排序方式: 共有78条查询结果,搜索用时 15 毫秒
21.
Sato M Yoshimura S Hirai R Goto A Kunii M Atik N Sato T Sato K Harada R Shimada J Hatabu T Yorifuji H Harada A 《Traffic (Copenhagen, Denmark)》2011,12(10):1383-1393
VAMP7 or tetanus neurotoxin-insensitive vesicle- associated membrane protein (TI-VAMP) has been proposed to regulate apical transport in polarized epithelial cells, axonal transport in neurons and lysosomal exocytosis. To investigate the function of VAMP7 in vivo, we generated VAMP7 knockout mice. Here, we show that VAMP7 knockout mice are indistinguishable from control mice and display a similar localization of apical proteins in the kidney and small intestine and a similar localization of axonal proteins in the nervous system. Neurite outgrowth of cultured mutant hippocampal neurons was reduced in mutant neurons. However, lysosomal exocytosis was not affected in mutant fibroblasts. Our results show that VAMP7 is required in neurons to extend axons to the full extent. However, VAMP7 does not seem to be required for epithelial cell polarity and lysosomal exocytosis. 相似文献
22.
23.
Cross-regulation between type I and type II NKT cells in regulating tumor immunity: a new immunoregulatory axis 总被引:2,自引:0,他引:2
Ambrosino E Terabe M Halder RC Peng J Takaku S Miyake S Yamamura T Kumar V Berzofsky JA 《Journal of immunology (Baltimore, Md. : 1950)》2007,179(8):5126-5136
Negative immunoregulation is a major barrier to successful cancer immunotherapy. The NKT cell is known to be one such regulator. In this study we explored the roles of and interaction between the classical type I NKT cell and the poorly understood type II NKT cell in the regulation of tumor immunity. Selective stimulation of type II NKT cells suppressed immunosurveillance, whereas stimulation of type I NKT cells protected against tumor growth even when responses were relatively skewed toward Th2 cytokines. When both were stimulated simultaneously, type II NKT cells appeared to suppress the activation in vitro and protective effect in vivo of type I NKT cells. In the absence of type I, suppression by type II NKT cells increased, suggesting that type I cells reduce the suppressive effect of type II NKT cells. Thus, in tumor immunity type I and type II NKT cells have opposite and counteractive roles and define a new immunoregulatory axis. Alteration of the balance between the protective type I and the suppressive type II NKT cell may be exploited for therapeutic intervention in cancer. 相似文献
24.
25.
Membrane trafficking is one of the most important mechanisms involved in the establishment and maintenance of the forms and
functions of the cell. However, it is poorly understood in skeletal muscle cells. In this study, we have focused on vesicle-associated
membrane proteins (VAMPs), which are components of the vesicle docking and fusion complex, and have performed immunostaining
to investigate the expression of VAMPs in rat skeletal muscle tissue. We have found that VAMP2, but not VAMP1 or VAMP3, is
expressed in satellite cells. VAMP2 is also expressed in myofibers in the soleus muscle and nerve endings. This is consistent
with previous studies in which VAMP2 has been shown to regulate GLUT4 trafficking in slow-twitch myofibers in soleus muscle
and neurotransmitter release in nerve endings. As satellite cells are quiescent myogenic cells, the expression of VAMP2 has
further been examined in regenerating muscles after injury by the snake venom, cardiotoxin; we have observed enhanced expression
of VAMP2 in immature myotubes with a peak at 3 days after injury. Our findings suggest that VAMP2 plays roles in quiescent
satellite cells and is involved in muscle regeneration. The nature of the material transported in the VAMP2-bearing vesicles
in satellite cells and myotubes is still under investigation.
This work was supported by a research grant (17A-10) for nervous and mental disorders from the Ministry of Health, Labor,
and Welfare of Japan, and Grants-in-Aid for Scientific Research from the Ministry of Education, Culture, Sports, Science,
and Technology of Japan. 相似文献
26.
