Media Release: 23 November 2009
By studying blood samples from patients recovering from bone marrow transplants, Australian scientists have been able to extract information that could help us fight certain cancers and autoimmune diseases.
B cells, the immune cells that produce antibodies, start their development in the bone marrow and complete it in peripheral blood and tissues. The developmental process in humans can be easily studied in people who have had their bone marrow destroyed and then reconstituted from donors, because clinical samples are collected at defined periods of time following the transplant.
PhD student Santi Suryani and Dr Stuart Tangye from the Garvan Institute of Medical Research have identified an important checkpoint in the development process, where the body gets rid of rogue B cells which see ‘self’ as the enemy and so allow the body to attack itself – as in autoimmune diseases such as lupus.
Their findings, which describe a ‘molecular signature’, or fingerprint, for B cells at this crucial stage of development are now online in the international journal Blood.
“By identifying exactly where B cells are in their stage of development, you can better understand and target specific B cell diseases” said Dr Tangye.
“Acute Lymphoblastic Leukemia, for instance, may be a malignancy of the B cell subset we’ve described. As we now know what the normal counterpart of the diseased B cell looks like, we are in a position to learn more about that type of leukemia.”
“In the case of lupus, an autoimmune disease where antibodies are produced that recognise self DNA, there seems to be a problem getting rid of the self-reactive B cells - at this point of the development process.”
“We will get to the stage where we know which genes are expressed in populations of cells at every phase of B cell development, allowing us to catalogue the subsets of cells.”
This knowledge should help us identify more specific therapeutic targets that will improve the treatment of diseases resulting from self-reactive or malignant B cells.