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Graft-specific MHC class II gene expression in response to allogeneic stimulus in heterotopic murine cardiac allografts.

Graft-specific MHC class II gene expression in response to allogeneic stimulus in heterotopic murine cardiac allografts.

Authors :
Xu, R.
Burdick, J. F.
Scott, A.
Beschorner, W. E.
Adler, W.
Kittur, D. S.
Source :
Immunology; Feb92, Vol. 75 Issue 2, p361-365, 5p
Publication Year :
1992

Abstract

Although, major histocompatibility complex (MHC) class H antigen expression in allografts is thoroughly studied, regulation of the genes for these antigens is not fully understood. The graft-specific MHC class II genes are potentially important in determining the immunogenicity of graft but their detection in a mixed-cell `population such as in the allograft would require unambiguous differentiation of graft-specific class II expression from those in host lymphoid cells. With an oligonucleotide probe that specifically hybridizes to I-Ab mRNA from He2<superscript>k</superscript> haplotype mice, we have studied I-A gene expression in cardiac allografts heterotopically transplanted from B10.Br (H2<superscript>k</superscript>) to B10.D2 (H-2<superscript>2</superscript>) mice. Normal B10.Br hearts do not have appreciable I-Ab transcripts as determined with this probe, but 4 days after allografting, a substantial increase in I-Ab<superscript>k</superscript> messenger RNA (mRNA) content was noted in the allografted hearts which persisted for the next 2 days and then decreased concomitant with destruction of the heart. The increase in I-Ab<superscript>k</superscript> mRNA preceded the expression of surface la<superscript>k</superscript> antigens on dendritic and endothelial cells in the allograft. These data indicate increased transcription of the 1-Ab gene in cells of graft origin suggesting that transcriptional regulation is the initial mechanism for expression of class II genes in allografts. The sustained rise in grail-specific class 11 mRNA also seen in these allografts suggests that increased mRNA stability may be another mechanism for the increased density of class II antigens in allografts undergoing rejection. [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
00192805
Volume :
75
Issue :
2
Database :
Complementary Index
Journal :
Immunology
Publication Type :
Academic Journal
Accession number :
14074245