| Project/Area Number |
10555290
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (B).
|
| Allocation Type | Single-year Grants |
|---|
| Section | 展開研究 |
|---|
| Research Field |
生物・生体工学
|
|---|
| Research Institution | OKAYAMA UNIVERSITY |
|---|
Principal Investigator |
OHMORI Hitoshi Okayama University, Department of Biotechnology, Professor, 工学部, 教授 (70116440)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
KOMORIYA Keiji Teijin Institute for Biomedical Research, Depertment of Pharmacology, Director, 医薬開発研究所, 部長
HIKIDA Masaki Okayama University, Department of Biotechnology, Lecturer, 工学部, 講師 (60228715)
|
|---|
| Project Period (FY) |
1998 – 2000
|
| Project Status |
Completed (Fiscal Year 2000)
|
| Budget Amount *help |
¥11,800,000 (Direct Cost: ¥11,800,000)
Fiscal Year 2000: ¥2,200,000 (Direct Cost: ¥2,200,000)
Fiscal Year 1999: ¥3,700,000 (Direct Cost: ¥3,700,000)
Fiscal Year 1998: ¥5,900,000 (Direct Cost: ¥5,900,000)
|
|---|
| Keywords | Allergy / IgE antibody / hybridoma / monoclonal antibody / RAG genes / V(D)J recombination / nematode / transgenic mouse |
|---|
| Research Abstract |
Although a high level of IgE is produced after primary infection with Nippostrongylus brasiliensis (Nb), most of the IgE antibodies (Abs) are not specific to the worm. Analyses with Western blotting and enzyme-linked immunosorbent assay revealed that the IgE Abs from Nb-infected BALB/c mice did not show reactivity with Nb-derived excretory-secretory proteins and antigens present in the cell-free extracts of the worm. Monoclonal IgE Abs obtained from the Nb-infected mice were not reactive with these Nb antigen either. To characterize Nb-induced IgE response, we used (QM x C57BL/6)F1 (QBF1) mice that bear the knock-in 17.2.25 VHDJH segment (VHT) encoding a VH region specific to 4-hydroxy-3-nitrophenylacetyl hapten, and express VHT-encoded antigen receptors on 80-85% of their B cells. Consistent with the frequency of VHT-positive B cells, more than 80% of IgE Abs induced in QBF1 B cells that were cultured with LPS plus IL-4 were found to bear VHT-encoded H chains. In contrast, when QBF1 mice were infected with Nb, less than 10% of Nb-induced IgE Abs were found to use VHT.The QBF1-derived IgE did not react with Nb antigens either. We have shown in mice that B cells reexpress RAG-1 and RAG-2 proteins, and undergo secondary rearrangement of Ig genes (receptor editing) in the periphery. Taken together, data suggest that Nb-induced IgE response in mice is not merely the result of polyclonal activation of B cells, but may involve a mechanism that revise Ig genes secondarily.
|
