A protective effect conferred by KIR3DL1 and its cognate ligand against cervical cancer among ethnic Han Chinese population and its potential mechanism / 中华医学遗传学杂志

OBJECTIVE@#To explore the role of inhibitory KIR (iKIR) and its cognate HLA ligand in the occurrence and development of cervical cancer among ethnic Han Chinese and its potential mechanism.@*METHODS@#Peripheral blood samples from 265 Han Chinese patients with cervical intraepithelial neoplasia (CIN)/cervical cancer and 200 ethnically matched healthy controls were collected. The results of KIR PCR-SSP, HLA PCR-rSSO and KIR3DL1 PCR-SBT, together with cervical cancer data from the TCGA database, were used to assess the association of iKIR genes, receptor-ligand gene combinations, iKIR transcription level in the tumor tissue and the KIR3DL1 alleles with the occurrence and development of cervical cancer.@*RESULTS@#Among the four iKIR genes (KIR2DL1, 2DL2/3, 3DL1 and 3DL2), the frequencies of KIR3DL1 and KIR3DL1-HLA-Bw4 genes among controls were significantly higher than those of the cervical cancer group (96.5% vs. 87.0%, P = 0.018; 81.5% vs. 64.8%, P=0.009). The survival rate of cervical cancer patients with a high transcription level of KIR3DL1 in tumor tissues was significantly higher than those with a low/medium transcription level (P=0.028). The frequency of strong-inhibitory and high-expression KIR3DL1*01502 allele among the healthy population was significantly higher than that of the cervical cancer group (76.0% vs. 59.3%, P =0.015).@*CONCLUSION@#Combined KIR3DL1 and KIR3DL1-HLA-Bw4 can confer a protective effect against the development of cervical cancer, which may be attributed to the strong-inhibitory and high-expression allele of KIR3DL1*01502.

Analysis of KIR3DL1 expression levels on 92 cases of normal donors for hematopoietic stem cells transplant / 中华血液学杂志

<p><b>OBJECTIVE</b>To study KIR3DL1 expression level on NK cell surface of normal donors for hematopoietic stem cell transplantation（HSCT）.</p><p><b>METHODS</b>Ninety- two donors were performed by using of KIR genotyping, HLA high resolution genotyping and KIR3DL1 expression level using sequencebased testing（SBT）, PCR- sequence specific primer（SSP）and flow cytometry methods.</p><p><b>RESULTS</b>In 92 donors, the frequencies of KIR-A/A, Bx1, Bx2 for common genotypes were 46.74%（43/92）, 18.48% （17/92）and 9.78%（9/92）respectively（P<0.001）; KIR-A, B1, B2, B3 for common KIR haplo-type were 70.33%（128/182）, 10.99%（20/182）, 7.14%（13/182） and 4.39%（8/182） respectively（P<0.001）; the frequencies of HLA-BW4/BW4, HLA-BW4/BW6, BW6/BW6 ligands were 13.79%, 67.81% and 18.39% respectively（P<0.001）. KIR3DL1 middle expression level among haplo- type KIR- A/A and KIR- Bx, KIR-B/B were 18.77%（3.11%-49.24%）, 13.14%（1.70%-63.32%）and 0.37%（0.20%-2.60%）respectively （P<0.05）. KIR3DL1 expression level［18.77%（3.11%-49.24%）］in haplo-type KIR-A/A was higher than haplo-type KIR-Bx at the same time did not express 2DL2 group［11.20%（3.50%-36.08%）］（P=0.019）. KIR3DL1 expression level in recognition group（HLA-BW4 positive group）［17.61%（1.40%-49.24%）］ was higher than KIR3DL1 unrecognized group（HLA-BW4 negative group）［10.60%（3.50%-18.56%）］ （P=0.006）.</p><p><b>CONCLUSION</b>The expression levels of KIR3DL1 in different KIR genotypes, haplotypes and HLA ligands were statistically significance.</p>

Inhibitory killer cell immunoglobulin-like KIR3DL1 in combination with HLA-B Bw4[iso] protect against ankylosing spondylitis

