A new study has provided the most detailed analysis so far of the prenatal development of blood and immune cells in the bone marrow.
The research team include Professor Irene Roberts and Associate Professor Andi Roy both of the MRC Molecular Haematology Unit, and the University of Oxford’s MRC Weatherall Institute of Molecular Medicine. Their research is supported by the NIHR Oxford Biomedical Research Centre.
The study, funded by the Wellcome Sanger Institute, pinpoints a specific six-to-seven-week window in the second trimester of pregnancy, during which the full range of blood and immune cells are established in the bone marrow.
This data will be a valuable reference for researchers exploring the nature of the blood and immune system, especially where changes in those processes lead to diseases such as cancers.
Throughout foetal development, our cells are in continual need of oxygen and nutrients and need to build the components of a sophisticated immune system ready to protect us from the moment of birth. The cells that do this are all provided by the blood and immune system.
The emergence of these systems happens in multiple phases across several organs in a process known as haematopoiesis. Early in development, production of both red blood cells and immune cells begins in the yolk sac, before transitioning to the foetal liver, and then to the foetal bone marrow, where it begins a lifelong role.
As part of the project researchers also studied the bone marrow of children with Down’s syndrome, who are known to be at increased risk of childhood leukaemias, as well as immune deficiency and autoimmune diseases. This makes understanding the development of the immune and blood systems very important.
Professor Roberts, a senior author on the paper, said: “We know that children with Down’s syndrome have a higher risk of developing leukaemia, but we don’t know why.
“This study characterises some of the differences in gene expression in their bone marrow, which will allow us to start figuring out whether these differences are significant and in what way. We hope this will ultimately help researchers develop better ways of treating, or even preventing, leukaemia in these children.”
Professor Roy, a senior co-author on the paper, added: “This project allowed us to study how haematopoiesis is established before birth in the bone marrow, the site for subsequent lifelong blood cell production. More importantly we show the utility of datasets such as this in understanding the effects on human health when these processes are perturbed.”
Researchers from the Oxford BRC’s Gastroenterology and Mucosal Immunity Theme are also involved in the HCA. Professor Paul Klenerman is leading research on the immune cells in the gastrointestinal organs and how they might influence inflammatory diseases.