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A common inhibitory receptor for major histocompatibility complex class I molecules on human lymphoid and myelomonocytic cells.

Colonna M, Navarro F, Bellón T, Llano M, García P, Samaridis J, Angman L, Cella M, López-Botet M - J. Exp. Med. (1997)

Bottom Line: In this study, we characterize a novel inhibitory MHC class I receptor of the immunoglobulin-superfamily, expressed not only by subsets of NK and T cells, but also by B cells, monocytes, macrophages, and dendritic cells.This receptor, called Ig-like transcript (ILT)2, binds MHC class I molecules and delivers a negative signal that inhibits killing by NK and T cells, as well as Ca2+ mobilization in B cells and myelomonocytic cells triggered through the B cell antigen receptor and human histocompatibility leukocyte antigens (HLA)-DR, respectively.In addition, myelomonocytic cells express receptors homologous to ILT2, which are characterized by extensive polymorphism and might recognize distinct HLA class I molecules.

View Article: PubMed Central - PubMed

Affiliation: Basel Institute for Immunology, Basel CH-4005, Switzerland.

ABSTRACT
Natural killer (NK) cell-mediated lysis is negatively regulated by killer cell inhibitory receptors specific for major histocompatibility complex (MHC) class I molecules. In this study, we characterize a novel inhibitory MHC class I receptor of the immunoglobulin-superfamily, expressed not only by subsets of NK and T cells, but also by B cells, monocytes, macrophages, and dendritic cells. This receptor, called Ig-like transcript (ILT)2, binds MHC class I molecules and delivers a negative signal that inhibits killing by NK and T cells, as well as Ca2+ mobilization in B cells and myelomonocytic cells triggered through the B cell antigen receptor and human histocompatibility leukocyte antigens (HLA)-DR, respectively. In addition, myelomonocytic cells express receptors homologous to ILT2, which are characterized by extensive polymorphism and might recognize distinct HLA class I molecules. These results suggest that diverse leukocyte lineages have adopted recognition of self-MHC class I molecules as a common strategy to control cellular activation during an immune response.

