Analysis of natural killer cells in TAP2-deficient patients: expression of functional triggering receptors and evidence for the existence of inhibitory receptor(s) that prevent lysis of normal autologous cells

Blood ◽  
2002 ◽  
Vol 99 (5) ◽  
pp. 1723-1729 ◽  
Author(s):  
Massimo Vitale ◽  
Jacques Zimmer ◽  
Roberta Castriconi ◽  
Daniel Hanau ◽  
Lionel Donato ◽  
...  

Natural killer (NK) cells are characterized by the ability to kill cells that lack HLA class I molecules while sparing autologous normal (HLA class I+) cells. However, patients with transporter-associated antigen processing (TAP) deficiency, though displaying strong reductions of HLA class I surface expression, in most instances do not experience NK-mediated autoimmune phenomena. A possible mechanism by which TAP−/− NK cells avoid autoreactivity against autologous HLA class I–deficient cells could be based on either quantitative or qualitative defects of surface receptors involved in NK cell triggering. In this study we show that NK cells derived from 2 patients with TAP2−/− express normal levels of all known triggering receptors. As revealed by the analysis of polyclonal and clonal NK cells, these receptors display normal functional capabilities and allow the killing of a panel of NK-susceptible targets, including autologous B-LCLs. On the other hand, TAP2−/− NK cells were unable to kill either allogeneic (HLA class I+) or autologous (HLA class I− ) phytohemagglutinin (PHA) blasts even in the presence of anti-HLA class I monoclonal antibody. These data suggest that TAP2−/− NK cells express still unknown inhibitory receptor(s) capable of down-regulating the NK cell cytotoxicity on binding to surface ligand(s) expressed by T cell blasts. Functional analyses, both at the polyclonal and at the clonal level, are consistent with the concept that the putative inhibitory receptor is expressed by virtually all TAP2−/− NK cells, whereas it is present only in rare NK cells from healthy persons. Another possibility would be that TAP2−/− NK cells are missing a still unidentified triggering receptor involved in NK cell-mediated killing of PHA blasts.

2019 ◽  
Author(s):  
Julia L. McKechnie ◽  
Davis Beltran ◽  
Arcelys Pitti ◽  
Lisseth Saenz ◽  
Ana B. Araúz ◽  
...  

AbstractDengue virus (DENV) is the most prevalent mosquito-borne virus in the world and a major cause of morbidity in the tropics and subtropics. Upregulation of HLA class I molecules has long been considered a feature of DENV infection, yet this has not been evaluated in the setting of natural infection. Natural killer (NK) cells, an innate immune cell subset critical for mounting an early response to viral infection, are inhibited by self HLA class I, suggesting that upregulation of HLA class I during DENV infection could dampen the NK cell response. Here we addressed whether upregulation of HLA class I molecules occurs during in vivo DENV infection and, if so, whether this suppresses the NK cell response. We found that HLA class I expression was indeed upregulated during acute DENV infection across multiple cell lineages in vivo. To better understand the role of HLA class I upregulation, we infected primary human monocytes, a major target of DENV infection, in vitro. Upregulation of total HLA class I is dependent on active viral replication and is mediated in part by cytokines and other soluble factors induced by infection, while upregulation of HLA-E occurs in the presence of replication-incompetent virus. Importantly, blocking DENV-infected monocytes with a pan-HLA class I Fab nearly doubles the frequency of degranulating NK cells, while blocking HLA-E does not significantly improve the NK cell response. These findings demonstrate that upregulation of HLA class I during DENV infection suppresses the NK cell response, potentially contributing to disease pathogenesis.


Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 2997-2997
Author(s):  
Sonja J. Verheyden ◽  
Michel Bernier ◽  
Christian J. Demanet

Abstract Introduction: Natural Killer (NK) cells play a key role in defense against tumor cells that have the capacity to downregulate Human Leukocyte Antigen (HLA) class I expression. It has been reported that leukemic cells can have down-regulated expression of HLA class I molecules. Apparently, the NK cells of these patients are not able to destroy these leukemic cells and may allow malignant cells to escape from innate immune control. This failure may be due to the fact that NK cells are part of the malignant clone and therefore might have a decreased function. An alternative hypothesis could be that these patients may display a NK cell Receptor (NKR) genotype incapable of destroying leukemic cells with aberrant expression of HLA class I molecules. The polymorphic nature of the NKR genes generates diverse repertoires in the human population, which display specificity in the innate immune response. Materials and Methods: In the present study, 11 Killer cell Immunoglobulin-like Receptor (KIRs) and 2 CD94/NKG2 receptors were genotyped by PCR-SSP in 96 leukemic patients and 148 healthy Caucasians. Results and Conclusion: We report a significant increased frequency of the more inhibitory AB KIR phenotype in leukemic patients compared to the controls (31.1% in healthy controls vs. 51.0% in leukemic patients, Pc = 0.002), which is related to the high prevalence of the inhibitory KIR2DL2 in this population (Pc = 0.007). Moreover, two specific KIR phenotypes AB1 and AB9, including all inhibitory KIRs, were significantly associated with leukemic patients. Our study suggests that an important percentage of leukemic patients express a KIR phenotype in favor of escape from NK cell immunity.


1998 ◽  
Vol 187 (1) ◽  
pp. 117-122 ◽  
Author(s):  
Jacques Zimmer ◽  
Lionel Donato ◽  
Daniel Hanau ◽  
Jean-Pierre Cazenave ◽  
Marie-Marthe Tongio ◽  
...  

In this paper we describe the function and phenotype of natural killer (NK) lymphocytes from HLA class I–deficient patients. These cells are, as has been previously reported, unable to lyse HLA class I− K562 cells, but are able to perform antibody-dependent cellular cytotoxicity (ADCC), although with lower efficiency as compared to NK cells from normal individuals. Transporter associated to antigen processing (TAP)− NK cells proliferate when cultured in the presence of lymphoblastoid B cells (B-LCs) and interleukin 2 and develop a spectrum of cytotoxicity similar to that of activated normal NK cells. Importantly, activation of the TAP− NK cells induces strong cytotoxicity to autologous B-LCs. Analysis of the phenotype of circulating TAP− NK lymphocytes showed them to display a normal diverse repertoire of HLA class I–specific NK receptors. These receptors were expressed at normal levels, apart from the CD94–NKG2A complex, which appeared to be overexpressed. This latter finding could reflect an adaptation to the low expression of HLA class I molecules. Finally, functional analyses indicated that the inhibitory receptors in TAP− individuals can transduce inhibitory signals. Our results suggest that in vivo, the NK cells of TAP− patients could participate in immune defense, at least through ADCC, but upon activation, may be involved in autoimmune processes.


1994 ◽  
Vol 180 (2) ◽  
pp. 545-555 ◽  
Author(s):  
A Moretta ◽  
M Vitale ◽  
S Sivori ◽  
C Bottino ◽  
L Morelli ◽  
...  

