Killer Cell Immunoglobulin-like Receptor 2DL4 Research Articles

The Comparison of Serum Exosome Protein Profile in Diagnosis of NSCLC Patients.

A thorough study of the exosomal proteomic cargo may enable the identification of proteins that play an important role in cancer development. The aim of this study was to compare the protein profiles of the serum exosomes derived from non-small lung cancer (NSCLC) patients and healthy volunteers (control) using the high-performance liquid chromatography coupled to mass spectrometry (HPLC-MS) method to identify potentially new diagnostic and/or prognostic protein biomarkers. Proteins exclusively identified in NSCLC and control groups were analyzed using several bioinformatic tools and platforms (FunRich, Vesiclepedia, STRING, and TIMER2.0) to find key protein hubs involved in NSCLC progression and the acquisition of metastatic potential. This analysis revealed 150 NSCLC proteins, which are significantly involved in osmoregulation, cell-cell adhesion, cell motility, and differentiation. Among them, 3 proteins: Interleukin-34 (IL-34), HLA class II histocompatibility antigen, DM alpha chain (HLA-DMA), and HLA class II histocompatibility antigen, DO beta chain (HLA-DOB) were shown to be significantly involved in the cancer-associated fibroblasts (CAFs) and tumor-associated macrophages (TAMs) infiltration processes. Additionally, detected proteins were analyzed according to the presence of lymph node metastasis, showing that differences in frequency of detection of protein FAM166B, killer cell immunoglobulin-like receptor 2DL1, and olfactory receptor 52R1 correlate with the N feature according to the TNM Classification of Malignant Tumors. These results prove their involvement in NSCLC lymph node spread and metastasis. However, this study requires further investigation.

Granzymes, IL-16, and poly(ADP-ribose) polymerase 1 increase during wildfire smoke exposure.

Given the increasing prevalence of wildfires worldwide, understanding the effects of wildfire air pollutants on human health-particularly in specific immunologic pathways-is crucial. Exposure to air pollutants is associated with cardiorespiratory disease; however, immune and epithelial barrier alterations require further investigation. We sought to determine the impact of wildfire smoke exposure on the immune system and epithelial barriers by using proteomics and immune cell phenotyping. A San Francisco Bay area cohort (n = 15; age 30 ± 10 years) provided blood samples before (October 2019 to March 2020; air quality index = 37) and during (August 2020; air quality index = 80) a major wildfire. Exposure samples were collected 11 days (range, 10-12 days) after continuous exposure to wildfire smoke. We determined alterations in 506 proteins, including zonulin family peptide (ZFP); immune cell phenotypes by cytometry by time of flight (CyTOF); and their interrelationship using a correlation matrix. Targeted proteomic analyses (n = 15) revealed a decrease of spondin-2 and an increase of granzymes A, B, and H, killer cell immunoglobulin-like receptor 3DL1, IL-16, nibrin, poly(ADP-ribose) polymerase 1, C1q TNF-related protein, fibroblast growth factor 19, and von Willebrand factor after 11 days' average continuous exposure to smoke from a large wildfire (P < .05). We also observed a large correlation cluster between immune regulation pathways (IL-16, granzymes A, B, and H, and killer cell immunoglobulin-like receptor 3DL1), DNA repair [poly(ADP-ribose) 1, nibrin], and natural killer cells. We did not observe changes in ZFP levels suggesting a change in epithelial barriers. However, ZFP was associated with immune cell phenotypes (naive CD4+, TH2 cells). We observed functional changes in critical immune cells and their proteins during wildfire smoke exposure. Future studies in larger cohorts or in firefighters exposed to wildfire smoke should further assess immune changes and intervention targets.

Roles of HLA-G/KIR2DL4 in Breast Cancer Immune Microenvironment.

