Faculty of Engineering, Okayama University
Acta Medica Okayama
0475-0071
36
2
2002
Regulatory Role for Complement Receptors (CD21/CD35) in the Recombination Activating Gene Expression in Mouse Peripheral B Cells
51
60
EN
Masaki
Hikida
Masaki
Magari
Yasunori
Nakayama
Naoki
Kanayama
Hitoshi
Ohmori
10.18926/47025
A population of peripheral B cells have been shown to express recombination activating gene products, RAG-1 and RAG-2, which are considered to be involved in revising the B cell antigen receptor (BCR) in the periphery. BCR engagement has been reported to turn off RAG expression in peripheral B cells, whereas the same treatment has an opposite effect in immature B cells in the bone marrow. In contrast to receptor editing that is involved in the removal of autoreactivity in immature B cells, it has been shown that secondary V(D)J rearrangement in peripheral B cells, termed receptor revision, contributes to affinity maturation of antibodies. Here, we show that RAG-2 expression in murine splenic B cells was abrogated by the coligation of BCR with complement receptors (CD21/CD35) much more efficiently than by the engagement of BCR alone. On the other hand, the same coligation augmented proliferation of anti-CD40-stimulated B cells. Consistent with these observations, RAG-2 expression was lower in the draining lymph nodes of the quasi-monoclonal mice when they were immunized with a high-affinity antigen than with a low-affinity one. These findings suggest a crucial role for CD21/CD35 in directing the conservation or the revision of
BCRs in peripheral B cells.
No potential conflict of interest relevant to this article was reported.
Faculty of Engineering, Okayama University
Acta Medica Okayama
0475-0071
38
1-2
2004
Generation of IgM and IgG1 monoclonal antibodies with identical variable regions: comparison of avidity
91
96
EN
Naoki
Kanayama
Kimi
Yamakoshi
Masaaki
Kiyomi
Masaki
Magari
Hitoshi
Ohmori
10.18926/46955
Generally, IgM antibodies (Abs) produced in a primary immune response show lower affinity for an inducing antigen (Ag) compared with the corresponding IgG Abs that are major switched isotypes formed in the secondary response. An IgM molecule is a pentamer with 10 Ag-binding sites that will contribute to an increase of avidity for an Ag. To estimate the contribution of the pentameric structure to the avidity of an IgM Ab, we generated IgM and IgG1 monoclonal Abs (mAbs) with identical V regions that are specific for 4-hydroxy-3-nitrophenylacetyl (NP) by in vitro class switching of B cells followed by the cell fusion with a mouse myeloma cell line. Compared with an anti-NP IgG1 mAb, the corresponding IgM mAb showed much higher avidity for NP-conjugated
bovine serum albumin, which was drastically reduced after being dissociated into monomers.
No potential conflict of interest relevant to this article was reported.
岡山大学環境管理センター
Acta Medica Okayama
10
1988
生物系の教育に伴って発生する廃液・排永
19
EN
Hitoshi
Ohmori
No potential conflict of interest relevant to this article was reported.