• Molecular assessment of antibody-mediated rejection in human pancreas allograft biopsies

      Roufosse, Candice; Drachenberg, Cinthia; Renaudin, Karine; Willicombe, Michelle; Toulza, Frederic; Dominy, Kathy; McLean, Adam; Simmonds, Naomi; de Kort, Hanneke; Cantarovitch, Diego; et al. (Wiley-Blackwell, 2020-08-17)
      Pancreas transplant longevity is limited by immune rejection, which is diagnosed by graft biopsy using the Banff Classification. The histological criteria for antibody-mediated rejection (AMR) are poorly reproducible and inconsistently associated with outcome. We hypothesized that a 34-gene set associated with antibody-mediated rejection in other solid organ transplants could improve diagnosis in pancreas grafts. The AMR 34-gene set, comprising endothelial, natural killer cell and inflammatory genes, was quantified using the NanoString platform in 52 formalin-fixed, paraffin-embedded pancreas transplant biopsies from 41 patients: 15 with pure AMR or mixed rejection, 22 with T cell-mediated rejection/borderline and 15 without rejection. The AMR 34-gene set was significantly increased in pure AMR and mixed rejection (P =.001) vs no rejection. The gene set predicted histological AMR with an area under the receiver operating characteristic curve (ROC AUC) of 0.714 (P =.004). The AMR 34-gene set was the only biopsy feature significantly predictive of allograft failure in univariate analysis (P =.048). Adding gene expression to DSA and histology increased ROC AUC for the prediction of failure from 0.736 to 0.770, but this difference did not meet statistical significance. In conclusion, assessment of transcripts has the potential to improve diagnosis and outcome prediction in pancreas graft biopsies. © 2020 The Authors.
    • Sequence variations in the ETEC CS6 operon affect transcript and protein expression

      Moon, Jonathan; Barry, Eileen M (Taylor and Francis Inc., 2021-10-21)
      Enterotoxigenic Escherichia coli (ETEC) is a leading cause of diarrheal disease in developing nations where it accounts for a significant disease burden in children between the ages of 0 to 59 months. It is also the number one bacterial causative agent of traveler's diarrhea. ETEC infects hosts through the fecal-oral route and utilizes colonization factors (CF) to adhere within the small intestine. Over 25 CFs have been identified; 7 are considered major CFs and a vaccine targeting these is predicted to provide protection against up to 66% of ETEC associated disease. Coli Surface Antigen 6 (CS6) is a major CF and is associated with disease-causing ETEC isolates. Analysis of the CS6 operon sequence led to the identification of two regions of variability among clinical isolates which we predicted exert effects on CS6 transcript and protein expression. A total of 7 recombinant E. coli strains were engineered to encode the CS6 operon in wild-type, hybrid, and mutant configurations. Western blot analysis and RT-qPCR provided evidence to support the importance of an intergenic hairpin structure on CS6 expression. Our results reveal the significance of CS6 sequence selection regarding ETEC vaccine development and present novel information regarding CS6 sequence variation in WT ETEC strains.