1998 Fiscal Year Final Research Report Summary
Experimental study on roll of cellular immunity (NK CTL) for inhibition of lung-metastases in mice
| Project/Area Number |
09470411
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
病態科学系歯学(含放射線系歯学)
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| Research Institution | Osaka University |
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Principal Investigator |
NUKATA Junichiro Osaka University Dental Hospital Assistant Professor, 歯学部・附属病院, 講師 (70189348)
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| Co-Investigator(Kenkyū-buntansha) |
KATO Itsuro Osaka University Dental Hospital Assistant, 歯学部・附属病院, 医員
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| Project Period (FY) |
1997 – 1998
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| Keywords | Pulmonary metastases / NK cell / killer T cell / Colon 26 / Cellular immunity / 腫瘍免疫 |
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| Research Abstract |
Mice were divided into five groups : mice inoculated with Colon 26 (Control), mice with enhanced NK activity at injection of Colon 26 (Group I), mice with NK activity enhanced immediately after the injection of Colon 26 (Group : II), mice with 11K activity enhanced on 5 days after the injection of Colon 26 (Group III) and mice with CTLs activity induced for more than a 14 day period after the injection of Colon 26 (Group IV).
1. Number of pulmonary metastases and accumulation rate of ^<51>Cr Colon 26 in the lungs.
The number of pulmonary metastases decreased in Group I, II and IV, Furthermore the rate of radioactivity accumulated in lungs 24 hours after the injectionof ^<51>Cr Colon 26 significantly decreased in Group I but not in Group IV.
2. Analysis of effector cells
In mice administered anti-asialo GM1 2 days before the injection of Colon 26 (anti-asialo Group), the number of pulmonary metastases increased compared with the control. The NK activity from the anti-asialo Group was lower than that of the control at the injection and on 14 days after the injection. Anti CD8 was administered twice after the inoculation of Colon 26 in Group IV (anti CD8 Group).
The number of pulmonary metastases was increased compared with Group IV but was not significantly different from that of the Control group. CTLs activity from anti CD8 Group was low compared with that of Group IV, but similar to the Control.
3. Distribution of effector cells in the lungs.
In immunohistochemical studies of pulmonary metastases, lymphocytes being positive to CD8 were found in the lungs of Group IV.
These results suggested that NK-mediated inhibition of experimental metastases is mainly due to increased destruction of circulating tumor cells before their extravasation and that CTL-mediated cytotoxicity inhibits metastases by suppressing the growth of tumor in the lungs.
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