Killer Cell Immunoglobulin-like Receptor Variants Are Associated with Protection from Symptoms Associated with More Severe Course in Parkinson Disease.
ABSTRACT: Immune dysfunction plays a role in the development of Parkinson disease (PD). NK cells regulate immune functions and are modulated by killer cell immunoglobulin-like receptors (KIR). KIR are expressed on the surface of NK cells and interact with HLA class I ligands on the surface of all nucleated cells. We investigated KIR-allelic polymorphism to interrogate the role of NK cells in PD. We sequenced KIR genes from 1314 PD patients and 1978 controls using next-generation methods and identified KIR genotypes using custom bioinformatics. We examined associations of KIR with PD susceptibility and disease features, including age at disease onset and clinical symptoms. We identified two KIR3DL1 alleles encoding highly expressed inhibitory receptors associated with protection from PD clinical features in the presence of their cognate ligand: KIR3DL1*015/HLA-Bw4 from rigidity (pc = 0.02, odds ratio [OR] = 0.39, 95% confidence interval [CI] 0.23-0.69) and KIR3DL1*002/HLA-Bw4i from gait difficulties (p c = 0.05, OR = 0.62, 95% CI 0.44-0.88), as well as composite symptoms associated with more severe disease. We also developed a KIR3DL1/HLA interaction strength metric and found that weak KIR3DL1/HLA interactions were associated with rigidity (pc = 0.05, OR = 9.73, 95% CI 2.13-172.5). Highly expressed KIR3DL1 variants protect against more debilitating symptoms of PD, strongly implying a role of NK cells in PD progression and manifestation.
Project description:NK cells recognize self-HLA via killer Ig-like receptors (KIR). Homeostatic HLA expression signals for inhibition via KIR, and downregulation of HLA, a common consequence of viral infection, allows NK activation. Like HLA, KIR are highly polymorphic, and allele combinations of the most diverse receptor-ligand pair, KIR3DL1 and HLA-B, correspond to hierarchical HIV control. We used primary cells from healthy human donors to demonstrate how subtype combinations of KIR3DL1 and HLA-B calibrate NK education and their consequent capacity to eliminate HIV-infected cells. High-density KIR3DL1 and Bw4-80I partnerships endow NK cells with the greatest reactivity against HLA-negative targets; NK cells exhibiting the remaining KIR3DL1/HLA-Bw4 combinations demonstrate intermediate responsiveness; and Bw4-negative KIR3DL1(+) NK cells are poorly responsive. Cytotoxicity against HIV-infected autologous CD4(+) T cells strikingly correlated with reactivity to HLA-negative targets. These findings suggest that the programming of NK effector function results from defined features of receptor and ligand subtypes. KIR3DL1 and HLA-B subtypes exhibit an array of binding strengths. Like KIR3DL1, subtypes of HLA-Bw4 are expressed at distinct, predictable membrane densities. Combinatorial permutations of common receptor and ligand subtypes reveal binding strength, receptor density, and ligand density to be functionally important. These findings have immediate implications for prognosis in patients with HIV infection. Furthermore, they demonstrate how features of KIR and HLA modified by allelic variation calibrate NK cell reactive potential.
Project description:Epidemiological studies have associated certain human disease outcomes with particular killer cell Ig-like receptor (KIR) and HLA genotypes. However, the functional explanation for these associations is poorly understood, because the KIRs were initially described as natural killer (NK) cell inhibitory receptors with specificity for HLA molecules on their cellular targets. Yet resolution of infections is often associated with genotypic pairing of inhibitory KIRs with their cognate HLA ligands. Recent studies in mice indicate a second role for MHC-specific inhibitory receptors, i.e., self-MHC recognition confers functional competence on the NK cell to be triggered through their activation receptors, a process termed licensing. As a result, licensed NK cells with self-MHC-specific receptors are more readily activated as compared with unlicensed NK cells without self-MHC-specific receptors. Such results predict that human NK cells may undergo a similar process. Here, we examined the human NK cell subset expressing KIR3DL1, the only known KIR specific for HLA-Bw4 alleles. The KIR3DL1(+) subset in normal donors with two HLA-B-Bw4 genes displayed increased responsiveness to tumor stimulation compared with the KIR3DL1(+) subset from individuals with only one or no Bw4 genes. By contrast, NK cells lacking KIR3DL1 showed no differences. Therefore, these data indicate that particular KIR and HLA alleles are associated with more responsive NK cells, strongly suggesting that human NK cells are also subjected to NK cell licensing, and providing a potential functional explanation for the influence of KIR and HLA genes in disease as well as interindividual differences in NK cell potency.