The HLA class I molecules serve as ligands for both T cell receptors and killer cell immunoglobulin-like receptors [KIRs]. We investigated the HLA-C and HLA-Bw4 alleles as well as KIRs expression on CD56 positive lymphocytes to evaluate whether these genes and molecules could influence Ankylosing spondylitis [AS] susceptibility, alone or in combination. We typed 40 AS patients and 40 normal controls for HLA-C asn[80] [group 1] and HLA-C lys[80] [group 2], HLA-B Bw4[thero], HLA-B Bw4[iso] and HLA-A Bw4 alleles by PCR-SSP method. We also assessed the expression of KIR2DL1/2DS1, KIR2DL2/2DL3, KIR3DLI and KIR2DS4 by flow cytometry. The Pearson chi-square or Fisher exact test was performed for statistical analysis. The frequency of HLA-B Bw4[iso] but not HLA-B Bw4[thero] and HLA-A Bw4, ligand for the inhibitory KIR3DL1, was significant reduced in AS patients as compared with controls [p<0.01]. No significant differences were observed in gene carrier frequencies of HLA-C group 1 and 2 between AS and controls. Although no differences were found in the expression of KIR receptors between AS and normal was reduced in patients with AS compared to healthy controls [p<0.009]. We conclude that HLA-B Bw4[iso], the ligand of inhibitory KIR3DL1, with and without the expression of KIR3DL1 might be involved in protection against AS. Our results suggest that besides the HLA and KIR genotype, expression levels of KIRs may be involved in the pathogenesis of AS disease

Killer immunoglobulin-like receptor gene genotype and expression pattern in healthy people / 中国实验血液学杂志

The aim of study was to clarify the repertoire of killer immunoglobulin-like receptor (KIR) at the level of DNA and RNA in healthy persons and to compare KIR on genotypes and expression patterns. KIR genotypes including KIR2DL1, 2DL2, 2DL3, 2DL4, 2DL5, 2DS1, 2DS2, 2DS3, 2DS4, 2DS5, 3DL1, 3DL2, 3DL3, 3DS1, 2DP1 and 3DP1 were analyzed by PCR. The phenotypes including KIR2DL1, KIR2DL2, KIR2DL3, KIR3DL1, KIR2DS1, KIR2DS3, KIR2DS2/4 gene were determined by RT-PCR. The results showed that the genes of KIR2DL1, KIR2DL3, KIR2DL4, KIR3DL2, KIR3DL3 and KIR3DP1 could be detected in all healthy persons, NK-92MI cells and Molt4 cells, but all corresponding receptors were not expressed by Molt4 T cells. Only partial transcripts of KIR2DL1, KIR2DL3 and KIR2DS2/4 were detectable in NK-92MI cells. If genotypes of KIR2DL1, 2DL2, 2DL3, 2DS1, 2DS2, 2DS3 and 2DS4 were detected in healthy persons, almost all transcripts of corresponding receptors were expressed in peripheral blood NK cells. The expression levels of KIR were different. In conclusion, the repertoires of KIR are individually specific. The expression pattern of KIR is also specific, the expression levels of different KIRs are different in one individual, and the expression levels of the same KIR are also different in different individuals.

Effect of demethylating treatment on cytotoxicity of NK-92MI cells / 中国实验血液学杂志

In order to investigate the effect of demethylating treatment on the expression of inhibitory KIR and the cytolytic activity of NK-92MI cells, and to study the possible relationship between the demethylation of inhibitory kir gene and the function of NK cells. NK-92MI cells were treated with 5-azacytidine to induce DNA demethylation. The expression of KIR3DL1, KIR2DL2/KIR2DL3, KIR2DL1 and the viability of NK-92MI cells were detected by flow cytometry. The KIR3DL1 positive and the KIR3DL1 negative NK-92MI cells were also sorted by flow cytometry. The cytotoxicity of NK-92MI against K562 cells was detected by the LDH release assay. The results demonstrated that the expressions of KIR3DL1, KIR2DL2/KIR2DL3 and KIR2DL1 in NK-92MI cells all increased after treating with 1.0, 2.5 and 5 micromol/L of 5-azacytidine for 72 hours. And the cytotoxicity of NK-92MI against K562 cells decreased. In these dose range, 5-azacytidine did not influence the viability of NK-92MI cells. Additionally, the cytotoxicity of KIR3DL1 positive NK-92MI cells was lower than that of the KIR3DL1 negative cells. It is concluded that the demethylating treatment suppresses the cytotoxicity of NK-92MI cells through increasing the expression of inhibitory KIR.

