What's new in biology
Return of the screwworm, new DNA vaccines, gene editing at scale, and more
Asimov Press’s Niko McCarty and our own Saloni Dattani return to review more important things happening in the world of biotechnology and medicine.
1. Biologists have long used ‘reporter’ genes, such as green fluorescent protein, to watch molecules move around inside living cells. But fluorescent proteins can only be seen from close up. MIT scientists have solved this problem by creating ‘hyperspectral reporters’, which are DNA sequences that instruct bacteria to make pigment molecules that subtly shift light in the hyperspectral wavelengths, thus creating unique fingerprints. When these hyperspectral reporters are inserted into soil bacteria, the bacteria can be seen using cameras mounted to drones from up to 90 meters away. Researchers can program cells to sense explosives, trigger reporter genes, and then spot these areas from afar.
2. Screwworms have returned to Central America. Costa Rica confirmed its first screwworm infection in over 30 years on February 7 2024, when physicians found dozens of larvae in an 80-year-old Canadian visitor’s leg ulcer; Toronto surgeons removed more than 40 larvae in two procedures. And earlier this year, physicians reported at least 30 cases of screwworm infections in Nicaragua. For over 50 years, the USDA has airdropped millions of sterilized male screwworm flies weekly along the Panama–Colombia border. Female screwworms only mate once in their lifetime; these sterile males mate with the females, but produce no offspring, thus slowly reducing insect populations. This ‘sterile-insect technique’ eradicated screwworms in the U.S. in the 1960s, when the pests killed cattle and inflicted about $100 million in annual losses. But now, the ‘screwworm wall’ between North and South America has been broken.
3. Scientists have developed a new gene-editing tool, STITCHR, to insert large pieces of DNA into genomes. Existing tools like CRISPR–Cas9 can make small edits easily but struggle to insert big pieces of DNA efficiently, which has limited efforts to replace entire genes or fix complex mutations. To find a better tool, researchers searched across thousands of species and identified R2Tg, a highly active retrotransposon from the zebra finch. They engineered it into a programmable system that can install edits up to 12.7 kilobases long – roughly the size of the average human gene – without leaving mistakes behind.
4. Scientists have developed a portable test to detect a tuberculosis infection from blood or respiratory samples. Tuberculosis (TB) is the largest infectious disease killer worldwide, killing around 1.2 million people annually, mostly in poor countries, where fast, accurate diagnosis is often hard to get. Researchers have built a handheld device paired with a ready-to-use tube that processes the sample, looks for DNA of Mycobacterium tuberculosis, and gives a simple readout. In tests on children and adults, the system detected a higher share of TB cases than standard methods (meaning it has ‘high sensitivity’). It also correctly ruled out TB in most people who didn’t have it (‘high specificity’), at levels that met World Health Organization targets.
5. Researchers have created the largest ‘brain wiring diagram’ to date. Researchers first mapped all 302 neurons in the C. elegans worm back in 1986 to link physical wiring with behavior. Now, a consortium of scientists has traced the largest connectome yet – about 75,000 neurons and 500 million synapses in a mouse, out of roughly 7 million total neurons.
6. DNA vaccines are easy to produce, stable at higher temperatures, and faster to design than many other types of vaccines. But they’ve usually needed special devices to push the DNA into cells, like ‘gene guns’ or electrical pulses. An alternative option was to include DNA vaccines within lipid nanoparticles (LNPs) – the same technology used to deliver mRNA COVID-19 vaccines – but until now, this hadn’t worked well for DNA vaccines. Scientists have created a new DNA-LNP formulation that better packages and protects DNA, helping it enter cells and activate the immune system. With this method, they developed new vaccines for influenza and COVID-19 and tested them in mice and rabbits, which showed strong antibody and T cell responses that lasted for over a year in some cases. This approach could be widely used to create simpler, more stable vaccines for various diseases.
