Imma Perfetto
Cosmos science journalist
There are an estimated 37.2 trillion cells in the human body and scientists are another step closer to mapping all of them with the publication of more than 40 papers across Nature Portfolio journals.
The studies from the Human Cell Atlas initiative reveal new insights into how the placenta and skeleton form, changes that occur during brain maturation, new gut and vascular cell states, lung responses to COVID-19, how genetic variation impacts on disease, and more.
The HCA consortium has been striving to build an atlas of every cell type in the human body and their properties since 2016. It’s an international effort, with more than 3,600 members across 102 countries, including Australia, contributing data related to 18 biological networks.
“This is a pivotal moment for the HCA community as we move towards achieving the first draft of the Human Cell Atlas,” says Dr Aviv Regev, founding co-chair of the HCA.
“This collection of studies showcases the major advances from biology to AI achieved since the publication of the HCA White Paper in 2017 and that now deliver numerous biological and clinical insights.
“This large-scale, community-driven, globally representative and rigorously curated atlas will evolve continuously and remain accessible to all to advance our understanding of the human body in health and treatments for disease.”
The latest studies highlight findings across 3 key areas of the consortium: human developmental tissues; analysis tools; and organs or biological systems.
The most comprehensive cell map of the human gut to date has been created by combining spatial and single-cell data from 1.6 million cells. The Nature study describes cells from the tissues of the mouth through to the oesophagus, stomach, intestines and colon in healthy adults and individuals with inflammatory diseases.
“We were able to uncover a pathogenic cell type that may play a role in some chronic conditions and could be a target for intervention in the future,” says co-senior author Dr Rasa Elmentaite of Ensocell Therapeutics, UK.
“This demonstrates the power of using integrated single-cell atlases in research, and I am confident that applying this approach to other tissues and organs will drive new therapeutic discoveries for a range of conditions.”
Another Nature paper describes the first atlas of human skeletal development.
“There are countless processes that act in concert during human skeleton and joint development,” says Dr Ken To, co-first author from the Wellcome Sanger Institute, UK.
“Our research has characterised cell types and mechanisms involved in the formation of bone and the fusing of the skull. By studying these, we were able to give context to DNA variants linked with congenital conditions, such as craniosynostosis, predicting how genetic changes impact the developing skeleton.”
And an atlas of the developing human thymus, the organ that trains T cells which protect against infections and cancer, also appears in Nature.
Co-first author of the study, Dr Veronika Kedlian of University of Cambridge, says their atlas of healthy thymus development could lead to new strategies for boosting immunity, particularly in older adults or those with thymus deficiencies.
“We are already applying this resource to study age-related immune changes and conditions like DiGeorge syndrome, where children are born without a functioning thymus and are highly vulnerable to infections.”
Cosmos has covered previous publications from HCA, such as the first atlas of cells in the human brain and the human heart.