Construction of kir3dl1 promoter expression vector and its activity in K562 cell line / 中国实验血液学杂志

To analyze the function of kir3dl1 core promoter and study the possible regulation mechanism of kir3dl1 gene expression, a kir3dl1 promoter-luciferase reporter vector was constructed and the promoter activity was evaluated in the K562 cell line. A core promoter fragment of the kir3dl1 5'-untranslated region was amplified by PCR. PCR products were cloned into BglII/NcoI-digested pGL3-basic reporter vector; the polycationic compound SuperFect-reporter vector complexes were transferred into K562 cells. The Dual-Luciferase Reporter Assay System was used to quantitate the reporter vector luciferase activity. MTT method was used to measure the influence of SuperFect-DNA complexes on the survival rate of K562 cells. The results indicated that a 254-bp promoter fragment of kir3dl1 gene was successfully constructed and cloned into the pGL3-basic reporter vector, which was authenticated by BglII/NcoI digestion and DNA sequencing. The luciferase activity of the minimal promoter construct was significantly higher than that of the pGL3-Basic promoter in K562 cells. Transiently transfected cells presented continuously optimal luciferase activity and relative luciferase activity up to 3 days. The cell activity was between 76% and 92%. It is concluded that a kir3dl1 promoter-luciferase reporter vector is successfully constructed, the transfection system used in this study can effectively transfer gene in K562 cells. The kir3dl1 core promoter possesses higher activity in K562 cells, and can promote significantly expression of luciferase reporter gene in K562 cells.

DNA methylation regulates kir3dl1 gene expression in K562 cell line / 中国实验血液学杂志

To analyze the methylation pattern of kir3dl1 promoter and its relationship with gene expression, and to study the possible regulation mechanism of kir3dl1 gene expression, the methylation status of kir3dl1 promoter in K562 cell line was detected by bisulfite sequencing technique. Then K562 cells were treated with 5-azacytidine so as to induce de-methylation of CpG island, and the relationship of CpG island methylation with kir3dl1 gene expression was investigated. The results demonstrated that CpG dinucleotides surrounding core promoter region of kir3dl1 gene was methylated at a frequency of 20% to 100% in K562 cell line. Comparison of promoter sequence with GenBank database revealed a base substitution within a putative binding site for the transcription factor E2F in K562 cell line. This mutation forms a new methylation site in kir3dl1 promoter. DNA-demethylating treatment resulted in de novo expression of kir3dl1 gene in formerly non-expressed K562 cell line. It is concluded that kir3dl1 expression in K562 cells is regulated by DNA methylation. Deeply to study E2F function contributes to profound understanding of its role in kir3dl1 gene expression regulation.

Molecular regulation of KIR3DL1 gene expression by transcription factor E2F1 / 中华血液学杂志

