BLIMP-I mediates extinction of major histocompatibility class II transactivator expression in plasma cells

Nat Immunol. 2000 Dec;1(6):526-32. doi: 10.1038/82788.


Class II transactivator (CIITA), a coactivator required for class II major histocompatibility complex (MHC) transcription, is expressed in B cells but extinguished in plasma cells. This report identifies B lymphocyte-induced maturation protein I (BLIMP-I), a transcriptional repressor that is capable of triggering plasma cell differentiation, as a developmentally regulated repressor of CIITA transcription. BLIMP-I represses the B cell-specific promoter of the human gene that encodes CIITA (MHC2TA) in a binding site-dependent manner. Decreased CIITA correlates with increased BLIMP-I during plasma cell differentiation in cultured cells. Ectopic expression of BLIMP-I represses endogenous mRNA for CIITA and the CIITA targets, class II MHC, invariant chain and H2-DM (the murine equivalent of HLA-DM) in primary splenic B cells as well as 18-81 pre-B cells. Thus, the BLIMP-I program of B cell differentiation includes loss of antigen presentation via extinction of CIITA expression.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Antigen Presentation
  • B-Lymphocytes / cytology
  • B-Lymphocytes / immunology
  • B-Lymphocytes / metabolism
  • Base Sequence
  • Cell Differentiation
  • Cell Line
  • DNA / genetics
  • DNA Primers / genetics
  • HLA-DR Antigens / genetics
  • HLA-DR alpha-Chains
  • Humans
  • Hybrid Cells
  • Mice
  • Models, Biological
  • Molecular Sequence Data
  • Nuclear Proteins*
  • Plasma Cells / immunology*
  • Plasma Cells / metabolism*
  • Positive Regulatory Domain I-Binding Factor 1
  • Promoter Regions, Genetic
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • Repressor Proteins*
  • Trans-Activators / genetics
  • Trans-Activators / metabolism*
  • Transcription Factors / genetics
  • Transcription Factors / metabolism*


  • DNA Primers
  • HLA-DR Antigens
  • HLA-DR alpha-Chains
  • MHC class II transactivator protein
  • Nuclear Proteins
  • Prdm1 protein, mouse
  • RNA, Messenger
  • Repressor Proteins
  • Trans-Activators
  • Transcription Factors
  • PRDM1 protein, human
  • DNA
  • Positive Regulatory Domain I-Binding Factor 1