scholarly journals Peptide-Dependent Recognition of HLA-B*57:01 by KIR3DS1

2015 ◽  
Vol 89 (10) ◽  
pp. 5213-5221 ◽  
Author(s):  
Geraldine M. O'Connor ◽  
Julian P. Vivian ◽  
Emma Gostick ◽  
Phillip Pymm ◽  
Bernard A. P. Lafont ◽  
...  
Keyword(s):  
Hiv Infection ◽  
Nk Cells ◽  
Natural Killer ◽  
Molecular Mechanisms ◽  
Viral Infections ◽  
Hla Class I ◽  
Class I ◽  
Disease Outcome ◽  
Immune Control ◽  
Peptide Epitopes

ABSTRACTKiller cell immunoglobulin-like receptors (KIRs) play an important role in the activation of natural killer (NK) cells, which in turn contribute to the effective immune control of many viral infections. In the context of HIV infection, the closely related KIR3DL1 and KIR3DS1 molecules, in particular, have been associated with disease outcome. Inhibitory signals via KIR3DL1 are disrupted by downregulation of HLA class I ligands on the infected cell surface and can also be impacted by changes in the presented peptide repertoire. In contrast, the activatory ligands for KIR3DS1 remain obscure. We used a structure-driven approach to define the characteristics of HLA class I-restricted peptides that interact with KIR3DL1 and KIR3DS1. In the case of HLA-B*57:01, we used this knowledge to identify bona fide HIV-derived peptide epitopes with similar properties. Two such peptides facilitated productive interactions between HLA-B*57:01 and KIR3DS1. These data reveal the presence of KIR3DS1 ligands within the HIV-specific peptide repertoire presented by a protective HLA class I allotype, thereby enhancing our mechanistic understanding of the processes that enable NK cells to impact disease outcome.IMPORTANCENatural killer (NK) cells are implicated as determinants of immune control in many viral infections, but the precise molecular mechanisms that initiate and control these responses are unclear. The activating receptor KIR3DS1 in combination with HLA-Bw4 has been associated with better outcomes in HIV infection. However, evidence of a direct interaction between these molecules is lacking. In this study, we demonstrate that KIR3DS1 recognition of HLA-Bw4 is peptide dependent. We also identify HIV-derived peptide epitopes presented by the protective HLA-B*57:01 allotype that facilitate productive interactions with KIR3DS1. Collectively, these findings suggest a mechanism whereby changes in the peptide repertoire associated with viral infection provide a trigger for KIR3DS1 engagement and NK cell activation.

scholarly journals The New Kid on the Block: HLA-C, a Key Regulator of Natural Killer Cells in Viral Immunity

Cells ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 3108
Author(s):  
Sarah Vollmers ◽  
Annabelle Lobermeyer ◽  
Christian Körner
Keyword(s):  
Immune System ◽  
Nk Cells ◽  
Natural Killer ◽  
Viral Infections ◽  
Killer Cell ◽  
Hla Class I ◽  
Class I ◽  
Proper Function ◽  
Cell Functions ◽  
Wide Range

The human leukocyte antigen system (HLA) is a cluster of highly polymorphic genes essential for the proper function of the immune system, and it has been associated with a wide range of diseases. HLA class I molecules present intracellular host- and pathogen-derived peptides to effector cells of the immune system, inducing immune tolerance in healthy conditions or triggering effective immune responses in pathological situations. HLA-C is the most recently evolved HLA class I molecule, only present in humans and great apes. Differentiating from its older siblings, HLA-A and HLA-B, HLA-C exhibits distinctive features in its expression and interaction partners. HLA-C serves as a natural ligand for multiple members of the killer-cell immunoglobulin-like receptor (KIR) family, which are predominately expressed by natural killer (NK) cells. NK cells are crucial for the early control of viral infections and accumulating evidence indicates that interactions between HLA-C and its respective KIR receptors determine the outcome and progression of viral infections. In this review, we focus on the unique role of HLA-C in regulating NK cell functions and its consequences in the setting of viral infections.

