We show in this article that the C4BP alpha(7)beta(0) isoform (hereafter called C4BP[beta(-)] [C4BP lacking the beta-chain]), overexpressed under acute-phase conditions, induces a semimature, tolerogenic state on human monocyte-derived dendritic cells (DCs) activated by a proinflammatory stimulus. C4BP isoforms containing beta-chain (alpha(7)beta(1) and alpha(6)beta(1);
C4BP[beta(+)]) neither interfered with the normal maturation of DCs nor competed with C4BP(beta(-)) activity on these cells. Immature DCs (iDCs) treated with C4BP(beta(-)) retained high endocytic activity, but, upon LPS treatment, they did not upregulate surface expression of CD83, CD80, and CD86. Transcriptional profiling of these semimature DCs revealed that treatment with C4BP(beta(-)) prevented
the induction of IDO and BIC-1, https://www.selleckchem.com/products/ulixertinib-bvd-523-vrt752271.html whereas TGF-beta 1 expression was maintained to the level of iDCs. C4BP(beta(-))-treated DCs were also unable to release proinflammatory Th1 cytokines (IL-12, TNF-alpha, IFN-gamma, IL-6, IL-8) and, conversely, increased IL-10 secretion. They prevented surface CCR7 overexpression and, accordingly, displayed reduced chemotaxis, being morphologically indistinguishable from iDCs. Moreover, C4BP(beta(-))-treated DCs failed to enhance allogeneic GM6001 in vivo T cell proliferation, impairing IFN-gamma production in these cells and, conversely, promoting CD4(+)CD127(low/neg) CD25(high)Foxp3(+) T cells. Deletion mutant analysis revealed that the complement control protein-6 domain of the alpha-chain is necessary for the tolerogenic activity of C4BP(beta(-)). Our QNZ datasheet data demonstrate a novel anti-inflammatory and immunomodulatory function of the complement regulator C4BP, suggesting a relevant role of the acute-phase C4BP(beta(-)) isoform in a number of pathophysiological conditions and potential applications in autoimmunity and transplantation. The Journal of Immunology, 2013, 190: 2857-2872.”
“Severe forms of dengue virus disease, known as dengue hemorrhagic fever and dengue shock syndrome, result from an aberrant immune response
involving antibody-dependent enhancement of infection, thrombocytopenia, and a loss of vascular integrity, culminating in hemorrhage, shock, and in some cases, death. Several studies have indicated that dengue virus infection results in the induction of apoptosis of certain cells believed to be contributory players in dengue pathogenesis. However, none have specifically examined the role of antibody enhancement in the context of induction of apoptosis. Here, we show that antibody-enhanced dengue virus infection of the FcR-bearing mast cell/basophil KU812 cell line results in a massive induction of apoptosis. Confocal microscopy and flow cytometry indicate two distinct subpopulations consisting of productively infected cells and apoptotic-uninfected bystanders.