Reduced isotype switching in splenic B cells from mice deficient in mismatch repair enzymes

Carol E. Schrader, Winfried Edelmann, Raju Kucherlapati, Janet Stavnezer

Research output: Contribution to journalArticle

179 Scopus citations

Abstract

Mice deficient in various mismatch repair (MMR) enzymes were examined to determine whether this repair pathway is involved in antibody class switch recombination. Splenic B cells from mice deficient in Msh2, Mlh1, Pms2, or Mlh1 and Pms2 were stimulated in culture with lipopolysaccharide (LPS) to induce immunoglobulin (Ig)G2b and IgG3, LPS and interleukin (IL)-4 to induce IgG1, or LPS, anti-δ-dextran, IL-4, IL-5, and transforming growth factor (TGF)-β1 to induce IgA. After 4 d in culture, cells were surface stained for IgM and non-IgM isotypes and analyzed by FACS®. B cells from MMR-deficient mice show a 35-75% reduction in isotype switching, depending on the isotype and on the particular MMR enzyme missing. IgG2b is the most affected, reduced by 75% in Mlh1-deficient animals. The switching defect is not due to a lack of maturation of the B cells, as purified IgM+IgD+ B cells show the same reduction. MMR deficiency had no effect on cell proliferation, viability, or apoptosis, as detected by [3H]thymidine incorporation and by propidium iodide staining. The reduction in isotype switching was demonstrated to be at the level of DNA recombination by digestion-circularization polymerase chain reaction (DC-PCR). A model of the potential role for MMR enzymes in class switch recombination is presented.

Original languageEnglish (US)
Pages (from-to)323-330
Number of pages8
JournalJournal of Experimental Medicine
Volume190
Issue number3
DOIs
StatePublished - Aug 2 1999

Keywords

  • Class switch recombination
  • Mlh1
  • Msh2
  • Pms2

ASJC Scopus subject areas

  • Immunology and Allergy
  • Immunology

Fingerprint Dive into the research topics of 'Reduced isotype switching in splenic B cells from mice deficient in mismatch repair enzymes'. Together they form a unique fingerprint.

  • Cite this