DELETIONAL SWITCH RECOMBINATION OCCURS IN INTERLEUKIN-4-INDUCED ISOTYPE SWITCHING TO IGE EXPRESSION BY HUMAN B-CELLS

作者：SHAPIRA SK; JABARA HH; THIENES CP; AHERN DJ; VERCELLI D; GOULD HJ; GEHA RS

来源：Proceedings of the National Academy of Sciences of the United States of America, 1991, 88(17): 7528-7532.

DOI：10.1073/pnas.88.17.7528

• IMMUNOGLOBULIN
• DNA REARRANGEMENT

There is controversy as to whether deletional rearrangement occurs between the IgM and IgE switch regions (S-mu and S-epsilon, respectively) during switching to the IgE isotype. We have addressed the issue by stimulating normal human B cells, sorted for lack of expression of surface IgE, to produce IgE by infection with Epstein-Barr virus (EBV) in the presence of interleukin 4 (IL-4). Genomic DNA was amplified for S-mu/S-epsilon switch junction fragments by utilizing the nested-primer polymerase chain reaction. Switch junction fragments were amplified from B cells infected with EBV in the presence of IL-4 but not from B cells infected with EBV alone. The DNA sequence of these "switch fragments" revealed direct joining of S-mu to S-epsilon in each case. The recombination sites within S-mu were clustered within 900 base pairs at the 5' end of the switch region, suggesting that there are "hot spots" for recombination within S-mu. The S-epsilon recombination sites were scattered throughout the S-epsilon region. These findings indicate that IL-4-induced isotype switching to IgE production in human B cells is accompanied by DNA rearrangements with joining of S-mu to S-epsilon.

• 出版日期1991-9