Researchers of the Epigenetics and Cancer Biology Program at IDIBELL, led by researcher Maribel Parra, have identified a transcriptional repressor, histone deacetylase HDAC7, involved in the identity of B cells, the cells responsible to create antibodies in our immune system.
The results of the study, published in PLoS Genetics, show that HDAC7 is expressed specifically in B lymphocytes and do not in cells of other lineages such as macrophages.
The blood stem cells go through a very complex system of differentiation to form the different blood cells. In the hematopoietic system, there are two main lines: the lymphoid, which results in T cells, B cells and NK cells, among others, and myeloid form erythrocytes (red blood cell) or macrophages among others.
As explained Maribel Parra, to take all the steps of differentiation, there must be changes in cell gene program. There are transcription factors that activate genes in each cell line but it also exist transcriptional repressors that impair the expression of "inappropriate" genes, characteristic of another lineage.
The lab of Maribel Parra studies the role of a family of transcriptional repressor proteins that are in the differentiation of cells of the hematopoietic system. The histone deacetylases (HDAC).
Repression of "inappropriate" genes.
In this work, researchers have shown that the role of HDAC7 protein is to suppress "inappropriate" gens characteristic of other lineages such as macrophages, in B lymphocytes.
Researchers rescheduled B lymphocyte precursor cells into macrophages (myeloid lineage), and found that the expression of HDAC7 decreased dramatically while returning to express this protein inducted blocking of key genes to macrophage biology.
Parra explained that "through this mechanism of transcriptional repression, Cell B ensures that genes characteristics of other cell types are not expressed and maintains its lymphoid identity." He also notes that "given its importance in the biology of B cells, HDAC7 function might be altered in haematological diseases such as leukaemia and lymphomas. Our research is now going on that direction".