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71.
Günthér Vogel Rolf Madaus Hans-Dieter Lehmann 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》1961,44(3):258-261
Zusammenfassung Es werden einige Daten zur Kenntnis des Blutbildes vom Rothirsch (Cervus elaphus L.) mitgeteilt. In hämatologischer Beziehung besteht eine weitgehende Übereinstimmung mit den kleinen Wiederkäuern Schaf und Ziege, nach Leukozytenzahl und Saponinempfindlichkeit der Erythrozyten weist das Hirschblut deutliche Unterschiede gegenüber domestizierten Wiederkäuern auf.Unter Mitwirkung der med.-techn. Assistentin, Fräulein Sybille Buchheim. 相似文献
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Immunomodulatory effects of inactivated parapoxvirus ovis (ORF virus) on human peripheral immune cells: induction of cytokine secretion in monocytes and Th1-like cells 下载免费PDF全文
Inactivated parapoxvirus ovis (Orf virus; PPVO) recently displayed strong immunostimulating and modulating capacities in several animal models for acute and chronic virus infections through the induction of gamma interferon (IFN-gamma) as a key mediator of antiviral activity. The data presented in this work demonstrate that inactivated PPVO has strong effects on cytokine secretion by human immune cells, including the upregulation of inflammatory and Th1-related cytokines (IFN-gamma, tumor necrosis factor alpha [TNF-alpha], interleukin 6 [IL-6], IL-8, IL-12, and IL-18) as well as anti-inflammatory and Th2-related cytokines (IL-4, IL-10, and IL-1 receptor antagonist [IL-1ra]). Studies on the mechanism of action revealed virus particles to be the effective components of the preparation. The virus particles activate monocytes or other antigen-presenting cells (APC), e.g., plasmacytoid dendritic cells, through signaling over CD14 and a Toll-like receptor and the intracellular presence of certain PPVO-specific components. The activation of monocytes or APC is followed by the release of early proinflammatory cytokines (TNF-alpha, IL-6, and IL-8) as well as the Th1-related cytokines IL-12 and IL-18. Both IL-18 and IL-12 are involved in PPVO-mediated IFN-gamma release by T cells and/or NK cells. The proinflammatory response is accompanied by the induction of anti-inflammatory and Th2-related cytokines (IL-4, IL-10, and IL-1ra), which exert a limiting efffect on the inflammatory response induced by PPVO. We conclude that the induction of a natural immune response with physiologically significant amounts of different cytokines and with antiviral potential might provide advantages over existing antiviral immunotherapies. 相似文献
75.
The holotype and only known specimen of the enigmatic small reptile Elachistosuchus huenei Janensch, 1949 from the Upper Triassic (Norian) Arnstadt Formation of Saxony-Anhalt (Germany) is redescribed using μCT scans of the material. This re-examination revealed new information on the morphology of this taxon, including previously unknown parts of the skeleton such as the palate, braincase, and shoulder girdle. Elachistosuchus is diagnosed especially by the presence of the posterolateral process of the frontal, the extension of the maxillary tooth row to the posterior margin of the orbit, the free posterior process of the jugal, and the notched anterior margin of the interclavicle. Phylogenetic analyses using two recently published character-taxon matrices recovered conflicting results for the phylogenetic position of Elachistosuchus–either as an archosauromorph, as a lepidosauromorph or as a more basal, non-saurian diapsid. These different placements highlight the need of a thorough revision of critical taxa and new character sets used for inferring neodiapsid relationships. 相似文献
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Translational fusions with fragments of the trpE gene improve the expression of a poorly expressed heterologous gene in Escherichia coli 总被引:3,自引:0,他引:3
A series of plasmids expressing fusions between the trpE gene product, anthranilate synthase component I and the major immunogen (VP1) of foot and mouth disease virus were constructed such that increasing amounts of the 3' end of trpE were deleted. Deletions removing up to 70% of trpE had little effect on the quantity of fusion protein expressed, while the number of molecules appeared to increase. Larger deletions led to a steady decrease in both the quantity of fusion protein produced and in the number of molecules. This is consistent with trpE being responsible for the high levels of expression of VP1 by its gene product stabilizing VP1 against proteolytic degradation. Some out-of-frame deletion mutants were also produced. All deletion mutants in one wrong reading frame expressed low levels of two VP1-containing polypeptides. This observation is interpreted as being due to re-initiation of translation at a site inside the VP1 sequence which is activated by local termination of translation. 相似文献
78.
