QPY/RAH haplotypes of the GZMB gene are associated with natural killer cell cytotoxicity.

Granzyme B (GzmB) is a component of cytolytic granules within NK cells and is involved in several pathologies. It has previously been reported that there are three non-synonymous coding SNPs (rs8192917; Q48R, rs11539752; P88A, and rs2236338; Y245H) in the GZMB gene and that the QPY/RAH allele was clustered together close to the C-terminal α-helix. However, it is unknown whether the function of GzmB produced from NK cells is influenced by QPY/RAH polymorphism. The authors investigated the distribution of QPY/RAH polymorphism of the GZMB gene in a Japanese population (n = 106), and the involvement of Q48R polymorphism in NK cell cytotoxicity, degranulation, and production of GzmB. A strong linkage disequilibrium was observed among these SNPs, and NK cell cytotoxicity was influenced by rs8192917 (Q48R). Moreover, it found that R48-GzmB is a stable protein that accumulates to similar levels in activated NK cells as Q48-GzmB. rs8192917 polymorphism may influence antitumor activity and the effect of antitumor cellular immunotherapy. The authors expect that these new informations about QPY/RAH polymorphism of the GZMB gene could help to assess the impact of NK cell cytotoxicity in several pathologies and aid their treatment.

Genetic Factors of Low-responsiveness to Hepatitis B Virus Vaccine Confirms the Importance of Human Leukocyte Antigen Class II Types in a Japanese Young Adult Population.

We investigated the genetic mechanisms underlying the association between human leukocyte antigen (HLA) types and the immune response to hepatitis B virus (HBV) vaccination in 84 healthy Japanese adults, and found that the HLA-DRB1＊04 and HLA-DQB1＊03 frequencies were higher in the low responders (<10 mIU/ml; n=9, 10.7%) compared to the responders (≥10 mIU/ml, n=75, 89.3%). The combination of DRB1＊04 and DQB1＊03 was associated with a low response to vaccination. The DRB1＊04 and DQB1＊03 haplotypes' frequencies were significantly higher in the low responders compared to responders. Novel candidate HLA types may be important in Japanese individuals.

Evaluation of new automated syphilis test reagents 'IMMUNOTICLES AUTO3' series: performance, biochemical reactivity, and clinical significance.

BACKGROUND: Automated nontreponemal and treponemal test reagents based on the latex agglutination method (immunoticles auto3 RPR: ITA3RPR and immunoticles auto3 TP: ITA3TP) have been developed to improve the issues of conventional manual methods such as their subjectivity, a massive amount of assays, and so on. We evaluated these reagents in regards to their performance, reactivity to antibody isotype, and their clinical significance. METHODS: ITA3RPR and ITA3TP were measured using a clinical chemistry analyzer. Reactivity to antibody isotype was examined by gel filtration analysis. RESULTS: ITA3RPR and ITA3TP showed reactivity to both IgM- and IgG-class antibodies and detected early infections. ITA3RPR was verified to show a higher reactivity to IgM-class antibodies than the conventional methods. ITA3RPR correlated with VDRL in the high titer range, and measurement values decreased with treatment. ITA3RPR showed a negative result earlier after treatment than conventional methods. ITA3TP showed high specificity and did not give any false-negative reaction. Significant differences in the measurement values of ITA3RPR between the infective and previous group were verified. CONCLUSIONS: The double test of ITA3RPR and ITA3TP enables efficient and objective judgment for syphilis diagnosis and treatments, achieving clinical availability.

[Increase in Alkaline Phosphatase Activity after High-Fat Meal Ingestion is Correlated to the Amount of ABH Substances in Saliva].

Intestinal alkaline phosphatase (IAP) appears in the circulation more frequently in blood group B or O secretors than in blood group A or AB secretors and non-secretors, and serum IAP activity rises following the ingestion of a high-fat meal. In a previous study, the occurrence of two IAP isoforms, with high (HIAP) and normal molecular mass (NIAP), in healthy sera was demonstrated by 6.0% polyacrylamide gel electrophoresis in the presence of 1% Triton X-100. NIAP was present in the fasting serum of only healthy blood group B or O secretors, but was present in all subjects following ingestion of a high-fat meal. We classified 56 healthy subjects into 3 blood groups: B (n = 19), O (n = 17), and A (n = 20), and measured their serum ALP activity in a fasting state and 6 h after a high-fat meal. The amount of ABH substances in the saliva of each subject was determined by the hemagglutination inhibition test. Correlation coefficients between the change in ALP activity after high-fat meal ingestion and the hemagglutination inhibition values in saliva were 0.925 in blood group B, 0.879 in blood group O, and 0.906 in blood group A. These results suggest that increases in ALP activity in the circulation following the ingestion of a high-fat meal are closely related to the amount of ABH substances in saliva.

