High mobility group protein 1 (HMG1) is an abundant non‐histone chromosomal protein which plays a role in several nuclear events involving DNA. Here we demonstrate that HMG1 physically interacts with ...the human adeno‐associated virus (AAV) Rep protein. HMG1 promotes the formation of Rep–DNA complexes and stimulates the activity of Rep in site‐ and strand‐specific cleavage of DNA and the hydrolysis of ATP, functions required for viral gene regulation, replication and site‐specific integration of viral DNA into human chromosome 19. We show that HMG1 enhances Rep‐mediated repression of the AAV p5 promoter in transfected cells, suggesting that HMG1 and Rep also interact in vivo. HMG1, Rep and DNA can be immunoprecipitated as a ternary complex. Kinetic studies indicate that complexes of Rep with DNA have similar stabilities in the presence and absence of HMG1.These results suggest that the effect of HMG1 on Rep binding is exerted at the step of complex formation and thereby may reflect an activity of HMG1 in promoting the assembly of complex cellular nucleoprotein structures.
Although current influenza vaccines are effective in general, there is an urgent need for the development of new technologies to improve vaccine production timelines, capacities and immunogenicity. ...Herein, we describe the development of an influenza vaccine technology which enables recombinant production of highly efficient influenza vaccines in bacterial expression systems. The globular head domain of influenza hemagglutinin, comprising most of the protein's neutralizing epitopes, was expressed in E. coli and covalently conjugated to bacteriophage-derived virus-like particles produced independently in E.coli. Conjugate influenza vaccines produced this way were used to immunize mice and found to elicit immune sera with high antibody titers specific for the native influenza hemagglutinin protein and high hemagglutination-inhibition titers. Moreover vaccination with these vaccines induced full protection against lethal challenges with homologous and highly drifted influenza strains.
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Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Galectin-1 is a homodimeric protein with potent anti-inflammatory properties due to its ability to induce apoptosis in thymocytes and T cells. The galectin-1 subunits are not covalently linked but ...the monomers are in a dynamic equilibrium with the dimeric form. Since the affinity of the monomers for each other is rather low (in the range of 10
−5
M), the in vivo efficacy of galectin-1 is limited because the equilibrium is shifted towards the inactive monomeric form at lower concentrations. In order to overcome this problem, we designed a covalently linked form of the dimer based on the galectin-1 crystal structure. Here we show that this irreversibly dimeric form of galectin-1 is a potent inducer of apoptosis in murine thymocytes as well as murine mature T cells at concentrations 10-fold lower than wild-type galectin-1. This structurally optimized form of galectin-1 may therefore be a potentially powerful tool to treat chronic inflammatory diseases.
Plasma cells are the main producers of antibody and key effector cells of the immune system. Despite their importance, analytics of plasma cells still suffers from the limited availability of ...specific markers. Currently, plasma cell identification relies on the expression of a single marker, CD138/syndecan-1. However, syndecan-1 is widely expressed on various cell types outside the hematopoietic compartment, and furthermore, not expressed on all subsets of plasma cells. To discover novel surface markers, a differential screening followed by signal sequence trap cloning was developed, leading to the identification of mouse Ly-6K (mLy-6K). Expression profiling confirmed that mLy-6K is expressed by plasma cells but not B cells or tissues not containing plasma cells. Expression at the surface of plasma cells isolated from spleen, lymph node, bone marrow, and lamina propria of the small intestine was demonstrated at the protein level using a polyclonal rabbit antibody. This novel plasma cell marker shows promise to help broaden our understanding of plasma cell differentiation and function.
Mating elicits two well-defined reactions in sexually matured females of many insects: reduction of receptivity and increased oviposition. These post-mating responses have been shown to be induced by ...factors synthesized in the reproductive tract of the adult male and transferred in the seminal fluid to the female during copulation. One of these factors, named sex-peptide (SP), has been identified in Drosophila melanogaster. Using an in vitro radiochemical assay, we show that synthetic sex-peptide considerably activates juvenile hormone III-bisepoxide (JHB3) synthesis in corpus allatum (CA) excised from Days 3 and 4 post-eclosion virgin females. Base levels are significantly lower at emergence (Day 0) than on subsequent days, and only weak stimulation is obtained on Day 1, while none is obtained on Day 2, where maximal basal synthesis occurs. The CA of mated females cannot be stimulated further for at least 7 days, but regain responsiveness by Day 10 after mating. Synthesis of JHB3 stimulated by SP in vitro persists for at least 4 h after removal of the peptide. Development of responsiveness of the CA to SP in vitro is compared with development of the post-mating reactions of sex-peptide injected virgin females. Our results suggest that the CA is a direct target for SP in vivo and that sexual maturity is established separately for the two post-mating reactions
T cell responses are regulated by the affinity/avidity of the T cell receptor for the MHC/peptide complex, available costimulation and duration of antigenic stimulation. Altered peptide ligands ...(APLs) are usually recognized with a reduced affinity/avidity by the T cell receptor and are often able to only partially activate T cells in vitro or may even function as antagonists. Here we assessed the ability of APLs derived from peptide p33 of lymphocytic choriomeningitis virus (LCMV) to mediate lysis of target cells in vivo, confer anti-viral protection and cause auto-immune disease. In general, in vitro cross-reactivity between APLs was rather limited, and even strongly cross-reactive cytotoxic T lymphocytes were only able to mediate moderate anti-viral protection. Partial protection was observed for infection with LCMV or low doses of recombinant vaccinia virus, while no reduced viral titers could be seen upon infection with high dose of vaccinia virus. In a transgenic mouse model expressing LCMV glycoprotein in the islets of the pancreas, APLs induced a transient insulitis but failed to induce autoimmune diabetes. Thus, effector functions induced by even highly homologous APLs are rather limited in vivo.
