scholarly journals Human Histocompatibility Leukocyte Antigen (HLA)-G Molecules Inhibit NKAT3 Expressing Natural Killer Cells

1997 ◽  
Vol 185 (3) ◽  
pp. 385-392 ◽  
Author(s):  
Christian Münz ◽  
Nicholas Holmes ◽  
Ashley King ◽  
Yung Wai Loke ◽  
Marco Colonna ◽  
...  

The crucial immunological function of the classical human major histocompatibility complex (MHC) class I molecules, human histocompatibility leukocyte antigen (HLA)-A, -B, and -C, is the presentation of peptides to T cells. A secondary function is the inhibition of natural killer (NK) cells, mediated by binding of class I molecules to NK receptors. In contrast, the function of the nonclassical human MHC class I molecules, HLA-E, -F, and -G, is still a mystery. The specific expression of HLA-G in placental trophoblast suggests an important role for this molecule in the immunological interaction between mother and child. The fetus, semiallograft by its genotype, escapes maternal allorecognition by downregulation of HLA-A and HLA-B molecules at this interface. It has been suggested that the maternal NK recognition of this downregulation is balanced by the expression of HLA-G, thus preventing damage to the placenta. Here, we describe the partial inhibition of NK lysis of the MHC class I negative cell line LCL721.221 upon HLA-G transfection. We present three NK lines that are inhibited via the interaction of their NKAT3 receptor with HLA-G and with HLA-Bw4 molecules. Inhibition can be blocked by the anti-NKAT3 antibody 5.133. In conclusion, NK inhibition by HLA-G via NKAT3 may contribute to the survival of the fetal semiallograft in the mother during pregnancy.

1993 ◽  
Vol 178 (2) ◽  
pp. 597-604 ◽  
Author(s):  
A Moretta ◽  
M Vitale ◽  
C Bottino ◽  
A M Orengo ◽  
L Morelli ◽  
...  

Human CD3-16+56+ natural killer (NK) cells have been shown to display a clonally distributed ability to recognize major histocompatibility complex (MHC) class I alleles. Opposite to T lymphocytes, in NK cells, specific recognition of MHC class I molecules appears to induce inhibition of cytolytic activity and, thus, to protect target cells. Since a precise correlation has been established between the expression of the NK-specific GL183 and EB6 surface molecules (belonging to the novel p58 molecular family) and the specificity of NK clones, we analyzed whether p58 molecules could function as receptors for MHC in human NK cells. NK clones displaying the previously defined "specificity 2" and characterized by the GL183+EB6+ phenotype, specifically recognize the Cw3 allele and thus fail to lyse the Fc gamma R+ P815 target cells transfected with Cw3. On the other hand, NK clones displaying "specificity 1" and expressing the GL183-EB6+ phenotype failed to lyse Cw4+ target cells. Addition of the F(ab')2 fragments of either GL183 or EB6 mAb as well as the XA141 mAb of IgM isotype (specific for the EB6 molecules) completely restored the lysis of Cw3-transfected P815 cells by the Cw3-specific NK clones EX2 and EX4. Similarly, both the entire EB6 mAb, its F(ab')2 fragment and the XA141 mAb reconstituted the lysis of C1R, a Fc gamma R- target cell expressing Cw4 as the only serologically detected class I antigen. Thus, it appears that masking of different members of p58 molecules prevents recognition of "protective" MHC class I alleles and thus the delivering of inhibitory signals. Further support to the concept that p58 molecules represent a NK receptor delivering a negative signal was provided by experiments in which the entire anti-p58 mAbs (of IgG isotype) could inhibit the lysis of unprotected Fc gamma R+ P815 target cells, thus mimicking the inhibitory effect of MHC class I molecules.


2001 ◽  
Vol 193 (3) ◽  
pp. 307-316 ◽  
Author(s):  
Dawn M. Tanamachi ◽  
Thomas Hanke ◽  
Hisao Takizawa ◽  
Amanda M. Jamieson ◽  
David H. Raulet

Ly49 receptor genes are expressed by subsets of natural killer (NK) cells in an overlapping fashion, accounting for the capacity of NK subsets to attack host cells that have selectively downregulated self–major histocompatibility complex (MHC) class I molecules. It was shown previously that most NK cells express only one or the other allele of a given Ly49 gene, while a smaller population expresses both alleles. However, the methods used to detect monoallelic and biallelic cells were nonquantitative. Here, new allele-specific antibodies were used to provide the first quantitative examination of biallelic and monoallelic expression of Ly49A and Ly49G2. The results demonstrate conclusively that most Ly49A+ and Ly49G2+ NK cells express the corresponding gene in a monoallelic fashion, with a smaller subset expressing both alleles. Unexpectedly, biallelic Ly49A+ NK cells were more numerous than predicted by completely independent allelic expression, suggesting some heterogeneity among NK progenitors in the potential to express a given Ly49 gene. The data also show that cells expressing one allele of Ly49G2 may express Ly49A from the same or opposite chromosome with equal likelihood, indicating that the expressed allele is chosen independently for different Ly49 genes. Finally, the data demonstrate that biallelic expression of Ly49A or Ly49G2 occurs least frequently in mice that express ligands for these receptors (H-2d mice), and most frequently in class I–deficient mice. Thus, biallelic expression of Ly49 genes is regulated by interactions of NK cell progenitors with MHC class I molecules.


