Mouse CD8+ CD122+ T cells with intermediate TCR increasing with age provide a source of early IFN-gamma production

Although CD8+ IL-2Rbeta (CD122)+ T cells with intermediate TCR reportedly develop extrathymically, their functions still remain largely unknown. In the present study, we characterized the function of CD8+ CD122+ T cells with intermediate TCR of C57BL/6 mice. The proportion of CD8+ CD122+ T cells in splenocytes gradually increased with age, whereas CD8+ IL-2Rbeta-negative or -low (CD122-) T cells conversely decreased. The IFN-gamma production from splenocytes stimulated with immobilized anti-CD3 Ab in vitro increased with age, whereas the IL-4 production decreased. When sorted CD8+ CD122+ T cells were stimulated in vitro by the anti-CD3 Ab, they promptly produced a much larger amount of IFN-gamma than did CD8+ CD122- T cells or CD4+ T cells, whereas only CD4+ T cells produced IL-4. The depletion of CD8+ CD122+ T cells from whole splenocytes greatly decreased the CD3-stimulated IFN-gamma production and increased the IL-4 production, whereas the addition of sorted CD8+ CD122+ T cells to CD8+ CD122+ T cell-depleted splenocytes restored the IFN-gamma production and partially decreased IL-4 production. It is of interest that CD8+ CD122+ T cells stimulated CD4+ T cells to produce IFN-gamma. The CD3-stimulated IFN-gamma production from each T cell subset was augmented by macrophages. Furthermore, CD3-stimulated CD8+ CD122+ T cells produced an even greater amount of IFN-gamma than did liver NK1.1+ T cells and also showed antitumor cytotoxicity. These results show that CD8+ CD122+ T cells may thus be an important source of early IFN-gamma production and are suggested to be involved in the immunological changes with aging.     

Pathogenicity of Hantaan virus in newborn mice: genetic reassortant study demonstrating that a single amino acid change in glycoprotein G1 is related to virulence

Two Hantaan virus strains, clone 1 (cl-1), which is virulent in newborn mice, and its attenuated mutant (mu11E10), were used to examine the pathogenesis of Hantaan virus infection in a mouse model and identify virus factors relating to virulence. After subcutaneous inoculation of newborn BALB/c mice, cl-1 caused fatal disease with high viral multiplication in peripheral organs, but mu11E10 produced nonfatal infection with a low level of virus multiplication. Intracerebral inoculation of either strain caused fatal disease. Histopathological changes in the dead animals were prominent in the brain, indicating that the brain is the target organ and produces the fatal outcome. These results indicate that mu11E10 has a generally less virulent phenotype, and because of decreased multiplication in peripheral tissues, neuroinvasiveness is also decreased. An experiment with genetic reassortant viruses showed that in newborn mice the M segment is the most related to virulence and the L segment is partly related. Sequence comparison detected a single deduced amino acid change (cl-1 Ile to mu11E10 Thr) at amino acid number 515 in glycoprotein G1. One nucleotide change, but no amino acid substitution, was observed in the noncoding region of the L segment. In mouse brain microvascular endothelial cells in vitro, viruses possessing a cl-1-derived M segment grew more rapidly than viruses containing a mu11E10-derived M segment. These results suggest that the single amino acid change in the glycoprotein alters peripheral growth, which affects invasion of the central nervous system in mice.     

THE WAVELENGTH DEPENDENCE OF MASSIVE CAROTENE SYNTHESIS IN DUNALIELLA BARDAWIL (CHLOROPHYCEAE)1

Dunaliella bardawil Ben-Amotz & Avron accumulates high concentrations of β-carotene when grown under high light intensity. The β-carotene is composed mainly of 9-cis and all-trans β-carotene. Accumulation of β-carotene and an increase in the ratio of the 9-cis to the all-trans isomer are strongly dependent on the light intensity under which the algae are cultivated but are independent of light quality within the photosynthetically active radiation range. Cells grown under continuous red (>645 nm) or white light of 500 W·m^?2 reach a value of about 32 pg β-carotene·cell^?1 and a ratio of 9-cis to all-trans β-carotene of around 2, whereas cells grown under low red or white light intensity of 25 W·m^?2 contain about 3 pg·cell^?1 and a ratio of isomers of around 0.3.     

