Measles virus-specific murine T cell clones: characterization of fine specificity and function

Measles virus (MV)-specific murine helper T cell clones (Thy-1.2+, CD4+, CD8-) were generated from mice immunized with MV-infected mouse brain homogenate by limiting dilution and in vitro stimulation of spleen cells with UV-inactivated MV Ag. The protein specificity of 7 out of 37 stable T cell clones, which displayed MHC-restricted MV Ag recognition, could be assessed by using purified MV proteins. Two fusion (F) protein-specific, two hemagglutinin-specific, and three nucleoprotein- or matrix protein-specific clones were shown to be established. The F protein-specific T cell clones together with a panel of previously generated F protein-specific T cell clones were characterized for their fine specificity by using beta-galactosidase fusion products, which contained different parts of the F protein. It was shown that at least two epitopes on the major part of the F protein (amino acid 2-513) can be recognized by mouse T cells. Functional characterization of three T cell clones showed that they were able to assist MV-specific B cells and bystander B cells for antibody production. Furthermore, they were shown to produce the lymphokines IL-2 and IFN-gamma. It was also shown that these T cell clones induced a MV-specific delayed type hypersensitivity response. These observations suggest that all of the T cell clones characterized belong to the TH1 helper subset.     

Normal and Fibrotic Rat Livers Demonstrate Shear Strain Softening and Compression Stiffening: A Model for Soft Tissue Mechanics

Tissues including liver stiffen and acquire more extracellular matrix with fibrosis. The relationship between matrix content and stiffness, however, is non-linear, and stiffness is only one component of tissue mechanics. The mechanical response of tissues such as liver to physiological stresses is not well described, and models of tissue mechanics are limited. To better understand the mechanics of the normal and fibrotic rat liver, we carried out a series of studies using parallel plate rheometry, measuring the response to compressive, extensional, and shear strains. We found that the shear storage and loss moduli G’ and G” and the apparent Young''s moduli measured by uniaxial strain orthogonal to the shear direction increased markedly with both progressive fibrosis and increasing compression, that livers shear strain softened, and that significant increases in shear modulus with compressional stress occurred within a range consistent with increased sinusoidal pressures in liver disease. Proteoglycan content and integrin-matrix interactions were significant determinants of liver mechanics, particularly in compression. We propose a new non-linear constitutive model of the liver. A key feature of this model is that, while it assumes overall liver incompressibility, it takes into account water flow and solid phase compressibility. In sum, we report a detailed study of non-linear liver mechanics under physiological strains in the normal state, early fibrosis, and late fibrosis. We propose a constitutive model that captures compression stiffening, tension softening, and shear softening, and can be understood in terms of the cellular and matrix components of the liver.     

Apolipoprotein E protects against bacterial lipopolysaccharide-induced lethality. A new therapeutic approach to treat gram-negative sepsis

Septic shock is the most common cause of death in intensive care units and no effective treatment is available at present. Lipopolysaccharide (LPS) is the primary mediator of Gram-negative sepsis by inducing the production of macrophage-derived cytokines. Previously, we showed that apolipoprotein E (apoE), an established modulator of lipid metabolism, can bind LPS, thereby redirecting LPS from macrophages to hepatocytes in vivo. We now report that intravenously administered LPS strongly increases the serum levels of apoE. In addition, apoE can prevent the LPS-induced production of cytokines and subsequent death in rodents. Finally, apoE-deficient mice show a significantly higher sensitivity toward LPS than control wild-type mice. These findings indicate that apoE may have a physiological role in the protection against sepsis, and recombinant apoE may be used therapeutically to protect against LPS-induced endotoxemia.     

Large-scale de novo transcriptome analysis reveals specific gene expression and novel simple sequence repeats markers in salinized roots of the euhalophyte <Emphasis Type="Italic">Salicornia europaea</Emphasis>

Glycophytic plants suffer from severe stress and injury when roots are exposed to high salinity in the rhizosphere. In contrast, the euhalophyte Salicornia europaea grows well at 200 mM NaCl and can withstand up to 1000 mM NaCl in the root zone. Analysis of gene expression profiles and the underlying molecular mechanisms responsible for this tolerance have been largely overlooked. Using the Illumina sequencing platform and the short-reads assembly programme Trinity, we generated a total of 40 and 39 million clean reads and further 140,086 and 122,728 unigenes from the 200 mM NaCl and 0 mM NaCl treated tissues of S. europaea roots, respectively. All unigenes in this study were functionally annotated within context of the COG, GO and KEGG pathways. Unigene functional annotation analysis allowed us to identify hundreds of ion transporters related to homeostasis and osmotic adaptation as well as a variety of proteins related to cation, amino acid, lipid and sugar transport. We found significant enrichment in response to stress including the functional categories of “antioxidant activity”, “catalytic activity” and “response to stimuli”. These findings represent for a useful resource for the scientific community working on salt tolerance mechanisms. Conversely, a total of 8639 EST-SSRs from 131,594 unigenes were identified and 4539 non-redundant SSRs primers pairs were developed. These data provide a good foundation for future studies on molecular adaptation mechanisms of euhalophytes roots under saline environments and will likely facilitate the identification of critical salt tolerance traits to be transferred in economically important crops.