Human leukocyte antigen (HLA)-G is a nonclassical MHC Class I molecule, which was initially reported as a mediator of immune tolerance when expressed in extravillous trophoblast cells at the maternal-fetal interface. HLA-G is the only known ligand of killer cell immunoglobulin-like receptor 2DL4 (KIR2DL4), an atypical family molecule that is widely expressed on the surface of NK cells. Unlike other KIR receptors, KIR2DL4 contains both an arginine–tyrosine activation motif in its transmembrane region and an immunoreceptor tyrosine-based inhibitory motif (ITIM) in its cytoplasmic tail, suggesting that KIR2DL4 may function as an activating or inhibitory receptor. The immunosuppressive microenvironment exemplified by a rewired cytokine network and upregulated immune checkpoint proteins is a hallmark of advanced and therapy-refractory tumors. Accumulating evidence has shown that HLA-G is an immune checkpoint molecule with specific relevance in cancer immune escape, although the role of HLA-G/KIR2DL4 in antitumor immunity is still uncharacterized. Our previous study had shown that HLA-G was a pivotal mediator of breast cancer resistance to trastuzumab, and blockade of the HLA-G/KIR2DL4 interaction can resensitize breast cancer to trastuzumab treatment. In this review, we aim to summarize and discuss the role of HLA-G/KIR2DL4 in the immune microenvironment of breast cancer. A better understanding of HLA-G is beneficial to identifying novel biomarker(s) for breast cancer, which is important for precision diagnosis and prognostic assessment. In addition, it is also necessary to unravel the mechanisms underlying HLA-G/KIR2DL4 regulation of the immune microenvironment in breast cancer, hopefully providing a rationale for combined HLA-G and immune checkpoints targeting for the effective treatment of breast cancer.

Catenin Alpha-2 Mutation Changes the Immune Microenvironment in Lung Adenocarcinoma Patients Receiving Immune Checkpoint Inhibitors.

Background: Lung cancer has always been the most prevalent cancer. Lung adenocarcinoma (LUAD) is the most common lung cancer subtype and has a high tumor mutation rate. In addition to KRAS, EGFR, ALK, HER2, ROS1, and BRAF, which are known to have high mutation rates, we discovered some new mutated genes, such as catenin alpha-2 (CTNNA2), in LUAD patients treated with immune checkpoint inhibitors (ICIs). These mutant genes are potential therapeutic targets for LUAD. Methods: We analyzed a cohort of LUAD patients with somatic mutation and survival data in the Cancer Genome Atlas (TCGA) database and a cohort of LUAD patients receiving immune checkpoint inhibitors with clinical data and whole-exome sequencing (WES) mutation data to evaluate the role of CTNNA2 gene mutation in LUAD. In addition, CIBERSORT was used to analyze the immune characteristics of CTNNA2 wild-type patients and CTNNA2 mutant-type patients, and gene set enrichment analysis (GSEA) was employed for pathway enrichment analysis. The results were verified by downloading data regarding the drug sensitivity of LUAD cell lines from the Genomics of Drug Sensitivity in Cancer (GDSC) database. Results: We found that CTNNA2 mutation was associated with longer overall survival (OS) in LUAD patients. Analysis of the cohort from the Cancer Genome Atlas showed that patients with CTNNA2 mutation had more tumor neoantigens and a greater tumor mutation burden (TMB). Through further analysis of the tumor immune microenvironment, we found that in LUAD patients with CTNNA2 mutations, the gene expression levels of chemokine C-X-C motif chemokine 9 (CXCL9) and granzyme B (GZMB) were elevated, and the gene expression level of inhibitory receptor killer cell immunoglobulin-like receptor 2DL1 (KIR2DL1) was significantly reduced. These alterations might affect gene expression in macrophages, NK cells, and mast cell markers. In addition, LUAD patients with CTNNA2 mutation had a significantly increased number of mutations in DNA damage response (DDR) genes. The drug susceptibility results and gene set enrichment analysis showed that after CTNNA2 mutation occurred, changes were found in the DNA damage response pathway, the phosphoinositide 3-kinase (PI3K) pathway and others, indicating that CTNNA2 mutation can regulate the activation of PI3K and DDR pathways. Conclusion: Our findings provide novel insights into the underlying pathogenesis of LUAD. CTNNA2 mutation can change the immune microenvironment, thereby improving patient prognosis. The results also suggest that CTNNA2 may become a new biomarker and therapeutic target for LUAD in the future.

The Molecular and Functional Characteristics of HLA-G and the Interaction with Its Receptors: Where to Intervene for Cancer Immunotherapy?

