Characterization of the Cryptosporidium antigens from sporulated oocysts of Cryptosporidium parvum.

The antigenic constituents of sporulated Cryptosporidium parvum oocyst antigens were characterized with antisera from mice immunized against C. parvum. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis followed by silver staining defined the major proteins. Six of seven lectins used recognized as many as 15 bands. The lectins concanavalin A, Dolichos biflorus, and wheat germ agglutinin showed strong activity against the same eight bands with molecular weights ranging from 72,000 to greater than 100,000. An enzyme-linked immunosorbent assay was used to detect antibody to C. parvum. Antibody binding was significantly decreased by heat and enzymatic treatment with trypsin, protease, and mixed glycosidases. C. parvum antigens were further defined by the reactivity of immune sera with a C. parvum sonicate preparation separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and electrophoretically transferred to nitrocellulose paper. Antisera from orally infected mice consistently recognized four antigens with molecular weights ranging from 72,000 to greater than 100,000. These antigens also bound concanavalin A. Treatment of the antigen preparation with mixed glycosidases reduced the reactivity of antisera with most antigens with molecular weights greater than 60,000. The data suggest that the antigenic composition of C. parvum is complex and that carbohydrates alone or in association with lipids or proteins may be important in the immune response to C. parvum.     

Pieces of the preeclampsia puzzle.

Introduction Several interesting articles have been published recently thataddress novel mechanisms for preeclampsia. These mechanismsall involve circulating factors, a favourite topic for preeclampsiaresearchers. These factors may interfere with angiogenesis,engage angiotensin (Ang) II signalling, and directly impairendothelial function. VEGF, PlGF and sFlt1 Vascular endothelial growth factor (VEGF) must be very busyduring pregnancy. The growth factor’s receptor, fms-liketyrosine kinase 1 (Flt1), exists in two forms, namely a membrane-boundreceptor tyrosine kinase that transmits angiogenic signals anda soluble secreted ectodomain (sFlt1), which may capture VEGFand keep the growth factor from its active bound receptor. Maynardet al. [     

IFN-alpha enhances CD40 ligand-mediated activation of immature monocyte-derived dendritic cells

Type I IFN are immune modulatory cytokines that are secreted during early stages of infection. Type I IFN bridge the innate and the adaptive immune system in humans and mice. We compared the capacity of type I and II IFN to induce the functional maturation of monocyte-derived dendritic cells (MoDC). Extending our earlier observation that type I IFN promote DC maturation, we report that these cytokines also enhance DC differentiation by augmenting CD40 ligand (CD40L)-induced cytokine secretion by MoDC. Type I IFN alone were poor inducers of MoDC maturation as compared with other stimuli. They up-regulated the expression of HLA-DR, CD80, CD86, partially CCR7 but not CD83, partially reduced antigen-uptake function, increased the levels of IL-12p35 mRNA, and prolonged surface expression of peptide-MHC class I complexes for presentation to cytotoxic T lymphocytes, but did not induce migration towards CCL21 chemokine. However, type I IFN were potent co-factors for CD40L-mediated function. Here, they enhanced CD40L-mediated IL-6, IL-10 and IL-12p70 secretion. Furthermore, when combined with IL-1beta and/or IL-4, IFN-alpha2a type I IFN increased CD40L-mediated IL-12p70 production by 2- to 3-fold, and biased the IL-12 p40/p70 ratio towards the IFN-gamma inducing p70 heterodimer, this correlating with higher levels of IFN-gamma secretion by allogeneic T cell subsets and NK cells. Our results suggest that the rapid expression of CD40L, IFN and IL-1beta at sites of infection and inflammation can act in concert on immature DC, thereby linking innate and adaptive immune responses. In this way, type I IFN play a dual role as DC maturation factors and enhancers of CD40L-mediated DC activation.     

Die H?henanpassung

Ohne ZusammenfassungAus dem Luftfahrtmedizinischen Forschungsinstitut des Reichsluftfahrtministeriums. Leiter: Prof.H. Strughold.Warum ich zuletzt am liebsten mit der Natur verkehre, ist, weil sie immer recht hat und der Irrtum bloss auf meiner Seite sein kann.Goethe