Project description:Viral infections can affect the glycosylation pattern of glycoproteins involved in antiviral immunity. Given the importance of protein glycosylation for immune function, we investigated the effect that modulation of the highly conserved HLA class I N-glycan has on KIR:HLA interactions and NK cell function. We focused on HLA-B*57:01 and its interaction with KIR3DL1, which has been shown to play a critical role in determining the progression of a number of human diseases, including human immunodeficiency virus-1 infection. 721.221 cells stably expressing HLA-B*57:01 were treated with a panel of glycosylation enzyme inhibitors, and HLA class I expression and KIR3DL1 binding was quantified. In addition, the functional outcomes of HLA-B*57:01 N-glycan disruption/modulation on KIR3DL1?+ Jurkat reporter cells and primary human KIR3DL1+ NK cells was assessed. Different glycosylation enzyme inhibitors had varying effects on HLA-B*57:01 expression and KIR3DL1-Fc binding. The most remarkable effect was that of tunicamycin, an inhibitor of the first step of N-glycosylation, which resulted in significantly reduced KIR3DL1-Fc binding despite sustained expression of HLA-B*57:01 on 721.221 cells. This effect was paralleled by decreased activation of KIR3DL1?+ Jurkat reporter cells, as well as increased degranulation of primary human KIR3DL1+ NK cell clones when encountering HLA-B*57:01-expressing 721.221 cells that were pre-treated with tunicamycin. Overall, these results demonstrate that N-glycosylation of HLA class I is important for KIR:HLA binding and has an impact on NK cell function.
Project description:Behçet's disease (BD) is an immune-mediated vasculitis related to imbalances between the innate and adaptive immune response. Infectious agents or environmental factors may trigger the disease in genetically predisposed individuals. HLA-B51 is the genetic factor stronger associated with the disease, although the bases of this association remain elusive. NK cells have also been implicated in the etiopathogenesis of BD. A family of NK receptors, Killer-cell Immunoglobulin-like Receptor (KIR), with a very complex organization, is very important in the education and control of the NK cells by the union to their ligands, most of them, HLA class I molecules. This study aimed to investigate the contribution of certain KIR functional polymorphisms to the susceptibility to BD. A total of 466 BD patients and 444 healthy individuals were genotyped in HLA class I (A, B, and C). The set of KIR genes and the functional variants of KIR3DL1/DS1 and KIR2DS4 were also determined. Frequency of KIR3DL1*004 was lower in patients than in controls (0.15 vs. 0.20, P = 0.005, Pc = 0.015; OR = 0.70; 95% CI 0.54-0.90) in both B51 positive and negative individuals. KIR3DL1*004, which encodes a misfolded protein, is included in a common telomeric haplotype with only one functional KIR gene, KIR3DL2. Both, KIR3DL1 and KIR3DL2 sense pathogen-associated molecular patterns but they have different capacities to eliminate them. The education of the NK cells depending on the HLA, the balance of KIR3DL1/KIR3DL2 licensed NK cells and the different capacities of these receptors to eliminate pathogens could be involved in the etiopathogenesis of BD.
Project description:Carriage of the natural killer (NK) receptor genotype KIR3DL1*h/*y with its HLA-B*57 ligand (*h/*y+B*57) is associated with slow time to AIDS and low viral load (VL). To provide a functional basis for these epidemiological observations, we assessed whether HIV-1-infected slow progressors (SP) carrying the *h/*y+B*57 compound genotype would have increased NK cell polyfunctional potential in comparison to SP with other killer immunoglobulin-like receptor (KIR)/HLA compound genotypes and whether this enhanced polyfunctionality was dependent upon the coexpression of both KIR3DL1*h/*y and HLA-B*57. The functional potential of NK cells was investigated by stimulating peripheral blood mononuclear cells with HLA-devoid targets or single HLA transfectants. Multiparametric flow cytometry was used to detect NK cells with seven functional profiles representing all permutations of CD107a expression and gamma interferon (IFN-?) and tumor necrosis factor alpha (TNF-?) secretion. NK cells from individuals carrying KIR3DL1 receptor-HLA-Bw4 ligand pairs had greater trifunctional responses than those from KIR3DL1 homozygotes (hmz), who were Bw6 homozygotes. NK cells from subjects carrying the *h/*y+B*57 genotypes exhibited the highest trifunctional potential, and this was dependent on cocarriage of the NK receptor and its ligand. Trifunctional cells secreted more of each function tested on a per-cell basis than each corresponding monofunctional NK subset. Although VL influenced NK functionality, individuals with defined KIR/HLA genotypes exhibited differences in NK cell polyfunctionality that could not be accounted for by VL alone. The protective effect of HLA-B*57 on slow progression to AIDS and low VL may be mediated through its interaction with KIR3DL1 alleles to educate NK cells for potent activity upon stimulation.