Human leukocyte antigen G (HLA-G) mediates maternal-fetal immune tolerance. It is also considered an immune checkpoint in cancer since it may mediate immune evasion and thus promote tumor growth. HLA-G is, therefore, a potential target for immunotherapy. However, existing monoclonal antibodies directed against HLA-G lack sufficient specificity and are not suitable for immune checkpoint inhibition in a clinical setting. For this reason, it is essential that alternative approaches are explored to block the interaction between HLA-G and its receptors. In this review, we discuss the structure and peptide presentation of HLA-G, and its interaction with the receptors Ig-like transcript (ILT) 2, ILT4, and Killer cell immunoglobulin-like receptor 2DL4 (KIR2DL4). Based on our findings, we propose three alternative strategies to block the interaction between HLA-G and its receptors in cancer immunotherapy: (1) prevention of HLA-G dimerization, (2) targeting the peptide-binding groove of HLA-G, and (3) targeting the HLA-G receptors. These strategies should be an important focus of future studies that aim to develop immune checkpoint inhibitors to block the interaction between HLA-G and its receptors for the treatment of cancer.

Association of KIR gene polymorphisms with Type 1 Diabetes: a meta-analysis.

Type 1 Diabetes (T1D) is a T cell-mediated disease, in which autoimmune destruction of insulin-producing β-cells in pancreatic islets occurs. In recent decades, the role of Killer cell immunoglobulin-like receptor (KIR) gene polymorphisms in susceptibility to T1D has been demonstrated in an increased number of studies. Nonetheless, inconsistency has been observed in the results of performed association studies. To comprehensively clarify the association among KIR gene polymorphisms and the risk of T1D, this meta-analysis on the previously published association studies was carried out via incorporating multiple research. No publication has been recorded from Nov 2017 until July 2020 about the KIR genes and T1D. The PubMed/MEDLINE and Scopus databases were systematically searched up to November 2017 to identify investigations on the impact of the polymorphisms of KIR genes on susceptibility to T1D. The odds ratio (OR) with a 95% confidence interval (95% CI) was calculated. Funnel plot and Egger test were used to assess the publication bias. Thirteen qualified published case-control articles were found for evaluation in this meta-analysis. Our results show statistical significance between the genetic variations in the KIR2DL1 (OR = 0.42, 95% CI = 0.23-0.77; P = 0.005), KIR2DL2 (OR = 1.15, 95% CI = 1.00-1.32; P = 0.048), and KIR2DL5 (OR = 0.86, 95% CI = 0.75-0.98; P = 0.03) with susceptibility to T1D. This meta-analysis study provides reliable evidence that KIR gene polymorphisms may contribute to T1D risk. KIR 2DL1 and 2DL5 genes might be considered as a protective factor for T1D, while 2DL2 seemed to be a susceptibility factor.

Genetic Predisposition to Unexplained Recurrent Pregnancy Loss: Killer Cell Immunoglobulin-Like Receptor Gene Polymorphisms as Potential Biomarkers.

The aim of this study was to investigate the association between killer cell immunoglobulin-like receptor (KIR) gene polymorphisms and unexplained recurrent pregnancy loss (URPL). This study included 70 URPL patients with a history of two or more miscarriages and 70 healthy multiparous women as a control group. KIR genotyping was performed in all subjects for the KIRs 2DL1-4 and 2DS1-5 genes using polymerase chain reaction with sequence-specific primers. There was a significant relationship between the KIR genotypes and URPL. We demonstrated that the KIR 2DL1, 2DL2, 2DL3, 2DL4, 2DS1, 2DS2, 2DS4, and 2DS5 polymorphisms are associated with URPL. The 2DS3 genotype was not detected in either the case or control group. Gene-gene interactions for all genes were statistically significant. The KIR Bx genotype was found primarily in the case group, and at a higher frequency when compared with the control group. There was a significant relationship between the URPL cases and Bx haplotypes. We demonstrated that the KIR 2DL1, 2DL2, 2DL3, 2DL4, 2DS1, 2DS2, 2DS4, and 2DS5 polymorphisms are associated with URPL. The 2DS3 genotype of the KIR gene, however, was not detected in either the case or control group. The observations reported herein on KIR genotyping offer a new avenue for innovations in biomarker research concerning URPL and other complex obstetrics diseases.

