I am looking at tumor cells + surrounding immune cells and their expression of IL-6 in B-cell derived cancer. In some samples I can recognize comet-like plasma cells, and their cytoplasm is very clearly stained for the IL-6 antibody. Can plasma cells express IL-6, and if not, what might (in theory) activate the expression of this gene?
Plasma cells can be problematic in IHC staining, as various primary antibodies can often stick to the plasma cell cytoplasm as non-specific binding. So that would be my first thought, especially in the absence of literature to support their IL-6 production.
Jean-Martin Lapointe This could definitely be one reason. There is also a possibility that the "plasma cells" are in fact plasmacytoid dendritic cells. Since we have only stained for IL-6 this is nothing more than speculations.
Good point. There is a good antibody for pDCs marker CD303 sold by Dendritics, so you could compare the staining with that. But the number and distribution of the positive cells should also give you a clue. When present, plasma cells will generally be fairly numerous, and generally distributed in aggregates. I would expect pDCs to be much more rare, and probably present more as individual cells rather than clumps.
- Badges
- Science topic