CELL-CYCLE REGULATION OF IMMUNOGLOBULIN CLASS SWITCH RECOMBINATION AND GERM-LINE TRANSCRIPTION - POTENTIAL ROLE OF ETS FAMILY MEMBERS

被引:44
作者
LUNDGREN, M
STROM, L
BERGQUIST, LO
SKOG, S
HEIDEN, T
STAVNEZER, J
SEVERINSON, E
机构
[1] KAROLINSKA INST,MED CELL BIOL LAB,DEPT CELL & MOLEC BIOL,S-17177 STOCKHOLM,SWEDEN
[2] KAROLINSKA INST,DEPT MED RADIOBIOL,STOCKHOLM,SWEDEN
[3] UNIV MASSACHUSETTS,DEPT MOLEC GENET & MICROBIOL,WORCESTER,MA
关键词
IMMUNOGLOBULIN ISOTYPE SWITCHING; TRANSCRIPTION; CELL CYCLE;
D O I
10.1002/eji.1830250736
中图分类号
R392 [医学免疫学]; Q939.91 [免疫学];
学科分类号
100102 ;
摘要
Previous studies have indicated that transcription of germ-line (GL) C-H genes is necessary to obtain immunoglobulin (Ig) class switching. We report here a correlation between proliferation, switching and GL transcripts. S mu-S gamma 1 switch recombination in lipopolysaccharide (LPS) + interleukin-4 (IL-4)-activated mouse B cells was assayed by a digestion-circularization polymerase chain reaction. Switching to gamma 1 is reduced upon inhibition of DNA synthesis with hydroxyurea (HU) or aphidicholin (AC). Incubation of activated B cells with HU severely reduces steady-state levels of GL gamma 1 and epsilon RNA. By utilizing elutriation to synchronize B cell blasts in different phases of the cell cycle, it was found that GL gamma 1 transcripts are mainly expressed in G(1) and S phases, but not in G(0). Using the electrophoretic mobility shift assay, we characterized two major LPS-induced complexes, which bind to the GL gamma 1 promoter and are expressed at levels which correlate with the amount of LPS-induced DNA synthesis. Furthermore, the intensity of the complexes is reduced when cells are arrested with the DNA synthesis inhibitors HU or AC. Elutriation experiments revealed that the complexes are expressed in G(1) and S, but not in G(0). They bind to an Ets consensus element near the major initiation sites used in proliferating cells. The possible implications of these findings for Ig isotype switching are discussed.
引用
收藏
页码:2042 / 2051
页数:10
相关论文
共 58 条