Imprinted antibody responses against SARS-CoV-2 Omicron sublineages

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron sublineages carry distinct spike mutations resulting in escape from antibodies induced by previous infection or vaccination. We show that hybrid immunity or vaccine boosters elicit plasma-neutralizing antibodies against Omicron BA.1, BA.2, BA.2.12.1, and BA.4/5, and that breakthrough infections, but not vaccination alone, induce neutralizing antibodies in the nasal mucosa. Consistent with immunological imprinting, most antibodies derived from memory B cells or plasma cells of Omicron breakthrough cases cross-react with the Wuhan-Hu-1, BA.1, BA.2, and BA.4/5 receptor-binding domains, whereas Omicron primary infections elicit B cells of narrow specificity up to 6 months after infection. Although most clinical antibodies have reduced neutralization of Omicron, we identified an ultrapotent pan-variant–neutralizing antibody that is a strong candidate for clinical development

Imprinted antibody responses against SARS-CoV-2 Omicron sublineages

SARS-CoV-2 Omicron sublineages carry distinct spike mutations and represent an antigenic shift resulting in escape from antibodies induced by previous infection or vaccination. We show that hybrid immunity or vaccine boosters result in potent plasma neutralizing activity against Omicron BA.1 and BA.2 and that breakthrough infections, but not vaccination-only, induce neutralizing activity in the nasal mucosa. Consistent with immunological imprinting, most antibodies derived from memory B cells or plasma cells of Omicron breakthrough cases cross-react with the Wuhan-Hu-1, BA.1 and BA.2 receptor-binding domains whereas Omicron primary infections elicit B cells of narrow specificity. While most clinical antibodies have reduced neutralization of Omicron, we identified an ultrapotent pan-variant antibody, that is unaffected by any Omicron lineage spike mutations and is a strong candidate for clinical development

SH2 domain protein E and ABL signaling regulate blood vessel size.

Blood vessels in different vascular beds vary in size, which is essential for their function and fluid flow along the vascular network. Molecular mechanisms involved in the formation of a vascular lumen of appropriate size, or tubulogenesis, are still only partially understood. Src homology 2 domain containing E (She) protein was previously identified in a screen for proteins that interact with Abelson (Abl)-kinase. However, its biological role has remained unknown. Here we demonstrate that She and Abl signaling regulate vessel size in zebrafish embryos and human endothelial cell culture. Zebrafish she mutants displayed increased endothelial cell number and enlarged lumen size of the dorsal aorta (DA) and defects in blood flow, eventually leading to the DA collapse. Vascular endothelial specific overexpression of she resulted in a reduced diameter of the DA, which correlated with the reduced arterial cell number and lower endothelial cell proliferation. Chemical inhibition of Abl signaling in zebrafish embryos caused a similar reduction in the DA diameter and alleviated the she mutant phenotype, suggesting that She acts as a negative regulator of Abl signaling. Enlargement of the DA size in she mutants correlated with an increased endothelial expression of claudin 5a (cldn5a), which encodes a protein enriched in tight junctions. Inhibition of cldn5a expression partially rescued the enlarged DA in she mutants, suggesting that She regulates DA size, in part, by promoting cldn5a expression. SHE knockdown in human endothelial umbilical vein cells resulted in a similar increase in the diameter of vascular tubes, and also increased phosphorylation of a known ABL downstream effector CRKL. These results argue that SHE functions as an evolutionarily conserved inhibitor of ABL signaling and regulates vessel and lumen size during vascular tubulogenesis

Additional file 1: of Identifying lower limb specific and generalised joint hypermobility in adults: validation of the Lower Limb Assessment Score

The Lower Limb Assessment Score. This file contains the name, patient and therapist instructions and criteria for each of the 12 tests of the Lower Limb Assessment score as described by the original authors that developed this tool. (DOCX 17 kb

Consensus ABL phosphorylation sites YXXP are required for SHE function.

(A) Consensus ABL phosphorylation sites are conserved between zebrafish, mice and humans. (B) Vascular endothelial expression of a mutant construct fli1:sheFXXP-2A-mCherry, where all four consensus tyrosines have been substituted into phenylalanine, fails to rescue the pericardial edema in she mutants at 4 dpf. The first bar showing she-/- embryos (no Tg) is copied from Fig 3I. ****pfli1:sheFXXP-2A-mCherry embryos and sibling mCherry-negative embryos at 28 hpf. 5 measurements were performed in each embryo, which were then averaged for statistical calculations. 2 replicate experiments were performed, shown in different colors. n corresponds to the number of embryos. Mean ± SD is shown. *p<0.05, Student’s t-test.</p

Expression of <i>abl1</i> and <i>abl2</i> in different cell types during zebrafish embryogenesis based on single-cell RNA seq expression atlas.

Data were generated by Daniocell atlas https://daniocell.nichd.nih.gov/ [31]. (TIF)</p

Diagrams and sequence chromatograms of <i>she</i>^<i>ci26</i> and ^<i>ci30</i> mutations.

(A) sheci26 mutants have a 7 bp deletion. Alignment of wild-type and sheci26 mutant sequences is shown starting with the first coding ATG. (B) Genomic DNA sequence chromatogram of sheci30 mutants. (C) sheci30 mutants carry a 575 bp deletion and 24 bp insertion present between exons 3 and 4 within she gene. (TIF)</p

Numerical original data used for graphs and summary statistics.

Tab numbers in the Excel table match to the figure numbers of corresponding graphs. (XLSX)</p

Blood flow does not affect <i>she</i> expression or <i>she</i> mutant phenotype.

(A,B) In situ hybridization analysis for she expression at 28 hpf in tnnt2 MO-injected embryos and uninjected controls. Trunk region is shown, anterior is to the left. Numbers in the lower right indicate embryos that showed normal expression pattern out of the total number of embryos in 3 replicate experiments. (C-H) DA size analysis at 28 hpf in wt (she+/+) and she-/- sibling embryos, injected with tnnt2 MO, compared to uninjected controls. Embryos were obtained from cross of she+/- parents in kdrl:GFP background and subsequently genotyped. Note that DA diameter is greatly reduced in tnnt2 MO-injected embryos compared to wild-type uninjected embryos, and increased in she mutants, injected with tnnt2 MO compared to wild-type embryos injected with tnnt2 MO. Data are combined from 3 replicate experiments, shown in different color. Mean±SD is shown. The number of embryos analyzed is shown at the bottom of each bar. The same wt+tnnt2 MO embryos were used for comparisons in (G) and (H). *p (TIF)</p