<p><b>OBJECTIVE</b>To study the role of transcription factor E2F1 in the transcription of KIR3DL1 promoter, and to identify its molecular mechanism of regulation of KIR3DL1 gene expression.</p><p><b>METHODS</b>The mutant promoter fragment of KIR3DL1 gene was amplified from genomic DNA of K562 cells by PCR. The PCR product was cloned into pGL3-basic reporter vector to construct KIR3DL1 promoter-luciferase reporter plasmid (PLRP). The binding of E2F1 to KIR3DL1 promoter was detected by chromatin immunoprecipitation (CHIP) assays. The KIR3DL1 PLRP construction was transfected into K562 cells using cationic liposome SuperFect. The binding of E2F1 to the construction was detected by CHIP assays and reporter activity was quantitated by the dual-luciferase reporter assay system. The mammalian expression vector containing E2F1 cDNA was co-transfected into K562 cells with wild-type KIR3DL1 PLR construction and reporter activity was quantitated.</p><p><b>RESULTS</b>The mutant KIR3DL1 PLR recombinant was constructed successfully and a naturally point mutation (TTTGGCGC-->TTCGGCGC) within a putative E2F1 binding site in the KIR3DL1 promoter region was authenticated by DNA sequencing. E2F1 absolutely could not bind to the mutant KIR3DL1 promoter in K562 cells, but could bind to the wild-type one in NK-92MI cells. The binding of E2F1 to the mutant KIR3DL1 PLR construction was partially reserved, however, its relative luciferase activity was decreased by 50% than that of wild-type. On the other hand, when co-transfected with E2F1 mammalian expression vector, the relative luciferase activity of wild-type construction was increased, over 2-fold higher than that of control group.</p><p><b>CONCLUSION</b>E2F1 participates in the regulation of the transcriptional activation of KIR3DL1 gene. The number of CpG dinucleotide and methylation pattern within the E2F1 binding site probably influence the binding of E2F1 to target sequence.</p>

Polymorphism of killer cell immunoglobulin-like receptor gene and its correlation with leukemia / 中国实验血液学杂志

The study was purposed to investigate the polymorphism of killer cell immunoglobulin-like receptor (KIR) gene of the patients with leukemia and to explore the correlation between the KIR gene and susceptibility of leukemia. The KIR genotype of 50 patients with leukemia and 60 healthy controls in northern. Hans were analyzed by PCR-SSP. The results indicated that the present known 18 KIR genes were detected and identified. The frequencies of KIR 3DL3, 3DL2 and 2DL4 were 100% in all subjects, with the most frequent genotype KIR 3DP1 (0.86) followed by 2DP1, 2DL3, 3DL1, 2DL1, 3DS1, 2DL5, 2DS4, 2DS2, 1D, 2DS5, 2DL2, 2DS1, 2DS3 and 3DP1v in leukemia successively. Compared with the control, the KIR 3DL1 (0.60) and 2DL1 (0.57) were significantly lower in the leukemia patient group than that in the control group (1.00) (P < 0.01). It is concluded that the polymorphism of KIR gene is associated with susceptibility of leukemia in Hans. There may be a negative correlation between pathogenesis of leukemia and KIR 3DL1, KIR 3DS1, KIR 2DL1, KIR 2DL5 genes.

Killer Ig-like receptor gene content diversity and haplotype analysis in Chinese Han population in Shanghai / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To detect the diversity of killer Ig-like receptor(KIR) gene content and the combination of haplotypes in Chinese Han population in Shanghai area.</p><p><b>METHODS</b>DNA samples from 87 randomly unrelated healthy individuals in Shanghai Han population were genotyped with SSP/PCR method.</p><p><b>RESULTS</b>(1) Frequencies of KIR genes: All of 18 known KIRs genes, such as 2DL1-5, 2DS1-5, 3DL1-3, 3DS1, KIR1D and the pseudogenes X, Xv and Z(KIR2DP1) were observed in Shanghai Hans. All individuals contain 3DL3, 2DL4, 3DL2 and 3DL1; the most common genes were 2DL3, Z, 2DL1 and X; the following were 2DS4, 1D, 2DL5, 2DS1, 3DS1 and 2DS5; the next were 2DS2, 2DL2, 2DS3 and Xv. (2) Frequencies of KIR gene haplotypes; there were 13 haplotypes detected in 87 Han individuals, among them, the most frequent one was type 2 (haplotypeA-2DS4). (3) Frequencies of KIR genotypes: 18 kinds of the combinations of the haplotypes were observed; the most frequent ones were AJ(2,2), AF (1,2). Also, In this study were identified five new genotypes FZ1 2 9 , FZ2 1 16 , FZ3 6 17 , FZ4 4 13 and FZ5 2 6 ,which had not been observed in Caucasians so far.</p><p><b>CONCLUSION</b>These findings suggest that there are distinctive frequencies of KIR gene content, haplotype as well as genotype in Chinese Han population in Shanghai area.</p>