Class II Y-box binding protein cDNA detects an mRNA species specific to class II-deficient cell lines

1988 ◽  
Vol 23 (2) ◽  
pp. 90
Author(s):  
D.K. Didier ◽  
S.L. Woulfe ◽  
M. Zacheis ◽  
K. Giacoletto ◽  
C. Bono ◽  
...  
1995 ◽  
Vol 181 (1) ◽  
pp. 223-234 ◽  
Author(s):  
C C Stebbins ◽  
G E Loss ◽  
C G Elias ◽  
A Chervonsky ◽  
A J Sant

Recently several cell lines have been identified with mutations in a major histocompatibility complex (MHC)-linked protein that lead to defects in class II-restricted antigen presentation and a defect in the formation of class II SDS-stable dimers. The defect in these cells has recently been shown to result from the inability to express the MHC-encoded nonclassical class II molecule called DM. To further examine the role of DM in class II-restricted antigen presentation, we asked if this defect would equally affect different allelic and species variants of class II molecules. To investigate this, we transfected the parent cell lines T1 and 8.1.6 and their respective antigen presentation mutants T2 and 9.5.3 with the genes encoding I-Ad and examined the derived transfectants for their ability to present antigen, the conformation of I-Ad at the cell surface, association of I-Ad with invariant chain (Ii), and the ability to form I-Ad SDS-stable dimers. The lack of functional DM expression did not affect any of the anti-I-Ad monoclonal antibody (mAb) epitopes tested or the ability of I-Ad to associate and dissociate with Ii. Surprisingly, these studies also revealed that the antigen presentation defect observed for DR in the 9.5.3 cells did not compromise I-Ad-restricted antigen presentation. In addition, we found that the level of SDS-stable dimer formation did not correlate with antigen presentation capacity for I-Ad and that the amount of SDS-stable I-Ad dimer depends on the cellular context in which the class II molecule is expressed. Our results suggest that the ability to form SDS-stable dimer is not strictly correlated with class II-restricted antigen presentation. Finally, when two allelic forms of murine class II molecules were compared in the defective T2 cell line, it was found that I-Ak but not I-Ad forms SDS-stable dimers equivalent to that seen in the parental cell lines. Overall, our results suggest that DM may modulate rather than play a requisite role in I-Ad-restricted antigen presentation and SDS-stable dimer formation and that dependency on DM may be allele or species specific.


2010 ◽  
Vol 222 (03) ◽  
Author(s):  
S Degen ◽  
S Kuhfittig-Kulle ◽  
JH Schulte ◽  
F Westermann ◽  
A Schramm ◽  
...  

2021 ◽  
Vol 20 ◽  
pp. 153303382110279
Author(s):  
SiZhe Yu ◽  
Yu Wang ◽  
KeJia Lv ◽  
Jia Hou ◽  
WenYuan Li ◽  
...  

Purpose: The high fatality-to-case ratio of hepatocellular carcinoma is directly related to metastasis. The signal transducer and activator of transcription-3 is a key mediator of the cytokine and growth factor signaling pathways and drives the transcription of genes responsible for cancer-associated phenotypes. However, so far, no specific inhibitor for signal transducer and activator of transcription-3 has been used in clinical practice. Therefore, targeting the signal transducer and activator of transcription-3 for cancer therapy is highly desired to improve outcomes in patients with hepatocellular carcinoma. Experimental Design: Using the small-molecule inhibitor NT157, the effect of signal transducer and activator of transcription-3 inhibition on cell migration was tested in hepatocellular carcinoma cell lines and a lung metastasis model of the disease. Results: NT157 significantly inhibited the migration of hepatocellular carcinoma cell lines in vitro and lung metastasis of hepatocellular carcinoma in vivo. Mechanistically, it inhibited the phospho-signal transducer and activator of transcription-3 in a dose- and time-dependent manner. Furthermore, NT157 treatment suppressed the c-Jun activation domain-binding protein-1 levels in the nucleus but no significant decrease was observed in its expression in the cytoplasm. Finally, high mRNA expression levels of signal transducer and activator of transcription-3 and c-Jun activation domain-binding protein-1 in hepatocellular carcinoma were associated with significantly low survival rates. Conclusion: NT157 inhibits hepatocellular carcinoma migration and metastasis by downregulating the signal transducer and activator of transcription-3/c-Jun activation domain-binding protein-1 signaling pathway and targeting it may serve as a novel therapeutic strategy for the clinical management of hepatocellular carcinoma in the future.


1989 ◽  
Vol 9 (10) ◽  
pp. 4560-4562 ◽  
Author(s):  
D J Martin ◽  
B G Van Ness

A novel kappa immunoglobulin-hybridizing mRNA in cell lines derived from human B cells arrested at several stages of development has been identified. Hybridization studies demonstrate that this 1.5-kilobase mRNA species is the spliced product of a precursor germ line transcript initiating upstream of the unrearranged JKappa locus.


