y Both authors contributed equally.The angiotensin II type 1 receptor (AT 1 R) is an emerging target of functional non-HLA antibodies (Ab). We examined the potential of determining the degree of presensitization against AT 1 R as a risk factor for graft survival and acute rejection (AR). The study included 599 kidney recipients between 1998 and 2007. Serum samples were analyzed in a blinded fashion for anti-AT 1 R antibodies (AT 1 R-Abs) using a quantitative solid-phase assay. A threshold of AT 1 R-Ab levels was statistically determined at 10 U based on the time to graft failure. An extended Cox model determined risk factors for occurrence of graft failure and a first AR episode. AT 1 R-Abs >10 U were detected in 283 patients (47.2%) before transplantation. Patients who had a level of AT 1 R-Abs >10 U had a 2.6-fold higher risk of graft failure from 3 years posttransplantation onwards (p ¼ 0.0005) and a 1.9-fold higher risk of experiencing an AR episode within the first 4 months of transplantation (p ¼ 0.0393). Antibody-mediated rejection (AMR) accounted for 1/3 of AR, whereby 71.4% of them were associated with >10 U of pretransplant AT 1 R-Abs. Pretransplant anti-AT 1 R-Abs are an independent risk factor for long-term graft loss in association with a higher risk of early AR episodes.

No abstract

Fluorescence in situ hybridization (FISH) was used for direct detection of Escherichia coli on pipe surfaces and coupons in drinking water distribution networks. Old cast iron main pipes were removed from water distribution networks in France, England, Portugal, and Latvia, and E. coli was analyzed in the biofilm. In addition, 44 flat coupons made of cast iron, polyvinyl chloride, or stainless steel were placed into and continuously exposed to water on 15 locations of 6 distribution networks in France and Latvia and examined after 1 to 6 months exposure to the drinking water. In order to increase the signal intensity, a peptide nucleic acid (PNA) 15-mer probe was used in the FISH screening for the presence or absence of E. coli on the surface of pipes and coupons, thus reducing occasional problems of autofluorescence and low fluorescence of the labeled bacteria. For comparison, cells were removed from the surfaces and examined with culture-based or enzymatic (detection of ␤-D-glucuronidase) methods. An additional verification was made by using PCR. Culture method indicated presence of E. coli in one of five pipes, whereas all pipes were positive with the FISH methods. E. coli was detected in 56% of the coupons using PNA FISH, but no E. coli was detected using culture or enzymatic methods. PCR analyses confirmed the presence of E. coli in samples that were negative according to culture-based and enzymatic methods. The viability of E. coli cells in the samples was demonstrated by the cell elongation after resuscitation in low-nutrient medium supplemented with pipemidic acid, suggesting that the cells were present in an active but nonculturable state, unable to grow on agar media. E. coli contributed to ca. 0.001 to 0.1% of the total bacterial number in the samples. The presence and number of E. coli did not correlate with any of physical and/or chemical characteristic of the drinking water (e.g., temperature, chlorine, or biodegradable organic matter concentration). We show here that E. coli is present in the biofilms of drinking water networks in Europe. Some of the cells are metabolically active but are often not detected due to limitations of traditionally used culture-based methods, indicating that biofilm should be considered as a reservoir that must be investigated further in order to evaluate the risk for human health.The drinking water supplier has to provide the consumer potable water of a quality identical to that leaving the treatment plant. However, it has been well documented that water that reaches the consumer's tap is often of worse microbiological quality than that which left the plant (29). Therefore, the analyses used for monitoring the hygiene of potable water must be rapid to perform and able to detect the major microbial groups of concern. Escherichia coli is still used as the principle indicator for drinking water pollution monitoring (39) and is even considered a superior indicator (11), since enterotoxic and enterohemorrhagic forms are one of the major causes of water-related outbreaks (29...

