Reciprocal patterns of methylation of H3K36 and H3K27 on proximal vs. distal IgVH genes are modulated by IL-7 and Pax5.
The usage of >100 functional murine Ig heavy chain V(H) genes, when rearranged to D(H)J(H) genes, generates a diverse antibody repertoire. The V(H) locus encompasses 2.5 Mb, and rearrangement of V(H) genes in the D(H)-distal half of the locus are controlled very differently from the V(H) genes in the proximal end of the locus. The rearrangement of distal but not proximal V(H) genes is impaired in mice deficient in the cytokine IL-7 or its receptor, in the transcription factor Pax5, or in Ezh2, a histone methyltransferase for Lys-27 of histone H3 (H3K27). The relative role of IL-7, Pax5, and Ezh2 in regulating distal vs. proximal V(H) rearrangement is not clear. Here, we show by ChIP and ChIP-on-chip that the active histone modification H3K36me2 is most highly associated with distal V(H) segments and the repressive histone modification H3K27me3 is exclusively present on proximal V(H) segments. We observed an absence of H3K27me3 in fetal pro-B cells, which predominantly rearrange proximal V(H) genes. Absence of IL-7 signaling reduces H3K36me2, and overexpression of IL-7 increases H3K36me2. In contrast, the major effect of the absence of Pax5 is the reduction in H3K27me3. Our data indicate that the cytokine IL-7 and the transcription factor Pax5 influence the rearrangement of the two regions of the V(H) locus by differentially modulating two reciprocal histone modifications during B lymphocyte development.
Xu
Cheng-Ran
CR
Department of Immunology, DNA Array Core Facility, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA.
Schaffer
Lana
L
Head
Steven R
SR
Feeney
Ann J
AJ
D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology; D002460:Cell Line; D000071221:Enhancer of Zeste Homolog 2 Protein; D015326:Gene Rearrangement, B-Lymphocyte, Heavy Chain; D050438:Genes, Immunoglobulin Heavy Chain; D011495:Histone-Lysine N-Methyltransferase / Q000378:metabolism*; D006657:Histones / Q000378:metabolism; D007143:Immunoglobulin Heavy Chains / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D007135:Immunoglobulin Variable Region / Q000235:genetics*; D015851:Interleukin-7 / Q000378:metabolism*; D008745:Methylation; D051379:Mice; D008807:Mice, Inbred BALB C; D008822:Mice, Transgenic; D051757:PAX5 Transcription Factor / Q000378:metabolism*; D063151:Polycomb Repressive Complex 2; D011506:Proteins / Q000378:metabolism; D015398:Signal Transduction
D006657:Histones; D007143:Immunoglobulin Heavy Chains; D007135:Immunoglobulin Variable Region; D015851:Interleukin-7; D051757:PAX5 Transcription Factor; D011506:Proteins; D000071221:Enhancer of Zeste Homolog 2 Protein; C498410:Ezh2 protein, mouse; D011495:Histone-Lysine N-Methyltransferase; D063151:Polycomb Repressive Complex 2