However, we found that SIRPα was rapidly induced on Kupffer cells following L. donovani infection, via a mechanism
involving G-protein-coupled receptors. Thus, we describe a novel amplification pathway affecting cytokine production by hepatic iNKT cells, which may facilitate the breakdown of hepatic tolerance after infection. “
“The transfer of alloreactive regulatory T (aTreg) cells into transplant recipients represents an attractive treatment option to improve long-term graft acceptance. We recently described a protocol for the generation of aTreg cells in mice using a nondepleting anti-CD4 antibody (aCD4). Here, we investigated whether adding TGF-β and retinoic acid (RA) or rapamycin (Rapa) can further improve aTreg-cell generation and function. Murine CD4+ T cells were cultured with allogeneic B cells in the
presence of aCD4 alone, aCD4+TGF-β+RA or aCD4+Rapa. GPCR Compound Library cell assay Addition of TGF-β+RA or Rapa resulted in an increase of CD25+Foxp3+-expressing T cells. Expression of CD40L and production of IFN-γ and IL-17 was abolished in aCD4+TGF-β+RA aTreg cells. Additionally, aCD4+TGF-β+RA aTreg cells showed the highest level of Helios and Neuropilin-1 co-expression. Although CD25+Foxp3+ cells from AG-014699 in vivo all culture conditions displayed complete demethylation of the Treg-specific demethylated region, aCD4+TGF-β+RA Treg cells showed the most stable Foxp3 expression upon restimulation. Consequently, aCD4+TGF-β+RA aTreg Methane monooxygenase cells suppressed effector T-cell differentiation more effectively in comparison to aTreg cells
harvested from all other cultures, and furthermore inhibited acute graft versus host disease and especially skin transplant rejection. Thus, addition of TGF-β+RA seems to be superior over Rapa in stabilising the phenotype and functional capacity of aTreg cells. Regulatory T (Treg) cells play an important role in the suppression of unwanted immune responses after transplantation  or after allogeneic stem cell transplantation . Treg cells are essential for maintaining peripheral tolerance and for preventing autoimmune diseases such as systemic lupus erythematosus , rheumatoid arthritis  or diabetes . Treg cells can be categorised into two groups, natural Treg (nTreg) cells, which develop in the thymus , and adaptive Treg cells or so-called induced (iTreg) Treg cells, which develop from CD4+CD25− cells in the periphery. Treg cells are mainly characterised by their expression of CD4 and CD25 . Although both subsets express the fork head transcription factor Foxp3, nTreg cells and iTreg cells differ in DNA methylation pattern of the Foxp3 gene . Furthermore, nTreg cells have been shown to express the Ikaros transcription family member Helios , although the selectivity of Helios expression in thymus-derived Treg cells was recently challenged .