Human leucine-rich repeat kinase 1 (LRRK1) is a multi-domain protein of unknown function belonging to the ROCO family of complex proteins. Here, we report the molecular characterization of human LRRK1 and show, for the first time, that LRRK1 is both a functional protein kinase and a GDP/GTP-binding protein. Binding of GTP to LRRK1 is specific, requires the GTPase-like Roc domain, and leads to a stimulation of LRRK1 kinase activity. LRRK1 is the first example of a GTP-regulated protein kinase harboring both the kinase effector domain and the GTP-binding regulatory domain. Hence, we propose a model in which LRRK1 cycles between a GTP-bound active and a GDP-bound inactive state. Moreover, we mutated LRRK1 to mimic mutations previously identified in LRRK2/dardarin, the only human paralogue of LRRK1, that have been linked to autosomal-dominant parkinsonism. We demonstrate that three of four mutations analyzed significantly downregulate LRRK1 kinase activity. Ultimately, the results presented for LRRK1 may contribute to the elucidation of LRRK2's role in the pathogenesis of Parkinson's disease. 相似文献
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Yan Liu Robert A. Childs Tatyana Matrosovich Stephen Wharton Angelina S. Palma Wengang Chai Rodney Daniels Victoria Gregory Jennifer Uhlendorff Makoto Kiso Hans-Dieter Klenk Alan Hay Ten Feizi Mikhail Matrosovich 《Journal of virology》2010,84(22):12069-12074
Mutations in the receptor-binding site of the hemagglutinin of pandemic influenza A(H1N1) 2009 viruses have been detected sporadically. An Asp222Gly (D222G) substitution has been associated with severe or fatal disease. Here we show that 222G variants infected a higher proportion of ciliated cells in cultures of human airway epithelium than did viruses with 222D or 222E, which targeted mainly nonciliated cells. Carbohydrate microarray analyses showed that 222G variants bind a broader range of α2-3-linked sialyl receptor sequences of a type expressed on ciliated bronchial epithelial cells and on epithelia within the lung. These features of 222G mutants may contribute to exacerbation of disease.Although the majority of disease cases have been mild, the pandemic influenza A(H1N1) 2009 (H1N1pdm) virus has caused a substantial number of severe and fatal infections (2). Mutants with a D222G or D222E substitution (D225G or D225E in the H3 numbering system) in the receptor-binding site of the virus hemagglutinin (HA) have been detected sporadically (1), and the D222G substitution has been observed to correlate with cases of severe or fatal disease (1, 3, 9, 14). Cell surface receptors for influenza viruses are sialyl glycans (α2-3 Sia or α2-6 Sia) with terminal sialic acid linked α2-3 or α2-6, respectively, to a penultimate galactose. These differ in distribution in the tissues and cells of different species. The sialyl glycans are differentially recognized by the HAs of human and animal influenza viruses and are critical determinants of host range and tissue tropism (16). Using an experimental system of differentiated cultures of human tracheobronchial epithelial cells (HTBE) for studying influenza virus cell tropism, we and others have established that in the initial stages of infection, seasonal human influenza viruses which recognize α2-6 Sia receptors infect mainly nonciliated cells, whereas avian viruses which recognize α2-3 Sia receptors predominantly infect ciliated cells (8, 17, 22).Previous analyses of human and swine influenza H1N1 viruses (5, 15, 21) and preliminary studies of H1N1pdm viruses (24) have indicated that amino acid substitutions in the HA at position 222 may affect the specificity of receptor binding. This, in turn, would be predicted to determine the range of cell types in human respiratory tissues infected by the viruses (17, 20, 22, 23). We have therefore examined the influence of the D222G and D222E substitutions on the cell tropism of H1N1pdm viruses in HTBE cultures (Table (Table1).1). Five viruses were isolated from clinical material in MDCK cells and passaged solely in these cells. Two of these, A/Hamburg/5/2009 (Ham) (4) isolated from a case of mild infection and A/Moldova/G186/2009 (Mol) from a serious but nonfatal infection, had 222D. A/Dakar/37/2009 (Dak) isolated from a mild case of the disease had 222E. Two isolates from fatal cases, A/Lviv/N6/2009 (Lvi) and A/Norway/3206-3/2009 (Nor), had 222G. A sixth virus tested, A/Hamburg/5/2009-e (Ham-e), was derived from Ham by egg passage and plaque purification in MDCK cells and differed by a single substitution, D222G.