scholarly journals The Education of NK Cells Determines Their Responsiveness to Autologous HIV-Infected CD4 T Cells

2019 ◽  
Vol 93 (23) ◽  
Author(s):  
Zahra Kiani ◽  
Franck P. Dupuy ◽  
Julie Bruneau ◽  
Bertrand Lebouché ◽  
Christelle Retière ◽  
...  
Keyword(s):  
T Cells ◽  
Hiv Infection ◽  
Nk Cells ◽  
Natural Killer ◽  
Nk Cell ◽  
Hla Class I ◽  
Class I ◽  
Cell Responses ◽  
Infected Cells ◽  
Ifn Γ

ABSTRACT Several studies support a role for specific killer immunoglobulin-like receptor (KIR)–HLA combinations in protection from HIV infection and slower progression to AIDS. Natural killer (NK) cells acquire effector functions through education, a process that requires the interaction of inhibitory NK cell receptors with their major histocompatibility complex (MHC) class I (or HLA class I [HLA-I]) ligands. HLA-C allotypes are ligands for the inhibitory KIRs (iKIRs) KIR2DL1, KIR2DL2, and KIR2DL3, whereas the ligand for KIR3DL1 is HLA-Bw4. HIV infection reduces the expression of HLA-A, -B, and -C on the surfaces of infected CD4 (iCD4) T cells. Here we investigated whether education through iKIR-HLA interactions influenced NK cell responses to autologous iCD4 cells. Enriched NK cells were stimulated with autologous iCD4 cells or with uninfected CD4 cells as controls. The capacities of single-positive (sp) KIR2DL1, KIR2DL2, KIR2DL3, and KIR3DL1 NK cells to produce CCL4, gamma interferon (IFN-γ), and/or CD107a were assessed by flow cytometry. Overall, we observed that the potency of NK cell education was directly related to the frequency of each spiKIR+ NK cell’s ability to respond to the reduction of its cognate HLA ligand on autologous iCD4 cells, as measured by the frequency of production by spiKIR+ NK cells of CCL4, IFN-γ, and/or CD107a. Both NK cell education and HIV-mediated changes in HLA expression influenced NK cell responses to iCD4 cells. IMPORTANCE Epidemiological studies show that natural killer (NK) cells have anti-HIV activity: they are able to reduce the risk of HIV infection and/or slow HIV disease progression. How NK cells contribute to these outcomes is not fully characterized. We used primary NK cells and autologous HIV-infected cells to examine the role of education through four inhibitory killer immunoglobulin-like receptors (iKIRs) from persons with HLA types that are able to educate NK cells bearing one of these iKIRs. HIV-infected cells activated NK cells through missing-self mechanisms due to the downmodulation of cell surface HLA expression mediated by HIV Nef and Vpu. A higher frequency of educated than uneducated NK cells expressing each of these iKIRs responded to autologous HIV-infected cells by producing CCL4, IFN-γ, and CD107a. Since NK cells were from non-HIV-infected individuals, they model the consequences of healthy NK cell–HIV-infected cell interactions occurring in the HIV eclipse phase, when new infections are susceptible to extinction.

scholarly journals Human natural killer cell receptors for HLA-class I molecules. Evidence that the Kp43 (CD94) molecule functions as receptor for HLA-B alleles.

1994 ◽  
Vol 180 (2) ◽  
pp. 545-555 ◽  
Author(s):  
A Moretta ◽  
M Vitale ◽  
S Sivori ◽  
C Bottino ◽  
L Morelli ◽  
...  
Keyword(s):  
Nk Cells ◽  
Natural Killer ◽  
Killer Cell ◽  
Hla Class I ◽  
Cytolytic Activity ◽  
Class I ◽  
Target Cells ◽  
Human Natural Killer Cell ◽  
Ligand Interaction ◽  
Hla Class I Molecules

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.