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(a) The HP-F1 mAb  reconstitutes NK cell–mediated  lysis of HLA class I transfectants.  Lysis of the class I–negative mutant cell line 721.221 by NKL is  inhibited upon transfection of  HLA-B*2702, -B*2705, -B*5101,  -A*0301, -B*0702, -Cw*0301,  and -G1 alleles in 721.221 (white  bars), regardless of the presence  of a control antibody (C218,  anti-CD56, IgG1). F(ab′)2 fragments of the HP-F1 mAb (black  bars) completely reconstitute lysis  of HLA-B*2702, -B*2705, and  -B*5101 transfectants. F(ab′)2  fragments of the anti-CD94 HP-3B1 mAb (gray bars) reconstitute lysis of the HLA-Cw*0301 transfectant almost  completely. A combination of both HP-F1 and HP-3B1 mAbs (hatched bars) is necessary to reconstitute lysis of  HLA-A*0301, -B*0702, and -G1 transfectants. The anti–class I HP-1F7 mAb (vertical bars) reconstitutes lysis of  all of the class I transfectants. Cytotoxicity was determined in a standard 4 h 51Cr-release assay. NKL expresses the  CD94–NKG2A heterodimer but no KIRs, as determined by cell surface staining with Z199 (anti–CD94– NKG2A heterodimer), HP-3E4, GL183, EB6 (anti-p58 KIRs), DX9, 5.133 (anti-p70 and -p70/140 KIRs)  mAbs, and by RT-PCR. (b) HP-F1 mAb inhibits CD16-dependent redirected lysis of P815 cells by NKL. 51Cr-labeled P815 cells were preincubated for 15 min with anti-CD16 alone, with HP-F1 (5–10 μg/ml), or with  HP-3B1 (anti-CD94, 5 μg/ml). In control samples, cells were incubated with medium, with anti-CD56 mAb  (IgG1), or with HP-F1 (5–10 μg/ml). After incubation, NKL cells were added at different effector/target ratios.  HP-F1 significantly reduced CD16-mediated lysis of P815 cells, mimicking the ligand of an inhibitory receptor.  HP-F1 mAb also reduced the low basal lysis of P815 by NKL in the absence of anti-CD16. Similar results were  obtained with the anti-CD94 mAb.
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Figure 1: (a) The HP-F1 mAb reconstitutes NK cell–mediated lysis of HLA class I transfectants. Lysis of the class I–negative mutant cell line 721.221 by NKL is inhibited upon transfection of HLA-B*2702, -B*2705, -B*5101, -A*0301, -B*0702, -Cw*0301, and -G1 alleles in 721.221 (white bars), regardless of the presence of a control antibody (C218, anti-CD56, IgG1). F(ab′)2 fragments of the HP-F1 mAb (black bars) completely reconstitute lysis of HLA-B*2702, -B*2705, and -B*5101 transfectants. F(ab′)2 fragments of the anti-CD94 HP-3B1 mAb (gray bars) reconstitute lysis of the HLA-Cw*0301 transfectant almost completely. A combination of both HP-F1 and HP-3B1 mAbs (hatched bars) is necessary to reconstitute lysis of HLA-A*0301, -B*0702, and -G1 transfectants. The anti–class I HP-1F7 mAb (vertical bars) reconstitutes lysis of all of the class I transfectants. Cytotoxicity was determined in a standard 4 h 51Cr-release assay. NKL expresses the CD94–NKG2A heterodimer but no KIRs, as determined by cell surface staining with Z199 (anti–CD94– NKG2A heterodimer), HP-3E4, GL183, EB6 (anti-p58 KIRs), DX9, 5.133 (anti-p70 and -p70/140 KIRs) mAbs, and by RT-PCR. (b) HP-F1 mAb inhibits CD16-dependent redirected lysis of P815 cells by NKL. 51Cr-labeled P815 cells were preincubated for 15 min with anti-CD16 alone, with HP-F1 (5–10 μg/ml), or with HP-3B1 (anti-CD94, 5 μg/ml). In control samples, cells were incubated with medium, with anti-CD56 mAb (IgG1), or with HP-F1 (5–10 μg/ml). After incubation, NKL cells were added at different effector/target ratios. HP-F1 significantly reduced CD16-mediated lysis of P815 cells, mimicking the ligand of an inhibitory receptor. HP-F1 mAb also reduced the low basal lysis of P815 by NKL in the absence of anti-CD16. Similar results were obtained with the anti-CD94 mAb.

Mentions: KIRs and CD94/NKG2A receptors do not completely explain class I recognition by a number of NK cell clones (6, 10). This is illustrated by a representative NK cell line, called NKL (Fig. 1 a). NKL-mediated lysis of the class I deletion mutant 721.221 is inhibited by transfection of HLA-B*2702, -B*2705 and -B*5101 genes into 721.221, although NKL does not express a p70 KIR specific for these HLA-B molecules. NKL-mediated lysis is also inhibited by HLA-A*0301, -B*0702, -Cw*0301 and -G1 transfected cells. This inhibition is not entirely accounted for by the CD94–NKG2A heterodimer expressed by NKL, since cytolysis of HLA-A*0301, -B*0702, and -G1 transfectants is only partially reconstituted by an anti-CD94 mAb. In an attempt to find additional inhibitory receptor(s) on NKL, we generated anti-NKL mAbs and selected those capable of restoring lysis of class I transfectants. Among them, the HP-F1 mAb reconstituted cytolysis of HLA-B*2702, -B*2705, and -B*5101 transfectants and, in combination with an anti-CD94 mAb, restored lysis of HLA-A*0301, -B*0702, and -G1 transfectants (Fig. 1 a).


