scholarly journals Control of rat natural killer cell-mediated allorecognition by a major histocompatibility complex region encoding nonclassical class I antigens.

1994 ◽  
Vol 180 (2) ◽  
pp. 641-651 ◽  
Author(s):  
J T Vaage ◽  
C Naper ◽  
G Løvik ◽  
D Lambracht ◽  
A Rehm ◽  
...  
Keyword(s):  
Major Histocompatibility Complex ◽  
Nk Cells ◽  
Natural Killer ◽  
Class I ◽  
F1 Hybrids ◽  
Major Histocompatibility ◽  
Histocompatibility Complex ◽  
Nonclassical Class

The ability of natural killer (NK) cells to eliminate normal allogeneic hemic cells is well established in several species including mice, rats, and humans. The controlling elements for NK susceptibility in these species map to the major histocompatibility complex (MHC), but in contrast to findings in mice and humans, the mode of inheritance is not always recessive in rats. This finding is not easily explained by the missing self and hemopoietic histocompatibility (Hh) models for NK recognition, and has led to the idea that certain alloantigens may trigger NK cell reactivity. In our in vitro system for assessing rat NK alloreactivity, we have employed target and inhibitor cells from a large panel of MHC congenic, intra-MHC recombinant and MHC mutant rat strains, as well as appropriate F1 hybrids between them, and we show the following: (a) The nonclassical class I (RT1.C) region was most important in determining the susceptibility of target cells to alloreactive NK cells in vitro. Lymphocyte susceptibility to lysis in vivo also mapped to the C region, which supports the concept that the in vivo and in vitro alloreactivity assays reflect the same recognition process. (b) Four different RT1-controlled NK allospecificities (represented by the u, l, a, and n haplotypes) could be discerned when we used polyclonal NK cells from the PVG (RT1c) strain as effector cells. Three of the target specificities recognized were controlled mainly by the RT1.C region. (c) The expression of RT1.C region-controlled parental strain NK allodeterminants could be demonstrated in F1 hybrids heterozygous for the C region alone and were therefore inherited nonrecessively. (d) Loss of an RT1.C region-controlled NK allospecificity could be shown with the MHC mutant LEW.1LM1 rat strain characterized by a genomic deletion of about 100 kb of the C region. Taken together, these observations have demonstrated a major importance of the nonclassical class I region, i.e., RT1.C, in controlling rat NK allorecognition, and have thereby assigned a hitherto undescribed immunological property to this region. Furthermore, some of the present data are consistent with the existence of polymorphic NK-triggering alloantigens that are coded for by the RT1.C region.

scholarly journals Natural Killer Cell Tolerance in Mice with Mosaic Expression of Major Histocompatibility Complex Class I Transgene

1997 ◽  
Vol 186 (3) ◽  
pp. 353-364 ◽  
Author(s):  
Maria H. Johansson ◽  
Charles Bieberich ◽  
Gilbert Jay ◽  
Klas Kärre ◽  
Petter Höglund
Keyword(s):  
Major Histocompatibility Complex ◽  
Nk Cells ◽  
Natural Killer ◽  
Mhc Class I ◽  
Nk Cell ◽  
Class I ◽  
Cell Tolerance ◽  
Histocompatibility Complex ◽  
Missing Self

We have studied natural killer (NK) cell tolerance in a major histocompatibility complex (MHC) class I transgenic line, DL6, in which the transgene product was expressed on only a fraction of blood cells. In contrast with transgenic mice expressing the same transgene in all cells, NK cells from mosaic mice failed to reject transgene-negative bone marrow or lymphoma grafts. However, they retained the capability to reject cells with a total missing-self phenotype, i.e., cells lacking also wild-type MHC class I molecules. Tolerance against transgene-negative cells was demonstrated also in vitro, and could be broken if transgene-positive spleen cells of mosaic mice were separated from negative cells before, or after 4 d of culture in interleukin-2. The results provide support for selective NK cell tolerance to one particular missing-self phenotype but not to another. We suggest that this tolerance is determined by NK cell interactions with multiple cells in the environment, and that it is dominantly controlled by the presence of cells lacking a specific MHC class I ligand. Furthermore, the tolerant NK cells could be reactivated in vitro, which suggests that the tolerance occurs without deletion of the potentially autoreactive NK cell subset(s), and that it may be dependent upon the continuous presence of tolerizing cells.

scholarly journals P58 molecules as putative receptors for major histocompatibility complex (MHC) class I molecules in human natural killer (NK) cells. Anti-p58 antibodies reconstitute lysis of MHC class I-protected cells in NK clones displaying different specificities.