Autoantibodies to killer cell immunoglobulin-like receptor 3DL1 in patients with systemic lupus erythematosus.

A genetic variant of the killer immunoglobulin-like receptor 3DL1 (KIR3DL1) has been found in patients with systemic lupus erythematosus (SLE). Herein, we investigated the presence of autoantibodies to KIR3DL1 in a cohort of patients with SLE. We tested sera from 28 patients with SLE, 11 patients with rheumatoid arthritis (RA) and 17 healthy control subjects for anti-KIR3DL1 activity by an enzyme-linked immunosorbent assay (ELISA) using recombinant KIR3DL1-enhanced green fluorescent protein (EGFP) and EGFP proteins. Anti-KIR3DL1 antibodies were detected in 22 (79%) of the 28 patients with SLE, whereas they were present in only three (27%) of the 11 patients with RA examined. Notably, 10 (91%) of the 11 samples from patients with SLE prior to therapy had anti-KIR3DL1 antibodies. None of the samples from healthy donors were positive for the antibodies. Here, we report the presence of anti-KIR3DL1 antibodies in the sera of patients with SLE for the first time. Anti-KIR3DL1 autoantibodies may be involved in the pathogenesis of autoimmune diseases.

Abnormal populations and functions of natural killer cells in patients with myelodysplastic syndromes.

Myelodysplastic syndromes (MDS) are clonal stem cell disorders characterized by ineffective hematopoiesis that lead to leukemia. Disorders of the immune system serve important functions in the pathophysiology and progression of this disease. Different levels or mechanisms of natural killer (NK) cells in patients with MDS have been measured in previous studies, making it challenging to understand the pathogenesis of NK cytotoxicity. The present study investigated the frequency of NK cell-mediated antibody-dependent cellular cytotoxicity and explored the function of NK cells by their activating receptors, inhibition signals, degranulation and cytotoxicity factors. In the present study, levels of cluster of differentiation (CD)3−CD56+ NK cells, CD16+-expressing NK cells and subset CD56dim NK cells were decreased in the peripheral blood of patients with MDS. Altered expression of NK protein 44, NK group 2 member D, killer cell immunoglobulin-like receptor 2DL1 (KIR2DL1) and KIR2DL3 on NK cell effector signaling pathways may trigger tumor cell lysis in patients with MDS. The weak cellular adhesion and decreased cytotoxicity of NK cells may lead to ineffective antitumor activity in MDS. These observations suggested that NK cells may serve as immunological determinants in MDS and may permit the development of NK cell-based immunotherapy for the treatment of patients with MDS.

Killer cell immunoglobulin-like receptor 2DL4 is expressed in and suppresses the cell growth of Langerhans cell histiocytosis.

Killer cell immunoglobulin-like receptor (KIR) 2DL4 (CD158d) is a receptor for human leukocyte antigen-G. The function of KIR2DL4 has been reported in human natural killer cell lymphoma and mastocytosis, but not in Langerhans cell histiocytosis (LCH). Herein, we examined the expression and function of KIR2DL4 in LCHs. In pathological specimens, 27 of 36 LCH cases (75.0%) were immunohistochemically positive for KIR2DL4. Its expression was independent of age, gender, location, multi- or single-system, and the status of BRAFV600E immunostaining. We also confirmed the expression of KIR2DL4 mRNA and protein in the human LCH-like cell lines ELD-1 and PRU-1. KIR2DL4 protein was distributed in the membrane and cytoplasm of ELD-1 cells, but only in the cytoplasm of PRU-1 cells. An agonistic antibody against KIR2DL4 reduced phosphorylation of extracellular signal-regulated kinases (ERKs) and suppressed the cell growth of ELD-1 cells in a Src homology region 2 domain-containing phosphatase-2 dependent manner, but it had no effect in PRU-1 cells. These results suggest that KIR2DL4-mediated ERK suppression is a possible therapeutic target for LCH cells.

Killer cell immunoglobulin-like receptor 3DL1 polymorphism defines distinct hierarchies of HLA class I recognition.