[Alkaline phosphatase activity in blood group B or O secretors is fluctuated by the dinner intake of previous night].

We previously reported that two intestinal alkaline phosphatase (IAP) isoforms, high molecular mass IAP (HIAP) and normal molecular mass IAP (NIAP), appear in healthy serum with our Triton-PAGE method for determination of ALP isozymes. In addition, HIAP is chiefly present in blood group B or O secretors, and a large amount of NIAP is secreted into the circulation after high-fat meal in blood group B or O secretors. In the present paper, we investigated the relationship between alkaline phosphatase (ALP) activity in early morning with the patient in a fasted state and the dinner intake of previous night. Two types of dinner were prepared; a low-fat meal (520 kcal), and a high-fat meal (1,040 kcal). Subjects ate the 2 types of dinner on different days. The mean ALP activities at 14 h after high-fat meal ingestion in blood group B or O secretors (n=14) from JSCC and IFCC methods were 8.8% and 5.2% higher than those at 14 h after low-fat meal ingestion in blood group B or O secretors, respectively. The increases in ALP activity between after high-fat meal and low-fat meal were nearly identical to the increases in NIAP activity. These results suggest that a high-fat meal is more likely to affect ALP activity at the early morning with the patient in a fasted state in blood group B or O secretors.

[Analysis of the complete hepatitis B virus genomes in a patient for repeated seroconversion to anti-HBe antibody due to co-infection with two virus clones].

We report a case of repeated seroconversion to anti-HBe antibody in a patient with chronic hepatitis B. We amplified and cloned sections of the hepatitis B virus (HBV) genes by polymerase chain reaction (PCR), and sequenced the PCR products. The results were analyzed by connecting all of the sequences to generate complete genomes. As a result, we confirmed the coexistence of two different HBV clones, both of which had the same subtype (adr) and genotype (C2). Neither clone had mutations in the S gene region in sequences involved in gene expression or in sequences involved in drug resistance. However, both clones had mutations in the core promoter(A1762T, G1764A). In one HBe antibody-positive clone, a pre-core mutation associated with HBe antigen negativity (G1896A) was found. In addition, pre-S2 deletion and 6 amino acid substitutions in the core protein gene were detected in this clone. The other HBe antigen-positive clone was essentially wild-type. Interestingly, this clone had accumulated mutations, which participated in DNA polymerase inactivation in the P gene region. Therefore, it is expected that this clone cannot replicate its own DNA polymerase. Consequently, this repeated seroconversion phenomenon was suggested to be responsible for the observed findings. In conclusion, analysis of the complete HBV genome has greatly expanded the number of mutations identified, and this method is useful for understanding the causes of rare cases of hepatitis B.

MicroRNA-150 suppresses p27Kip1 expression and promotes cell proliferation in HeLa human cervical cancer cells.

MicroRNAs (miRNAs) exert critical roles in the majority of biological and pathological processes. Recent studies have associated miR-150 with a number of different cancer types. However, little is known about miR-150 targets in cervical cancer. In the present study, the HeLa human cervical cancer cell line was transfected with hsa-miR-150-5p mimics, hsa-miR-150-5p inhibitors or miRNA controls. miR-150 was predicted to bind the 3'untranslated region (3'UTR) of the CDKN1B gene, which encodes the cyclin-dependent kinase inhibitor 1B (p27Kip1). The direct binding between miR-150 and the 3'UTR of CDKN1B was confirmed using dual-luciferase reporter assays. The effects of miR-150 on CDKN1B mRNA expression, p27Kip1 protein expression, cell cycle and cell proliferation were determined using reverse-transcription quantitative PCR, western blot analysis, flow cytometry and WST-8 assays, respectively. miR-150 was demonstrated to directly target the 3'UTR of CDKN1B in transfected HeLa cells. The expression of CDKN1B mRNA and p27Kip1 protein was reduced by miR-150 mimics, and increased by miR-150 inhibitors. Moreover, the overexpression of miR-150 promoted cell cycle progression from the G0/G1 to the S phase and led to a significant increase in HeLa cell proliferation. The results of the present study indicated that miR-150 promotes HeLa cell cycle progression and proliferation via the suppression of p27Kip1 expression.