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 ◽  
...  
Keyword(s):  
Nk Cells ◽  
Natural Killer ◽  
Antigen Processing ◽  
Nk Cell ◽  
Hla Class I ◽  
Surface Expression ◽  
Class I ◽  
Inhibitory Receptor ◽  
Surface Receptors ◽  
Hla Class I Molecules

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.

scholarly journals HLA upregulation during dengue virus infection suppresses the natural killer cell response

2019 ◽  
Author(s):  
Julia L. McKechnie ◽  
Davis Beltran ◽  
Arcelys Pitti ◽  
Lisseth Saenz ◽  
Ana B. Araúz ◽  
...  
Keyword(s):  
Dengue Virus ◽  
Nk Cells ◽  
Natural Killer ◽  
Cell Response ◽  
Nk Cell ◽  
Hla Class I ◽  
Denv Infection ◽  
Class I ◽  
Hla Class I Molecules

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.

scholarly journals A Human Histocompatibility Leukocyte Antigen (HLA)-G–specific Receptor Expressed on All Natural Killer Cells

1999 ◽  
Vol 189 (7) ◽  
pp. 1093-1100 ◽  
Author(s):  
Sumati Rajagopalan ◽  
Eric O. Long
Keyword(s):  
Nk Cells ◽  
Natural Killer ◽  
Killer Cell ◽  
Hla Class I ◽  
Class I ◽  
Target Cells ◽  
Trophoblast Cells ◽  
Leukocyte Antigen ◽  
Hla Class I Molecules ◽  
Decidual Cells

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.

A Defined Donor Activating Natural Killer Cell Receptor Phenotype Protects Against Leukemic Relapse after HLA-Identical Hematopoietic Stem Cell Transplantation.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 3338-3338
Author(s):  
Christian J. Demanet ◽  
Sonja J. Verheyden ◽  
Rik J. Schots
Keyword(s):  
Stem Cell ◽  
Hematopoietic Stem Cell Transplantation ◽  
Stem Cell Transplantation ◽  
Nk Cells ◽  
Natural Killer ◽  
Hla Class I ◽  
Class I ◽  
Leukemic Cells ◽  
Hematopoietic Stem ◽  
Leukemic Relapse

Abstract Objective: Killer immunoglobulin-like receptors (KIRs) on Natural Killer (NK) cells recognize groups of HLA class I alleles. Failure to recognize the appropriate KIR ligand on a HLA class I-mismatched cell triggers NK cytotoxicity. Because KIR and HLA genes are located on different chromosomes matching for HLA does mostly not result in matched KIR genes in related HLA-identical hematopoietic stem cell transplantation (HSCT). Moreover, KIR genotypes are very diverse in the population and therefore we explored whether this KIR diversity could have any Graft-versus-Leukemia (GvL) effect in related, HLA-identical HSCT. Methods: A total of 65 consecutive patients with leukemia (AML, CML, ALL) who received a first transplant at our institution, were included in the analysis. The median age of the patients was 34 years. The conditioning regimen included TBI + cytosine arabinoside + cyclophosphamide in the majority of the patients (85%). The source of stem cells was bone marrow (72%) or peripheral blood (28%). The NK KIR genotype (6 inhibiting and 5 activating KIRs) and molecular HLA compatibility (locus A, B, C, DRB1, DQB1, DPB1) were studied in all patients and their sibling donors. Results and conclusion: Our analysis showed that the combined presence of the activating KIR receptors 2DS1 and 2DS2 on the donor NK cells is of major importance in protection against leukemic relapse in HLA-identical HSCT. In the patient group with a KIR2DS1(+)2DS2(+) donor, relapse was significantly lower (2/15; 13%) compared to all other donors (23/50; 46%) (P=0.01). Additionally, we found a direct relationship between the number of HLA class I - activating KIR interactions and relapse. The more activating KIR receptor-HLA-C ligand interactions possible, the less relapse observed (P=0.05). However, we cannot exclude at this moment that a hitherto unknown ligand (such as a viral protein or a tumor associated or -specific protein) could substitute for a HLA class I antigen. HLA class I down-regulation is frequently observed on leukemic cells and decreases the interaction with inhibitory NK receptors. The presence of sufficient donor activating NK receptors to overcome the remaining inhibition is likely the mechanism that mediates the elimination of residual leukemic cells.