Open in a separate windowaAmino acids differing from those of Moldova/G186/2009 are shown. H3 numbering is in parentheses.bThe percentage of infected ciliated cells relative to the total number of infected cells. Standard deviations are shown in parentheses.cSubstitution acquired during isolation and propagation in MDCK cells.dP < 0.0001 (unpaired two-sided t test versus A/Moldova/G186/2009).The preparation of differentiated HTBE cultures, viral infection of the cultures for cell tropism analysis, and double immunostaining for viral antigen and cilia of ciliated cells were done as described previously (17). Infected cells were counted in the epithelial segment that included 15 to 30 consecutive microscopic fields containing between 5 and 20% ciliated cells relative to the total number of superficial cells. Percentages of infected ciliated cells relative to the total number of infected cells were calculated for each segment. Ten segments per culture were analyzed, and the results were averaged.Two distinctive patterns of cell tropism were observed (Fig. (Fig.11 and Table Table1).1). The viruses with 222D (Mol and Ham) and 222E (Dak) showed a pattern of cell tropism typical of seasonal influenza A and B viruses (17, 22) infecting predominantly nonciliated cells known to be rich in α2-6 Sia sequences (17): less than 5% of infected cells were ciliated. In contrast, the three viruses with 222G, Lvi, Nor, and Ham-e, infected both ciliated and nonciliated cells, and 20% or more of the infected cells were ciliated and known to express α2-3 Sia sequences (11, 17). This change in cell tropism, with a 5- to 10-fold increase in the infection of ciliated cells, thus correlated with the presence of the D222G substitution in the HA, and other amino acid differences, in particular D222E, had little or no effect. Furthermore, there were no differences between the amino acid sequences of the neuraminidases (NA) of the 222D, 222G, and 222E viruses which might have an impact on cell tropism: the NA sequences of Mol, Nor, Lvi, and Dak were identical.Open in a separate windowFIG. 1.Difference in cell tropism between the clinical isolate Ham (left image) and its 222G variant Ham-e (right image) in HTBE cultures. The cultures were infected at a multiplicity of infection of approximately 1, fixed 8 h after infection, and double immunostained for virus antigen using rabbit antisera against A/California/4/2009(H1N1pdm) (red) and for cilia of ciliated cells using an anti-β tubulin monoclonal antibody (dark gray). Arrowheads point to infected ciliated cells. Bars, 10 μm.To investigate whether changes in receptor binding specificity could account for the distinct cell tropism of the 222G variants, we performed carbohydrate microarray analyses (Fig. (Fig.22 and Table Table2;2; see Fig. S1 and S2 and Table S1 in the supplemental material). The virus preparations were analyzed in the absence of or following inactivation by treatment with beta-propiolactone; the conditions used (4) had no perceptible effect on the receptor-binding profiles. Virus suspensions were concentrated by pelleting, adjusted to contain equivalent concentrations of viruses as assessed by HA titration with human red blood cells and gel electrophoresis with immunoblotting, and stored at 4°C in phosphate-buffered saline (pH 7.4) containing 0.05% sodium azide. The microarray analyses were performed as described previously (4) using the same array series of lipid-linked probes (see Table S1 in the supplemental material). Unless stated otherwise, the viruses were analyzed at an HA titer of 2,000.Open in a separate windowFIG. 2.Carbohydrate microarray analyses of H1N1pdm viruses. The microarray data are for the two 222D viruses (Mol and Ham), the 222E mutant virus (Dak), and the three 222G mutant viruses (Nor, Lvi, and Ham-e) analyzed at an HA titer of 2,000. The microarrays consisted of 80 sialylated and 6 neutral lipid-linked glycan probes arranged according to sialic acid linkage, glycan backbone chain length, and sequence (see Table S1 in the supplemental material). The numerical scores for the fluorescent binding signals are means (with error bars) for duplicate spots at 5 fmol/spot. The various types of terminal sialic acid linkage are indicated by the colored panels as defined at the bottom.
