The week’s most astounding developments from the neobiological frontier.

February 17, 2022

New Yorker becomes first woman cured of HIV/AIDS

Fifteen years ago, an American named Timothy Ray Brown became the first person ever cured of HIV/AIDS after receiving a bone marrow transplant from a donor who carried the Delta32 variant of the CCR5 gene, which made his cells resistant to the virus. Brown was dubbed “the Berlin patient,” after the city where his procedure took place, and a few years ago, he was joined by a U.K. man named Adam Castillejo, who had the same procedure, was also cured, and became “the London patient.” Now researchers have announced a New York woman has become the third person ever cured—after she received a similar transplant of umbilical cord blood. Experts caution that while these cases are outstanding proof that HIV/AIDS is curable, the approach is not really viable for most people because all three had leukemia. They needed the transplants to treat their cancer, and they faced significant risks in their procedures. BBC

Genome sequencing in the ER—fast, cheap, and now within reach

The increasing speed and decreasing cost of whole genome sequencing have far outpaced Moore’s law, advancing so rapidly in the last 20 years that it’s now possible to think about delivering genomic analysis as a real-time, point-of-care diagnostic to guide treatment for people who are critically ill. Toward that end, a small study led by researchers at Stanford University sequenced the genomes of 12 people who arrived at two California hospitals between December 2020 and May 2021. Using a commercial Oxford Nanopore sequencer and distributed cloud-based computing, the team sequenced genomes in a matter of hours and leveraged the data to make definitive diagnoses. They identified a genetic cause of early-onset epilepsy in a 3-month old baby, for instance, and showed that they could go from a blood draw to a genome-based diagnosis in less than eight hours. New England Journal of Medicine

Slower responses from older people are not due to slower thinking

A new study of 1,185,882 people aged 10–80 shatters the notion that the mind dulls with age after we turn 20—a commonly held belief that has profound implications for workplace hiring. We tend to assume older people are slower thinkers, and there’s lots of experimental evidence that seems to back that up, showing that average response times on elementary cognitive tasks increase as we age. But analyzing the data in this new study, psychologists at Heidelberg University in Germany attribute the slowing to decision-making caution—mentally, how much we look before we leap. They found that this caution decreases over our teenage years, bottoms out by the time we are in college (surprise, surprise), and steadily increases thereafter. They attribute measured age-related declines in test response times with a growth in caution and with non-mental processes, like fumbling old fingers on the keyboard, rather than actual declines in mental speed. Nature Human Behavior

Viruses in the gut linked to human cognitive processes

Examining the microbiomes of more than 1,000 people, researchers at the University of Girona and the University of Alicante, both in Spain, discovered that people with increased levels of Caudovirales and Siphoviridae bacteriophage viruses in their gut performed better on cognitive tests of executive function and verbal memory—whereas people with more of another type of bacteriophage, called Microviridae, had impaired executive ability. The researchers showed that transplanting microbiota samples from people with more Caudovirales increased the expression of memory-promoting genes in the prefrontal cortex of mice and helped them perform better on memory tests—and that supplementing the diet of fruit flies with Siphoviridae did the same thing. Altogether these experiments suggest that bacteriophages may play a key role in the connection between the microbiome and the brain. Cell & Host Microbe

A molecular profile of the human brain vasculature

A comprehensive profile of the complete “transcriptomes” of 143,793 neurovascular cells in the brain has shown how genes are differentially expressed in these blood vessel cells in different parts of the human brain. Assembled by researchers at Stanford University in Palo Alto, California, the profile includes post-mortem samples taken from nine people with Alzheimer’s disease and eight who suffered no cognitive impairment. From this data and similar samples taken from mice, the researchers teased out how the brain’s vasculature is organized molecularly, and they also discovered 30 of the top 45 genes linked to Alzheimer’s risk in past genome-wide association studies (GWASs) are in fact expressed in those vasculature cells. In addition to shedding light on the molecular pathology of Alzheimer’s disease and potentially helping to design new therapeutic approaches, the researchers write that their work will also inform our overall understanding of brain health and disease. Nature

Keto diet gives hope for pancreatic cancer survival

In what some are billing as “cutting carbs to treat cancer,” researchers at Princeton University in New Jersey have shown that putting mice with pancreatic cancer on a ketogenic diet—low carbs, some protein, high fat—enhances a standard therapy by sensitizing tumors to cytotoxic chemo drugs. Based on the success of the experiments, coupled with the fact that pancreatic cancer remains one of the most deadly forms of the disease, the team has launched a randomized clinical trial that’s currently recruiting about 40 people who suffer from metastatic pancreatic cancer to test whether chemotherapy plus a ketogenic diet is better than chemo alone. It’s worth emphasizing that both arms of the clinical trial will be taking chemo—neither relying on diet alone. Med

An important precursor of LSD grown in yeast

Researchers from the National University of Singapore and Imperial College London have developed a new way of producing the natural product D-lysergic acid (DLA), a precursor of LSD and an important chemical used to make pharmaceutical drugs that treat everything from Parkinson’s to dementia to hypertension. There is a lot of demand for DLA for making these pharmaceuticals, and some 10–15 tons of it are produced each year. But current production methods usually involve the fermentation of ergot fungus and suffer from high cost and low efficiency. In a proof-of-concept, the researchers created a synthetic form of baker’s yeast and showed that it may be possible to produce DLA more easily and cheaply in a fermenter. Nature Communications

Gut microbiome butyrate and rheumatoid arthritis

Researchers at Peking University People’s Hospital in Beijing and the Chinese Academy of Sciences have identified an intestinal imbalance in the microbiomes of people who suffer from rheumatoid arthritis linked to the levels of a short-chain fatty acid known as butyrate. Sequencing the gut bacteria of 25 people with untreated rheumatoid arthritis and comparing them to 29 people without the disease, they found people with the disease have lower levels of a number of bacterial species producing butyrate—and elevated levels of bacteria that metabolize it. They showed that feeding mice dietary butyrate supplements reduced aspects of the disease, suggesting the potential for butyrate supplementation therapy for people with rheumatoid arthritis. Science Advances