B cells are essentially described for their capacity to produce antibodies ensuring anti-infectious immunity or deleterious responses in the case of autoimmunity or allergy. However, abundant data described their ability to restrain inflammation by diverse mechanisms. In allergy, some regulatory B-cell subsets producing IL-10 have been recently described as potent suppressive cells able to restrain inflammatory responses both in vitro and in vivo by regulatory T-cell differentiation or directly inhibiting T-cell-mediated inflammation. A specific deficit in regulatory B cells participates to more severe allergic inflammation. Induction of allergen tolerance through specific immunotherapy induces a specific expansion of these cells supporting their role in establishment of allergen tolerance. However, the regulatory functions carried out by B cells are not exclusively IL-10 dependent. Indeed, other regulatory mechanisms mediated by B cells are (i) the production of TGF-b, (ii) the promotion of T-cell apoptosis by Fas-Fas ligand or granzyme-B pathways, and (iii) their capacity to produce inhibitory IgG4 and sialylated IgG able to mediate anti-inflammatory mechanisms. This points to Bregs as interesting targets for the development of new therapies to induce allergen tolerance. In this review, we highlight advances in the study of regulatory mechanisms mediated by B cells and outline what is known about their phenotype as well as their suppressive role in allergy from studies in both mice and humans.Allergic diseases encompass many heterogeneous pathologies with distinct clinical manifestations. These pathologies generally result from an uncontrolled inflammatory response to allergens and can lead to a number of disorders, including asthma, allergic rhinoconjunctivitis, anaphylaxis, urticaria, and atopic dermatitis. Mechanisms promoting allergic inflammation in mucosal tissues are characterized by dysregulated type 2 immunity with a dramatic T H 2-driven immunity, elevated allergen-specific IgE, leading to goblet cell hyperplasia and mucus overproduction. One significant cause of the development and persistence of allergic inflammation is an alteration in the immune regulatory processes (1). Regulatory T cells have long been the focus of all attention in the maintenance of allergen tolerance (2, 3), but recently, a new subset of B cells has been identified as regulatory (Bregs), due to their capacity to secrete IL-10 and constrain severe inflammation (4). In humans, B-cell depletion was recently suggested to exacerbate ulcerative colitis, promote psoriasis, or aggravate inflammation in patients with multiple sclerosis (5-7). These observations demonstrated the role of Bregs in the control of T-cell-mediated inflammation in vivo. Bregs cells are of special interest in allergic diseases also, as demonstrated by recent reports showing their potential implication in the development of allergen tolerance (8-10). However, the regulatory functions carried out by B cells are not exclusively IL-10 dependent. Indeed, ...

There are lines of evidence that B cells may play a role in transplantation. B cell activating factor, BAFF, is a homotrimer that has been shown to play a role in B cell survival, maturation and activation. To date, little is known of the role of BAFF and its receptors in transplantation. We analyzed the level of BAFF mRNA and its soluble protein, as well as transcripts coding for its receptors, BAFF-R, TACI and BCMA, in the blood of 143 patients with stable kidney transplant function 5 years or more posttransplantation. Three endpoints were analyzed: the time to renal dysfunction, the time to appearance of anti-HLA antibodies and the time to development of donor-specific antibodies. We established threshold values for BAFF and BAFF-R and showed that (1) stable patients with high BAFF-R levels had a higher risk of developing graft dysfunction, (2) patients with lower levels of BAFF transcripts or a higher level of soluble BAFF had a significantly higher risk of developing donor-specific antibodies. These data suggest that BAFF constitutes a risk factor for renal graft dysfunction and development of donor-specific antibodies. They also suggest that agents targeting BAFF-R interactions may offer new therapeutic opportunities in transplantation.

