scholarly journals Radiation modulates the peptide repertoire, enhances MHC class I expression, and induces successful antitumor immunotherapy

2006 ◽  
Vol 203 (5) ◽  
pp. 1259-1271 ◽  
Author(s):  
Eric A. Reits ◽  
James W. Hodge ◽  
Carla A. Herberts ◽  
Tom A. Groothuis ◽  
Mala Chakraborty ◽  
...  
Keyword(s):  
Antigen Presentation ◽  
Mhc Class I ◽  
Cytotoxic T Lymphocyte ◽  
Colon Adenocarcinoma ◽  
Peptide Pool ◽  
Class I ◽  
Cell Surface Expression ◽  
Dependent Manner ◽  
Γ Irradiation ◽  
Mhc Class I Molecules

Radiotherapy is one of the most successful cancer therapies. Here the effect of irradiation on antigen presentation by MHC class I molecules was studied. Cell surface expression of MHC class I molecules was increased for many days in a radiation dose-dependent manner as a consequence of three responses. Initially, enhanced degradation of existing proteins occurred which resulted in an increased intracellular peptide pool. Subsequently, enhanced translation due to activation of the mammalian target of rapamycin pathway resulted in increased peptide production, antigen presentation, as well as cytotoxic T lymphocyte recognition of irradiated cells. In addition, novel proteins were made in response to γ-irradiation, resulting in new peptides presented by MHC class I molecules, which were recognized by cytotoxic T cells. We show that immunotherapy is successful in eradicating a murine colon adenocarcinoma only when preceded by radiotherapy of the tumor tissue. Our findings indicate that directed radiotherapy can improve the efficacy of tumor immunotherapy.

scholarly journals Strictly transporter of antigen presentation (TAP)-dependent presentation of an immunodominant cytotoxic T lymphocyte epitope in the signal sequence of a virus protein.

1995 ◽  
Vol 182 (5) ◽  
pp. 1615-1619 ◽  
Author(s):  
J Hombach ◽  
H Pircher ◽  
S Tonegawa ◽  
R M Zinkernagel
Keyword(s):  
Antigen Presentation ◽  
Mhc Class I ◽  
T Lymphocyte ◽  
Cytotoxic T Lymphocyte ◽  
Signal Sequence ◽  
Class I ◽  
Signal Peptidase ◽  
Leader Peptide ◽  
Virus Protein ◽  
Mhc Class I Molecules

Peptides presented by major histocompatibility complex (MHC) class I molecules are derived from intracellularly synthesized proteins. Cytosolic proteins are fragmented into peptides, which are subsequently transported via the transporter of antigen presentation (TAP) into the endoplasmic reticulum (ER), where they bind to MHC class I molecules. We have investigated the requirements for MHC class I presentation of the immunodominant gp33 cytotoxic T lymphocyte epitope of the lymphocytic choriomeningitis virus. This epitope is located within the leader peptide of the virus glycoprotein. Such an epitope is expected to be presented in a TAP-independent manner, since it is released into the ER by signal peptidase. Taking advantage of TAP1-/- mice, however, we show both in vitro and in vivo that, after virus infection, the presentation of the gp33 epitope is strictly dependent on a functional TAP heterodimer. The results are discussed with respect to peptide trimming processes in the ER.

scholarly journals Modulation of Transporter Associated with Antigen Processing (TAP)-Mediated Peptide Import into the Endoplasmic Reticulum by Flavivirus Infection

2001 ◽  
Vol 75 (12) ◽  
pp. 5663-5671 ◽  
Author(s):  
Frank Momburg ◽  
Arno Müllbacher ◽  
Mario Lobigs
Keyword(s):  
Endoplasmic Reticulum ◽  
Cell Surface ◽  
Mhc Class I ◽  
Antigen Processing ◽  
Surface Expression ◽  
Class I ◽  
Peptide Transport ◽  
Cell Surface Expression ◽  
Flavivirus Infection ◽  
Mhc Class I Molecules

ABSTRACT In contrast to many other viruses that escape the cellular immune response by downregulating major histocompatibility complex (MHC) class I molecules, flavivirus infection can upregulate their cell surface expression. Previously we have presented evidence that during flavivirus infection, peptide supply to the endoplasmic reticulum is increased (A. Müllbacher and M. Lobigs, Immunity 3:207–214, 1995). Here we show that during the early phase of infection with different flaviviruses, the transport activity of the peptide transporter associated with antigen processing (TAP) is augmented by up to 50%. TAP expression is unaltered during infection, and viral but not host macromolecular synthesis is required for enhanced peptide transport. This study is the first demonstration of transient enhancement of TAP-dependent peptide import into the lumen of the endoplasmic reticulum as a consequence of a viral infection. We suggest that the increased supply of peptides for assembly with MHC class I molecules in flavivirus-infected cells accounts for the upregulation of MHC class I cell surface expression with the biological consequence of viral evasion of natural killer cell recognition.

scholarly journals Cell Surface Expression of Major Histocompatibility Complex Class I Molecules Is Reduced in Hepatitis C Virus Subgenomic Replicon-Expressing Cells

2003 ◽  
Vol 77 (21) ◽  
pp. 11644-11650 ◽  
Author(s):  
Keith D. Tardif ◽  
Aleem Siddiqui
Keyword(s):  
Major Histocompatibility Complex ◽  
Hepatitis C ◽  
Cell Surface ◽  
Mhc Class I ◽  
Surface Expression ◽  
Protein Glycosylation ◽  
Class I ◽  
Cell Surface Expression ◽  
Histocompatibility Complex ◽  
Mhc Class I Molecules