A common inhibitory receptor for major histocompatibility complex class I molecules on human lymphoid and myelomonocytic cells.

Colonna M, Navarro F, Bellón T, Llano M, García P, Samaridis J, Angman L, Cella M, López-Botet M - J. Exp. Med. (1997)

(a) The HP-F1 mAb  reconstitutes NK cell–mediated  lysis of HLA class I transfectants.  Lysis of the class I–negative mutant cell line 721.221 by NKL is  inhibited upon transfection of  HLA-B*2702, -B*2705, -B*5101,  -A*0301, -B*0702, -Cw*0301,  and -G1 alleles in 721.221 (white  bars), regardless of the presence  of a control antibody (C218,  anti-CD56, IgG1). F(ab′)2 fragments of the HP-F1 mAb (black  bars) completely reconstitute lysis  of HLA-B*2702, -B*2705, and  -B*5101 transfectants. F(ab′)2  fragments of the anti-CD94 HP-3B1 mAb (gray bars) reconstitute lysis of the HLA-Cw*0301 transfectant almost  completely. A combination of both HP-F1 and HP-3B1 mAbs (hatched bars) is necessary to reconstitute lysis of  HLA-A*0301, -B*0702, and -G1 transfectants. The anti–class I HP-1F7 mAb (vertical bars) reconstitutes lysis of  all of the class I transfectants. Cytotoxicity was determined in a standard 4 h 51Cr-release assay. NKL expresses the  CD94–NKG2A heterodimer but no KIRs, as determined by cell surface staining with Z199 (anti–CD94– NKG2A heterodimer), HP-3E4, GL183, EB6 (anti-p58 KIRs), DX9, 5.133 (anti-p70 and -p70/140 KIRs)  mAbs, and by RT-PCR. (b) HP-F1 mAb inhibits CD16-dependent redirected lysis of P815 cells by NKL. 51Cr-labeled P815 cells were preincubated for 15 min with anti-CD16 alone, with HP-F1 (5–10 μg/ml), or with  HP-3B1 (anti-CD94, 5 μg/ml). In control samples, cells were incubated with medium, with anti-CD56 mAb  (IgG1), or with HP-F1 (5–10 μg/ml). After incubation, NKL cells were added at different effector/target ratios.  HP-F1 significantly reduced CD16-mediated lysis of P815 cells, mimicking the ligand of an inhibitory receptor.  HP-F1 mAb also reduced the low basal lysis of P815 by NKL in the absence of anti-CD16. Similar results were  obtained with the anti-CD94 mAb.
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Related In: Results  -  Collection

