Research Roundup: The China Coronavirus and More
Every week there are numerous scientific studies published. Here’s a look at some of the more interesting ones.
Early Genetic Information on the China Coronavirus
As the China coronavirus outbreak becomes a pandemic and shows little signs of slowing down, researchers are feverishly studying the virus for any insights into how to treat it. Early work by Fang Li of the University of Minnesota, who did in-depth research into the SARS virus, which bears many similarities to the China coronavirus, were recently released. The research was published in the Journal of Virology.
“Our analyses confidently predict that the Wuhan coronavirus uses ACE2 as its host receptor,” the researchers wrote. Angiotensin-converting enzyme-2 (ACE2) is how the viruses enter the cells. Normally ACE2 acts as a regulator for heart function.
“Alarmingly, our data predict that a single mutation [at a specific spot in the genome] could significantly enhance [the Wuhan coronavirus’s] ability to bind with human ACE2,” they wrote. As such, they say patients should be closely watched for the emergence of novel mutations at the 501 position in the virus’s genome, and to a lesser extent, the 494 position, so predictions can be made about the outbreak becoming even more dangerous than it is now.
Chromosome 21 and Down Syndrome
Down syndrome is the result of an individual having three (instead of two) copies of chromosome 21. Researchers at the University College London identified for the first time specific regions of chromosome 21, at least in mice, that cause the memory and decision-making problems in Down syndrome. They found that specific mouse strains, Dp10Yey and DP1Tyb, had irregular brain circuits in the hippocampus, which was involved in the memory and decision-making issues. But another strain, Dy17Yey, did not have unusual electrical brain activity.
“We have shown—for the first time—that different and multiple genes are contributing to the various cognitive problems associated with Down syndrome,” said Matthew Walker, co-author of the study.
Modeling the Spread of the Chinese Coronavirus
In addition to sequencing the genome of the China coronavirus, researchers are working to get a handle on how it might spread. New modeling research estimates that up to 75,800 people in Wuhan, China, the original source of the outbreak, may have been infected with 2019-nCoV as of Jan. 25, 2020. They warn, though, that this may not be the true size. Many people who are infected would not seek medical attention, particularly since early signs of the illness resemble that of the cold or flu. Their research, however, suggests that multiple cities in China may already have imported the virus from Wuhan in large enough numbers to initiate local epidemics.
“If the transmissibility of 2019-nCoV is similar nationally and over time, it is possible that epidemics could be already growing in multiple major Chinese cities, with a time lag of one to two weeks behind the Wuhan outbreak,” said Joseph Wu of the University of Hong Kong, and lead author of the study. “Large cities overseas with close transport links to China could potentially also become outbreak epicenters because of the substantial spread of pre-symptomatic cases unless substantial public health interventions at both the population and personal levels are implemented immediately.”
Even More Effective Gene Editing Technique
Researchers at Arizona State University developed a new TREE method (transient reporter for editing enrichment) technique that allows for bulk enrichment of DNA base-edited cell populations. This also allows for high efficiency in human stem cell lines. The technique is an update to CRISPR base editing and appears to make highly accurate, single DNA base editing with an efficiency of up to 90% of human stem cells, which is considered to be significantly better than traditional CRISPR gene editing.
Making CAR-T Safer
CAR-T, or chimeric antigen-receptor T-cell, is an immuno-oncology therapy. It is very effective for some cancers, but also has a high risk of side effects. Researchers with the Ludwig Institute for Cancer Research developed a new form of CAR-T that can be turned on and off on demand. This has the potential to work around one of the most problematic adverse events in CAR-T therapy, runaway immune reactions. They dubbed the system STOP-CAR-T, which involves attaching the CD3-zeta activation domain on one molecule and the antigen-detecting part on the other, which are linked together by two unrelated proteins that spontaneously pair up inside the cell.
Uh-oh! Strain of Strep Throat Moving Toward Antibiotic Resistance
Investigators with Houston Methodist Hospital identified strains of group A streptococcus that are less susceptible to antibiotics. They take this as an indication the infection may be moving closer to becoming resistant to penicillin and other antibiotics called beta-lactams. Group A streptococcus is responsible for 20-30% of sore throats in children and 5-15% in adults.
The role of piRNA in Defending Fertility and the Genome
Scientists at the University of Tokyo uncovered more details about short strands of RNA called piRNA, who protect the genomes of specialized germ cells, which produce eggs and sperm. They found that a protein called Zucchini processes piRNA from a long immature form into a shorter intermediate form, which then matures into a functional form by another protein dubbed Trimmer.