GL183 or EB6 (p58) molecules have been shown to function as receptors for different HLA-C alleles and to deliver an inhibitory signal to natural killer (NK) cells, thus preventing lysis of target cells. In this study, we analyzed a subset of NK cells characterized by a p58-negative surface phenotype. We show that p58-negative clones, although specific for class I molecules do not recognize HLA-C alleles. In addition, by the use of appropriate target cells transfected with different HLA-class I alleles we identified HLA-B7 as the protective element recognized by a fraction of p58-negative clones. In an attempt to identify the receptor molecules expressed by HLA-B7-specific clones, monoclonal antibodies (mAbs) were selected after mice immunization with such clones. Two of these mAbs, termed XA-88 and XA-185, and their F(ab')2 fragments, were found to reconstitute lysis of B7+ target cells by B7-specific NK clones. Both mAbs were shown to be directed against the recently clustered Kp43 molecule (CD94). Thus, mAb-mediated masking of Kp43 molecules interferes with recognition of HLA-B7 and results in target cell lysis. Moreover, in a redirected killing assay, the cross-linking of Kp43 molecules mediated by the XA185 mAb strongly inhibited the cytolytic activity of HLA-B7-specific NK clones, thus mimicking the functional effect of B7 molecules. Taken together, these data strongly suggest that Kp43 molecules function as receptors for HLA-B7 and that this receptor/ligand interaction results in inhibition of the NK-mediated cytolytic activity. Indirect immunofluorescence and FACS analysis of a large number of random NK clones showed that Kp43 molecules (a) were brightly expressed on a subset of p58-negative clones, corresponding to those specific for HLA-B7; (b) displayed a medium/low fluorescence in the p58-negative clones that are not B7-specific as well as in most p58+ NK clones; and (c) were brightly expressed as in the p58+ clone ET34 (GL183-/EB6+, Cw4-specific). Functional analysis revealed that Kp43 functioned as an inhibitory receptor only in NK clones displaying bright fluorescence. These studies also indicate that some NK clones (e.g., the ET34) can coexpress two distinct receptors (p58 and Kp43) for different class I alleles (Cw4 and B7). Finally, we show that Kp43 molecules function as receptors only for some HLA-B alleles and that still undefined receptor(s) must exist for other HLA-B alleles including B27.


1997 ◽  
Vol 27 (2) ◽  
pp. 563-567 ◽  
Author(s):  
Marta Carretero ◽  
Claudia Cantoni ◽  
Teresa Bellón ◽  
Cristina Bottino ◽  
Roberto Biassoni ◽  
...  

1999 ◽  
Vol 189 (5) ◽  
pp. 787-796 ◽  
Author(s):  
Claudia Cantoni ◽  
Cristina Bottino ◽  
Massimo Vitale ◽  
Anna Pessino ◽  
Raffaella Augugliaro ◽  
...  

Surface receptors involved in natural killer (NK) cell triggering during the process of tumor cell lysis have recently been identified. Of these receptors, NKp44 is selectively expressed by IL-2– activated NK cells and may contribute to the increased efficiency of activated NK cells to mediate tumor cell lysis. Here we describe the molecular cloning of NKp44. Analysis of the cloned cDNA indicated that NKp44 is a novel transmembrane glycoprotein belonging to the Immunoglobulin superfamily characterized by a single extracellular V-type domain. The charged amino acid lysine in the transmembrane region may be involved in the association of NKp44 with the signal transducing molecule killer activating receptor–associated polypeptide (KARAP)/DAP12. These molecules were found to be crucial for the surface expression of NKp44. In agreement with data of NKp44 surface expression, the NKp44 transcripts were strictly confined to activated NK cells and to a minor subset of TCR-γ/δ+ T lymphocytes. Unlike genes coding for other receptors involved in NK cell triggering or inhibition, the NKp44 gene is on human chromosome 6.


2021 ◽  
Vol 12 ◽  
Author(s):  
Burcu Duygu ◽  
Timo I. Olieslagers ◽  
Mathijs Groeneweg ◽  
Christina E. M. Voorter ◽  
Lotte Wieten

Natural killer (NK) cells are innate lymphocytes that can kill diseased- or virally-infected cells, mediate antibody dependent cytotoxicity and produce type I immune-associated cytokines upon activation. NK cells also contribute to the allo-immune response upon kidney transplantation either by promoting allograft rejection through lysis of cells of the transplanted organ or by promoting alloreactive T cells. In addition, they protect against viral infections upon transplantation which may be especially relevant in patients receiving high dose immune suppression. NK cell activation is tightly regulated through the integrated balance of signaling via inhibitory- and activating receptors. HLA class I molecules are critical regulators of NK cell activation through the interaction with inhibitory- as well as activating NK cell receptors, hence, HLA molecules act as critical immune checkpoints for NK cells. In the current review, we evaluate how NK cell alloreactivity and anti-viral immunity are regulated by NK cell receptors belonging to the KIR family and interacting with classical HLA class I molecules, or by NKG2A/C and LILRB1/KIR2DL4 engaging non-classical HLA-E or -G. In addition, we provide an overview of the methods to determine genetic variation in these receptors and their HLA ligands.