Femoral artery neointimal hyperplasia is reduced after wire injury in Ref-1+/- mice

Redox factor-1 (Ref-1) is a multifunctional protein that regulates redox, DNA repair, and the response to cell stress. We previously demonstrated that Ref-1(+/-) mice exhibit a significantly reduced Ref-1 mRNA and protein levels within the vasculature, which are associated with increased oxidative stress. The goal of this study was to test the hypothesis that partial loss of Ref-1 altered the cellular response to vascular injury. Fourteen days after femoral artery wire injury, we found that vessel intima-to-media ratio was significantly reduced in Ref-1(+/-) mice compared with that in wild-type mice (P < 0.01). Bromodeoxyuridine labeling and transferase-mediated dUTP nick-end labeling staining at 14 days did not differ in the Ref-1(+/-) mice. In vitro studies found no significant changes in either serum-induced proliferation or baseline apoptosis in Ref-1(+/-) vascular smooth muscle cells. Exposure to Fas ligand; however, did result in increased susceptibility of Ref-1(+/-) vascular smooth muscle cells to apoptosis (P < 0.001). Ref-1(+/-) mice exhibited an increase in circulating baseline levels of IL-10, IL-1alpha, and VEGF compared with those in wild-type mice but a marked impairment in these pathways in response to injury. In sum, loss of a single allele of Ref-1 is sufficient to reduce intimal lesion formation and to alter circulating cytokine and growth factor expression.     

Synthesis and antiviral property of allophenylnorstatine-based HIV protease inhibitors incorporating D-cysteine derivatives as P2/P3 moieties

We designed several HIV protease inhibitors with various d-cysteine derivatives as P(2)/P(3) moieties based on the structure of clinical drug candidate, KNI-764. Herein, we report their synthesis, HIV protease inhibitory activity, HIV IIIB cell inhibitory activity, cellular toxicity, and inhibitory activity against drug-resistant HIV strains. KNI-1931 showed distinct selectivity against HIV proteases and high potency against drug-resistant strains, surpassing those of Ritonavir and Nelfinavir.     

PERK eIF2 alpha kinase is required to regulate the viability of the exocrine pancreas in mice

Background

The lymphatic system complements the blood circulatory system in absorption and transport of nutrients, and in the maintenance of homeostasis. Angiopoietins 1 and 2 (Ang1 and Ang2) are regulators of both angiogenesis and lymphangiogenesis through the Tek/Tie-2 receptor tyrosine kinase. The response of endothelial cells to stimulation with either Ang1 or Ang2 is thought to be dependent upon the origin of the endothelial cells. In this study, we examined the effects of the angiopoietins on lymphatic, venous and arterial primary endothelial cells (bmLEC, bmVEC and bmAEC, respectively), which were isolated and cultured from bovine mesenteric vessels.

Results

BmLEC, bmVEC and bmAEC cell populations all express Tie-2 and were shown to express the appropriate cellular markers Prox-1, VEGFR3, and Neuropilin-1 that define the particular origin of each preparation. We showed that while bmLECs responded slightly more readily to angiopoietin-2 (Ang2) stimulation, bmVECs and bmAECs were more sensitive to Ang1 stimulation. Furthermore, exposure of bmLECs to Ang2 induced marginally higher levels of proliferation and survival than did exposure to Ang1. However, exposure to Ang1 resulted in higher levels of migration in bmLECs than did to Ang2.

Conclusion

Our results suggest that although both Ang1 and Ang2 can activate the Tie-2 receptor in bmLECs, Ang1 and Ang2 may have distinct roles in mesenteric lymphatic endothelial cells.