Identification of a novel transport system in Borrelia burgdorferi that links the inner and outer membranes

Borrelia burgdorferi, the spirochete that causes Lyme disease, is a diderm organism that is similar to Gram-negative organisms in that it contains both an inner and outer membrane. Unlike typical Gram-negative organisms, however, B. burgdorferi lacks lipopolysaccharide (LPS). Using computational genome analyses and structural modeling, we identified a transport system containing six proteins in B. burgdorferi that are all orthologs to proteins found in the lipopolysaccharide transport (LPT) system that links the inner and outer membranes of Gram-negative organisms and is responsible for placing LPS on the surface of these organisms. While B. burgdorferi does not contain LPS, it does encode over 100 different surface-exposed lipoproteins and several major glycolipids, which like LPS are also highly amphiphilic molecules, though no system to transport these molecules to the borrelial surface is known. Accordingly, experiments supplemented by molecular modeling were undertaken to determine whether the orthologous LPT system identified in B. burgdorferi could transport lipoproteins and/or glycolipids to the borrelial outer membrane. Our combined observations strongly suggest that the LPT transport system does not transport lipoproteins to the surface. Molecular dynamic modeling, however, suggests that the borrelial LPT system could transport borrelial glycolipids to the outer membrane

Association of COVID-19 Versus COVID-19 Vaccination With Kidney Function and Disease Activity in Primary Glomerular Disease: A Report of the Cure Glomerulonephropathy Study

Patients with glomerular disease (GN) may be at increased risk of severe COVID-19, yet concerns over vaccines causing disease relapse may lead to vaccine hesitancy. We examined the associations of COVID-19 with longitudinal kidney function and proteinuria and compared these to similar associations with COVID-19 vaccination. Observational cohort study from July 1, 2021 to Jan. 1, 2023. & Participants: A prospective observational study network of 71 centers from North America and Europe (CureGN) with children and adults with primary minimal change disease, focal segmental glomerulosclerosis, membranous nephropathy, or IgA nephropathy. COVID-19 and COVID-19 vaccination. Repeated measure of estimated glomerular filtration rate (eGFR); recurrent time-to-event outcome of GN disease worsening as defined by doubling of UPCR to at least 1.5g/g or increase in dipstick urine protein by two ordinal levels to 3+ (300mg/dL) or above. Interrupted time series analysis for eGFR. Prognostic matched sequential stratification recurrent event analysis for GN disease worsening. Among 2,055 participants, 722 (35%) reported COVID-19; of these, 92 (13%) were hospitalized and 3 died (<1%). eGFR slope pre-COVID-19 was -1.40ml/min/1.73m2 (SD 0.29), and -4.26ml/min/1.73m2 (SD 3.02) within 6 months post-COVID-19, which were not significantly different (p=0.34). COVID-19 was associated with increased risk of worsening GN disease activity (HR 1.35, 95% CI 1.01-1.80). Vaccination was not associated with change in eGFR (-1.34ml/min/1.73m2, SD 0.15 vs -2.16ml/min/1.73m2, SD 1.74; p=0.6) or subsequent GN disease worsening (HR 1.02, 95% CI 0.79–1.33) in this cohort. Infrequent or short follow-up. Among patients with primary GN, COVID-19 was severe for 1 in 8 cases and was associated with subsequent worsening of GN disease activity, as defined by proteinuria. In contrast, vaccination against COVID-19 was not associated with change in disease activity or kidney function decline. These results support COVID-19 vaccination for patients with GN. In this cohort study of 2,055 patients with minimal change disease, focal segmental glomerulosclerosis, membranous nephropathy, or IgA nephropathy, COVID-19 resulted in hospitalization or death for 1 in 8 cases and was associated with a 35% increase in risk for worsening proteinuria. In contrast, vaccination did not appear to adversely affect kidney function or proteinuria. Our data support vaccination for COVID-19 in patients with glomerular disease