2000 Fiscal Year Final Research Report Summary
Inhibition of tumor metastasis and immunotherapy by a microbial polysaccharaide
| Project/Area Number |
11650816
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
生物・生体工学
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| Research Institution | Nagoya University |
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Principal Investigator |
MIYAKE Katsuhide Dept.of Biotechnol., Grad.School of Eng., Nagoya Univ., Assist.Prof., 工学研究科, 助手 (90252254)
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| Co-Investigator(Kenkyū-buntansha) |
NISHIJIMA Kenichi Dept.of Biotechnol, Grad.School of Eng., Nagoya Univ., Assis.Prof., 工学研究科, 助手 (10262891)
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| Project Period (FY) |
1999 – 2000
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| Keywords | Streptococcus agalactiae / Sialyllactosamine / Sialyl Lewis carbohydrate / L-selectin / MEL-14 |
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| Research Abstract |
Structure of type specific capsular polysaccharide from group B streptococci, Streptococcus agalactiae type Ia and Ib have branched sialyl lactosamines linked to a lactose polymer. This structure is very similar to those of sugar chains, which are expressed in mammalian cells. Sialyl Lewis carbohydrates and several gangliosides expressed in cancer and hematopoietic cells have the sialyl lactosamine structure. These mammalian sugar chains are known to play important roles in metastasis and activation of immune system. In this study, we investigated effects of the capsular polysaccharide from S.agalactiae on hematopoietic cells. These polysaccharides showed activation effect on T-cells. This effect was inhibited by addition of anti-capsular polysaccharide antisera. This fact indicated that the effects caused by the type specific polysaccharide was due to sugar chain, because this antisera recognizes only sugar chain. We next studied targets of the polysaccharides on T-cells. T-cells are known to express L-selectin which binds sialyl Lewis carbohydrates. By using anti-L-selectin antibody (NEL-14), we analyzed reaction of T-cells to the signals caused by MEL-14. MEL-14 did not show any stimulation of T-cells, but this antibody showed similar effects to capsular polysaccharides in the presence of other signals such as CD3 and CD28 stimulation. These facts suggested that the bacterial specific capsular polysaccharide may bind to L-selectin and other unknown receptors.
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