Association of HLA-E Polymorphism with the Incidence of Severe Bacterial Infections in Sickle Cell Anemia.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 2335-2335
Author(s):  
Ryad Tamouza ◽  
Catherine Fortier ◽  
Ibrahima Diagne ◽  
Dapa A. Diallo ◽  
Dominique Labie ◽  
...  

Abstract While it is commonly admitted that the susceptibility to severe infections (septicemia, meningitis, or osteomyelitis) in Sickle Cell Anemia (SCA) patients is a major cause of mortality and morbidity, these complications remains poorly explained. However, several lines of evidence highlight the involvement of an immunogenetic modulation, including both innate and adaptive immune responses. HLA-E belongs to the HLA-class I non-classical family and is ubiquitously expressed. HLA-E molecules bind either to self-peptides from the leader sequences of various HLA-class I molecules and thus modulate NK (Natural killer) cell activation/inhibition, or to the microbial derived-peptides from human viruses or bacteria to induce T cell responses. Only two functional alleles, HLA-E*0101 and HLA-E*0103, differing by a single amino acid substitution in the α2 heavy chain domain and by their cell surface expression level, have been reported so far. In order to evaluate whether the HLA-E polymorphism could influence the incidence of severe bacterial infections in SCA, we analyzed a cohort of 99 SCA patients living in Paris, but for the majority, originating from black Africa. All patients were older than 5 years of age at inclusion. Among the cohort, 51 presented at least one severe bacterial infection and 48 did not disclose any major infectious episode in their clinical history. Statistical analysis showed that the incidence of severe bacterial infections are high when the patient’s genotype was HLA-E*0101/E*0101 (47% in the first group versus 21% in the second group; χ2 = 7.54 p = 0.006, pc = 0.01, OR: 3.28, [95%CI = 1.28–9.07]), supporting a negative effect of this genotype. The genetic association herein found between HLA-E polymorphism and severe bacterial infections is of relevance, given the emerging evidence for the involvement of HLA-E molecules in pathogen-derived peptide presentation to human CD8+ T cells and hence in host response to pathogens. Furthermore, these data are in agreement with our previous findings in bone marrow transplantation settings, were the homozygous state for HLA-E*0101 allele is also a risk factor for early severe bacterial infections. Both situations by constitutively lowering the overall threshold of resistance to infection, might unmask anti infectious genetic factors normally silent.

2006 ◽  
Vol 203 (3) ◽  
pp. 633-645 ◽  
Author(s):  
Makoto Yawata ◽  
Nobuyo Yawata ◽  
Monia Draghi ◽  
Ann-Margaret Little ◽  
Fotini Partheniou ◽  
...  

Interactions between killer cell immunoglobulin-like receptors (KIRs) and human leukocyte antigen (HLA) class I ligands regulate the development and response of human natural killer (NK) cells. Natural selection drove an allele-level group A KIR haplotype and the HLA-C1 ligand to unusually high frequency in the Japanese, who provide a particularly informative population for investigating the mechanisms by which KIR and HLA polymorphism influence NK cell repertoire and function. HLA class I ligands increase the frequencies of NK cells expressing cognate KIR, an effect modified by gene dose, KIR polymorphism, and the presence of other cognate ligand–receptor pairs. The five common Japanese KIR3DLI allotypes have distinguishable inhibitory capacity, frequency of cellular expression, and level of cell surface expression as measured by antibody binding. Although KIR haplotypes encoding 3DL1*001 or 3DL1*005, the strongest inhibitors, have no activating KIR, the dominant haplotype encodes a moderate inhibitor, 3DL1*01502, plus functional forms of the activating receptors 2DL4 and 2DS4. In the population, certain combinations of KIR and HLA class I ligand are overrepresented or underrepresented in women, but not men, and thus influence female fitness and survival. These findings show how KIR–HLA interactions shape the genetic and phenotypic KIR repertoires for both individual humans and the population.


Author(s):  
Zhihui Deng ◽  
Jianxin Zhen ◽  
Genelle F Harrison ◽  
Guobin Zhang ◽  
Rui Chen ◽  
...  

