학술논문
CIITA promoter I CARD-deficient mice express functional MHC class II genes in myeloid and lymphoid compartments
Document Type
Report
Author
Source
Genes and Immunity. June 1, 2012, Vol. 13 Issue 4, p299, 12 p.
Subject
Language
English
ISSN
1466-4879
Abstract
INTRODUCTION The major histocompatibility complex class II (MHC-II) region encodes genes required for the presentation of antigenic peptide to CD4 T cells. (1) The process results in various immune responses [...]
Three distinct promoters control the master regulator of major histocompatibility complex (MHC) class II expression, class II transactivator (CIITA), in a cell type-specific manner. Promoter I (pI) CIITA, expressed primarily by dendritic cells (DCs) and macrophages, expresses a unique isoform that contains a caspase-recruitment domain (CARD). The activity and function of this isoform are not understood, but are believed to enhance the function of CIITA in antigen-presenting cells. To determine whether isoform I of CIITA has specific functions, CIITA mutant mice were created in which isoform I was replaced with isoform III sequences. Mice in which pI and the CARD-encoding exon were deleted were also created. No defect in the formation of CD4 T cells, the ability to respond to a model antigen or bacterial or viral challenge was observed in mice lacking CIITA isoform I. Although CIITA and MHC-II expression was decreased in splenic DCs, pI knockout animals expressed CIITA from downstream promoters, suggesting that control of pI activity is mediated by unknown distal elements that could act at pIII, the B-cell promoter. Thus, no critical function is linked to the CARD domain of CIITA isoform I with respect to basic immune system development, function and challenge. Genes and Immunity (2012) 13, 299-310; doi: 10.1038/gene.2011.86; published online 5 January 2012 Keywords: MHC class II; gene expression; CIITA; antigen presentation
Three distinct promoters control the master regulator of major histocompatibility complex (MHC) class II expression, class II transactivator (CIITA), in a cell type-specific manner. Promoter I (pI) CIITA, expressed primarily by dendritic cells (DCs) and macrophages, expresses a unique isoform that contains a caspase-recruitment domain (CARD). The activity and function of this isoform are not understood, but are believed to enhance the function of CIITA in antigen-presenting cells. To determine whether isoform I of CIITA has specific functions, CIITA mutant mice were created in which isoform I was replaced with isoform III sequences. Mice in which pI and the CARD-encoding exon were deleted were also created. No defect in the formation of CD4 T cells, the ability to respond to a model antigen or bacterial or viral challenge was observed in mice lacking CIITA isoform I. Although CIITA and MHC-II expression was decreased in splenic DCs, pI knockout animals expressed CIITA from downstream promoters, suggesting that control of pI activity is mediated by unknown distal elements that could act at pIII, the B-cell promoter. Thus, no critical function is linked to the CARD domain of CIITA isoform I with respect to basic immune system development, function and challenge. Genes and Immunity (2012) 13, 299-310; doi: 10.1038/gene.2011.86; published online 5 January 2012 Keywords: MHC class II; gene expression; CIITA; antigen presentation