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Figure 1: (a) The HP-F1 mAb reconstitutes NK cell–mediated lysis of HLA class I transfectants. Lysis of the class I–negative mutant cell line 721.221 by NKL is inhibited upon transfection of HLA-B*2702, -B*2705, -B*5101, -A*0301, -B*0702, -Cw*0301, and -G1 alleles in 721.221 (white bars), regardless of the presence of a control antibody (C218, anti-CD56, IgG1). F(ab′)2 fragments of the HP-F1 mAb (black bars) completely reconstitute lysis of HLA-B*2702, -B*2705, and -B*5101 transfectants. F(ab′)2 fragments of the anti-CD94 HP-3B1 mAb (gray bars) reconstitute lysis of the HLA-Cw*0301 transfectant almost completely. A combination of both HP-F1 and HP-3B1 mAbs (hatched bars) is necessary to reconstitute lysis of HLA-A*0301, -B*0702, and -G1 transfectants. The anti–class I HP-1F7 mAb (vertical bars) reconstitutes lysis of all of the class I transfectants. Cytotoxicity was determined in a standard 4 h 51Cr-release assay. NKL expresses the CD94–NKG2A heterodimer but no KIRs, as determined by cell surface staining with Z199 (anti–CD94– NKG2A heterodimer), HP-3E4, GL183, EB6 (anti-p58 KIRs), DX9, 5.133 (anti-p70 and -p70/140 KIRs) mAbs, and by RT-PCR. (b) HP-F1 mAb inhibits CD16-dependent redirected lysis of P815 cells by NKL. 51Cr-labeled P815 cells were preincubated for 15 min with anti-CD16 alone, with HP-F1 (5–10 μg/ml), or with HP-3B1 (anti-CD94, 5 μg/ml). In control samples, cells were incubated with medium, with anti-CD56 mAb (IgG1), or with HP-F1 (5–10 μg/ml). After incubation, NKL cells were added at different effector/target ratios. HP-F1 significantly reduced CD16-mediated lysis of P815 cells, mimicking the ligand of an inhibitory receptor. HP-F1 mAb also reduced the low basal lysis of P815 by NKL in the absence of anti-CD16. Similar results were obtained with the anti-CD94 mAb.
Mentions: KIRs and CD94/NKG2A receptors do not completely explain class I recognition by a number of NK cell clones (6, 10). This is illustrated by a representative NK cell line, called NKL (Fig. 1 a). NKL-mediated lysis of the class I deletion mutant 721.221 is inhibited by transfection of HLA-B*2702, -B*2705 and -B*5101 genes into 721.221, although NKL does not express a p70 KIR specific for these HLA-B molecules. NKL-mediated lysis is also inhibited by HLA-A*0301, -B*0702, -Cw*0301 and -G1 transfected cells. This inhibition is not entirely accounted for by the CD94–NKG2A heterodimer expressed by NKL, since cytolysis of HLA-A*0301, -B*0702, and -G1 transfectants is only partially reconstituted by an anti-CD94 mAb. In an attempt to find additional inhibitory receptor(s) on NKL, we generated anti-NKL mAbs and selected those capable of restoring lysis of class I transfectants. Among them, the HP-F1 mAb reconstituted cytolysis of HLA-B*2702, -B*2705, and -B*5101 transfectants and, in combination with an anti-CD94 mAb, restored lysis of HLA-A*0301, -B*0702, and -G1 transfectants (Fig. 1 a).

Bottom Line: In this study, we characterize a novel inhibitory MHC class I receptor of the immunoglobulin-superfamily, expressed not only by subsets of NK and T cells, but also by B cells, monocytes, macrophages, and dendritic cells.This receptor, called Ig-like transcript (ILT)2, binds MHC class I molecules and delivers a negative signal that inhibits killing by NK and T cells, as well as Ca2+ mobilization in B cells and myelomonocytic cells triggered through the B cell antigen receptor and human histocompatibility leukocyte antigens (HLA)-DR, respectively.In addition, myelomonocytic cells express receptors homologous to ILT2, which are characterized by extensive polymorphism and might recognize distinct HLA class I molecules.

View Article: PubMed Central - PubMed

Affiliation: Basel Institute for Immunology, Basel CH-4005, Switzerland.

ABSTRACT
Natural killer (NK) cell-mediated lysis is negatively regulated by killer cell inhibitory receptors specific for major histocompatibility complex (MHC) class I molecules. In this study, we characterize a novel inhibitory MHC class I receptor of the immunoglobulin-superfamily, expressed not only by subsets of NK and T cells, but also by B cells, monocytes, macrophages, and dendritic cells. This receptor, called Ig-like transcript (ILT)2, binds MHC class I molecules and delivers a negative signal that inhibits killing by NK and T cells, as well as Ca2+ mobilization in B cells and myelomonocytic cells triggered through the B cell antigen receptor and human histocompatibility leukocyte antigens (HLA)-DR, respectively. In addition, myelomonocytic cells express receptors homologous to ILT2, which are characterized by extensive polymorphism and might recognize distinct HLA class I molecules. These results suggest that diverse leukocyte lineages have adopted recognition of self-MHC class I molecules as a common strategy to control cellular activation during an immune response.

Show MeSH
Related in: MedlinePlus