Scientists at the Human Cell Atlas (HCA) are mapping the 37 trillion cells in the body, pinpointing each location for disease research and finding suitable drugs.
Image of a developing fetus’s skeleton, with cartilage (purple) acting as a support for the bones (blue) that appear later. Image: A. Chédotal & R. Blain, Institut de la Vision, Paris & MeLiS UCBL HCL, Lyon
On November 20, HCA scientists published more than 40 studies in a number of journals under Naturecontributing to the development of the groundbreaking first draft of the human cell map. These studies chart cells in multiple organs and organ systems – including the lungs, brain and skin – and describe the advanced computational tools needed to process all that data.
Aviv Regev, founding co-chair of HCA, compared this advance to the leaps in traditional cartography. It’s like going from a 15th-century world map to Google Maps, with detailed terrain, street views, and dynamic traffic models. “That is the leap we have taken,” Regev said at a press conference on November 19.
The new study includes a detailed map of the digestive tract, from the esophagus to the colon. Researchers mapped the healthy digestive tract based on 1.1 million cells sampled from nearly 190 people. They also compiled data from people with various gastrointestinal diseases, including ulcerative colitis and Crohn’s disease. Through their research, they discovered a type of cell that appears to contribute to inflammation in these diseases, possibly by summoning immune cells.
Itai Yanai, scientific director of the Applied Bioinformatics Laboratory at NYU Langone Health, an American academic medical center, wrote in a commentary: “Intestinal inflammation can cause cells to undergo metaplasia, conversion from one cell type to another. With data from healthy and diseased intestines, the researchers were able to determine exactly which stem cells give rise to the “anaplastic” cells. Once transformed, the anaplastic cells then cause more inflammation.
In other studies, scientists have explored early human development, revealing how the placenta develops and the skeleton begins to form during the first trimester of pregnancy. The second study revealed previously unseen states that cells enter as they prepare to form the skull. They also studied genes that may be involved in craniosynostosis, a birth defect that causes the soft spots of the skull to fuse too early.
Other research focuses on “organoids” (clusters of cells in culture), miniature versions of human organs grown in the lab. Scientists compared the map of the human brain with that of organoids, finding that, at least through the middle of pregnancy (from weeks 13 to 26), organoids match the fetal brain quite closely. tight. There are still unanswered questions about the last three months of pregnancy.
Another lab did a similar study looking at skin organoids, to see how closely they resembled real skin.
This map helps researchers come up with “better recipes” for organoids, Muzlifah Haniffa, a member of the HCA organizing committee, said at the press conference.
But “this information is interactive,” added Sarah Teichmann, HCA co-chair, because organoids also reveal subtle details about what’s happening inside the body. Scientists can “poke at the cells, disturb them” in ways that aren’t possible in humans, she said. Creating lifelike organoids could therefore help reveal how diseases arise and what drugs can effectively treat them.
HCA’s thirty-plus studies represent a major step forward. “Overall, the maps have the potential to constitute a resource that others can be inspired to explore and compare with other biological contexts, such as different species and diseases rare. Then, researchers can discover aspects of the human body that have not yet been imagined,” according to Yanai.
Scientists at the Human Cell Atlas Consortium (HCA), an international research consortium, have profiled 100 million cells from more than 10,000 people around the world. Working in more than 100 countries, researchers aim to identify similarities and differences in the cells of people from different demographic groups and genetic backgrounds.
By the end of 2026, the research team is expected to publish a map of the entire human body, detailing the location, characteristics and functions of each cell at different stages of life.