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Background@#and Purpose To determine the imaging characteristics and cutoff value of18F-florapronol (FC119S) quantitative analysis for detecting β-amyloid positivity and Al- zheimer’s disease (AD), we compared the findings of FC119S and 18F-florbetaben (FBB) positron-emission tomography (PET) in patients with cognitive impairment. @*Methods@#We prospectively enrolled 35 patients with cognitive impairment who underwent FBB-PET, FC119S-PET, and brain magnetic resonance imaging. We measured global and vertex-wise standardized uptake value ratios (SUVRs) using a surface-based method with the cerebellar gray matter as reference. Optimal global FC119S SUVR cutoffs were determined using receiver operating characteristic curves for β-amyloid positivity based on the global FBB SUVR of 1.478 and presence of AD, respectively. We evaluated the global and vertex-wise SUVR correlations between the two tracers. In addition, we performed correlation analysis for global or vertex-wise SUVR of each tracer with the vertex-wise cortical thicknesses. @*Results@#The optimal global FC119S SUVR cutoff value was 1.385 both for detecting β-amyloid positivity and for detecting AD. Based on the global SUVR cutoff value of each tracer, 32 (91.4%) patients had concordant β-amyloid positivity. The SUVRs of FC119S and FBB had strong global (r=0.72) and vertex-wise (r>0.7) correlations in the overall cortices, except for the parietal and temporal cortices (0.4
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The spike protein of SARS-CoV-2 is a critical antigen present in all approved SARS-CoV-2 vaccines. This surface viral protein is also the target for all monoclonal antibody therapies, but it is unclear whether antibodies targeting other viral proteins can also improve protection against COVID-19. Here, we interrogate whether nucleocapsid-specific antibodies can improve protection against SARS-CoV-2. We first immunized mice with a nucleocapsid-based vaccine, and then transferred sera from these mice into naive mice. On the next day, the recipient mice were challenged intranasally with SARS-CoV-2 to evaluate whether nucleocapsid-specific humoral responses affect viral control. Interestingly, mice that received nucleocapsid-specific sera exhibited enhanced control of a SARS-CoV-2 infection. These findings provide the first demonstration that humoral responses specific to an internal coronavirus protein can help clear infection, warranting the inclusion of other viral antigens in next-generation SARS-CoV-2 vaccines and providing a rationale for the clinical evaluation of nucleocapsid-specific monoclonals to treat COVID-19. HighlightsA SARS-CoV-2 nucleocapsid vaccine elicits robust nucleocapsid-specific antibody responses. This nucleocapsid vaccine generates memory B cells (MBC). Nucleocapsid-specific humoral responses do not prevent SARS-CoV-2 infection. Nucleocapsid-specific humoral responses help control a SARS-CoV-2 infection.