Open in a separate windowa Probe number and position in microarrays.b Abbreviations for monosaccharides: Fuc, fucose; Gal, galactose; Glc, glucose; GlcNAc, N-acetylglucosamine; NeuAc, N-acetylneuraminic acid. Other abbreviations: Cer, natural glycolipids with various ceramide moieties; Cer36, synthetic glycolipids with ceramide having a total of 36 carbon atoms; DH, neoglycolipids prepared from reducing oligosaccharides by reductive amination with the amino lipid 1,2-dihexadecyl-sn-glycero-3-phosphoethanolamine.c —, Signal intensity of <500.For all of the viruses, the intensities of binding to α2-6 Sia sequences were greater overall than the intensities of binding to the α2-3 Sia sequences. There were, however, marked differences between the two 222D viruses, Mol and Ham, and the three 222G variants, Lvi, Nor, and Ham-e, in binding to the α2-3 Sia sequences (highlights are in Table Table2).2). With the 222D viruses, relatively low intensities of binding to α2-3 Sia sequences were detected and they bound mostly to α2-3 Sia sequences that were modified with fucose (Fuc) on the outer N-acetylglucosamine (GlcNAc), as in the blood group-related antigens sialyl Lewisa (SLea) and SLex (probes 28, 29, and 31) and/or with sulfate (SU) on GlcNAc (probes 27 and 35, Table Table2;2; see Fig. S2b in the supplemental material). This is in accord with our previous study of Ham (see Fig. S3 in the supplemental material for reference 4). In contrast, the 222G mutants not only bound more strongly to these α2-3 Sia sequences but bound to additional sequences, such as the VIM-2 antigen sequence (probe 39) with Fuc on internal GlcNAc and to sequences lacking Fuc or SU (probes 23 and 24, Table Table2;2; see Fig. S2a in the supplemental material). All of the pdm viruses investigated here showed greater binding to the 6SU-SLex sequence (probe 35) than to the analogue lacking SU (probe 31) and 6′SU SLex (probe 33, Table Table2).2). This is a property shared with highly pathogenic poultry viruses (6, 7). The pattern of binding to the α2-6 Sia sequences was largely unchanged (Fig. (Fig.2;2; see Fig. S2c in the supplemental material).As passage in MDCK cells tends to select “complementary” amino acid changes such as K154E or G155E in addition to the single D222G mutation present in the virus of the clinical specimen, two more viruses were investigated as controls for the effects of this substitution in Lvi, the double mutant (G155E D222G). These were A/Athens/16606/2009 (Ath) and A/Lisbon/120/2009 (Lis), which possess the G155E substitution in the absence of D222G. The binding profiles observed for Ath and Lis (see Fig. S3 in the supplemental material) indicated that the 155 substitution did not contribute to the increased α2-3 Sia binding of Lvi, which was therefore due exclusively to the D222G substitution.The D222E mutant Dak exhibited a carbohydrate-binding profile that was intermediate between those of the 222D and 222G viruses. Compared to the 222D viruses (Mol and Ham) that targeted preferentially nonciliated cells, Dak displayed slightly increased binding to some α2-3 Sia sequences. It was clearly distinguishable from the 222G variants by weaker or negligible binding to a number of other α2-3 Sia sequences, for example, probes 24 and 33 and the VIM-2 antigen sequence, probe 39 (Fig. (Fig.22 and Table Table2;2; see Fig. S1 and S2 in the supplemental material). These are properties that Dak shared with 222D viruses. The similarities