1999 ◽  
Vol 189 (7) ◽  
pp. 1093-1100 ◽  
Author(s):  
Sumati Rajagopalan ◽  
Eric O. Long

Human natural killer (NK) cells express several killer cell immunoglobulin (Ig)-like receptors (KIRs) that inhibit their cytotoxicity upon recognition of human histocompatibility leukocyte antigen (HLA) class I molecules on target cells. Additional members of the KIR family, including some that deliver activation signals, have unknown ligand specificity and function. One such KIR, denoted KIR2DL4, is structurally divergent from other KIRs in the configuration of its two extracellular Ig domains and of its transmembrane and cytoplasmic domains. Here we show that recombinant soluble KIR2DL4 binds to cells expressing HLA-G but not to cells expressing other HLA class I molecules. Unlike other HLA class I–specific KIRs, which are clonally distributed on NK cells, KIR2DL4 is expressed at the surface of all NK cells. Furthermore, functional transfer of KIR2DL4 into the cell line NK-92 resulted in inhibition of lysis of target cells that express HLA-G, but not target cells that express other class I molecules including HLA-E. Therefore, given that HLA-G expression is restricted to fetal trophoblast cells, KIR2DL4 may provide important signals to maternal NK decidual cells that interact with trophoblast cells at the maternal–fetal interface during pregnancy.


Blood ◽  
2005 ◽  
Vol 105 (11) ◽  
pp. 4416-4423 ◽  
Author(s):  
Nadine C. Fernandez ◽  
Emmanuel Treiner ◽  
Russell E. Vance ◽  
Amanda M. Jamieson ◽  
Suzanne Lemieux ◽  
...  

Abstract It is widely believed that self-tolerance of natural killer (NK) cells occurs because each NK cell expresses at least one inhibitory receptor specific for a host major histocompatibility complex (MHC) class I molecule. Here we report that some NK cells lack all known self-MHC–specific inhibitory receptors, yet are nevertheless self-tolerant. These NK cells exhibit a normal cell surface phenotype and some functional activity. However, they respond poorly to class I–deficient normal cells, tumor cells, or cross-linking of stimulatory receptors, suggesting that self-tolerance is established by dampening stimulatory signaling. Thus, self-tolerance of NK cells in normal animals can occur independently of MHC-mediated inhibition, and hyporesponsiveness plays a role in self-tolerance of NK cells, as also proposed for B and T cells.


Blood ◽  
2008 ◽  
Vol 111 (3) ◽  
pp. 1309-1317 ◽  
Author(s):  
Jumei Shi ◽  
Guido J. Tricot ◽  
Tarun K. Garg ◽  
Priyangi A. Malaviarachchi ◽  
Susann M. Szmania ◽  
...  

AbstractHuman leukocyte antigen class I molecules expressed by tumor cells play a central role in the regulation of natural killer (NK) cell–mediated immune responses. The proteasome inhibitor bortezomib has demonstrated significant activity in multiple myeloma (MM). We hypothesized that treatment of MM with bortezomib results in the reduction of cell-surface expression of class I and thereby sensitizes MM to NK cell–mediated lysis. Here we report that bortezomib down-regulates class I in a time- and dose-dependent fashion on all MM cell lines and patient MM cells tested. Downregulation of class I can also be induced in vivo after a single dose of 1.0 mg/m2 bortezomib. Bortezomib significantly enhances the sensitivity of patient myeloma to allogeneic and autologous NK cell–mediated lysis. Further, the level of decrease in class I expression correlates with increased susceptibility to lysis by NK cells. Clinically relevant bortezomib concentrations do not affect NK-cell function. Our findings have clear therapeutic implications for MM and other NK cell–sensitive malignancies in the context of both allogeneic and autologous adoptively transferred NK cells.


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