Major Histocompatibility Complex (MHC) Class II Antigen (HLA-DR, DQ, and DP) Expression in Human Fetal Endocrine Organs and Gut

1988 ◽  
Vol 27 (6) ◽  
pp. 731-737 ◽  
Author(s):  
A. M. OLIVER ◽  
A. W. THOMSON ◽  
H. F. SEWELL ◽  
D. R. ABRAMOVCH
Keyword(s):  
Major Histocompatibility Complex ◽  
Mhc Class Ii ◽  
Class Ii ◽  
Major Histocompatibility ◽  
Histocompatibility Complex ◽  
Hla Dr ◽  
Endocrine Organs ◽  
Class Ii Antigen ◽  
Mhc Class Ii Antigen

scholarly journals Alternative Endogenous Protein Processing via an Autophagy-Dependent Pathway Compensates for Yersinia-Mediated Inhibition of Endosomal Major Histocompatibility Complex Class II Antigen Presentation

2010 ◽  
Vol 78 (12) ◽  
pp. 5138-5150 ◽  
Author(s):  
Holger Rüssmann ◽  
Klaus Panthel ◽  
Brigitte Köhn ◽  
Stefan Jellbauer ◽  
Sebastian E. Winter ◽  
...  
Keyword(s):  
Major Histocompatibility Complex ◽  
Antigen Presentation ◽  
Mhc Class Ii ◽  
Virulence Factors ◽  
Antigen Processing ◽  
Class Ii ◽  
T Cell Response ◽  
Histocompatibility Complex ◽  
Class Ii Antigen ◽  
Mhc Class Ii Antigen

ABSTRACT Extracellular Yersinia pseudotuberculosis employs a type III secretion system (T3SS) for translocating virulence factors (Yersinia outer proteins [Yops]) directly into the cytosol of eukaryotic cells. Recently, we used YopE as a carrier molecule for T3SS-dependent secretion and translocation of listeriolysin O (LLO) from Listeria monocytogenes. We demonstrated that translocation of chimeric YopE/LLO into the cytosol of macrophages by Yersinia results in the induction of a codominant antigen-specific CD4 and CD8 T-cell response in orally immunized mice. In this study, we addressed the requirements for processing and major histocompatibility complex (MHC) class II presentation of chimeric YopE proteins translocated into the cytosol of macrophages by the Yersinia T3SS. Our data demonstrate the ability of Yersinia to counteract exogenous MHC class II antigen presentation of secreted hybrid YopE by the action of wild-type YopE and YopH. In the absence of exogenous MHC class II antigen presentation, an alternative pathway was identified for YopE fusion proteins originating in the cytosol. This endogenous antigen-processing pathway was sensitive to inhibitors of phagolysosomal acidification and macroautophagy, but it did not require the function either of the proteasome or of transporters associated with antigen processing. Thus, by an autophagy-dependent mechanism, macrophages are able to compensate for the YopE/YopH-mediated inhibition of the endosomal MHC class II antigen presentation pathway for exogenous antigens. This is the first report demonstrating that autophagy might enable the host to mount an MHC class II-restricted CD4 T-cell response against translocated bacterial virulence factors. We provide critical new insights into the interaction between the mammalian immune system and a human pathogen.

The FcγRIa (CD64) Ligand Binding Chain Triggers Major Histocompatibility Complex Class II Antigen Presentation Independently of Its Associated FcR γ-Chain

Blood ◽  
1999 ◽  
Vol 94 (2) ◽  
pp. 808-817 ◽  
Author(s):  
Martine J. van Vugt ◽  
Monique J. Kleijmeer ◽  
Tibor Keler ◽  
Ingrid Zeelenberg ◽  
Marc A. van Dijk ◽  
...  
Keyword(s):  
Major Histocompatibility Complex ◽  
Ligand Binding ◽  
Antigen Presentation ◽  
Mhc Class Ii ◽  
Cytoplasmic Tail ◽  
Class Ii ◽  
Major Histocompatibility ◽  
Histocompatibility Complex ◽  
Rabbit Igg ◽  
Class Ii Antigen

