Identification and Quantification of Antigens Associated with HLA Class I Molecules on a Bladder Tumour Cell Line

2003 ◽  
Vol 70 (3) ◽  
pp. 154-160 ◽  
Author(s):  
Nasir Torabi-Pour ◽  
W. John W. Morrow ◽  
Roghieh Saffie ◽  
Prashant G. Gowda ◽  
D. Perrett ◽  
...  
Keyword(s):  
Cell Line ◽  
Tumour Cell ◽  
Bladder Tumour ◽  
Hla Class I ◽  
Class I ◽  
Tumour Cell Line ◽  
Hla Class I Molecules ◽  
Identification And Quantification

scholarly journals Expression and function of CD8 in a murine T cell hybridoma.

1987 ◽  
Vol 166 (6) ◽  
pp. 1747-1757 ◽  
Author(s):  
S E Ratnofsky ◽  
A Peterson ◽  
J L Greenstein ◽  
S J Burakoff
Keyword(s):  
T Cell ◽  
Cell Line ◽  
T Cell Activation ◽  
Cell Activation ◽  
Hla Class I ◽  
Class Ii ◽  
Class I ◽  
Parent Cell ◽  
Class I Mhc ◽  
Hla Class I Molecules

In general, the human CD8 molecule is expressed on T cells specific for HLA class I molecules. Studies designed to delineate the function and to define the ligand of the CD8 molecule have been complicated by the fact that the presumptive ligand for CD8 is on the HLA class I molecule, the same molecule encoding the ligand for the antigen-specific T cell receptor. The ability to express genes in cells other than their natural host has produced a new technology with which to approach CD8 functional studies. The insertion of a cDNA clone for CD8 in a defective retroviral vector has allowed the transfer of CD8 by infection with the resulting defective retrovirus. CD8 was then expressed in an HLA class II-specific T cell, thus separating the ligand requirements of the TCR and CD8. By this approach, the human CD8 molecule was expressed in a murine T cell hybridoma specific for human class II antigens. The resulting CD8+ hybridomas demonstrated a 10-fold increase in IL-2 production over the parent cell line when stimulated with JY, a human B lymphoblastoid cell line expressing both class I and II HLA antigens, demonstrating that expression of CD8 increases T cell activation. mAbs directed against the CD8 molecule inhibited the response of CD8+ hybridomas to JY, supporting the conclusion that the CD8 molecule was fractional. The role of CD8 as a receptor for class I MHC antigens was addressed by stimulation with a cell line expressing HLA-DR antigens, but lacking the expression of HLA class I antigens (Daudi). Stimulation of the CD8+ hybridomas by Daudi did not result in increased IL-2 production. The response to Daudi was unaltered by the addition of anti-CD8 mAb, in contrast to the ability of anti-CD8 mAb to block JY stimulation. Furthermore, mAbs directed against the class I antigens present on JY cells were able to block the enhanced response of the CD8+ hybridomas to JY. These data support the hypothesis that HLA class I molecules are the ligands involved in the CD8-dependent enhancement of T cell activation.

844 Immunomodulatory activity of epigenetic drugs combinations in mesothelioma: laying the ground for new immunotherapeutic strategies

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A896-A896
Author(s):  
Sara Cannito ◽  
Health Biology ◽  
Ornella Cutaia ◽  
Carolina Fazio ◽  
Maria Fortunata Lofiego ◽  
...  
Keyword(s):  
Cell Line ◽  
Cell Lines ◽  
Hla Class I ◽  
Class I ◽  
Immunomodulatory Activity ◽  
Epigenetic Drugs ◽  
Hla Class I Antigens ◽  
Hla Class I Molecules ◽  
Mesothelioma Cell Line ◽  
Mesothelioma Cell

BackgroundGrowing evidence are demonstrating the therapeutic efficacy of immune checkpoint inhibitors (ICI) in mesothelioma; however, a limited percentage of patients benefits from this therapeutic approach. Epigenetic modifications play a relevant role in negatively regulating the cross-talk between neoplastic and immune cells, and in contributing to the highly immunosuppressive mesothelioma microenvironment. A better understanding of mesothelioma epigenetic landscape could open the path to novel and potentially more effective approaches combining ICI and epigenetic drugs. We investigated the immunomodulatory potential of epigenetic agents by comparing the activity of DNA hypomethylating agents (DHA) with histone deacetylases inhibitors (HDACi) and EZH2 inhibitors (EZH2i), alone or combined with DHA, in mesothelioma cells.MethodsFour mesothelioma cell lines were treated with the DHA guadecitabine 1μM, or with the HDACi, Valproic Acid (VPA) 1mM, or the EZH2i, EPZ-6438 1μM, alone or combined with guadecitabine. We investigated the expression of HLA class I molecules by flow-cytometry and of PD-L1, cancer testis antigens (CTA: NY-ESO, MAGE-A1), Natural Killer Group 2 member D Ligands (NKG2DLs: MIC-A, MIC-B, ULBP2) and EMT-regulating cadherins (CDH1, CDH2) by quantitative Real-Time PCR. Fold change (FC) expression for each treatment vs untreated cells was reported as mean values (FCm) among investigated cell lines. A positive modulation of the expression was considered if FCm>1.5.ResultsGuadecitabine upregulated the expression of HLA class I antigens (FCm=1.75), PD-L1 (FCm=2.38), NKG2DLs (MIC-A FCm=1.96, MIC-B FCm=2.57, and ULBP2 FCm=3.56), and upregulated/induced CTA expression. Similarly, VPA upregulated HLA class I antigens (FCm=1.67), PD-L1 (FCm=3.17), NKG2DLs (MIC-A FCm=1.78, MIC-B FCm=3.04, and ULBP2 FCm=3.75) expression; however, CTA expression was modulated only in 1 mesothelioma cell line. Conversely, EPZ-6438 up-regulated only NY-ESO-1 and MIC-B expression in 1 mesothelioma cell line.The addition of both VPA and EPZ-6483 to guadecitabine strengthened its immunomodulatory activity. Specifically, guadecitabine plus VPA or EPZ-6438 upregulated the expression of HLA class I antigens FCm=2.55 or 2.69, PD-L1 FCm=8.04 or 2.65, MIC-A FCm=3.81 or 2.26, MIC-B FCm=8.00 or 3.03, ULBP2 FCm=6.24 or 4.53, respectively. Higher levels of CTA upregulation/induction were observed with combination treatments vs guadecitabine alone.Cadherins modulation was mesothelioma histotype-related: CDH1 expression was induced in the 2 constitutively-negative sarcomatoid mesothelioma cells by guadecitabine alone or combined with VPA or EPZ-6438; CDH2 expression was upregulated by VPA alone (FCm=1.53) or plus guadecitabine (FCm=2.54).ConclusionsCombination of DHA-based immunotherapies with other classes of epigenetic drugs could be an effective strategy to be pursued in the mesothelioma clinic.

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