Natural killer (NK) cells play a key role in immunity, but how HLA class I (HLA-I) and killer cell immunoglobulin-like receptor 3DL1 (KIR3DL1) polymorphism impacts disease outcome remains unclear. KIR3DL1 (*001/*005/*015) tetramers were screened for reactivity against a panel of HLA-I molecules. This revealed different and distinct hierarchies of specificity for each KIR3DL1 allotype, with KIR3DL1*005 recognizing the widest array of HLA-I ligands. These differences were further reflected in functional studies using NK clones expressing these specific KIR3DL1 allotypes. Unexpectedly, the Ile/Thr80 dimorphism in the Bw4-motif did not categorically define strong/weak KIR3DL1 recognition. Although the KIR3DL1*001, *005, and *015 polymorphisms are remote from the KIR3DL1-HLA-I interface, the structures of these three KIR3DL1-HLA-I complexes showed that the broader HLA-I specificity of KIR3DL1*005 correlated with an altered KIR3DL1*005 interdomain positioning and increased mobility within its ligand-binding site. Collectively, we provide a generic framework for understanding the impact of KIR3DL1 polymorphism on the recognition of HLA-I allomorphs.

KIR and HLA haplotype analysis in a family lacking the KIR 2DL1-2DP1 genes.

The killer cell immunoglobulin-like receptor (KIR) gene cluster exhibits extensive allelic and haplotypic diversity that is observed as presence/absence of genes, resulting in expansion and contraction of KIR haplotypes and by allelic variation of individual KIR genes. We report a case of KIR pseudogene 2DP1 and 2DL1 gene absence in members of one family with the children suffering from acute myelogenous leukemia (AML). Killer cell immunoglobulin-like receptor low resolution genotyping was performed by the polymerase chain reaction (PCR)-sequence-specific primers (SSP)/sequence-specific oligonucleotide (SSO) method and haplotype assignment was done by gene content analysis. Both parents and the maternal grandfather, shared the same Cen-B2 KIR haplotype, containing KIR 3DL3, -2DS2, -2DL2 and -3DP1 genes. The second haplotype in the KIR genotype of the mother and grandfather was Tel-A1 with KIR 2DL4 (normal and deleted variant), -3DL1, -22 bp deletion variant of the 2DS4 gene and -3DL2, while the second haplotype in the KIR genotype of the father was Tel-B1 with 2DL4 (normal variant), -3DS1, -2DL5, -2DS5, -2DS1 and 3DL2 genes. Haplotype analysis in all three offsprings revealed that the children inherited the Cen-B2 haplotype with the same gene content but two of the children inherited a deleted variant of the 2DL4 gene, while the third child inherited a normal one. The second haplotype of all three offspring contained KIR 2DL4, -2DL5, -2DS1, -2DS4 (del 22bp variant), -2DS5, -3DL1 and -3DL2 genes, which was the basis of the assumption that there is a hybrid haplotype and that the present 3DL1 gene is a variant of the 3DS1 gene. Due to consanguinity among the ancestors, the results of KIR segregation analysis showed the existence of a very rare KIR genotype in the offspring. The family who is the subject of this case is even more interesting because the father was 10/10 human leukocyte antigen (HLA)-matched to his daughter, all members of the family have the “best” donor KIR-B content and the presence of a rare KIR genotype with KIR 2DP1-2DL1 genes absence.

Effects of methylated CpG islands in promoter region on the expression of KIR3DL1 protein

Objective To investigate the effects of methylated CpG islands in the promoter region on the expression of killer cell immunoglobulin-like receptor 3DL1 (KIR3DL1). Methods Three voluntary unpaid blood donors carrying high expression allele KIR3DL1*01502 and three donors carrying low expression allele KIR3DL1*005 were recruited in this study. The nucleotide sequences and the methylated CpG islands in the promoter regions of KIR3DL1*01502 allele and KIR3DL1*005 allele were analyzed. The NK cells expressing KIR3DL1*01502 and KIR3DL1*005 were respectively treated with 5-aza for the demethylation of CpG islands within the promoters. The expression of KIR3DL1 protein on the surface of NK cells was measured with flow cytometer. Results Two differences at nucleotide sites -65 and -269 were detected within the promoter regions of KIR3DL1*01502 and KIR3DL1*005, resulting in two distinct CpG islands. The CpG islands within the promoter of KIR3DL1*01502 allele were highly methylated. The expression of KIR3DL1 protein on NK cells which carried KIR3DL1*01502 allele was significantly increased after the demethylation of CpG islands. However, the treatment of demethylation had no significant effects on the expression KIR3DL1 protein on NK cells harboring KIR3DL1*005 allele. Conclusion The methylated CpG islands within the promoter of KIR3DL1*01502 allele affected the antigen expression on the surface of NK cells. Different KIR3DL1 alleles might show different mechanisms in regulating antigen expression. Key words: Killer cell immunoglobulin like receptor; Methylation; Promoter

