scholarly journals Adenovirus 12-mediated down-regulation of the major histocompatibility complex (MHC) class I promoter: identification of a negative regulatory element responsive to Ad12 E1A

1994 ◽  
Vol 22 (22) ◽  
pp. 4779-4788 ◽  
Author(s):  
Joanne L. Proffitt ◽  
Ela Sharma ◽  
G. Eric Blair
1991 ◽  
Vol 11 (8) ◽  
pp. 4217-4227 ◽  
Author(s):  
J D Weissman ◽  
D S Singer

A novel regulatory element which contributes to the regulation of quantitative, tissue-specific differences in gene expression has been found between -771 and -676 bp upstream of the major histocompatibility complex (MHC) class I gene, PD1. Molecular dissection of this element reveals the presence of two overlapping functional activities: an enhancer and a silencer. Distinct nuclear factors bind to the overlapping enhancer and silencer DNA sequence elements within the regulatory domain. The levels of factors binding the silencer DNA sequence in different cell types are inversely related to levels of class I expression; in contrast, factors binding the enhancer DNA sequence can be detected in all cells. In cultured cell lines, inhibition of protein synthesis leads to the rapid loss of silencer complexes, with a concomitant increase in both enhancer complexes and MHC class I RNA. From these data, we conclude that a labile silencer factor competes with a constitutively expressed, stable enhancer factor for overlapping DNA-binding sites; the relative abundance of the silencer factor contributes to establishing steady-state levels of MHC class I gene expression.


1991 ◽  
Vol 11 (8) ◽  
pp. 4217-4227 ◽  
Author(s):  
J D Weissman ◽  
D S Singer

A novel regulatory element which contributes to the regulation of quantitative, tissue-specific differences in gene expression has been found between -771 and -676 bp upstream of the major histocompatibility complex (MHC) class I gene, PD1. Molecular dissection of this element reveals the presence of two overlapping functional activities: an enhancer and a silencer. Distinct nuclear factors bind to the overlapping enhancer and silencer DNA sequence elements within the regulatory domain. The levels of factors binding the silencer DNA sequence in different cell types are inversely related to levels of class I expression; in contrast, factors binding the enhancer DNA sequence can be detected in all cells. In cultured cell lines, inhibition of protein synthesis leads to the rapid loss of silencer complexes, with a concomitant increase in both enhancer complexes and MHC class I RNA. From these data, we conclude that a labile silencer factor competes with a constitutively expressed, stable enhancer factor for overlapping DNA-binding sites; the relative abundance of the silencer factor contributes to establishing steady-state levels of MHC class I gene expression.


2015 ◽  
Vol 167 (3-4) ◽  
pp. 166-170
Author(s):  
Larissa Sarmento dos Santos ◽  
Juliana Pinto da Silva Mol ◽  
Auricélio Alves de Macedo ◽  
Ana Patrícia Carvalho Silva ◽  
Diego Luiz dos Santos Ribeiro ◽  
...  

1997 ◽  
Vol 8 (1) ◽  
pp. 47-57 ◽  
Author(s):  
E Stang ◽  
J Kartenbeck ◽  
R G Parton

Simian virus 40 (SV40) has been shown to enter mammalian cells via uncoated plasma membrane invaginations. Viral particles subsequently appear within the endoplasmic reticulum. In the present study, we have examined the surface binding and internalization of SV40 by immunoelectron microscopy. We show that SV40 associates with surface pits which have the characteristics of caveolae and are labeled with antibodies to the caveolar marker protein, caveolin-1. SV40 is believed to use major histocompatibility complex (MHC) class I molecules as cell surface receptors. Using a number of MHC class I-specific monoclonal antibodies, we found that both viral infection and association of virus with caveolae were strongly reduced by preincubation with anti-MHC class I antibodies. Because binding of SV40 to MHC class I molecules may induce clustering, we investigated whether antibody cross-linked class I molecules also redistributed to caveolae. Clusters of MHC class I molecules were indeed shown to be specifically associated with caveolin-labeled surface pits. Taken together, the results suggest that SV40 may make use of MHC class I molecule clustering and the caveolae pathway to enter mammalian cells.


1992 ◽  
Vol 12 (7) ◽  
pp. 3078-3086
Author(s):  
J E Maguire ◽  
W I Frels ◽  
J C Richardson ◽  
J D Weissman ◽  
D S Singer

Major histocompatibility complex class I genes are expressed in nearly all somatic tissues, although their level of expression varies. By analysis of a set of promoter deletion mutants introduced into transgenic mice, a complex regulatory element, consisting of overlapping enhancer and silencer activities, is demonstrated to function as a tissue-specific regulator of class I expression. The enhancer activity predominates in lymphoid tissues but not in nonlymphoid tissues. In contrast to the tissue-specific functions of the complex regulatory element, a second novel silencer element is shown to function in both lymphoid and nonlymphoid tissues. The complement of DNA-binding factors in different cell lines is shown to correlate with the levels of class I expression.


1993 ◽  
Vol 13 (3) ◽  
pp. 1554-1564
Author(s):  
A G Frauman ◽  
P Chu ◽  
L C Harrison

The overexpression of major histocompatibility complex (MHC) class I molecules in endocrine epithelial cells is an early feature of autoimmune thyroid disease and insulin-dependent diabetes mellitus, which may reflect a cellular response, e.g., to viruses or toxins. Evidence from a transgenic model in pancreatic beta cells suggests that MHC class I overexpression could play an independent role in endocrine cell destruction. We demonstrate in this study that the transgenic overexpression of an allogeneic MHC class I protein (H-2Kb) linked to the rat thyroglobulin promoter, in H-2Kk mice homozygous for the transgene, leads to thyrocyte atrophy, hypothyroidism, growth retardation, and death. Thyrocyte atrophy occurred in the absence of lymphocytic infiltration. Tolerance to allogeneic class I was revealed by the reduced ability of primed lymphocytes from transgenic mice to lyse H-2Kb target cells in vitro. This nonimmune form of thyrocyte destruction and hypothyroidism recapitulates the beta-cell destruction and diabetes that results from transgenic overexpression of MHC class I molecules in pancreatic beta cells. Thus, we conclude that overexpression of MHC class I molecules may be a general mechanism that directly impairs endocrine epithelial cell viability.


2011 ◽  
Vol 63 (12) ◽  
pp. 821-834 ◽  
Author(s):  
Lasse Eggers Pedersen ◽  
Mikkel Harndahl ◽  
Michael Rasmussen ◽  
Kasper Lamberth ◽  
William T. Golde ◽  
...  

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