The killer cell lectin-like receptor G1 (KLRG1) is expressed by NK cells and by T cells. In both humans and mice, KLRG1 identifies Ag-experienced T cells that are impaired in their proliferative ...capacity but are capable of performing effector functions. In this study, we identified E-cadherin as a ligand for murine KLRG1 by using fluorescently labeled, soluble tetrameric complexes of the extracellular domain of the murine KLRG1 molecule as staining reagents in expression cloning. Ectopic expression of E-cadherin in B16.BL6 target cells did not affect cell-mediated lysis by lymphokine-activated NK cells and by CD8 T cells but inhibited Ag-induced proliferation and induction of cytolytic activity of CD8 T cells. E-cadherin is expressed by normal epithelial cells, Langerhans cells, and keratinocytes and is usually down-regulated on metastatic cancer cells. KLRG1 ligation by E-cadherin in healthy tissue may thus exert an inhibitory effect on primed T cells.
AIM： To investigate the anti-inflammatory properties of Lacto-Wolfberry （LWB）, bothin vitro and using a mouse model of experimental colitis. METHODS： The effects of LWB on lipopolysaccharide ...（LPS）-induced reactive oxygen species （ROS） and interleukin （IL）-6 secretion were assessed in a murine macrophage cell line. in vitro assessment also included characterizing the effects of LWB on the activation of NF-E2 related 2 pathway and inhibition of tumor necrosis factor-α （TNF-α）-induced nuclear factor-κB （NFκB） activation, utilizing reporter cell lines. Following the in vitro assessment, the anti-inflammatory efficacy of an oral intervention with LWB was tested in vivo using a preclinical model of intestinal inflammation. Multiple outcomes including body weight, intestinal histology, colonic cytokine levels and anti-oxidative measures were investigated.RESULTS： LWB reduced the LPS-mediated inductionof ROS production ＋LPS vs 1% LWB ＋ LPS, 1590 ± 188.5 relative luminescence units （RLU） vs 389 ± 5.9 RLU, P 〈 0.001. LWB was more effective than wolfberry alone in reducing LPS-induced IL-6 secretion in vitro （wolfberry vs 0.5% LWB, 15% ± 7.8% vs 64% ± 5%, P 〈 0.001）. In addition, LWB increased reporter gene expression via the anti-oxidant response element activation （wolfberry vs LWB, 73% ± 6.9% vs 148% ± 28.3%, P 〈 0.001） and inhibited the TNF-α-induced activation of the NF-κB pathway （milk vs LWB, 10% ± 6.7% vs 35% ± 3.3%, P 〈 0.05）. Furthermore, oral supplementation with LWB resulted in a reduction of macroscopic （-LWB vs ＋LWB, 5.39 ± 0.61 vs 3.66 ± 0.59, P = 0.0445） and histological scores （-LWB vs ＋LWB, 5.44 ± 0.32 vs 3.66 ± 0.59, P = 0.0087） in colitic mice. These effects were associated with a significant decrease in levels of inflammatory cytokines such as IL-1β （-LWB vs ＋LWB, 570 ± 245 μg/L vs 89 ± 38 μg/L, P = 0.0106）, keratinocyte-derived chemokine/growth regulated protein-α （-LWB vs ＋LWB, 184 ± 49 μg/Lvs 75 ± 20 μg/L,P = 0.0244）, IL-6 （-LWBvs ＋LWB, 318 ± 99 μg/L vs 117 ± 18 μg/L, P = 0.0315） and other pro-inflammatory proteins such as cyclooxygenase-2 （-LWB vs ＋LWB, 0.95 ± 0.12 AU vs 0.36 ± 0.11 AU, P = 0.0036） and phosphorylated signal transducer and activator of transcription-3 （-LWB vs ＋LWB, 0.51 ± 0.15 AU vs 0.1 ± 0.04 AU, P = 0.057）. Moreover, antioxidant biomarkers, including expression of gene encoding for the glutathione peroxidase, in the colon and the plasma anti-oxidant capacity were significantly increased by supplementation with LWB （-LWB vs ＋LWB, 1.2 ± 0.21 mmol/L vs 2.1 ± 0.19 mmol/L, P = 0.0095）.CONCLUSION： These results demonstrate the antiinflammatory properties of LWB and suggest that the underlying mechanism is at least in part due to NF-κB inhibition and improved anti-oxidative capacity.
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