The mechanism of down-regulation of major histocompatibility complex (MHC) class I antigens in highly oncogenic adenovirus 12-transformed cells

1997 ◽  
Vol 25 (2) ◽  
pp. 353S-353S
Author(s):  
KERSTEN T. HALL ◽  
G.E. BLAIR
Keyword(s):  
Major Histocompatibility Complex ◽  
Mhc Class I ◽  
Class I ◽  
Transformed Cells ◽  
Major Histocompatibility ◽  
Down Regulation ◽  
Histocompatibility Complex ◽  
Mhc Class I Antigens

scholarly journals Evidence for the involvement of a nuclear NF-kappa B inhibitor in global down-regulation of the major histocompatibility complex class I enhancer in adenovirus type 12-transformed cells.

1996 ◽  
Vol 16 (1) ◽  
pp. 398-404 ◽  
Author(s):  
X Liu ◽  
R Ge ◽  
R P Ricciardi
Keyword(s):  
Major Histocompatibility Complex ◽  
Major Histocompatibility Complex Class ◽  
Adenovirus Type ◽  
Class I ◽  
Transformed Cells ◽  
Complex Class ◽  
Major Histocompatibility ◽  
Nf Kappa B ◽  
Down Regulation ◽  
Histocompatibility Complex

Diminished expression of major histocompatibility complex class I antigens on the surface of adenovirus type 12 (Ad12)-transformed cells contributes to their high tumorigenic potential by enabling them to escape immune recognition by cytotoxic T lymphocytes. This low class I antigen expression is due to a block in class I transcription, which is mediated by Ad12 E1A. Genetic analysis has shown that the class I enhancer is the target for transcriptional down-regulation. In this study, we show that the ability of the R1 element of the class I enhancer to stimulate transcription is greatly reduced in Ad12-transformed cells. The loss of functional activity by the R1 element was attributed to loss of binding by the NF-kappa B p50-p65 heterodimer. NF-kappa B binding appears to be blocked within the nucleus rather than at the level of nuclear translocation. Significantly, NF-kappa B binding activity could be recovered from the nuclear extracts of Ad12-transformed cells following detergent treatment, suggesting that the block is mediated through a nuclear inhibitor present in the Ad12-transformed cells. These results, taken together with the fact that the R2 element of the class I enhancer exhibits strong binding to the transcriptional repressor COUP-TF, suggest that the class I enhancer is globally down-regulated in Ad12-transformed cells.

Transcription of non-classic major histocompatibility complex (MHC) class I in the bovine placenta throughout gestation and after Brucella abortus infection

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 ◽  
...  
Keyword(s):  
Major Histocompatibility Complex ◽  
Mhc Class I ◽  
Brucella Abortus ◽  
Class I ◽  
Major Histocompatibility ◽  
Bovine Placenta ◽  
Histocompatibility Complex

scholarly journals Major histocompatibility complex class I molecules mediate association of SV40 with caveolae.

1997 ◽  
Vol 8 (1) ◽  
pp. 47-57 ◽  
Author(s):  
E Stang ◽  
J Kartenbeck ◽  
R G Parton
Keyword(s):  
Major Histocompatibility Complex ◽  
Mhc Class I ◽  
Mammalian Cells ◽  
Simian Virus 40 ◽  
Class I ◽  
Major Histocompatibility ◽  
Surface Binding ◽  
Histocompatibility Complex ◽  
Mhc Class I Molecule ◽  
Mhc Class I Molecules

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.

Nonimmune thyroid destruction results from transgenic overexpression of an allogeneic major histocompatibility complex class I protein

1993 ◽  
Vol 13 (3) ◽  
pp. 1554-1564
Author(s):  
A G Frauman ◽  
P Chu ◽  
L C Harrison
Keyword(s):  
Major Histocompatibility Complex ◽  
Beta Cells ◽  
Mhc Class I ◽  
Pancreatic Beta Cells ◽  
Class I ◽  
General Mechanism ◽  
Major Histocompatibility ◽  
Cell Destruction ◽  
Histocompatibility Complex ◽  
Mhc Class I Molecules

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.

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