doi:10.1038/nindia.2011.3 Published online 19 January 2011
Biologists have got first evidence that Interleukin-3 (IL-3), a cell signalling protein that can improve the body's response to diseases, plays an important role in modulation of regulatory T cells (Treg).
Treg cells are a component of the immune system that suppress immune responses of other cells. The finding opens up the possibility of the use of IL-3 in treatment of autoimmune diseases such as rheumatoid arthritis.
Interleukin-3 (IL-3), cytokine or a biological signal, is part of the immune system. It is secreted by the T cells and functions as a link between the immune and the hematopoietic (blood making) system. IL-3 has a novel role in development of regulatory T (Treg) cells.
The researchers found that IL-3 increases the percentage of a kind of Treg cells called Foxp3+ Treg indirectly through secretion of IL-2 by non-Treg cells. IL-3 treatment significantly reduces the severity of arthritis and restores the loss of Foxp3+ Treg cells in thymus, lymph nodes, and spleen in arthritic mice.
The researchers showed that IL-3 decreases the production of inflammation promoting cytokines IL-6, IL-17A, TNF-α, and IL-1 and increases the production of anti-inflammatory cytokines IFN-γ and IL-10 in the experimental mice.