In renal transplantation, the unresponsiveness of patients undergoing chronic antibody mediated rejection (CAMR) to classical treatment stress on the need for accurate biomarkers to improve its diagnosis. We aim to determine whether microRNA expression patterns may be associated with a diagnosis of CAMR. We performed expression profiling of miRNAs in peripheral blood mononuclear cells (PBMC) of kidney transplant recipients with CAMR or stable graft function. Among 257 expressed miRNAs, 10 miRNAs associated with CAMR were selected. Among them, miR-142-5p was increased in PBMC and biopsies of patients with CAMR as well as in a rodent model of CAMR. The lack of modulation of miR-142-5p in PBMC of patients with renal failure, suggests that its over-expression in CAMR was associated with immunological disorders rather than renal dysfunction. A ROC curve analysis performed on independent samples showed that miR-142-5p is a potential biomarker of CAMR allowing a very good discrimination of the patients with CAMR (AUC = 0.74; p = 0.0056). Moreover, its expression was decreased in PHA-activated blood cells and was not modulated in PBMC from patients with acute rejection, excluding a non-specific T cell activation expression. The absence of modulation of this miRNA in immunosuppressed patients suggests that its expression was not influenced by treatment. Finally, the analysis of miR-142-5p predicted targets under-expressed in CAMR PBMC in a published microarray dataset revealed an enrichment of immune-related genes. Altogether, these data suggest that miR-142-5p could be used as a biomarker in CAMR and these finding may improve our understanding of chronic rejection mechanisms.

Several Vibrio species are known to be pathogenic to the Pacific oyster Crassostrea gigas. Survival varies according to pathogen exposure and high mortality events usually occur in summer during gametogenesis. In order to study the effects of gametogenetic status and ploidy (a factor known to affect reproduction allocation in oysters) on vibriosis survival, we conducted two successive experiments. Our results demonstrate that a common bath challenge with pathogenic Vibrio splendidus and Vibrio aestuarianus on a mixture of mature, spawning and non-mature oysters can lead to significant mortality. Previous bath challenges, which were done using only non-mature oysters, had not produced mortality. Immunohistochemical analyses showed the affinity of Vibrio for gonadic tissues, highlighting the importance of sexual maturity for vibriosis infection processes in oysters. Mortality rate results showed poor repeatability between tanks, however, in this bath challenge. We then tested a standardized and repeatable injection protocol using two different doses of the same combination of two Vibrio species on related diploid and triploid oysters at four different times over a year. Statistical analyses of mortality kinetics over a 6-day period after injection revealed that active gametogenesis periods correspond to higher susceptibility to vibriosis and that there is a significant interaction of this seasonal effect with ploidy. However, no significant advantage of triploidy was observed. Triploid oysters even showed lower survival than diploid counterparts in winter. Results are discussed in relation to differing energy allocation patterns between diploid and triploid Pacific oysters.

The present study described the evolution of antimicrobial resistance in equine pathogens isolated from 2016 to 2019. A collection of 7806 bacterial isolates were analysed for their in vitro antimicrobial susceptibility using the disk diffusion method. The most frequently isolated pathogens were group C Streptococci (27.0%), Escherichia coli (18.0%), Staphylococcus aureus (6.2%), Pseudomonas aeruginosa (3.4%), Klebsiella pneumoniae (2.3%) and Enterobacter spp. (2.1%). The majority of these pathogens were isolated from the genital tract (45.1%, n = 3522). With the implementation of two French national plans (named ECOANTIBIO 1 and 2) in 2012–2016 and 2017–2021, respectively, and a reduction in animal exposure to veterinary antibiotics, our study showed decreases in the resistance of group C Streptococci, Klebsiella pneumoniae and Escherichia coli against five classes, four classes and one class of antimicrobials tested, respectively. However, Staphylococcus aureus, Escherichia coli and Enterobacter spp. presented an increased resistance against all the tested classes, excepted for two fifths of E. coli. Moreover, the percentages of multi-drug resistant strains of Staphylococcus aureus and Enterobacter spp. also increased from 24.5% to 37.4% and from 26.3% to 51.7%, respectively. The data reported here are relevant to equine practitioners and will help to improve knowledge related to antimicrobial resistance in common equine pathogens.