Project description:NK cell activity is regulated by the integration of positive and negative signals. One important source of these signals for human NK cells is the killer Ig-like receptor (KIR) family, which includes both members that transduce positive and those that generate negative signals. KIR3DL1 inhibits NK cell activity upon engagement by its ligand HLA-Bw4. The highly homologous KIR3DS1 is an activating receptor, which is implicated in the outcome of a variety of pathological situations. However, unlike KIR3DL1, direct binding of KIR3DS1(+) cells to HLA has not been demonstrated. We analyzed four key amino acid differences between KIR3DL1*01502 and KIR3DS1*013 to determine their role in KIR binding to HLA. Single substitutions of these residues dramatically reduced binding by KIR3DL1. In the reciprocal experiment, we found that the rare KIR3DS1 allotype KIR3DS1*014 binds HLA-Bw4 even though it differs from KIR3DS1*013 at only one of these positions (position 138). This reactivity was unexpectedly dependent on residues at other variable positions, as HLA-Bw4 binding was lost in receptors with KIR3DL1-like residues at both positions 199 and 138. These data provide the first evidence, to our knowledge, for the direct binding of KIR3DS1(+) cells to HLA-Bw4 and highlight the key role for position 138 in determining ligand specificity of KIR3DS1. They also reveal that KIR3DS1 reactivity and specificity is dictated by complex interactions between the residues in this region, suggesting a unique functional evolution of KIR3DS1 within the activating KIR family.
Project description:Combinations of KIR3DL1 and HLA-Bw4 alleles protect against HIV infection and/or disease progression. These combinations enhance NK cell responsiveness through the ontological process of education. However, educated KIR3DL1(+) NK cells do not have enhanced degranulation upon direct recognition of autologous HIV-infected cells. Since antibody-dependent cellular cytotoxicity (ADCC) is associated with improved HIV infection outcomes and NK cells overcome inhibition through killer cell immunoglobulin-like receptors (KIR) to mediate ADCC, we hypothesized that KIR3DL1-educated NK cells mediate anti-HIV ADCC against autologous cells. A whole-blood flow cytometry assay was used to evaluate ADCC-induced activation of NK cells. This assay assessed activation (gamma interferon [IFN-?] production and/or CD107a expression) of KIR3DL1(+) and KIR3DL1(-) NK cells, from HLA-Bw4(+) and HLA-Bw4(-) HIV-positive and HIV-negative individuals, in response to autologous HIV-specific ADCC targets. KIR3DL1(+) NK cells were more functional than KIR3DL1(-) NK cells from HLA-Bw4(+), but not HLA-Bw4(-), healthy controls. In HIV-infected individuals, no differences in NK cell functionality were observed between KIR3DL1(+) and KIR3DL1(-) NK cells in HLA-Bw4(+) individuals, consistent with dysfunction of NK cells in the setting of HIV infection. Reflecting the partial normalization of NK cell responsiveness following initiation of antiretroviral therapy, a significant correlation was observed between the peripheral CD4(+) T-lymphocyte counts in antiretroviral therapy-treated subjects and the functionality of NK cells. However, peripheral CD4(+) T-lymphocyte counts were not correlated with an anti-HIV ADCC functional advantage in educated KIR3DL1(+) NK cells. The abrogation of the functional advantage of educated NK cells may enhance HIV disease progression. Strategies to enhance the potency of NK cell-mediated ADCC may improve HIV therapies and vaccines.
Project description:Purpose Disease relapse remains a major challenge to successful outcomes in patients who undergo allogeneic hematopoietic cell transplantation (HCT). Donor natural killer (NK) cell alloreactivity in HCT can control leukemic relapse, but capturing alloreactivity in HLA-matched HCT has been elusive. HLA expression on leukemia cells-upregulated in the post-HCT environment-signals for NK cell inhibition via inhibitory killer immunoglobulin-like (KIR) receptors and interrupts their antitumor activity. We hypothesized that varied strengths of inhibition among subtypes of the ubiquitous KIR3DL1 and its cognate ligand, HLA-B, would titrate NK reactivity against acute myelogenous leukemia (AML). Patients and Methods By using an algorithm that was based on polymorphism-driven expression levels and specificities, we predicted and tested inhibitory and cytotoxic NK potential on the basis of KIR3DL1/HLA-B subtype combinations in vitro and evaluated their impact in 1,328 patients with AML who underwent HCT from 9/10 or 10/10 HLA-matched unrelated donors. Results Segregated by KIR3DL1 subtype, NK cells demonstrated reproducible patterns of strong, weak, or noninhibition by target cells with defined HLA-B subtypes, which translated into discrete cytotoxic hierarchies against AML. In patients, KIR3DL1 and HLA-B subtype combinations that were predictive of weak inhibition or noninhibition were associated with significantly lower relapse (hazard ratio [HR], 0.72; P = .004) and overall mortality (HR, 0.84; P = .030) compared with strong inhibition combinations. The greatest effects were evident in the high-risk group of patients with all KIR ligands (relapse: HR, 0.54; P < .001; and mortality: HR, 0.74; P < .008). Beneficial effects of weak and noninhibiting KIR3DL1 and HLA-B subtype combinations were separate from and additive to the benefit of donor activating KIR2DS1. Conclusion Consideration of KIR3DL1-mediated inhibition in donor selection for HLA-matched HCT may achieve superior graft versus leukemia effects, lower risk for relapse, and an increase in survival among patients with AML.
