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Updated: Aug 24, 2026

Mouse Naïve CD4+ T Cell Isolation and In vitro Differentiation into T Cell Subsets
Published on: April 16, 2015
CpG DNA redirects class-switching towards "Th1-like" Ig isotype production via TLR9 and MyD88
Ling Lin1, Andrea J Gerth, Stanford L Peng
1Department of Internal Medicine/Rheumatology, Washington University School of Medicine, St. Louis, MO 63110, USA.
Unmethylated CpG-containing DNA plays a critical role in immunity via the augmentation of Th1 but suppression of Th2 T cell responses. We describe here that CpG motifs also redirect isotype production by murine B cells to "Th1-like" Ig isotypes (IgG2a, IgG2b, and IgG3) while suppressing Th2 isotypes (IgG1 and IgE). Using genetically mutant B cells, we find that the IgG2a, IgG2b and IgG3 isotypes are transcriptionally regulated via the promotion of class-switching, in a manner critically dependent upon TLR9 and MyD88. Thus, CpG DNA redirects Ig isotype production by regulating the specificity of class-switch recombination.
Unmethylated CpG-containing DNA plays a critical role in immunity via the augmentation of Th1 but suppression of Th2 T cell responses. We describe here that CpG motifs also redirect isotype production by murine B cells to "Th1-like" Ig isotypes (IgG2a, IgG2b, and IgG3) while suppressing Th2 isotypes (IgG1 and IgE). Using genetically mutant B cells, we find that the IgG2a, IgG2b and IgG3 isotypes are transcriptionally regulated via the promotion of class-switching, in a manner critically dependent upon TLR9 and MyD88. Thus, CpG DNA redirects Ig isotype production by regulating the specificity of class-switch recombination.
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