FGF-4 Protein

CD86 is a well-known costimulatory molecule in its interaction with CD28 and/or CTLA present on T cells, and is essential for full activation of naive T-cell and subsequent differentiation. Usually, the B7 molecules are expressed mainly on APCs and B cells and in specific conditions on other activated cells. These costimulatory molecules are involved in the development of allergic inflammation and airways hyperreactivity (AHR) in allergen-challenged mice. Activated T cells, CD4+CD25+, express CD86 in the first 60 minutes after the specific inhalation exposure. These T cells can be relevant in IgE mediated allergic reaction possibly by an autocrine co-stimulation via CD28/CTLA activation pathway. The blockage of the expression of CD86 could be a potential therapeutical target to reduce the magnitude or the progression of the allergic reaction.Fibroblast Growth Factor 4, a secreted heparin-binding protein, is a member of the fibroblast growth factor (FGF) family. FGF4 plays an essential role in the midgut patterning as it inhibits the foregut development and promotes the midgut and hindgut identity. Thus FGF4 induces the intestinal fate, repressing anterior markers such as hematopoietically expressed homeobox 1 (HEX1) and enhancing midgut markers such as PDX1 and CDX2. Also, Wnt signaling is essential to the midgut and hindgut development; high Wnt activity is required to repress foregut development and push towards an intestinal fate. As an example, the a fore mentioned transcription factor BARX1, which is expressed during foregut embryogenesis, induces SFRP1 and SFRP2 which in turn inhibit Wnt signaling, thus repressing midgut fate and favoring the foregut fate. Another crucial transcription factor of intestinal specification is CDX2. CDX2 is expressed early during the anterior-posterior formation of the gut tube and is essential for specifying the intestinal endoderm. Wnt induces the expression of CDX2, thus reinforcing its predominant role in intestinal specification.