The Influence Of KIR Haplotype In ITP Incidence, Treatment Response and Bleeding Symptoms

The pathogenesis of immune thrombocytopenia (ITP) is multifactorial, with both cellular and humoural immune dysfunction. The role of NK cells has not been well defined in ITP but in other diseases NK cells have a role in rejecting “foreign” eg transplanted organ or tumor, and also acting against self as occurs in autoimmunity. NK cell activity is orchestrated by the balance of activating vs. inhibitory signalling, in particular via the killer cell immunoglobulin-like receptor (KIR) family of receptors. Significant variation exists in KIR allelic subtype and copy number for the KIR between individuals, and associations have been made with certain haplotypes and a number of autoimmune disorders including rheumatoid arthritis, scleroderma and diabetes. Previous reports have demonstrated a reduction in natural killer (NK) cell number and function in ITP and expression of inhibitory KIR genes is increased in patients in remission vs. active ITP. MethodsTo explore whether a particular KIR haplotype might predispose to ITP, and also affect response to ITP treatment, we performed KIR genotyping using the Invitrogen SSP kit on 92 patients attending a haematology centre in New York and compared the results to data from 213 controls taken from the USA Eastern Database. Genomic DNA was typed for the inhibitory KIR genes KIR2DL1, KIR2DL2, KIR2DL5A (alleles 001 and 002), KIR2DL5B (alleles 002-004, 06, and 007), KIR3DL1, KIR3DL3; the activating KIR genes KIR2DS1, KIR2DS2, KIR2DS3, KIR2DS4, KIR2DS5, KIR3DS1; the framework genes KIR2DL3, KIR2DL4, KIR3DL2, KIR3DP1; and the pseudogene KIR2DP1. The patients with ITP had been or were receiving treatment with IVIG (n=64), corticosteroids (72) and rituximab (37). Bleeding symptoms were recorded. Response to treatment was defined as complete - platelet count increase to > 100 x 109/mL; partial - platelet count increase to > 50 x 109/mL; or no response. For the purpose of analysis, PRs and CRs were combined. A comprehensive database allowed a logistic regression, assessing both responses to treatments, platelet counts, neutrophil counts, CRP, lymphocyte subsets and bleeding symptoms. ResultsThe expression of two inhibitory KIR genes, 2DL1 and 3DL1, was significantly lower in the patients with ITP as compared to controls (87% 2DL1 and 87% 3DL1 compared to 99% in controls - P < 0.02). Response to rituximab was strongly related to KIR haplotype expression. 2DL1 expression was higher among nonresponders to Rituximab (100% of non responders compared to 82% of responders), whereas 2DL3 expression was significantly lower (79% compared to 90%) (P < 0.05, Figure 1B). Separately, patients with the 2DS3 allele, an activatory KIR, were 5.5 times more likely to have experienced significant bleeding. ConclusionsAlthough these findings are preliminary and require further investigation, these data suggest that increased cytotoxic autoimmunity due to reduced KIR inhibition may be associated with the development of ITP and possibly contribute importantly to the pathogenesis. Anti-CD20 targeting therapy directed at B cells was strongly influenced by 2 different KIRs (1 upregulated and one down-regulated) emphasizing the potential role of NK cells in elimination of tissue-based (nodal) B cells. Finally a more pronounced clinical phenotype with a markedly higher incidence of severe bleeding associated with an increased activatory KIR expression demonstrates the role of NK cells in bleeding presumably via their effects on either endothelial cells or platelet function.These exciting findings will be pursued for confirmation in a larger number of patients. Disclosures:Bussel:Amgen: Family owns stock Other, Membership on an entity's Board of Directors or advisory committees, Research Funding; Cangene: Research Funding; Genzyme: Research Funding; GlaxoSmithKline: Family owns stock, Family owns stock Other, Membership on an entity's Board of Directors or advisory committees, Research Funding; IgG of America: Research Funding; Immunomedics: Research Funding; Ligand: Membership on an entity's Board of Directors or advisory committees, Research Funding; Eisai: Membership on an entity's Board of Directors or advisory committees, Research Funding; Shionogi: Membership on an entity's Board of Directors or advisory committees, Research Funding; Sysmex: Research Funding; Symphogen: Membership on an entity's Board of Directors or advisory committees.