Carfilzomib Enhances Natural Killer Cell-Mediated Lysis of Myeloma Linked with Decreasing Expression of HLA Class I

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 1854-1854
Author(s):  
Jumei Shi ◽  
Guang Yang ◽  
Yuanyuan Kong ◽  
Minjie Gao ◽  
Yi Tao ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Nk Cells ◽  
Natural Killer ◽  
Hematological Malignancies ◽  
Nk Cell ◽  
Killer Cell ◽  
Hla Class I ◽  
Class I ◽  
Dependent Manner ◽  
Down Regulation

Abstract Multiple myeloma (MM) is a malignant disorder characterized by uncontrolled monoclonal plasma cell proliferation. It accounts for 10% of all hematological malignancies and causes 15-20% of deaths from hematological malignancies. Although new therapies were introduced and overall survival of MM was improved in the last 10 years, MM still remains an incurable disease due to drug resistance. Natural killer (NK) cell-based treatments are promising therapies for multiple myeloma (MM). Carfilzomib (CFZ), a second-generation proteasome inhibitor, is used to treat patients with MM who are refractory or intolerant to both bortezomib and lenalidomide (or thalidomide). In this study, we determined that CFZ treatment enhanced the sensitivity of MM cells to NK cell-mediated lysis. Here, we report that CFZ decreased the expression of human leukocyte antigen (HLA) class I on MM cell lines and primary MM cells, the mean reduction was 47.7 ± 9.4% and 42.8 ± 12.4%, respectively. The down-regulation caused by CFZ occurred in a dose- and time- dependent manner. We compared the cell surface levels of HLA class I on MM cells in the presence or absence of CFZ after acid treatment. CFZ also down-regulated the expression of newly formed HLA class I on MM cells. CD107a expression levels were used to measure NK-cell degranulation. When NK cells were incubated with MM cells with CFZ treatment, the percentage of NK cells expressing CD107a on the surface greatly increased (mean ± SD: 33.6 ± 2.1%, for treated cells vs 16.7 ± 2.3%, for control cells, P < 0.05). We also showed that CFZ augmented NK-cell cytotoxity by a perforin/granzyme-mediated mechanism, because such enhancement was abolished when CMA, but not anti-TRAIL or anti-Fas-L antibodies, was added. Treatment of MM with CFZ significantly sensitized patients' MM cells to NK cell-mediated lysis (mean ± SD: 43.1 ± 6.4%, for treated cells vs 16.1 ± 4.0%, for control cells at effector/target (E/T) ratio of 10:1, n = 9, P < 0.01). Furthermore, the exogenous HLA-C binding peptides, used in the CFZ treated group rescued the down-regulation of HLA-C and reduced NK cell-mediated lysis to a similar level as in the untreated group. Blocking NKG2D, NCRs and TRAIL did not have a significant impact on NK cell lysis of myeloma cells. These implied the enhancement of NK cell-mediated lysis was mainly linked with the decreased expression of HLA class I. Our findings show a novel activity of CFZ as an immunomodulating agent and suggest a possible approach to therapeutically augment NK cell function in MM patients. Disclosures No relevant conflicts of interest to declare.

scholarly journals Evolution and Immunogenetics of Natural Killer Cell Receptors in Health and Disease

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. SCI-25-SCI-25
Author(s):  
Peter Parham
Keyword(s):  
Nk Cells ◽  
Natural Killer ◽  
Mhc Class I ◽  
Nk Cell ◽  
Killer Cell ◽  
Hla Class I ◽  
Class I ◽  
Mhc Class I Molecules ◽  
Kir Gene ◽  
Kir Haplotypes