7. Drug companies are pooling data to improve AlphaFold3. AlphaFold 3 is Google DeepMind’s latest AI model for predicting protein shapes from genetic sequences. It was trained on over 200,000 protein structures, but it has few examples of drug–protein complexes. To fill this gap, pharmaceutical companies – including AbbVie, J&J, and Sanofi – are pooling their proprietary protein–ligand structures into a secret dataset off-limits to academics. They’ll retrain an open-source AlphaFold 3 replica to predict both protein folds and how candidate drugs bind. Hopefully this proprietary model will be able to virtually optimize drug candidates while requiring far fewer experiments in the laboratory.
8. For decades, the FDA required drug developers to prove safety in animals –often dogs or non-human primates – before first-in-human trials, despite animal data frequently failing to predict human outcomes. But the agency recently unveiled a detailed roadmap to phase out, or dramatically reduce, animal testing, allowing companies to submit AI or organoid data instead. At first, this roadmap applies to a class of drugs called monoclonal antibodies, but only for those used to target non-human antigens (like bacteria). Monoclonal antibodies are some of the most common drugs on the market and include bestsellers like adalimumab (Humira), pembrolizumab (Keytruda), and dupilumab (Dupixent). The FDA is also offering case-by-case waivers for other types of drugs.
9. The FDA approved a new long-acting hemophilia treatment. Hemophilia is a rare genetic condition that slows down blood clotting, which can lead to frequent bleeding. For years, patients have relied on regular infusions of clotting factors or similar products to prevent or treat bleeds. These can be inconvenient and time-consuming, especially for people who need frequent dosing. In March, the FDA approved a new treatment called Qfitlia, a shot under the skin that’s taken as infrequently as once every two months, and in trials, it reduced bleeding episodes by over 70% compared to standard on-demand treatment.
10. A new lab-based study found that nitisinone, an existing FDA-approved drug, can kill malaria-spreading mosquitoes after they feed on treated blood. Malaria is spread by Anopheles mosquitoes, which need to digest large amounts of protein after feeding on blood. As part of this, they break down the amino acid tyrosine (one of the building blocks of proteins), which is toxic if it builds up. Nitisinone, a drug used to treat rare metabolic disorders, blocks the enzyme that mosquitoes rely on to process tyrosine. When female mosquitoes fed on blood samples from patients taking this drug, they died, even if they were resistant to standard insecticides. This approach is similar to how ivermectin, a drug used to treat parasitic infections, can kill mosquitoes that feed on people taking this drug, and has also been used in anti-mosquito bed nets.
11. Researchers developed a potential Lyme vaccine that prevented the disease in mice. Nearly 500,000 Americans contract Lyme disease each year from tick-transmitted Borrelia burgdorferi, and the only FDA-approved vaccine was withdrawn in 2002 after poor sales due, in part, to vaccine skepticism, and its inconvenient, three-dose schedule.
12. Researchers are also making headway against another major bacterial threat: Clostridioides difficile, a bacterial infection that often strikes after antibiotic use, causing gut inflammation and serious diarrhea, especially in hospitals. Past vaccines targeting the bacteria’s two major toxins, TcdA and TcdB, have failed. Now, researchers have developed a mRNA vaccine encoding parts of the bacteria’s toxins and a protein that helps the bacteria move. Injected into mice in two doses, the vaccine triggered strong antibody responses: all unvaccinated mice died, all the vaccinated mice survived.
13. In the United States, about 3 million antimicrobial-resistant infections occur each year. One way to counteract this problem is to discover new classes of antibiotics that microbes have not yet evolved resistance against. Researchers recently identified a new antibiotic with a novel molecular mechanism. Lariocidin, a small, knotted protein naturally produced by Paenibacillus bacteria, is effective against both Gram‑positive and Gram‑negative bacteria – including multidrug‑resistant Acinetobacter baumannii – and, in laboratory experiments, researchers did not detect any toxicity to human cells. It will need to go through further clinical testing and, like other new antibiotics, will likely face major economic hurdles in reaching patients, as limited financial incentives have slowed antibiotic development for decades.
14. What may be the first cure for a prion disease was recently given permission by the FDA to start human trials. Eric and Sonia Minikel have been researching prion disease for around a decade, hoping to find an effective treatment for Sonia Minikel’s inherited prion disease, fatal familial insomnia (FFI). With improvements of gene-editing technology, they developed a potential drug that silences the prion protein in infected mice.
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