in receptor binding and cell tropism of the 222E and 222D viruses are consistent with their circulation in the population, in contrast to the 222G variants that have emerged sporadically and do not appear to be transmitted readily to other individuals (18).There is thus a clear correlation between enhanced binding to α2-3 Sia sequences by the 222G variants and increased infection of ciliated epithelial cells. The increased capacity of 222G mutant viruses to infect ciliated epithelial cells prominent along the entire airway epithelium would be predicted to interfere with the important mucociliary clearance function of these cells and increase the severity of disease. Another human pathogen, Mycoplasma pneumoniae, which can also cause severe respiratory disease targets the microvilli of ciliated cells in the human bronchus (10) that express the VIM-2 antigen (12, 13). The enhanced capacity of the 222G variants to target α2-3 Sia receptors present in relatively larger amounts on ciliated epithelial cells of the tracheobronchial epithelium (11, 17) and on cells in bronchioles and alveoli (20) may also contribute to more severe pulmonary infection, as suggested by the more frequent identification of 222G variants in specimens from the lower respiratory tract (3), and may explain why they are infrequently transmitted. It is also pertinent to note that the D222G substitution was identified in the HAs from two of five victims of the 1918 pandemic (19). Glycan array analyses of recombinant HAs from one of the 1918 222G mutant viruses (A/New York/1/18) showed (21) a narrow profile of binding to certain α2-3 Sia sequences which had an additional negative charge such as SU or sialic acid. The pattern was more restricted than the repertoire of α2-3 Sia sequences bound by the 222G 2009 pdm viruses that we have investigated here. The New York variant showed little binding to α2-6 Sia sequences, in contrast to the strong and broad α2-6 Sia binding profiles of the 2009 pdm viruses observed here and in an earlier study (24). These differences between the 1918 and 2009 pdm viruses are most likely a reflection of differences in other residues in the receptor-binding pocket.Whether the selection of the D222G mutation is a cause or a consequence of more severe lower respiratory tract infection is still to be resolved. It is evident, however, that its emergence is likely to exacerbate the severity of disease. The altered receptor specificity and distinctive cell tropism of the D222G mutants of H1N1pdm are hallmarks of a more dangerous pathogen, emphasizing the importance of close monitoring of the evolution of these viruses. 相似文献
TABLE 1.
Differences in amino acid sequence of the HAs of the H1N1pdm viruses and cell tropism in HTBE culturesVirus | Outcome | Substitution at HA position:a | Infected ciliated cellsb | ||||
---|---|---|---|---|---|---|---|
137 (140) | 154 (157) | 155 (158) | 203 (206) | 222 (225) | |||
A/Moldova/G186/2009 (Mol) | Nonfatal | P | K | G | T | D | 4.7 (2.2) |
A/Dakar/37/2009 (Dak) | Nonfatal | E | 2.7 (1.8) | ||||
A/Hamburg/5/2009 (Ham) | Nonfatal | S | 3.3 (2.1) | ||||
A/Hamburg/5/2009-e (Ham-e) | S | G | 25 (12)d | ||||
A/Norway/3206-3/2009 (Nor) | Fatal | S | Ec | G | 19 (6.7)d | ||
A/Lviv/N6/2009 (Lvi) | Fatal | Ec | G | 34 (15)d |
TABLE 2.
Virus binding of selected α2-3 Sia sequences in carbohydrate microarrays grouped according to backbone sequence and lipid moietyOpen in a separate window |