Abstract Natural killer (NK) cells are phenotypically diverse lymphocytes that contribute to innate immunity, adaptive immunity and placental reproduction. Unlike B and T cells, NK cells do not use rearranging genes to make diverse antigen receptors that are clonally expressed. Instead, NK cells express diverse combinations of a variety of receptors that are encoded by conventional non-rearranging genes. Several of these receptors are specific for conserved and variable determinants of major histocompatibility complex (MHC) class I molecules. In humans, the killer-cell immunoglobulin-like receptors (KIR) are a diverse and polymorphic family of NK-cell receptors that recognize determinants of human leukocyte antigen (HLA)-A, B and C, the polymorphic human MHC class I molecules. HLA-A, B and C are the most polymorphic of human genes, and they correlate with susceptibility to a wide range of diseases and clinical outcomes, including allogeneic hematopoietic cell transplantation (HCT). During NK-cell development, interactions between epitopes of HLA class I and KIR educate the NK cells to recognize the normal expression of these epitopes on healthy cells, and to respond to unhealthy cells in which that expression is perturbed. In the context of HCT, certain types of HLA class I mismatch enable donor-derived NK cells to make an alloreactive and beneficial graft-versus-leukemia response. Although it is likely that all placental mammals have NK cells, only a small minority of these species has a diverse KIR family like that in humans. These comprise the simian primates: New World monkeys, Old World monkeys and the great apes. Under pressure from diverse and rapidly evolving pathogens, both the MHC class I and KIR gene families have been driven to evolve rapidly. Consequently, much of their character is species-specific. This is especially true for the human KIR gene family, which is qualitatively different from that of our closest relatives, the chimpanzees. Whereas chimpanzee KIR haplotype diversity represents variations on a theme of genes encoding robust MHC class I receptors, humans have an even balance between group A KIR haplotypes encoding robust HLA class I receptors and group B KIR haplotypes encoding receptors that, to varying degree, have been subject to natural selection for reduced functional recognition of HLA class I. A balance of A and B is present in all human populations and thus appears essential for the long-term survival and competitiveness of human communities. Whereas the A KIR haplotypes correlate with successful defense against viral infection, maternal B KIR haplotypes correlate with reproductive success and donor B KIR haplotypes improve the outcome of allogeneic HCT as therapy for acute myeloid leukemia. Disclosures No relevant conflicts of interest to declare.

scholarly journals Molecular Signatures of Natural Killer Cells in CMV-Associated Anterior Uveitis, A New Type of CMV-Induced Disease in Immunocompetent Individuals

2021 ◽  
Vol 22 (7) ◽  
pp. 3623
Author(s):  
Nobuyo Yawata ◽  
Mariko Shirane ◽  
Kaing Woon ◽  
Xinru Lim ◽  
Hidenori Tanaka ◽  
...  
Keyword(s):  
Nk Cells ◽  
Natural Killer ◽  
Anterior Uveitis ◽  
Genetic Background ◽  
Nk Cell ◽  
Hla Class I ◽  
Class I ◽  
Molecular Signatures ◽  
Receptor Ligand ◽  
Ligand Interactions

Cytomegalovirus (CMV) causes clinical issues primarily in immune-suppressed conditions. CMV-associated anterior uveitis (CMV-AU) is a notable new disease entity manifesting recurrent ocular inflammation in immunocompetent individuals. As patient demographics indicated contributions from genetic background and immunosenescence as possible underlying pathological mechanisms, we analyzed the immunogenetics of the cohort in conjunction with cell phenotypes to identify molecular signatures of CMV-AU. Among the immune cell types, natural killer (NK) cells are main responders against CMV. Therefore, we first characterized variants of polymorphic genes that encode differences in CMV-related human NK cell responses (Killer cell Immunoglobulin-like Receptors (KIR) and HLA class I) in 122 CMV-AU patients. The cases were then stratified according to their genetic features and NK cells were analyzed for human CMV-related markers (CD57, KLRG1, NKG2C) by flow cytometry. KIR3DL1 and HLA class I combinations encoding strong receptor–ligand interactions were present at substantially higher frequencies in CMV-AU. In these cases, NK cell profiling revealed expansion of the subset co-expressing CD57 and KLRG1, and together with KIR3DL1 and the CMV-recognizing NKG2C receptor. The findings imply that a mechanism of CMV-AU pathogenesis likely involves CMV-responding NK cells co-expressing CD57/KLRG1/NKG2C that develop on a genetic background of KIR3DL1/HLA-B allotypes encoding strong receptor–ligand interactions.

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