Antigens for COVID-19 serological testing; plus mapping glycans on SARS-CoV-2 spike, tumor sampling method and therapy for Parkinson’s
BioCentury’s roundup of preclinical news
SARS-CoV-2 antigens beyond the spike protein
Described in a medRxiv preprint, researchers from the University of Hong Kong identified SARS-CoV-2 antigens beyond the spike protein that could be used to detect antibodies at early time points in the disease. Plasma samples from 15 COVID-19 patients were used to test a panel of 15 potential antigens; significant antibody levels were detected for 11 antigens, with anti-nucleocapsid (N) antibodies dominating. Combining antibody tests detecting anti-SARS-CoV-2 N, open reading frame (ORF) 3b and ORF8 antibodies enabled the team to identify all 15 COVID-19 patients, even early in the disease, which tests detecting spike alone could not do.
Carbohydrate binding sites mapped onto SARS-CoV-2 spike protein
Researchers at the University of Southampton and the University of Texas at Austin characterized the composition of glycans on the SARS-CoV-2 spike protein and mapped them onto a 3D structure of the spike surface. Glycans can shield sites for antibody binding, and the team found that SARS-CoV-2 spike is less densely glycosylated than other viral glycoproteins, which could be beneficial for evoking neutralizing antibodies in the infected host. The data, published in Science, could guide development of COVID-19 vaccines and therapeutics, many of which target the spike.
Improved tumor sampling technique
Roche (SIX:ROG; OTCQX:RHHBY), Francis Crick Institute and Royal Marsden NHS Foundation Trust researchers have developed a technique to improve the accuracy of personalized tumor diagnostics which works by sequencing a homogenized, entire resected tumor sample rather than a sample from a single location within a tumor. Named representative sequencing (Rep-Seq) and described in Cell Reports, the method yielded results with 95% reproducibility in a case of renal cell carcinoma vs. 77% for single-site sampling. In cases of various types of solid tumors, Rep-Seq outperformed single sampling at predicting a polyclonal tumor structure and generating mutational burden scores. The researchers are validating the findings in a larger cohort of 500 patients.
Cell-permeable protein therapy for Parkinson’s
A team from Cellivery Therapeutics Inc. (KOSDAQ:268600) has designed a cell-permeable PARK2 protein therapy that could reverse motor deficits in Parkinson’s disease. Reported in Science Advances, the therapy dubbed CV-06 prevented chemical-induced accumulation of pathologic insoluble SNCA in neuronal cell culture. In mouse and rat PD models, the therapy ameliorated motor deficits and reduced dopaminergic neuron loss in the substantia nigra. CV-06 is partnered with Ildong Pharmaceutical Co. Ltd. (KRX:000230).
PARK2 - Parkin
SARS-CoV-2 N - SARS-CoV-2 nucleocapsid protein
SARS-CoV-2 S - SARS-CoV-2 spike protein
SNCA - Alpha synuclein