A bead-based multiplex assay covering all coronaviruses pathogenic for humans for sensitive and specific surveillance of SARS-CoV-2 humoral immunity

Serological assays measuring antibodies against SARS-CoV-2 are key to describe the epidemiology, pathobiology or induction of immunity after infection or vaccination. Of those, multiplex assays targeting multiple antigens are especially helpful as closely related coronaviruses or other antigens can be analysed simultaneously from small sample volumes, hereby shedding light on patterns in the immune response that would otherwise remain undetected. We established a bead-based 17-plex assay detecting antibodies targeting antigens from all coronaviruses pathogenic for humans: SARS-CoV-2, SARS-CoV, MERS-CoV, HCoV strains 229E, OC43, HKU1, and NL63. The assay was validated against five commercial serological immunoassays, a commercial surrogate virus neutralisation test, and a virus neutralisation assay, all targeting SARS-CoV-2. It was found to be highly versatile as shown by antibody detection from both serum and dried blot spots and as shown in three case studies. First, we followed seroconversion for all four endemic HCoV strains and SARS-CoV-2 in an outbreak study in day-care centres for children. Second, we were able to link a more severe clinical course to a stronger IgG response with this 17-plex-assay, which was IgG1 and IgG3 dominated. Finally, our assay was able to discriminate recent from previous SARS-CoV-2 infections by calculating the IgG/IgM ratio on the N antigen targeting antibodies. In conclusion, due to the comprehensive method comparison, thorough validation, and the proven versatility, our multiplex assay is a valuable tool for studies on coronavirus serology

Mechanism of the oscillatory reduction of peroxodisulfate on gold(110) at electrode potentials positive to the point of zero charge

The oscillatory reduction of S2O2−8 ions on the Au(110) electrode in dilute solutions of NaF at potentials positive to the known value of the potential of zero charge (PZC) has been studied. Experimental results based on cyclic voltammetry with rotating disk electrodes and potentiostatic current transients indicate that in the course of S2O2−8 reduction the surface state of the electrode is modified. It is proposed that the point of zero charge shifts to a more positive potential, and that the oscillatory S2O2−8 reduction is governed by the Frumkin effect

Cross-species transcriptomics identifies core regulatory changes differentiating the asymptomatic asexual and virulent sexual life cycles of grass-symbiotic <i>Epichloë</i> fungi

AbstractFungi from the genus EpichloëEpichloëEpichloëEpichloëEpichloëEpichlo