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Specificity of immunoglobulin heavy chain switch correlates with activity of germline heavy chain genes prior to switching.
Author(s) -
StavnezerNordgren J.,
Sirlin S.
Publication year - 1986
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1002/j.1460-2075.1986.tb04182.x
Subject(s) - idiotype , immunoglobulin class switching , biology , isotype , immunoglobulin heavy chain , germline , gene , antibody , immunoglobulin light chain , immunoglobulin e , microbiology and biotechnology , b cell , gene rearrangement , genetics , monoclonal antibody
IgM+ cells cultured from the I.29 B cell lymphoma can be induced with lipopolysaccharide (LPS) or, to a greater extent, with LPS plus anti‐idiotype antibody to switch to IgG2a, IgE or IgA expression. The isotype switch is accompanied by rearrangement of immunoglobulin (Ig) heavy (H) chain genes. Here we demonstrate that the commitment of the I.29 IgM+ cells to switch to IgA appears to be manifested by hypomethylation of the alpha constant region genes in IgM+ cells, and by the presence of small amounts of RNAs transcribed from non‐rearranged alpha gene(s) in IgM+ cells. The commitment to switch to IgE or IgG2a is also in accord with the presence of small amounts of RNA transcripts from the non‐rearranged epsilon and gamma 2a genes, although the hypomethylation of the epsilon and gamma 2a genes is not as dramatic as that of the alpha genes. These results suggest that I.29 cells switch specifically to IgA, IgE or IgG2a due to the activation of the corresponding H chain constant region genes in IgM+ cells prior to the actual switch recombination event.