[Evaluation of the anti-TP antibody latex agglutination immunoassay in routine testing and a clinical viewpoint].

We evaluated TP-LAIA (anti-TP latex agglutination immunoassay) and compared the results with those obtained using Serological Tests for Syphilis (STS), namely Venereal Disease Research Laboratory (VDRL) method and Rapid Plasma Reagin (RPR) test. We also examined early-stage antibody reaction using rabbits infected with active pathogen, and analyzed early-stage syphilis patient serum with IgM class anti-TP antibody. Based on routine test results and case history reviews for possible syphilis infection, TP-LAIA showed high specificity, 0.64% false positive results in comparison with 13.5% by VDRL method. Sensitivity was also significantly higher than TP-Hemagglutination Assay(TPHA). In the examination of TP early-stage infection, the fastest positive antibody reaction was observed with TP-LAIA, indicating its significance in the diagnosis of early-stage syphilis. TP-LAIA was confirmed to give a reliable reaction with IgM class anti-TP antibody. TP-LAIA results coincided with VDRL method results in the decrease in anti-treponemal antibody titers following medical treatment, suggesting that TP-LAIA will be a valuable tool for monitoring the effect of medical treatments. We concluded that not only the high sensitivity and specificity of TP-LAIA assay and its suitability for automation make it an ideal screening test, but also the assay performs sufficiently and satisfactorily for its use in monitoring medical treatments.

[Analysis of the relevance of the mutations of the precore and basic core promoter in HBV genome with the DNA amount of HBV viremia].

In the course of hepatitis B, serum concentrations of the virus usually fall following sero-conversion, characterized by the loss of HBe antigen and appearance of detectable anti-HBe. However, hepatitis B viremia may persist even after sero-conversion. We assessed the association of continuous viremia with the precore (PC) (G1896A) mutation, basic core promoter (BCP) (A1762T, G1764A) mutations, the viral genotype and the quantity of viral DNA. Neither PC nor BCP mutations were detected in the viral DNA isolated from cases in which HBV became negative during the course of infection. The virus quantity increased after sero-conversion in all of the cases of persistent viremia with HBV genotype C harboring BCP mutations, indicating that the BCP mutation in genotype C is a determinant of continuous viremia. This feature was not evident in infections with HBV genotype B. Although the PC mutation was detected in the viral DNA from both genotypes B and C in continuous viremia, the mutation was not relevant to the quantity of virus. Our data suggest that HBV genotype C has a predisposition to acquire BCP mutations and these mutations activate virus replication after sero-conversion. This mechanism may be a cause of the poor prognosis of hepatitis with HBV genotype C. In conclusion, analyses of HBV genotype and BCP mutations are imperative to determine the prognosis of hepatitis B.

[A case of repeated seroconversion to HBe antibody due to co-infection with Mutant- and wild-type hepatitis B virus clones].

It is reported that co-infection with different hepatitis B virus (HBV) clones in a patient with chronic hepatitis B induces rare serotypes (adywr) or abnormal laboratory data such as negative HBs antigen, in the presence of positive HBV DNA. In this study, we experienced a case of repeated seroconversion to HBe antibody in a patient with chronic hepatitis B. Since seroconversion is considered to be related to genetic mutations, we investigated the HBV genes in this male patient in his 30's. We amplified and cloned parts of the HBV genes by the polymerase chain reaction (PCR), and sequenced the PCR products. As a result, mutated HBV genes were found in the serum of each specified period. By DNA sequencing we confirmed the coexistence of different HBV clones (wild-type clone and pre-S deletion mutant) and that both clones had the same genotype C. These clones took turns to be dominant; when the wild-type clone was dominant, HBe antigen was positive, and when the mutant clone was dominant, HBe antibody was positive. These findings demonstrated that repeated seroconversion of HBe antigen to HBe antibody was induced by co infection with mutant- and wild-type HBV clones. It is interesting that increased aspartate aminotransferase (AST) and alanine aminotransferase (ALT) was noted at the time of the change from positive wild-type HBV clone to positive mutant clone.