Abstract Human natural killer (NK) cells are essential for controlling infection, cancer and fetal development. NK cell functions are modulated by interactions between polymorphic inhibitory killer cell immunoglobulin-like receptors (KIR) and polymorphic HLA-A, -B and -C ligands expressed on tissue cells. All HLA-C alleles encode a KIR ligand and contribute to reproduction and immunity. In contrast, only some HLA-A and -B alleles encode KIR ligands and they focus on immunity. By high-resolution analysis of KIR and HLA-A, -B and -C genes, we show that the Chinese Southern Han are significantly enriched for interactions between inhibitory KIR and HLA-A and -B. This enrichment has had substantial input through population admixture with neighboring populations, who contributed HLA class I haplotypes expressing the KIR ligands B*46:01 and B*58:01, which subsequently rose to high frequency by natural selection. Consequently, over 80% of Southern Han HLA haplotypes encode more than one KIR ligand. Complementing the high number of KIR ligands, the Chinese Southern Han KIR locus combines a high frequency of genes expressing potent inhibitory KIR, with a low frequency of those expressing activating KIR. The Southern Han centromeric KIR region encodes strong, conserved, inhibitory HLA-C specific receptors, and the telomeric region provides a high number and diversity of inhibitory HLA-A and -B specific receptors. In all these characteristics, the Chinese Southern Han represent other East Asians, whose NK cell repertoires are thus enhanced in quantity, diversity and effector strength, likely augmenting resistance to endemic viral infections.


2021 ◽  
Vol 12 ◽  
Author(s):  
Silvia D’Amico ◽  
Valerio D’Alicandro ◽  
Mirco Compagnone ◽  
Patrizia Tempora ◽  
Giusy Guida ◽  
...  

The endoplasmic reticulum aminopeptidase ERAP1 regulates innate and adaptive immune responses by trimming peptides for presentation by major histocompatibility complex (MHC) class I molecules. Previously, we have shown that genetic or pharmacological inhibition of ERAP1 on murine and human tumor cell lines perturbs the engagement of NK cell inhibitory receptors Ly49C/I and Killer-cell Immunoglobulin-like receptors (KIRs), respectively, by their specific ligands (MHC class I molecules), thus leading to NK cell killing. However, the effect of ERAP1 inhibition in tumor cells was highly variable, suggesting that its efficacy may depend on several factors, including MHC class I typing. To identify MHC class I alleles and KIRs that are more sensitive to ERAP1 depletion, we stably silenced ERAP1 expression in human HLA class I-negative B lymphoblastoid cell line 721.221 (referred to as 221) transfected with a panel of KIR ligands (i.e. HLA-B*51:01, -Cw3, -Cw4 and -Cw7), or HLA-A2 which does not bind any KIR, and tested their ability to induce NK cell degranulation and cytotoxicity. No change in HLA class I surface expression was detected in all 221 transfectant cells after ERAP1 depletion. In contrast, CD107a expression levels were significantly increased on NK cells stimulated with 221-B*51:01 cells lacking ERAP1, particularly in the KIR3DL1-positive NK cell subset. Consistently, genetic or pharmacological inhibition of ERAP1 impaired the recognition of HLA-B*51:01 by the YTS NK cell overexpressing KIR3DL1*001, suggesting that ERAP1 inhibition renders HLA-B*51:01 molecules less eligible for binding to KIR3DL1. Overall, these results identify HLA-B*51:01/KIR3DL1 as one of the most susceptible combinations for ERAP1 inhibition, suggesting that individuals carrying HLA-B*51:01-like antigens may be candidates for immunotherapy based on pharmacological inhibition of ERAP1.


1996 ◽  
Vol 183 (4) ◽  
pp. 1817-1827 ◽  
Author(s):  
J E Gumperz ◽  
N M Valiante ◽  
P Parham ◽  
L L Lanier ◽  
D Tyan