2001 ◽  
Vol 75 (17) ◽  
pp. 7944-7955 ◽  
Author(s):  
Noriko Nakajima ◽  
Richard Lu ◽  
Alan Engelman

ABSTRACT Functional retroviral integrase protein is thought to be essential for productive viral replication. Yet, previous studies differed on the extent to which integrase mutant viruses expressed human immunodeficiency virus type 1 (HIV-1) genes from unintegrated DNA. Although one reason for this difference was that class II integrase mutations pleiotropically affected the viral life cycle, another reason apparently depended on the identity of the infected cell. Here, we analyzed integrase mutant viral infectivities in a variety of cell types. Single-round infectivity of class I integration-specific mutant HIV-1 ranged from <0.03 to 0.3% of that of the wild type (WT) across four different T-cell lines. Based on this approximately 10-fold influence of cell type on mutant gene expression, we examined class I and class II mutant replication kinetics in seven different cell lines and two primary cell types. Unexpectedly, some cell lines supported productive class I mutant viral replication under conditions that restricted class II mutant growth. Cells were defined as permissive, semipermissive, or nonpermissive based on their ability to support the continual passage of class I integration-defective HIV-1. Mutant infectivity in semipermissive and permissive cells as quantified by 50% tissue culture infectious doses, however, was only 0.0006 to 0.005% of that of WT. Since the frequencies of mutant DNA recombination in these lines ranged from 0.023 to <0.093% of the WT, we conclude that productive replication in the absence of integrase function most likely required the illegitimate integration of HIV-1 into host chromosomes by cellular DNA recombination enzymes.


1993 ◽  
Vol 13 (11) ◽  
pp. 6810-6818 ◽  
Author(s):  
X Y Zhang ◽  
N Jabrane-Ferrat ◽  
C K Asiedu ◽  
S Samac ◽  
B M Peterlin ◽  
...  

A mammalian protein called RFX or NF-X binds to the X box (or X1 box) in the promoters of a number of major histocompatibility (MHC) class II genes. In this study, RFX was shown to have the same DNA-binding specificity as methylated DNA-binding protein (MDBP), and its own cDNA was found to contain a binding site for MDBP in the leader region. MDBP is a ubiquitous mammalian protein that binds to certain DNA sequences preferentially when they are CpG methylated and to other related sequences, like the X box, irrespective of DNA methylation. MDBP from HeLa and Raji cells formed DNA-protein complexes with X-box oligonucleotides that coelectrophoresed with those containing standard MDBP sites. Furthermore, MDBP and X-box oligonucleotides cross-competed for the formation of these DNA-protein complexes. DNA-protein complexes obtained with MDBP sites displayed the same partial supershifting with an antiserum directed to the N terminus of RFX seen for complexes containing an X-box oligonucleotide. Also, the in vitro-transcribed-translated product of a recombinant RFX cDNA bound specifically to MDBP ligands and displayed the DNA methylation-dependent binding of MDBP. RFX therefore contains MDBP activity and thereby also EF-C, EP, and MIF activities that are indistinguishable from MDBP and that bind to methylation-independent sites in the transcriptional enhancers of polyomavirus and hepatitis B virus and to an intron of c-myc.


Blood ◽  
2006 ◽  
Vol 109 (8) ◽  
pp. 3325-3332 ◽  
Author(s):  
Anders Woetmann ◽  
Paola Lovato ◽  
Karsten W. Eriksen ◽  
Thorbjørn Krejsgaard ◽  
Tord Labuda ◽  
...  

AbstractBacterial toxins including staphylococcal enterotoxins (SEs) have been implicated in the pathogenesis of cutaneous T-cell lymphomas (CTCLs). Here, we investigate SE-mediated interactions between nonmalignant T cells and malignant T-cell lines established from skin and blood of CTCL patients. The malignant CTCL cells express MHC class II molecules that are high-affinity receptors for SE. Although treatment with SE has no direct effect on the growth of the malignant CTCL cells, the SE-treated CTCL cells induce vigorous proliferation of the SE-responsive nonmalignant T cells. In turn, the nonmalignant T cells enhance proliferation of the malignant cells in an SE- and MHC class II–dependent manner. Furthermore, SE and, in addition, alloantigen presentation by malignant CTCL cells to irradiated nonmalignant CD4+ T-cell lines also enhance proliferation of the malignant cells. The growth-promoting effect depends on direct cell-cell contact and soluble factors such as interleukin-2. In conclusion, we demonstrate that SE triggers a bidirectional cross talk between nonmalignant T cells and malignant CTCL cells that promotes growth of the malignant cells. This represents a novel mechanism by which infections with SE-producing bacteria may contribute to pathogenesis of CTCL.


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