2015 Fiscal Year Final Research Report
Origin and evolution of the adaptive immune system
| Project/Area Number |
25670229
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| Research Category |
Grant-in-Aid for Challenging Exploratory Research
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| Allocation Type | Multi-year Fund |
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| Research Field |
Immunology
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| Research Institution | University of Fukui (2015)
The University of Tokyo (2013-2014) |
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Principal Investigator |
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| Project Period (FY) |
2013-04-01 – 2016-03-31
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| Keywords | 無顎類 / 抗原受容体 / VLR / 自己抗体 / アロ白血球抗原 / MHC / 獲得免疫 / 進化 |
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| Outline of Final Research Achievements |
All vertebrates possess adaptive immune systems that can detect and inactivate non-self-antigens through a vast repertoire of antigen receptors. Unlike jawed vertebrates, the hagfish utilizes variable lymphocyte receptors (VLRs) that are unrelated to immunoglobulin molecules but are diversified by copy-choice gene conversion mechanism. Here, we report that hagfish VLRs react with allogenic leukocyte antigens but not with self-antigens. We found that a highly polymorphic membrane protein, NICIR3, is recognized by VLRs as an allogenic leukocyte antigen (ALA). In a serological cross-reactivity test, a close correlation was observed between the amino acid differences in the protein sequences and the VLR cross-reactivities. This leukocyte antigen was predominantly expressed in phagocytic leukocytes, where it was associated with phagocytosed protein antigens. These findings suggest that a polymorphic leukocyte antigen, NICIR3/ALA, plays a pivotal role in jawless vertebrate adaptive immunity.
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| Free Research Field |
分子生物学
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