1993 ◽  
Vol 178 (2) ◽  
pp. 597-604 ◽  
Author(s):  
A Moretta ◽  
M Vitale ◽  
C Bottino ◽  
A M Orengo ◽  
L Morelli ◽  
...  
Keyword(s):  
Major Histocompatibility Complex ◽  
Nk Cells ◽  
Natural Killer ◽  
Mhc Class I ◽  
Cytolytic Activity ◽  
Class I ◽  
Target Cells ◽  
Major Histocompatibility ◽  
Histocompatibility Complex ◽  
Mhc Class I Molecules

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.

scholarly journals Tumorigenicity conferred to lymphoma mutant by major histocompatibility complex-encoded transporter gene.

1993 ◽  
Vol 177 (1) ◽  
pp. 201-205 ◽  
Author(s):  
L Franksson ◽  
E George ◽  
S Powis ◽  
G Butcher ◽  
J Howard ◽  
...  
Keyword(s):  
Major Histocompatibility Complex ◽  
Nk Cells ◽  
Mhc Class I ◽  
Nk Cell ◽  
Class I ◽  
Antigenic Peptides ◽  
Major Histocompatibility ◽  
Histocompatibility Complex ◽  
Mhc Class I Molecules

Presentation of antigenic peptides by major histocompatibility complex (MHC) class I molecules requires MHC-encoded molecules of the adenosine triphosphate binding cassette (ABC) family. Defects in these proteins represent a potential risk, since they are essential links in the machinery of T cell-mediated surveillance which continuously scrutinizes peptide samples of cellular proteins. Nevertheless, transfection of the mouse lymphoma mutant RMA-S with the rat ABC gene mtp2a (homologue to mouse HAM2 and human RING11), commonly termed TAP-2 genes, led to a marked increase in tumor outgrowth potential in vivo. This occurred despite restored antigen presentation and sensitivity to cytotoxic T lymphocytes, and was found to be due to escape from natural killer (NK) cell-mediated rejection. It has previously been proposed that adequate expression of self-MHC class I is one important mechanism to avoid elimination by NK cells. Our data argue that a defect in the machinery responsible for processing and loading of peptides into MHC class I molecules is sufficient to render cells sensitive to elimination by NK cells. The latter thus appear to function as a surveillance of the peptide surveillance machinery.

scholarly journals 2B4 Acts As a Non–Major Histocompatibility Complex Binding Inhibitory Receptor on Mouse Natural Killer Cells

2004 ◽  
Vol 199 (9) ◽  
pp. 1245-1254 ◽  
Author(s):  
Kyung-Mi Lee ◽  
Megan E. McNerney ◽  
Susan E. Stepp ◽  
Porunelloor A. Mathew ◽  
John D. Schatzle ◽  
...  
Keyword(s):  
Major Histocompatibility Complex ◽  
Nk Cells ◽  
Natural Killer ◽  
Tumor Cells ◽  
Nk Cell ◽  
Negative Regulator ◽  
Major Histocompatibility ◽  
Major Histocompatibility Complex Binding ◽  
Histocompatibility Complex

Natural killer (NK) cells are critical in the immune response to tumor cells, virally infected cells, and bone marrow allografts. 2B4 (CD244) is expressed on all NK cells and the ligand for 2B4, CD48, is expressed on hematopoietic cells. Cross-linking 2B4 on NK cells with anti-2B4 monoclonal antibody leads to NK cell activation in vitro. Therefore, 2B4 is considered to be an activating receptor. Surprisingly, we have found, using antibody-blocking and 2B4-deficient NK cells, that NK lysis of CD48+ tumor and allogeneic targets is inhibited by 2B4 ligation. Interferon γ production by NK cells is also inhibited. Using a peritoneal tumor clearance assay, it was found that 2B4−/− mice have increased clearance of CD48+ tumor cells in vivo. Retroviral transduction of 2B4 was sufficient to restore inhibition in 2B4−/− primary NK cells. It was found that although mature NK cells express SH2D1A, in vitro–derived NK cells do not. However, both populations are inhibited by 2B4 ligation. This indicates that 2B4 inhibitory signaling occurs regardless of the presence of SH2D1A. These findings reveal a novel role for 2B4 as a non–major histocompatibility complex binding negative regulator of NK cells.