Soluble Human Leukocyte Antigen-G5 Activates Extracellular Signal-Regulated Protein Kinase Signaling and Stimulates Trophoblast Invasion

Soluble human leukocyte antigen-G (HLA-G) is a non-classical class Ib HLA molecule that is secreted from blastocysts. Soluble HLA-G modulates the immune tolerance of the mother and can be used as a prognostic factor for the clinical pregnancy rate. However, the underlying mechanism of how soluble HLA-G5 affects pregnancy remains largely unknown. We hypothesized that soluble HLA-G5 promotes successful implantation and pregnancy by modulating trophoblast invasion through receptor binding and activation of extracellular signal-regulated protein kinase (ERK) signaling pathway. Recombinant HLA-G5 protein over-expressed in E. coli BL21 was purified to near homogeneity. We studied the expression of HLA-G5 and its receptors, the leukocyte immunoglobulin-like receptor subfamily B1 (LILRB1) and killer cell immunoglobulin-like receptor 2DL4 (KIR2DL4), in primary trophoblasts and trophoblastic (JAr and JEG-3) cell lines by florescence-labeled HLA-G5. HLA-G5 was detected in the primary trophoblasts and JEG-3 cells. The LILRB1 and KIR2DL4 receptors were expressed in both primary trophoblasts and trophoblastic cell lines. HLA-G5 stimulated cell invasion (p<0.05) and increased urokinase (uPA) and matrix metalloproteinases (MMPs) transcripts and their activity (p<0.05) in trophoblastic cells. HLA-G5 activated the ERK signaling pathway and induced ERK1/2 phosphorylation in the trophoblastic cell lines. Addition of ERK inhibitors (U0126 and PD98059) nullified the stimulatory effect of HLA-G5 on trophoblastic cell invasion. Taken together, HLA-G5 induced trophoblast invasion by binding to KIR2DL4 and LILRB1, by increasing uPA and MMPs expressions and by activating the ERK signaling pathway.

Natural Killer Cell Immunoglobulin-like Receptor (KIR) genotypes in Follicular Lymphoma patients: Results of a pilot study

AimsThe Natural Killer Cell Immunoglobulin-like Receptor (KIR) genotype profiling in Follicular Lymphoma has not been reported before in the literature. Materials and methodsDNA extracted from 20 Follicular Lymphoma patients and 62 healthy controls was analyzed for KIR genotyping using a polymerase chain reaction/sequence specific primers technique (PCR/SSP) for the presence of 16 KIR gene and pseudogene loci. ResultsThe AA, AB, and BB genotype frequencies were, respectively, 20%, 60% and 20% with an A:B ratio of 1:1. KIR 2DL4, KIR 3DL2, KIR 3DL3, and KIR 3DP1*003 were presented in all individuals. No significant difference between patients and controls was detected. ConclusionKIR genotyping profile does not seem to be associated with Follicular Lymphoma. The results presented in this pilot research represent the first international report about this important clinical entity.

