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41.
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43.
MCW Chan CY Cheung WH Chui SW Tsao JM Nicholls YO Chan RWY Chan HT Long LLM Poon Y Guan JSM Peiris 《Respiratory research》2005,6(1):135
Background
Fatal human respiratory disease associated with influenza A subtype H5N1 has been documented in Hong Kong, and more recently in Vietnam, Thailand and Cambodia. We previously demonstrated that patients with H5N1 disease had unusually high serum levels of IP-10 (interferon-gamma-inducible protein-10). Furthermore, when compared with human influenza virus subtype H1N1, the H5N1 viruses in 1997 (A/Hong Kong/483/97) (H5N1/97) were more potent inducers of pro-inflammatory cytokines (e.g. tumor necrosis factor-a) and chemokines (e.g. IP-10) from primary human macrophages in vitro, which suggests that cytokines dysregulation may play a role in pathogenesis of H5N1 disease. Since respiratory epithelial cells are the primary target cell for replication of influenza viruses, it is pertinent to investigate the cytokine induction profile of H5N1 viruses in these cells.Methods
We used quantitative RT-PCR and ELISA to compare the profile of cytokine and chemokine gene expression induced by H5N1 viruses A/HK/483/97 (H5N1/97), A/Vietnam/1194/04 and A/Vietnam/3046/04 (both H5N1/04) with that of human H1N1 virus in human primary alveolar and bronchial epithelial cells in vitro.Results
We demonstrated that in comparison to human H1N1 viruses, H5N1/97 and H5N1/04 viruses were more potent inducers of IP-10, interferon beta, RANTES (regulated on activation, normal T cell expressed and secreted) and interleukin 6 (IL-6) in primary human alveolar and bronchial epithelial cells in vitro. Recent H5N1 viruses from Vietnam (H5N1/04) appeared to be even more potent at inducing IP-10 than H5N1/97 virus.Conclusion
The H5N1/97 and H5N1/04 subtype influenza A viruses are more potent inducers of proinflammatory cytokines and chemokines in primary human respiratory epithelial cells than subtype H1N1 virus. We suggest that this hyper-induction of cytokines may be relevant to the pathogenesis of human H5N1 disease. 相似文献44.
45.
The role of site-specific N-glycosylation in secretion of soluble forms of rabies virus glycoprotein 总被引:1,自引:1,他引:0
Wojczyk BS; Stwora-Wojczyk M; Shakin-Eshleman S; Wunner WH; Spitalnik SL 《Glycobiology》1998,8(2):121-130
Rabies virus glycoprotein is important in the biology and pathogenesis of
neurotropic rabies virus infection. This transmembrane glycoprotein is the
only viral protein on the surface of virus particles, is the viral
attachment protein that facilitates virus uptake by the infected cell, and
is the target of the host humoral immune response to infection. The
extracellular domain of this glycoprotein has N- glycosylation sequons at
Asn37, Asn247, and Asn319. Appropriate glycosylation of these sequons is
important in the expression of the glycoprotein. Soluble forms of rabies
virus glycoprotein were constructed by insertion of a stop codon just
external to the transmembrane domain. Using site-directed mutagenesis and
expression in transfected eukaryotic cells, it was possible to compare the
effects of site-specific glycosylation on the cell-surface expression and
secretion of transmembrane and soluble forms, respectively, of the same
glycoprotein. These studies yielded the surprising finding that although
any of the three sequons permitted cell surface expression of full-length
rabies virus glycoprotein, only the N-glycan at Asn319 permitted secretion
of soluble rabies virus glycoprotein. Despite its biological and medical
importance, it has not yet been possible to determine the crystal structure
of the full-length transmembrane form of rabies virus glycoprotein which
contains heterogeneous oligosaccharides. The current studies demonstrate
that a soluble form of rabies virus glycoprotein containing only one sequon
at Asn319 is efficiently secreted in the presence of the N-glycan
processing inhibitor 1-deoxymannojirimycin. Thus, it is possible to purify
a conformationally relevant form of rabies virus glycoprotein that contains
only one N-glycan with a substantial reduction in its microheterogeneity.
This form of the glycoprotein may be particularly useful for future studies
aimed at elucidating the three-dimensional structure of this important
glycoprotein.
相似文献
46.
ABSTRACT Wolverines (Gulo gulo) are distributed across much of northern and western Canada and Alaska, USA, and they extend south into the mountainous western United States. Wolverines occur in most regions of British Columbia, Canada, with the highest population densities occurring in the interior mountainous areas. Wolverine populations in British Columbia have been primarily managed to provide a sustainable harvest for trappers and hunters. We used spatially based population estimates, population vital rate data, and spatially based harvest data to evaluate the sustainability of wolverine harvest (trapping and hunting) from 1985 to 2004. The median annual provincial wolverine harvest from 1985 to 2004 was 172 wolverines per year ( = 174.8), which was less than the median simulated estimate of provincial recruitment (195.9 wolverines/yr; = 209.7). Harvests in individual population units ranged from 0 to 280 over the 20-year period. Spatially, wolverine harvest was likely to have been unsustainable in 15 of the 71 population units with wolverines, and it was likely to have been sustainable in the remaining population units. Harvest in 5 of the other 56 population units was marginally sustainable and thus of potential management concern. To improve harvest management of wolverines in British Columbia, wildlife managers should focus on improved data collection and monitoring at a provincial scale, and they should work with trappers and hunters at regional scales to address issues specific to individual population units. Further research is required to improve the reliability of wolverine vital rate and population data. 相似文献
47.
48.
Sequence variation in ZFX introns in human populations 总被引:1,自引:2,他引:1
DNA variation in human populations was studied by examining the last intron
of the ZFX gene (about 1, 151 bp) with a worldwide sample of 29
individuals. Only one polymorphic site was found, which is located in an
Alu sequence. This polymorphism is present at an intermediate frequency in
all populations studied, and could be a shared polymorphism or due to
migration among populations in Asia, Europe, and Africa. The nucleotide
diversity is 0.04%, supporting the view that the level of nucleotide
variation in nuclear DNA is very low in humans. From the sequence data, the
age (T) of the most recent common ancestor of the sampled sequences is
estimated: the mode of T is about 306,000 years, and the 95% confidence
interval of T is 162,000-952,000 years. This mode estimate is considerably
older than the estimates from Y- linked sequences.
相似文献
49.
Rates and dates of divergence between AIDS virus nucleotide sequences 总被引:25,自引:3,他引:25
50.
Samar Farha Daniel Laskowski Deepa George Margaret M Park WH Wilson Tang Raed A Dweik Serpil C Erzurum 《Respiratory research》2013,14(1):6