Abstract Within multi-subunit Ig receptors, the FcR γ-chain immunoreceptor tyrosine-based activation motif (ITAM) plays a crucial role in enabling antigen presentation. This process involves antigen-capture and targeting to specific degradation and major histocompatibility complex (MHC) class II loading compartments. Antigenic epitopes are then presented by MHC class II molecules to specific T cells. The high-affinity receptor for IgG, hFcγRIa, is exclusively expressed on myeloid lineage cells and depends on the FcR γ-chain for surface expression, efficient ligand binding, and most phagocytic effector functions. However, we show in this report, using the IIA1.6 cell model, that hFcγRIa can potentiate MHC class II antigen presentation, independently of a functional FcR γ-chain ITAM. Immunoelectron microscopic analyses documented hFcγRIa -chain/rabbit IgG-Ovalbumin complexes to be internalized and to migrate via sorting endosomes to MHC class II-containing late endosomes. Radical deletion of the hFcγRIa -chain cytoplasmic tail did not affect internalization of rabbit IgG-Ovalbumin complexes. Importantly, however, this resulted in diversion of receptor-ligand complexes to the recycling pathway and decreased antigen presentation. These results show the hFcγRIa cytoplasmic tail to contain autonomous targeting information for intracellular trafficking of receptor-antigen complexes, although deficient in canonical tyrosine- or dileucine-targeting motifs. This is the first documentation of autonomous targeting by a member of the multichain FcR family that may critically impact the immunoregulatory role proposed for hFcγRIa (CD64).

scholarly journals Two DNA-binding proteins discriminate between the promoters of different members of the major histocompatibility complex class II multigene family

1990 ◽  
Vol 10 (3) ◽  
pp. 965-971
Author(s):  
M Kobr ◽  
W Reith ◽  
C Herrero-Sanchez ◽  
B Mach
Keyword(s):  
Gene Expression ◽  
Major Histocompatibility Complex ◽  
Mhc Class Ii ◽  
Dna Sequences ◽  
Multigene Family ◽  
Class Ii ◽  
Major Histocompatibility ◽  
Histocompatibility Complex ◽  
Hla Dr ◽  
Beta Chain Genes

The regulation of major histocompatibility complex (MHC) class II gene expression is a key feature of the control of normal and abnormal immune responses. In humans, class II alpha - and beta-chain genes are organized in a multigene family with three distinct subregions, HLA-DR, -DQ, and -DP. The regulation of these genes is generally coordinated, and their promoters contain highly conserved motifs, in particular the X and Y boxes. We have identified five distinct proteins that bind to specific DNA sequences within the first 145 base pairs of the HLA-DR promoter, a segment known to be functionally essential for class II gene regulation. Among these, RF-X is of special interest, since mutants affected in the regulation of MHC class II gene expression have a specific defect in RF-X binding. Unexpectedly, RF-X displays a characteristic gradient of binding affinities for the X boxes of three alpha-chain genes (DRA greater than DPA much greater than DQA). The same observation was made with recombinant RF-X. We also describe a novel factor, NF-S, which bound to the spacer region between the X and Y boxes of class II promoters. NF-S exhibited a reverse gradient of affinity compared with RF-X (DQA greater than DPA much greater than DRA). As expected, RF-X bound well to the mouse IE alpha promoter, while NF-S bound well to IA alpha. The drastic differences in the binding of RF-X and NF-S to different MHC class II promoters contrasts with the coordinate regulation of HLA-DR, -DQ, and -DP genes.

scholarly journals Two DNA-binding proteins discriminate between the promoters of different members of the major histocompatibility complex class II multigene family.

1990 ◽  
Vol 10 (3) ◽  
pp. 965-971 ◽  
Author(s):  
M Kobr ◽  
W Reith ◽  
C Herrero-Sanchez ◽  
B Mach
Keyword(s):  
Gene Expression ◽  
Major Histocompatibility Complex ◽  
Mhc Class Ii ◽  
Dna Sequences ◽  
Multigene Family ◽  
Class Ii ◽  
Major Histocompatibility ◽  
Histocompatibility Complex ◽  
Hla Dr ◽  
Beta Chain Genes

The regulation of major histocompatibility complex (MHC) class II gene expression is a key feature of the control of normal and abnormal immune responses. In humans, class II alpha - and beta-chain genes are organized in a multigene family with three distinct subregions, HLA-DR, -DQ, and -DP. The regulation of these genes is generally coordinated, and their promoters contain highly conserved motifs, in particular the X and Y boxes. We have identified five distinct proteins that bind to specific DNA sequences within the first 145 base pairs of the HLA-DR promoter, a segment known to be functionally essential for class II gene regulation. Among these, RF-X is of special interest, since mutants affected in the regulation of MHC class II gene expression have a specific defect in RF-X binding. Unexpectedly, RF-X displays a characteristic gradient of binding affinities for the X boxes of three alpha-chain genes (DRA greater than DPA much greater than DQA). The same observation was made with recombinant RF-X. We also describe a novel factor, NF-S, which bound to the spacer region between the X and Y boxes of class II promoters. NF-S exhibited a reverse gradient of affinity compared with RF-X (DQA greater than DPA much greater than DRA). As expected, RF-X bound well to the mouse IE alpha promoter, while NF-S bound well to IA alpha. The drastic differences in the binding of RF-X and NF-S to different MHC class II promoters contrasts with the coordinate regulation of HLA-DR, -DQ, and -DP genes.

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