Natural killer (NK) cells that express the NKB1 receptor are inhibited from killing target cells that possess human histocompatibility leukocyte antigen (HLA) B molecules bearing the Bw4 serological epitope. To investigate whether NKB1 expression is affected by HLA type, peripheral blood lymphocytes of 203 HLA-typed donors were examined. Most donors had a single population of NKB1+ cells, but some had two populations expressing different cell surface levels of NKB1, and others had no detectable NKB1+ cells. Among the donors expressing NKB1, both the relative abundance of NKB1+ NK cells and their level of cell surface expression varied substantially. The percentage of NKB1+ NK cells ranged from 0 to >75% (mean 14.7%), and the mean fluorescence of the positive population varied over three orders of magnitude. For each donor, the small percentage of T cells expressing NKB1 (usually <2%), had a pattern of expression mirroring that of the NK cells. NKB1 expression by NK and T cells remained stable over the 2-yr period that five donors were tested. Patterns of NKB1 expression were not associated with Bw4 or Bw6 serotype of the donor or with the presence of any individual HLA-A or -B antigens. Cells expressing NKB1 are often found in donors who do not possess an appropriate class I ligand, and can be absent in those who express Bw4+ HLA-B antigens. Family studies further suggested that the phenotype of NKB1 expression is inherited but not HLA linked. Whereas identical twins show matching patterns of NKB1 expression, HLA-identical siblings can differ in NKB1 expression, and conversely, HLA-disparate siblings can be similar. Thus NKB1 expression phenotypes are tightly regulated and extremely heterogeneous, but not correlated with HLA type.


2019 ◽  
Vol 20 (21) ◽  
pp. 5496 ◽  
Author(s):  
Leonid Kanevskiy ◽  
Sofya Erokhina ◽  
Polina Kobyzeva ◽  
Maria Streltsova ◽  
Alexander Sapozhnikov ◽  
...  

HLA-E is a nonclassical member of the major histocompatibility complex class I gene locus. HLA-E protein shares a high level of homology with MHC Ia classical proteins: it has similar tertiary structure, associates with β2-microglobulin, and is able to present peptides to cytotoxic lymphocytes. The main function of HLA-E under normal conditions is to present peptides derived from the leader sequences of classical HLA class I proteins, thus serving for monitoring of expression of these molecules performed by cytotoxic lymphocytes. However, opposite to multiallelic classical MHC I genes, HLA-E in fact has only two alleles—HLA-E*01:01 and HLA-E*01:03—which differ by one nonsynonymous amino acid substitution at position 107, resulting in an arginine in HLA-E*01:01 (HLA-ER) and glycine in HLA-E*01:03 (HLA-EG). In contrast to HLA-ER, HLA-EG has higher affinity to peptide, higher surface expression, and higher thermal stability of the corresponding protein, and it is more ancient than HLA-ER, though both alleles are presented in human populations in nearly equal frequencies. In the current review, we aimed to uncover the reason of the expansion of the younger allele, HLA-ER, by analysis of associations of both HLA-E alleles with a number of diseases, including viral and bacterial infections, cancer, and autoimmune disorders.


Blood ◽  
2000 ◽  
Vol 95 (11) ◽  
pp. 3562-3567 ◽  
Author(s):  
Lori A. Styles ◽  
Carolyn Hoppe ◽  
William Klitz ◽  
Elliott Vichinsky ◽  
Bertram Lubin ◽  
...  

Abstract Cerebral infarction occurs in one quarter of all children with sickle cell anemia (SCA). There is an increased risk of stroke in siblings with SCA, suggesting genetic factors may influence risk of stroke. The authors investigated whether HLA type was associated with risk of stroke in children with SCA. Fifty-three patients with SCA underwent complete HLA typing at both HLA class I (HLA-A, B) and HLA class II (HLA-DR, DQ, DP) loci. Of the 53 patients, 22 had magnetic resonance imagining (MRI)–documented evidence of cerebral infarction, and the remaining 31 patients had negative MRI scans. Comparison of the results of HLA typing between the SCA patients with a positive and those with a negative MRI documented that the 2 groups differed with respect to the class I HLA-B (P = .012), and the class II HLA-DRB1 (P = .0008) and DQB1 (P = .029). Susceptibility associations at the HLA-DRB1 locus included both DR3 alleles, where DRB1*0301 and *0302 were both associated with an increased risk of stroke. Protective associations were found in the DR2 group, where DRB1*1501 was protective for stroke. DQB1*0201, which is in linkage disequilibrium with DRB1*0301, was also associated with stroke. Similarly, DQB1*0602, in linkage disequilibrium with DRB1*1501, was protective. Specific HLA alleles may influence the risk of stroke in children with SCA. HLA typing may prove useful in identifying SCA patients at higher risk for stroke.


2016 ◽  
Vol 39 (1) ◽  
pp. 14-23 ◽  
Author(s):  
Suliman Y. Al Omar ◽  
Afrah Alkuriji ◽  
Saleh Alwasel ◽  
javid Ahmed Dar ◽  
Alwaleed Alhammad ◽  
...  

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.


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