1992 Fiscal Year Final Research Report Summary
Form-maintaining factors of the trypomastigote of Trypanosoma cruzi
| Project/Area Number |
03670195
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
寄生虫学(含医用動物学）
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| Research Institution | Nagasaki University |
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Principal Investigator |
KANBARA Hiroji Nagasaki University Institute of Tropical Medicine Professor, 熱帯医学研究所, 教授 (20029789)
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| Project Period (FY) |
1991 – 1992
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| Keywords | Trypanosoma cruzi / Trypomastigote / Amastigote / Transformation |
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| Research Abstract |
Trypomastigotes of Trypanosoma cruzi developed various functions, by which they can survive in body fluid of mammals. One of the functions is the prompt invasion in host cells such as muscle cells which make trypomastigotes possible to avoid the attack from the host. On the other hand trypomastigotes need to be sucked by an insect ( a kissing bug ) to maintain the species, which require them to stay long in the bloodstream. We found that lowered pH of the MEM medium supplemented 1% bovine serum albumin ( BSA ) accelerated the transformation of the trypomastigote to the amastigote. Using this culture system we have tried to look for the factors that maintain the form of the trypomastigote. First of all we observed the morphological change by electronmicroscopy and confirmed that the accelerated transformation was a physiological reaction but not a denaturation reaction. The immunoblotting using a mouse antiserum to the paraflagellar protein reconfirmed the transformation from trypomastigotes to amastigotes. Trypomastigotes can not survive in the neutral pH medium as well as in the low pH in the absence of BSA. Previously we thought that the effect of BSA was to neutralize the released substances from trypomastigotes which lyse themselves, but it seems to be to stabilize the membrane structure by binding to some surface component. Several serum components ban blind to trypomastigotes besides BSA, but we could not determine which was the most effective for the form maintenance of the trypomastigote. Some protein components of the trypomastigote besides the paraflagellar protein were lost during transformation, one of them was trans-sialidase. At present, however, what is the component maintaining the trypomastigote remains to be solved.
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