Cross-immunity against SARS-COV-2 variants of concern in naturally infected critically ill COVID-19 patients.

Critically ill patients infected with SARS-CoV-2 display adaptive immunity, but it is unknown if they develop cross-reactivity to variants of concern (VOCs). We profiled cross-immunity against SARS-CoV-2 VOCs in naturally infected, non-vaccinated, critically ill COVID-19 patients. Wave-1 patients (wild-type infection) were similar in demographics to Wave-3 patients (wild-type/alpha infection), but Wave-3 patients had higher illness severity. Wave-1 patients developed increasing neutralizing antibodies to all variants, as did patients during Wave-3. Wave-3 patients, when compared to Wave-1, developed more robust antibody responses, particularly for wild-type, alpha, beta and delta variants. Within Wave-3, neutralizing antibodies were significantly less to beta and gamma VOCs, as compared to wild-type, alpha and delta. Patients previously diagnosed with cancer or chronic obstructive pulmonary disease had significantly fewer neutralizing antibodies. Naturally infected ICU patients developed adaptive responses to all VOCs, with greater responses in those patients more likely to be infected with the alpha variant, versus wild-type.

Investigation into accuracy and reproducibility of a 3D breast imaging system using multiple stereo cameras.

BACKGROUND: The aim of this study was to evaluate the validity of a three-dimensional (3D) multiple stereo camera system for objective breast assessment. METHODS: A multiple stereo camera system, which consisted of four pods and eight cameras, two cameras on each pod, developed by Glasgow University, was used. Nine specially shaped plaster breast models were captured once, 3Dmodels were constructed and the volume of each plaster model was measured 10 times by the breast analysis tool (BAT) software. A comparison was conducted with water displacement method, and measurements were repeated 10 times. The breast of six live volunteers was captured six times; from each breast capture, a 3D model was constructed and the volume was measured with BAT software. Breast volume assessment by the water displacement method was repeated six times. RESULTS: In all plaster casts, the discrepancies in volume measurements between 3D imaging and water displacement methods did not exceed 40 cc. The overall mean relative difference was 5%. The differences of the two methods were not significant at p = 0.189, overall mean difference: 11.1 cc and 95% confidence interval (CI) was (-6.732, 28.976). In the live models, the differences in breast volume measurements between the 3D imaging and water displacement methods were significant at p ≤ 0.017, overall mean difference: 207.05 cc and 95% CI (56.12, 357.98). Measurements by 3D imaging were consistently smaller. In the live models, 3D imaging overall was a more reproducible method for measuring breast volume than the water displacement method with a standard deviation of 36 units cc(-1) and 62.6 units cc(-1), respectively. CONCLUSIONS: The 3D breast imaging system using multiple stereo cameras was accurate for measuring the volumes of breast-shaped plaster models, and it was more reproducible than the water displacement method in live models. 3D imaging is a reliable method for the comparative assessment of breast volume.

Impact of constitutive IGF1/IGF2 stimulation on the transcriptional program of human breast cancer cells.

Insulin-like growth factor (IGF) signaling is a key regulator of breast development and breast cancer. We have analyzed the expression of the IGF signaling cascade in 17 human breast cancer and 4 mammary epithelial cell lines. Five cell lines expressed high levels of IGF1 receptor, insulin (INS)/IGF receptor substrate 1, IGF-binding proteins 2 and 4, as well as the estrogen receptor (ESR), indicating a co-activation of IGF and ESR signaling. Next, we stably overexpressed IGF1 and IGF2 in MCF7 breast cancer cells, which did not affect their epithelial characteristics and the expression and localization of the epithelial marker genes E-cadherin and beta-catenin. Conversely, IGF1 and IGF2 overexpression potently increased cellular proliferation rates and the efficiency of tumor formation in mouse xenograft experiments, whereas the resistance to chemotherapeutic drugs such as taxol was unaltered. Expression profiling of overexpressing cells with whole-genome oligonucleotide microarrays revealed that 21 genes were upregulated >2-fold by both IGF1 and IGF2, 9 by IGF1, and 9 by IGF2. Half of the genes found to be upregulated are involved in transport and biosynthesis of amino acids, including several amino acid transport proteins, argininosuccinate and asparagine synthetases, and methionyl-tRNA synthetase. Upregulation of these genes constitutes a novel mechanism apparently contributing to the stimulatory effects of IGF signaling on the global protein synthesis rate. We conclude that the induction of cell proliferation and tumor formation by long-term IGF stimulation may primarily be due to anabolic effects, in particular increased amino acid production and uptake.

Plectin scaffolds recruit energy-controlling AMP-activated protein kinase (AMPK) in differentiated myofibres.

Plectin, a cytolinker protein greater than 500 kDa in size, has an important role as a mechanical stabiliser of cells. It interlinks the various cytoskeletal filament systems and anchors intermediate filaments to peripheral junctional complexes. In addition, there is increasing evidence that plectin acts as a scaffolding platform that controls the spatial and temporal localisation and interaction of signaling proteins. In this study we show that, in differentiated mouse myotubes, plectin binds to the regulatory gamma1 subunit of AMP-activated protein kinase (AMPK), the key regulatory enzyme of energy homeostasis. No interaction was observed in undifferentiated myoblasts, and plectin-deficient myotubes showed altered positioning of gamma1-AMPK. In addition we found that plectin affects the subunit composition of AMPK, because isoform alpha1 of the catalytic subunit decreased in proportion to isoform alpha2 during in vitro differentiation of plectin(-/-) myotubes. In plectin-deficient myocytes we could also detect a higher level of activated (Thr172-phosphorylated) AMPK, compared with wild-type cells. Our data suggest a differentiation-dependent association of plectin with AMPK, where plectin selectively stabilises alpha1-gamma1 AMPK complexes by binding to the gamma1 regulatory subunit. The distinct plectin expression patterns in different fibre types combined with its involvement in the regulation of isoform compositions of AMPK complexes could provide a mechanism whereby cytoarchitecture influences energy homeostasis.

DeltaEF1 is a transcriptional repressor of E-cadherin and regulates epithelial plasticity in breast cancer cells.

Downregulation of E-cadherin is a crucial event for epithelial to mesenchymal transition (EMT) in embryonic development and cancer progression. Using the EpFosER mammary tumour model we show that during EMT, upregulation of the transcriptional regulator deltaEF1 coincided with transcriptional repression of E-cadherin. Ectopic expression of deltaEF1 in epithelial cells was sufficient to downregulate E-cadherin and to induce EMT. Analysis of E-cadherin promoter activity and chromatin immunoprecipitation identified deltaEF1 as direct transcriptional repressor of E-cadherin. In human cancer cells, transcript levels of deltaEF1 correlated directly with the extent of E-cadherin repression and loss of the epithelial phenotype. The protein was enriched in nuclei of human cancer cells and physically associated with the E-cadherin promoter. RNA interference-mediated downregulation of deltaEF1 in cancer cells was sufficient to derepress E-cadherin expression and restore cell to cell adhesion, suggesting that deltaEF1 is a key player in late stage carcinogenesis.