Researchers have found a key cell in the bone marrow that develops into the immune system. A discovery that leads to understanding what goes wrong in diseases like blood cancer.

The researchers were "intrigued to find this particular bone marrow cell because it opens up a lot of new possibilities in terms of understanding how human immunity is produced from stem cells throughout life," said Dr. Gay Crooks, a professor of pathology and pediatrics and senior author of the study.

Stem cells have the ability to become any kind of cells. Blood stem cells (in the bone marrow) divide and form cells like red blood cells, white blood cells and platelets. The research team wanted to know what stem cells gave rise to cells in the immune system - the progenitor of lymphocytes.

According to first author Lisa Kohn, from University of California Los Angeles, the progenitor cell that they've discovered can produce the entire immune system. Researchers have also studied how this cell changes genetic expression when it differentiates from a stem cell to a progenitor cell.

"The gene expression data convinced us that we had found a unique stage of development in the immune system. There was a set of genes that the lymphoid-primed cell shares with the bone marrow stem cells and a unique gene expression of its own once it becomes active. This data provided us with an understanding of what genes are important in creating all the cells of the immune system," Dr. Crooks said.

Crooks added that "the information could allow us to manipulate bone marrow to help create a stronger immune system."

"The identification of a progenitor in human bone marrow primed for full lymphoid differentiation will now permit delineation of the molecular regulation of the first stages of lymphoid commitment in human hematopoiesis. It will also allow understanding of how these processes are affected during aberrant hematopoiesis in disease states," study states.

In other words, the study will help researchers better understand how the immune system develops and what causes the changes in the way blood and immune system work during a disease or a condition like cancer.

The study is published in the journal Nature Immunology.