Park JM Terabe M Donaldson DD Forni G Berzofsky JA 《Cancer immunology, immunotherapy : CII》2008,57(6):907-912
Introduction We and others previously observed immunosurveillance against transplantable tumors in mice, and enhancement thereof by blockade
of negative regulation by T reg cells or the NKT-IL-13-myeloid cell-TGF-β regulatory circuit. However, it was unknown whether
natural immunosurveillance inhibits growth of completely spontaneous autochthonous tumors, and whether it can be improved
by inhibition of negative regulation.
Materials and methods To examine the existence of T cell-mediated immunosurveillance against spontaneous tumors, BALB-neuT mice were treated with
anti-CD4 and/or anti-CD8. A role for IL-13 in the suppression of immunosurveillance was investigated by treating mice with
IL-13 inhibitor.
Results We show that even spontaneous autochthonous breast carcinomas arising in
Her-2/neu transgenic mice appear more quickly when the mice are depleted of T cells, evidence for T-cell mediated immunosurveillance
slowing tumor growth. This immunosurveillance could be further enhanced by blockade of IL-13 (but not IL-4) which slowed the
appearance of these autologous tumors compared to control antibody-treated mice.
Conclusion Thus, even completely spontaneous, autochthonous breast cancers can be controlled in part by natural immunosurveillance, and
blockade of negative regulation can improve this control.
This work was in part supported by the Intramural Research Program of the NIH, National Cancer Institute, Center for Cancer
Research. 相似文献
27.
There are many mechanisms that regulate and dampen the immune response to cancers, including several types of regulatory T cells. Besides the T reg cell, we have identified another immunoregulatory circuit initiated by NKT cells that produce IL-13 in response to tumor growth and this IL-13 then induces myeloid cells to make TGF-beta that inhibits cytotoxic T cell-mediated tumor immunosurveillance in several mouse tumor models. This finding created a paradox in the role of NKT cells in tumor immunity, in that they can also contribute to protection. We resolve this paradox by the finding that the suppressive NKT cell is a type II NKT cell that lacks the canonical invariant T cell receptor, whereas the protective cell is a type I NKT cell that expresses the invariant receptor. Further, we see that these two subsets of NKT cells counter-regulate each other, defining a new immunoregulatory axis. The balance along this axis may determine the outcome of tumor immunosurveillance as well as influence the efficacy of anti-cancer vaccines and immunotherapy. 相似文献
28.
To elucidate the characteristics of spatial heterogeneity in a human-dominated landscape, vegetation and community structure
of pine (Pinus densiflora andP. rigida) forests were studied at rural Teokseong-ri in Chollanam-do, in the southwestern part of Korea. Daily removal of undergrowth
for firewood affects the stratification and species composition in the community. In general, stratification of the pine forest
develops in proportion to its distance from the main habitat of farmers, involving the residential and cultivated land. In
pine forests near the main habitat of farmers, sun-demanding herbaceous plants grow well, while in remote forests, Fagaceous
plants such asQuercus serrata, Q. actissima andCastanea crenata grow well. This zonation results from the fact that removal of undergrowth is greater in the forest near the main habitat
of farmers, than in the remote forest. Construction and maintenance of graveyards, however, prevents development of stratification
of the forest even in remote stands. 相似文献
29.
Streptomyces subtilisin inhibitor-like proteins are distributed widely in streptomycetes. 总被引:4,自引:2,他引:2
下载免费PDF全文
![点击此处可从《Applied microbiology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
S Taguchi H Kikuchi M Suzuki S Kojima M Terabe K Miura T Nakase H Momose 《Applied microbiology》1993,59(12):4338-4341
Streptomyces subtilisin inhibitor-like proteins were found to be distributed widely in streptomycetes by using the combination of the convenient, newly developed plate assay system and an established liquid culture assay. Almost all the strains formerly categorized as Streptoverticillium species produced proteins that exhibited inhibitory activity against both subtilisin BPN' and trypsin. N-terminal regions of three purified proteins showed high structural similarity to those of other previously reported SIL inhibitors. 相似文献
30.