subject: PU.1 shown to be key to development of dendritic cells through CD 135 expression [print this page] PU.1 shown to be key to development of dendritic cells through CD 135 expression
Transcription factors regulate DNA transcription by interacting with RNA polymerases, often as part of a large transcriptional regulation complex. Recently, two of the transcription factors on our antibody database, CD 135 (also known as Flt3) and PU.1, were revealed to play a combined role in dendritic cell (DC) development. DCs are a small but complex group of immune cells which play a vital defence role against environmentally-borne antigens.
Dendritic cells are found in small numbers, in areas exposed to the external environment, including the skin, gut and nasal passages. Their purpose is as antigen-presenters, i.e. processing and delivering foreign proteins to killer T and B cells, triggering an immune response. Immature DCs develop from haemopoietic progenitor cells in the bone marrow. Pattern recognition proteins such as toll-like receptors then begin "sampling" the surrounding environment for foreign proteins. Once presented with an antigen, the cells are activated into maturity.
Dendritic cells are known to comprise a number of different subsets, and within the last 10 years, a number of antigen-specific individual DCs have been identified. However, little is known about their initial development. Antibody studies have shown that the cytokine receptor CD 135/Flt3, found in haemopoietic stem cells, is also found on the surface of DC progenitor cells and is key to DC development. However, the factors affecting its regulation have so far been a mystery.
Now, Dr Li Wu et al, of the Walter and Eliza Hall Institute, Melbourne, have shown that expression of the Flt3 gene may be regulated by PU.1, a transcription factor encoded by the SPI1 gene. PU.1 is known to regulate gene expression during the development of B-lymphoid and myeloid cells. In this latest study, it was shown that blocking PU.1 function in DC progenitor cells led to a complete loss of DC development.
We at Novus Biologicals have a growing number of transcription factors in our antibody catalog, which are implicated in dendritic cell development.
