Twenty-nine murine monoclonal antibodies (MAbs) were prepared against antigenic determinants in the core and lipid A regions of Escherichia coli and Salmonella minnesota lipopolysaccharide (LPS). At least eight distinct MAb specificities were identified. Epitopes recognized by MAbs bearing these specificities were localized in the hexose, heptose, and 2-keto-3-deoxy-D-manno-octulosonic acid regions of the core oligosaccharide and on lipid A. Two groups of MAbs exhibited multispecificity for similar but distinct core- and lipid A-related epitopes. Some core-reactive MAbs cross-reacted with corresponding E. coli and Salmonella rough mutant chemotypes; others were specific for E. coli J5 LPS. Lipid A-specific MAbs reacted with free lipid A from diverse sources. Few MAbs reacted with smooth LPS. Antibody cross-reactivity was restricted by inter- and intraspecies differences in covalent core structure and by epitope concealment by overlying O-side chain and core sugars. The putative cross-reactive and antiendotoxic properties of MAbs specific for the core-lipid A complex may be limited by the inability of such MAbs to recognize determinants on "native" LPS.
a b s t r a c t C-type natriuretic peptide (CNP) is a member of the small family of natriuretic peptides that also includes atrial natriuretic peptide (ANP) and brain, or B-type natriuretic peptide (BNP). Unlike them, it performs its major functions in an autocrine or paracrine manner. Those functions, mediated through binding to the membrane guanylyl cyclase natriuretic peptide receptor B (NPR-B), or by signaling through the non-enzyme natriuretic peptide receptor C (NPR-C), include the regulation of endochondral ossification, reproduction, nervous system development, and the maintenance of cardiovascular health. To date, the regulation of CNP gene expression has not received the attention that has been paid to regulation of the ANP and BNP genes. CNP expression in vitro is regulated by TGF- and receptor tyrosine kinase growth factors in a cell/tissue-specific and sometimes species-specific manner. Expression of CNP in vivo is altered in diseased organs and tissues, including atherosclerotic vessels, and the myocardium of failing hearts. Analysis of the human CNP gene has led to the identification of a number of regulatory sites in the proximal promoter, including a GC-rich region approximately 50 base pairs downstream of the Tata box, and shown to be a binding site for several putative regulatory proteins, including transforming growth factor clone 22 domain 1 (TSC22D1) and a serine threonine kinase (STK16). The purpose of this review is to summarize the current literature on the regulation of CNP expression, emphasizing in particular the putative regulatory elements in the CNP gene and the potential DNA-binding proteins that associate with them.Published by Elsevier Inc.
In vitro and in vivo antibacterial and protective properties of murine monoclonal antibodies (MAbs) to Escherichia coli O111:B4 lipopolysaccharide (LPS) were evaluated in relation to antibody isotype and complement-fixing activity. Six O side chain-specific MAbs, including two IgMs and one of each IgG subclass, were analyzed for quantitative binding and C3 deposition on intact bacteria, complement-mediated bactericidal and opsonophagocytic activity, and protection against intraperitoneal infections in mice. Although C3 was deposited on bacteria in the presence of normal human serum (NHS) alone, LPS-specific MAbs increased C3 attachment in a dose-dependent manner. Bacterial killing occurred only in the presence of both antibody and complement NHS and required an intact alternative pathway. The efficiency of bacterial killing varied by antibody isotype (IgM greater than IgG2a greater than other IgG subclasses) and correlated with C3-fixing capacity. Opsonophagocytic activity of MAbs exhibited a similar isotype-related rank order. Likewise, IgM was more active than IgG, and IgG2a was superior to other IgG subclasses, in MAb-mediated protection against intraperitoneal infection. These data document the interdependent antibacterial and complement-fixing properties of LPS-reactive MAbs and the degree to which both activities are determined by antibody class and isotype.
AVL was identified in 19.5 % of OIF deployers and travel to northwest Iraq correlated with infection. Further studies are needed to inform risk for reactivation VL in U.S. veterans and to target additional blood safety and surveillance measures.
Sixteen murine monoclonal antibodies (MAbs) reactive with the O-side chain, core oligosaccharide, or lipid A of Escherichia coli O111:B4 and Salmonella minnesota lipopolysaccharide (LPS) were evaluated for binding activity against wild-type and rough mutant strains using a fluorescence-activated cell sorter (FACS) and fluorescein-conjugated antiimmunoglobulin probe. O-side-chain-reactive MAbs produced immunofluorescence against homologous, smooth strains up to 500-fold higher than controls. Many core- and lipid A-reactive MAbs exhibited limited reactivity with smooth bacteria. Some core- and lipid A-associated epitopes, however, were better recognized by MAbs on intact bacteria than on isolated LPS. FACS analysis of binding by the core-reactive MAb, J8-4C10, to E. coli O26:B6 smooth bacteria revealed staining and non-staining bacterial phenotypes that were sorted and stably expressed in subculture. FACS analysis thus documented differences in the whole-cell reactivity of MAbs specific for various LPS subcomponents, differences in MAb reactivity with isolated and cell-associated LPS, and spontaneous changes in the phenotypic expression of certain LPS-associated epitopes on intact bacteria.
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