1991 ◽  
Vol 174 (3) ◽  
pp. 737-740 ◽  
Author(s):  
S K Sanders ◽  
P A Giblin ◽  
P Kavathas

The lymphocyte differentiation marker CD8 acts as a coreceptor with the T cell receptor (TCR) during recognition of peptide presented by major histocompatibility complex (MHC) class I molecules. The functions of CD8 in the TCR complex are thought to be signaling through the association of CD8 with the protein tyrosine kinase p56lck and adhesion to MHC class I through the alpha 3 domain. While the ability of the CD8 alpha/alpha homodimer to bind to classical MHC class I molecules has been shown, it is unclear whether CD8 can also bind nonclassical molecules. Of particular interest is human histocompatibility leukocyte antigen (HLA)-G which is expressed on placental cytotrophoblast cells. These cells do not express HLA-A, -B and -C molecules. In this report, we demonstrate that CD8 can bind to HLA-G. It is possible, therefore, that a cell bearing CD8 may interact with HLA-G-expressing cells.


Blood ◽  
2004 ◽  
Vol 104 (7) ◽  
pp. 2087-2094 ◽  
Author(s):  
Matthew I. Bonaparte ◽  
Edward Barker

Abstract In the current study, we evaluated whether the capacity of HIV to modulate major histocompatibility complex (MHC) class I molecules has an impact on the ability of autologous natural killer (NK) cells to kill the HIV-infected cells. Analysis of HIV-infected T-cell blasts revealed that the decrease in MHC class I molecules on the infected cell surface was selective. HLA-A and -B were decreased on cells infected with HIV strains that could decrease MHC class I molecules, whereas HLA-C and -E remained on the surface. Blocking the interaction between HLA-C and -E and their corresponding inhibitory receptors increased NK cell killing of T-cell blasts infected with HIV strains that reduced MHC class I molecules. Moreover, we demonstrate that NK cells lacking HLA-C and -E inhibitory receptors kill T-cell blasts infected with HIV strains that decrease MHC class I molecules. In contrast, NK cells are incapable of destroying T-cell blasts infected with HIV strains that were unable to reduce MHC class I molecules. These findings suggest that NK cells lacking inhibitory receptors to HLA-C and -E kill HIV-infected CD4+ T cells, and they indicate that the capacity of NK cells to destroy HIV-infected cells depends on the ability of the virus to modulate MHC class I molecules. (Blood. 2004;104:2087-2094)


1994 ◽  
Vol 180 (2) ◽  
pp. 687-692 ◽  
Author(s):  
B F Daniels ◽  
F M Karlhofer ◽  
W E Seaman ◽  
W M Yokoyama

Target cell expression of major histocompatibility complex (MHC) class I molecules correlates with resistance to lysis by natural killer (NK) cells. Prior functional studies of the murine NK cell surface molecule, Ly-49, suggested its role in downregulating NK cell cytotoxicity by specifically interacting with target cell H-2Dd molecules. In support of this hypothesis, we now demonstrate a physical interaction between H-2Dd and Ly-49 in both qualitative and quantitative cell-cell binding assays employing a stable transfected Chinese hamster ovary (CHO) cell line expressing Ly-49 and MHC class I transfected target cells. Binding occurred only when CHO cells expressed Ly-49 at high levels and targets expressed H-2Dd by transfection. Monoclonal antibody blocking experiments confirmed this interaction. These studies indicate that the specificity of natural killing is influenced by NK cell receptors that engage target cell MHC class I molecules.


2020 ◽  
Author(s):  
Xizheng Sun ◽  
Reika Tokunaga ◽  
Yoko Nagai ◽  
Ryo Miyahara ◽  
Akihiro Kishimura ◽  
...  

<p><a></a><a></a><a>We have validated that ligand peptides designed from antigen peptides could be used for targeting specific major histocompatibility complex class I (MHC-I)</a> molecules on cell surface. To design the ligand peptides, we used reported antigen peptides for each MHC-I molecule with high binding affinity. From the crystal structure of the peptide/MHC-I complexes, we determined a modifiable residue in the antigen peptides and replaced this residue with a lysine with an ε-amine group modified with functional molecules. The designed ligand peptides successfully bound to cells expressing the corresponding MHC-I molecules via exchange of peptides bound to the MHC-I. We demonstrated that the peptide ligands could be used to transport a protein or a liposome to cells expressing the corresponding MHC-I. The present strategy may be useful for targeted delivery to cells overexpressing MHC-I, which have been observed autoimmune diseases.</p>


1997 ◽  
Vol 8 (1) ◽  
pp. 47-57 ◽  
Author(s):  
E Stang ◽  
J Kartenbeck ◽  
R G Parton

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.


1993 ◽  
Vol 13 (3) ◽  
pp. 1554-1564
Author(s):  
A G Frauman ◽  
P Chu ◽  
L C Harrison

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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