New Molecules on Dendritic Cells and Their Interactions with T Lymphocytes

Abstract

Dendritic cells (DC) are a subpopulation of leucocytes with an important role as specialist antigen presenting cells (APC), being the only APC capable of initiating a strong primary T lymphocyte response. Using this functional property (ie their ability to stimulate a primary mixed leucocyte reaction) to detect DC we have identified a small population of potential DC precursors within human bone marrow (BM) (1). Further fractionation of this minor population of BM mononuclear cells (BMMC) using mAb with immunomagnetic separation and flow cytometry suggests this population has a close relationship with myeloid precursors and that even CD34 positive BMMC initiate an allogeneic MLR (2). It is possible to maintain these mAb mix-negative, lineage negative, BMMC in culture but it is not yet clear which cytokines optimize their growth and differentiation. The CDla antigen has not proven to be a marker restricted to human DC in BM. In our hands, GM-CSF and TNFα induce CDla expression on myeloid cells, but also distort myeloid differentiation, altering phenotypic appearances without selectively encouraging DC stimulatory function (3).KeywordsBone MarrowDendntlc CellHuman Bone MarrowBone Marrow Mononuclear CellHuman Dendritic CellThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.