scholarly journals Mouse CD94/NKG2A Is a Natural Killer Cell Receptor for the Nonclassical Major Histocompatibility Complex (MHC) Class I Molecule Qa-1b

1998 ◽  
Vol 188 (10) ◽  
pp. 1841-1848 ◽  
Author(s):  
Russell E. Vance ◽  
Jennifer R. Kraft ◽  
John D. Altman ◽  
Peter E. Jensen ◽  
David H. Raulet
Keyword(s):  
Major Histocompatibility Complex ◽  
Nk Cells ◽  
Natural Killer ◽  
Mhc Class I ◽  
Killer Cell ◽  
Class I ◽  
Target Cells ◽  
Major Histocompatibility ◽  
Histocompatibility Complex ◽  
Mhc Class I Molecule

Natural killer (NK) cells preferentially lyse targets that express reduced levels of major histocompatibility complex (MHC) class I proteins. To date, the only known mouse NK receptors for MHC class I belong to the Ly49 family of C-type lectin homodimers. Here, we report the cloning of mouse NKG2A, and demonstrate it forms an additional and distinct class I receptor, a CD94/NKG2A heterodimer. Using soluble tetramers of the nonclassical class I molecule Qa-1b, we provide direct evidence that CD94/NKG2A recognizes Qa-1b. We further demonstrate that NK recognition of Qa-1b results in the inhibition of target cell lysis. Inhibition appears to depend on the presence of Qdm, a Qa-1b-binding peptide derived from the signal sequences of some classical class I molecules. Mouse NKG2A maps adjacent to CD94 in the heart of the NK complex on mouse chromosome six, one of a small cluster of NKG2-like genes. Our findings suggest that mouse NK cells, like their human counterparts, use multiple mechanisms to survey class I expression on target cells.

scholarly journals Acquisition of External Major Histocompatibility Complex Class I Molecules by Natural Killer Cells Expressing Inhibitory Ly49 Receptors

2001 ◽  
Vol 194 (10) ◽  
pp. 1519-1530 ◽  
Author(s):  
Anna Sjöström ◽  
Mikael Eriksson ◽  
Cristina Cerboni ◽  
Maria H. Johansson ◽  
Charles L. Sentman ◽  
...  
Keyword(s):  
Major Histocompatibility Complex ◽  
Nk Cells ◽  
Natural Killer ◽  
Mhc Class I ◽  
Nk Cell ◽  
Indirect Evidence ◽  
Class I ◽  
Target Cells ◽  
Major Histocompatibility ◽  
Histocompatibility Complex

Murine natural killer (NK) cells express inhibitory Ly49 receptors specific for major histocompatibility complex (MHC) class I molecules. We report that during interactions with cells in the environment, NK cells acquired MHC class I ligands from surrounding cells in a Ly49-specific fashion and displayed them at the cell surface. Ligand acquisition sometimes reached 20% of the MHC class I expression on surrounding cells, involved transfer of the entire MHC class I protein to the NK cell, and was independent of whether or not the NK cell expressed the MHC class I ligand itself. We also present indirect evidence for spontaneous MHC class I acquisition in vivo, as well as describe an in vitro coculture system with transfected cells in which the same phenomenon occurred. Functional studies in the latter model showed that uptake of H-2Dd by Ly49A+ NK cells was accompanied by a partial inactivation of cytotoxic activity in the NK cell, as tested against H-2Dd-negative target cells. In addition, ligand acquisition did not abrogate the ability of Ly49A+ NK cells to receive inhibitory signals from external H-2Dd molecules. This study is the first to describe ligand acquisition by NK cells, which parallels recently described phenomena in T and B cells.

scholarly journals Expression of Natural Killer Receptor Alleles at Different Ly49 Loci Occurs Independently and Is Regulated by Major Histocompatibility Complex 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
Keyword(s):  
Major Histocompatibility Complex ◽  
Nk Cells ◽  
Natural Killer ◽  
Mhc Class I ◽  
Host Cells ◽  
Class I ◽  
Major Histocompatibility ◽  
Biallelic Expression ◽  
Histocompatibility Complex ◽  
Mhc Class I Molecules

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.

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