 high vs C3d+/ CD68 low: HR=2.43, p=0.04; C3d+/CD68 low vs C3d-: HR=4.99, p=0.006). The isolated C3d test has an excellent value negative prediction (89,5% for the 1 year graft loss) but perfectible positive prediction (52,9%) [4] . The monocyte quantification allows to accurate the prognosis of patients in the C3d+ group. Using this novel reproducible approach for topological quantification of inflammation, we observed that histopathological features of complement-binding DSA are different from that of non-complement. The computer-assisted analysis of graft inflammation improves the risk stratification of graft loss

Endovascular Stent Graft Repair of Abdominal and Thoracic Aortic Aneurysms: A Ten-Year Experience With 817 Patients

OBJECTIVE: On November 23, 1992, the first endovascular stent graft (ESG) repair of an aortic aneurysm was performed in North America. Following the treatment of this patient, we have continued to evaluate ESG over the past 10 years in the treatment of 817 patients. SUMMARY AND BACKGROUND DATA: Abdominal (AAA) or thoracic (TAA) aortic aneurysms are a significant health concern traditionally treated by open surgical repair. ESG therapy may offer protection from aneurysm rupture with a reduction in procedure morbidity and mortality. METHODS: Over a 10-year period, 817 patients were treated with ESGs for AAA (723) or TAA (94). Patients received 1 of 12 different stent graft devices. Technical and clinical success of ESGs was reviewed, and the incidence of procedure-related complications was analyzed. RESULTS: The mean age was 74.3 years (range, 25–95 years); 678 patients (83%) were men; 86% had 2 or more comorbid medical illnesses, 67% of which included coronary artery disease. Technical success, on an intent-to-treat basis was achieved in 93.8% of patients. Primary clinical success, which included freedom from aneurysm-related death, type I or III endoleak, graft infection or thrombosis, rupture, or conversion to open repair was 65 ± 6% at 8 years. Of great importance, freedom from aneurysm rupture after ESG insertion was 98 ± 1% at 9 years. There was a 2.3% incidence of perioperative mortality. One hundred seventy five patients died of causes not related to their aneurysm during a mean follow-up of 15.4 months. CONCLUSIONS: Stent graft therapy for aortic aneurysms is a valuable alternative to open aortic repair, especially in older sicker patients with large aneurysms. Continued device improvements coupled with an enhanced understanding of the important role of aortic pathology in determining therapeutic success will eventually permit ESGs to be a more durable treatment of aortic aneurysms

Computer-assisted topological analysis of renal allograft inflammation adds to risk evaluation at diagnosis of humoral rejection

International audienceAntibody-mediated rejection is associated with heterogeneous kidney allograft outcomes. Accurate evaluation of risk for graft loss at time of diagnosis is necessary to offer personalized treatment. In contrast with serological and molecular assessment, morpho-histological evaluation of antibody-mediated rejection lesions has not significantly evolved. This relies on Banff classifications designed to be of diagnostic discriminatory power rather than prognostic and face quantitative and qualitative limitations. Here we developed a method of Computer-assisted Analysis of Graft Inflammation (CAGI) to improve the classification of allograft inflammation. Digitization of immunostained biopsy sections, image processing and algorithm-driven analysis allowed quantification of macrophages, T cells, B cells, and granulocytes per unit surface of interstitium, capillaries or glomeruli. CAGI was performed on biopsy specimens of 52 patients with extensively phenotyped antibody-mediated rejection. Macrophage numbers in capillaries and interstitium, but not Banff scores or the amount of other immune cell subsets, correlated with donor-specific antibody (DSA) mean fluorescence intensity and DSA-C3d status. The quantity of macrophages in the interstitium and DSA-C3d status were the only independent predictors for significant allograft loss at the time of antibody-mediated rejection diagnosis (hazard ratio 3.71 and 2.34, respectively). A significant strategy integrating the DSA-C3d assay and the quantification of interstitial macrophages allowed identification of three groups with distinct renal prognosis: DSA-C3d-, DSA-C3d+/macrophages-low and DSAC3d+/macrophages-high. Thus, CAGI brings a missing piece to the antibody-mediated rejection puzzle by identifying morpho-histological processes that bridge in~vitro parameters of DSA pathogenicity and graft loss. Hence, this approach could be useful in future integrated strategies of risk evaluation