Killer cell immunoglobulin‐like receptor along with HLA‐C ligand genes are associated with type 1 diabetes in Chinese Han population

Killer cell immunoglobulin-like receptor (KIR) genes and their putative ligands human leukocyte antigen (HLA)-C genes have been associated with type 1 diabetes (T1D). We hypothesize that KIR genes and their ligands HLA-C genes are important in T1D aetiology. KIR and HLA-C ligand genotyping was performed in 259 T1D patients and 262 healthy children. No significant difference was observed in the distribution of KIR genes between T1D patients and healthy controls. However, frequency of HLA-C1 gene and HLA-C2 gene (marginal association) was higher in patient group. The combinations 2DL2-/HLA-C1+; 2DL3+/HLA-C1+; 2DS2-/HLAC1+ were positively associated with T1D. The combinations 2DL1+/HLA-C2-; 2DL2-/HLA-C1-; 2DL3+/HLA-C1-; 2DS2-/HLAC1- were found to be negatively associated with T1D. Among the genes we tested, a combination of HLA-C1 and -C2 conferred the strongest association with T1D and the strength of this association was higher than that of HLA-C1 alone. The frequencies of KIR 2DL1, 2DL2 and 2DL3 and HLA-C1 were higher in T1D patients positive for GAD65 autoantibody; frequency of KIR 2DS4 is higher in T1D patients positive for IA-2 autoantibody. The association between KIR/HLA-C gene and autoantibody status was not statistically significant after applying Bonferroni correction. In our study of a Han population (East China), we found no direct association of KIR genes with T1D. However, a combination of HLA-C1 and -C2 showed a positive association with T1D. Different combinations of HLA-C and KIR showed positive and negative association with T1D.

Killer cell immunoglobulin-like receptor 3DL1 licenses CD16-mediated effector functions of natural killer cells

Activating receptor-mediated recognition of stress-induced ligands or IgG antibody bridging of tumor or pathogen-associated antigens to the FcγRIII CD16 triggers NK cells to kill transformed and infected cells with reduced HLA-I expression. According to the licensing hypothesis, NK cells become competent for activating receptor-mediated triggering after a formative encounter between a NK inhibitory receptor and its ligand. This general hypothesis is supported by murine and human studies, but to date, evidence of a role for such licensing in human ADCC is ambiguous. Inhibitory receptor interactions with HLA-C promote NK cell ADCC licensing, but interactions between KIR3DL1 and its HLA-Bw4 ligand may be insufficient. We investigated the impact of KIR3DL1 and HLA-Bw4 coexpression on NK cell ADCC using a robust, genuine target system of antibody-bearing EBV-transformed B lymphocytes. Although numbers of KIR3DL1(+) NK cells were similar in HLA-Bw4(+) and HLA-Bw4(-) individuals, general levels of ADCC mediated against target cells were significantly higher in a group of HLA-Bw4(+)KIR3DL1(+) individuals than in a comparable HLA-Bw4(-) group. Flow cytometry demonstrated directly that a significantly higher fraction of KIR3DL1(+) NK cells derived from HLA-Bw4(+) compared with HLA-Bw4(-) individuals produced IFN-γ following stimulation with ADCC targets. Murine FcR-bearing P815 target cells also triggered higher levels of CD16-mediated cytotoxicity by NK cells from HLA-Bw4(+)KIR3DL1(+) individuals. These results indicate a prominent role for KIR3DL1/HLA-Bw4 interactions in licensing NK cells for CD16-mediated effector function.

Investigation of killer cell immunoglobulin‐like receptor gene diversity, KIR2DL1 and KIR2DS1

Polymorphism in the alleles of the killer cell immunoglobulin-like receptor 2DL1 and 2DS1 genes has been investigated by the development of polymerase chain reaction-sequence-specific oligonucleotide probing systems. The methods have been applied to 77 Northern Irish families, establishing allele frequencies from the unrelated parents. Additionally, cell line DNA from individuals and CEPH families of the 13th International Histocompatibility Workshop panel were investigated. Eight of the reported KIR2DL1 alleles and only the KIR2DS1*002 allele were identified in the groups studied. Two individuals were positive for three alleles of KIR2DL1, and a putative variant of KIR2DL1*001 was observed. Results also indicated an inherited KIR2DL1/2DS1 splice variant present in a haplotype with several core loci absent, in two families.

KIR2DL1 allelic diversity: four new alleles characterized in a bone marrow transplant population and three families

Sequencing of PCR amplified genomic DNA including most of the coding region was used to identify killer cell immunoglobulin-like receptor 2DL1 alleles from three families and 77 bone marrow transplant patients and donors. Alleles 2DL1*00302 and *002 were frequently observed in addition to two other known alleles and four new alleles, 2DL1*00402, 2DL1*007, 2DL1*008, and 2DL1*009.