TLR-2+ monocytes were reduced in Group 1 compared with Groups 2 and 3, and TLR-4+ monocytes were reduced in Groups 1 and 2 compared with Group 3. The frequencies and numbers of naïve CD4+ T and CD19+ B cells were higher in the three groups of neonates compared with adults, while
CD4+ effector and effector memory T cells and CD19+ memory B cells were elevated in adults compared with neonates, as expected. Our study provides reference values for leucocytes in cord blood from term and preterm newborns, which may facilitate the identification of immunological deficiencies in protection against extracellular pathogens. “
“CD28/B7 co-stimulation blockade with belatacept prevents alloreactivity in kidney transplant patients. However, cells lacking CD28 ABT199 are not susceptible to belatacept treatment. As CD8+CD28− T-cells have Y-27632 cost cytotoxic and pathogenic properties, we investigated whether mesenchymal stem
cells (MSC) are effective in controlling these cells. In mixed lymphocyte reactions (MLR), MSC and belatacept inhibited peripheral blood mononuclear cell (PBMC) proliferation in a dose-dependent manner. MSC at MSC/effector cell ratios of 1:160 and 1:2·5 reduced proliferation by 38·8 and 92·2%, respectively. Belatacept concentrations of 0·1 μg/ml and 10 μg/ml suppressed proliferation by 20·7 and 80·6%, respectively. Both treatments in combination did not inhibit each other’s function. Allostimulated CD8+CD28− T cells were able to proliferate and expressed the cytolytic and cytotoxic effector molecules granzyme
B, interferon (IFN)-γ and tumour necrosis factor (TNF)-α. Inositol monophosphatase 1 While belatacept did not affect the proliferation of CD8+CD28− T cells, MSC reduced the percentage of CD28− T cells in the proliferating CD8+ T cell fraction by 45·9% (P = 0·009). CD8+CD28− T cells as effector cells in MLR in the presence of CD4+ T cell help gained CD28 expression, an effect independent of MSC. In contrast, allostimulated CD28+ T cells did not lose CD28 expression in MLR–MSC co-culture, suggesting that MSC control pre-existing CD28− T cells and not newly induced CD28− T cells. In conclusion, alloreactive CD8+CD28− T cells that remain unaffected by belatacept treatment are inhibited by MSC. This study indicates the potential of an MSC–belatacept combination therapy to control alloreactivity. CD28/B7 co-stimulation blockade to prevent T cell activation and proliferation has been of interest for many therapeutic areas [1]. Belatacept, the latest immunosuppressive drug approved for therapy of kidney transplant recipients, utilizes this blocking mechanism. It is a fusion protein consisting of the extracellular domain of cytotoxic T lymphocyte antigen-4 (CTLA-4) and the Fc region of a human immunoglobulin (Ig)G1 immunoglobulin. By binding to CD80 (B7.1) and CD86 (B7.2) with a higher affinity than CD28, belatacept blocks the co-stimulatory signal [2].