Project description:Natural killer (NK) cells are key participants in the innate immune response. Killer cell immunoglobulin-like receptors (KIRs) are involved in the activation and inhibition of NK cells through the recognition of human leukocyte antigen (HLA) class I molecules. We investigated the impact of KIR/HLA combinations on susceptibility and long-term clinical outcome in Japanese patients with type 1 autoimmune hepatitis (AIH). Methods:A total of 154 cases of AIH were recruited at Shinshu University Hospital between 1974 and 2018. KIR genes and HLA class I and II alleles were genotyped in all patients along with 201 healthy individuals. Associations between KIR/HLA pairs and clinical outcomes (liver decompensation and liver-related death) were evaluated using the Cox proportional hazards model with stepwise method. Results:After a median follow-up period of 11.1 years, 12% of patients experienced liver decompensation and 8% died from liver disease. KIR3DL1/HLA-B Bw4-80Ile (p = 0.0062) and the HLA-DRB1*04:05-DQB1*04:01 haplotype (p ?0.001) were significantly associated with AIH. Conversely, significant protective associations were found for KIR3DL1/HLA-B Bw4-80Thr (p = 0.0092) and KIR2DL1/HLA-C2 (p = 0.0025). The KIR3DL1/HLA-B Bw4-positive phenotype was strongly associated with a favorable clinical outcome (liver decompensation: hazard ratio [HR] 0.37, p = 0.037; liver-related death: HR 0.26, p = 0.038). Cirrhosis was detected in 16 (10%) patients at diagnosis and was significantly related to poor survival (HR 17.87, p ?0.001) and progression to liver decompensation (HR 9.00, p ?0.001). Conclusions:This study revealed the impact of specific KIR/HLA pairs in AIH susceptibility and progression in Japanese patients. KIR3DL1/HLA-B Bw4-negative patients with AIH and cirrhosis at diagnosis are at high risk of adverse outcomes and require careful surveillance. Lay summary:Autoimmune hepatitis (AIH) is a disease of the liver that can present in acute or chronic hepatitis. We examined whether KIR/HLA pairs were associated with AIH susceptibility or disease progression. KIR3DL1/HLA-B Bw4 was a novel KIR/HLA pair related to a favorable clinical outcome, while cirrhosis at the initial diagnosis was a risk factor for poor prognosis. Thus, frequent and careful surveillance is advised for KIR3DL1/HLA-B Bw4-negative patients with AIH and cirrhosis.
Project description:Carriage of the genetic combination encoding a high expression inhibitory Killer Immunoglobulin-like Receptor (KIR)3DL1 with its ligand, HLA-B*57 (*h/*y+B*57) is associated with slower time to AIDS and better HIV viral load control than being a Bw6 homozygote (Bw6hmz). Natural Killer (NK) cells from *h/*y+B*57 carriers receive potent educational signals through HLA-B*57 KIR3DL1 ligation leading to high functional potential. NK cells from Bw6hmz are not educated through KIR3DL1 because Bw6 antigens do not interact with this inhibitory receptor. To better understand the impact of KIR/HLA combinations on NK cell mediated anti-viral activity we measured NK cell mediated inhibition of HIV replication in autologous infected CD4 (iCD4) cells by assessing the frequency of p24 positive CD4 targets and supernatant levels of HIV p24 longitudinally in the presence versus absence of NK cells. Forty-seven HIV uninfected subjects were studied, including carriers of *h/*y+B*57, a low expression KIR3DL1 genotype with HLA-B*57 termed *l/*x+B*57, a genotype designated 3DS1+*80I and Bw6hmz. NK cells from *h/*y+B*57 carriers, like those from 3DS1+*80I subjects, inhibited HIV replication in autologous iCD4 cells better than those from Bw6hmz and *l/*x+B*57 carriers. Cell contact between NK and iCD4 cells activated NK cells to inhibit viral replication in a non-contact dependent fashion through secretion of CC-chemokines. iCD4 stimulated NK cells from *h/*y+B*57 and 3DS1+*80I carriers produced higher levels of CC-chemokines than those from Bw6hmz or *l/*x+B*57 carriers. Higher levels of CC-chemokines were produced by KIR3DL1(+) than KIR3DL1(-) NK cells. We conclude that NK-mediated inhibition of viral replication in autologous iCD4 cells is partially due to a block at the level of HIV entry into new targets by secreted CC-chemokines.