ABSTRACT The hepatitis C virus (HCV) causes chronic hepatitis in most infected individuals by evading host immune defenses. In this investigation, we show that HCV-infected cells may go undetected in the immune system by suppressing major histocompatibility complex (MHC) class I antigen presentation to cytotoxic T lymphocytes. Cells expressing HCV subgenomic replicons have lower MHC class I cell surface expression. This is due to reduced levels of properly folded MHC class I molecules. HCV replicons induce endoplasmic reticulum (ER) stress (K. Tardif, K. Mori, and A. Siddiqui, J. Virol. 76:7453-7459, 2002), which results from a decline in protein glycosylation. Decreasing protein glycosylation can disrupt protein folding, preventing the assembly of MHC class I molecules. This results in the accumulation of unfolded MHC class I. Therefore, the persistence and pathogenesis of HCV may depend upon the ER stress-mediated interference of MHC class I assembly and cell surface expression.

Controlled Intracellular Release of Peptides from Microcapsules Enhances Antigen Presentation on MHC Class I Molecules

Small ◽  
2009 ◽  
Vol 5 (19) ◽  
pp. 2168-2176 ◽  
Author(s):  
Raghavendra Palankar ◽  
André G. Skirtach ◽  
Oliver Kreft ◽  
Matthieu Bédard ◽  
Malgorzata Garstka ◽  
...  
Keyword(s):  
Antigen Presentation ◽  
Mhc Class I ◽  
Class I ◽  
Intracellular Release ◽  
Mhc Class I Molecules

scholarly journals E3/19K from adenovirus 2 is an immunosubversive protein that binds to a structural motif regulating the intracellular transport of major histocompatibility complex class I proteins.

1990 ◽  
Vol 172 (6) ◽  
pp. 1653-1664 ◽  
Author(s):  
W A Jefferies ◽  
H G Burgert
Keyword(s):  
Major Histocompatibility Complex ◽  
Cell Surface ◽  
Mhc Class I ◽  
Intracellular Transport ◽  
Surface Expression ◽  
Class I ◽  
Cell Surface Expression ◽  
Major Histocompatibility ◽  
Histocompatibility Complex ◽  
Mhc Class I Molecules

We have previously expressed in transgenic mice a chimeric H-2Kd/Kk protein called C31, which contains the extracellular alpha 1 domain of Kd, whereas the rest of the molecule is of Kk origin. This molecule functions as a restriction element for alloreactive and influenza A-specific cytotoxic T lymphocytes (CTL) but is only weakly expressed at the cell surface of splenocytes. Here, we show that the low cell surface expression is the result of slow intracellular transport and processing of the C31 protein. A set of hybrid molecules between Kd and Kk were used to localize the regions in major histocompatibility complex (MHC) molecules that are important for their intracellular transport and to further localize the structures responsible for binding to the adenovirus 2 E3/19K protein. This protein appears to be an important mediator of adenovirus persistence. It acts by binding to the immaturely glycosylated forms of MHC class I proteins in the endoplasmic reticulum (ER), preventing their passage to the cell surface and thereby reducing the recognition of infected cells by virus-specific T cells. We find the surprising result that intracellular transport and E3/19K binding are controlled primarily by the first half of the second domain of Kd, thus localizing these phenomena to the five polymorphic residues in this region of the Kd protein. This result implies that the E3/19K protein may act by inhibiting peptide binding or by disrupting the oligomerization of MHC class I molecules required for transport out of the ER. Alternatively, the E3/19K protein may inhibit the function of a positively acting transport molecule necessary for cell surface expression of MHC class I molecules.

scholarly journals Presentation of Exogenous Protein Antigens on Major Histocompatability Complex Class I Molecules by Dendritic Cells: Pathway of Presentation and Regulation by Cytokines

Blood ◽  
1997 ◽  
Vol 90 (4) ◽  
pp. 1594-1599 ◽  
Author(s):  
Peter Brossart ◽  
Michael J. Bevan
Keyword(s):  
Dendritic Cells ◽  
Mhc Class I ◽  
Class I ◽  
Cell Surface Expression ◽  
Major Histocompatability Complex ◽  
Peptide Epitopes ◽  
Proinflammatory Mediators ◽  
Tnf Α ◽  
Ifn Γ ◽  
Mhc Class I Molecules

Abstract Several recent studies have shown that dendritic cells (DC) pulsed with soluble proteins can present peptide epitopes derived from these exogenous antigens on major histocompatability complex (MHC) class I molecules and induce an antigen-specific cytotoxic T lymphocyte (CTL) response. We provide evidence here that DC use macropinocytosis to capture soluble antigens that are then presented on MHC class I molecules. The presentation of an epitope derived from soluble ovalbumin was transporter associated with antigen presentation (TAP)-dependent, brefeldin A-sensitive, blocked by inhibitors of proteasomes, and resistant to chloroquine. These data suggest that exogenous antigens access the cytosol of DC and are proccessed for presentation via the same pathway described for conventional MHC class I-restricted cytosolic antigens. Proinflammatory mediators such as tumor necrosis factor-α (TNF-α) and lipopolysaccharide (LPS) reduced the efficiency of ovalbumin presentation via this pathway. This reduced presentation was not due to impaired expression of class I molecules because these substances upregulated the cell surface expression of Kb-molecules comparable to levels induced by interferon-γ (IFN-γ) treatment. The addition of IFN-γ increased ovalbumin presentation even in the presence of TNF-α or LPS. These results show that DC might be involved in the cross-priming phenomenon. This could offer the immune system an additional pathway for effective priming of cytotoxic T cells and provide the possibility to activate both CD4 and CD8 T-cell responses.

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