Influence of single nucleotide polymorphisms of cytokine genes on anti-HBs antibody production after hepatitis B vaccination in a Japanese young adult population.

Hepatitis B (HB) vaccination is one of the most efficient tools to prevent the transmission of the virus. Considerable variability exists in HB vaccine responses, with 5-10% of healthy Japanese adults demonstrating no response following a standard vaccination. Recently, polymorphisms of immune-regulatory genes, such as cytokine genes, have been reported to influence the immune response to HB vaccine. The aim of this study was to investigate the underlying mechanisms of the genetic association between several cytokine gene polymorphisms and the immune response to HB vaccination in a Japanese population. One hundred and twenty three vaccinated young adults were classified according to the level of antibody-titer (anti-HBs). Single nucleotide polymorphism typing for IFN-γ (+874, 3'-UTR), IL-10 (-591, -819, -1082), and TNF-α (-308, -857), was accomplished using the PCR-RFLP or SSP-PCR method. The TNF-α (-857) CC type and the IL-10 (-1082) AG type were present more frequently in the low titer group than in the high titer group. The TNF-α (-857) CC type was found to be significantly associated with low response of serum anti-HBs. The anti-HBs antibody was not readily produced in the IL-10 (-1082) AG and TNF-α (-857) CC haplotype. Conversely, the antibody was readily produced in the IL-10 (-1082) AA and TNF-α (-857) CC haplotype, and the IL-10 (-1082) AA and TNF-α (-857) CT haplotype, suggesting a high likelihood of the IL-10 (-1082) AG type to be included in the low anti-HBs group, and high anti-HBs antibody production in those with the TNF-α (-857) CT type. These SNPs may produce ethnically-specific differences in the immune response to HB vaccine in the Japanese population. J. Med. Invest. 63: 256-261, August, 2016.

SNPs rs4656317 and rs12071048 located within an enhancer in FCGR3A are in strong linkage disequilibrium with rs396991 and influence NK cell-mediated ADCC by transcriptional regulation.

CD16 receptors are mainly expresses on the surface of NK cells and mediate antibody-dependent cellular cytotoxicity (ADCC). The authors previously reported that NK cell-mediated ADCC is influenced by the single nucleotide polymorphism (SNP) rs396991 (T>G; F158V), and the structure and expression levels of CD16 differed among these genotypes. The authors examined haplotype frequency distributions among rs396991 and other SNPs, rs10917571 (G>T), rs4656317 (C>G), and rs12071048 (G>A), located in an enhancer of the FCGR3A gene. A total of 101 healthy Japanese were genotyped for the presence of these SNPs. The authors also measured ADCC activity, FCGR3A transcript levels, and surface CD16 expression on NK cells. We found that the regulatory SNPs (rSNPs) rs4656317 and rs12071048 were in strong linkage disequilibrium with rs396991. These two SNPs with major alleles had higher ADCC activity than those with minor alleles. In addition, FCGR3A transcript levels and surface CD16 expression levels were regulated by these SNPs. These findings suggest that NK cell-mediated ADCC could be influenced by transcriptional regulation of these rSNPs. These findings help to clarify our understanding of the linkage disequilibrium among functional SNPs in the FCGR3A gene, and provide a resource for investigating the roles of functional SNPs in NK cell-mediated ADCC.

Flow Cytometric Evaluation of Surface CD56 Expression on Activated Natural Killer Cells as Functional Marker.

Surface CD56 is the most important cell marker for defining NK cells. However, the relationship between the expression of surface CD56 and NK cell activity has not yet been elucidated in detail. Thirteen healthy volunteers were enrolled in the present study. Peripheral blood mononuclear cells (PBMCs) were stimulated with rIL-2 or rIL-12 (1, 10, 100 U/mL) for 18 h at 37°C. After incubation, surface CD56 expression on NK cells was evaluated using a flow cytometric analysis. A colorimetric-based lactate dehydrogenase (LDH) assay was used for experiments on cytotoxicity. IFN-γ mRNA gene expression was quantified by real-time PCR. The expression level of surface CD56 on NK cells, cytotoxicity, and IFN-γ mRNA gene expression were significantly increased by the rIL-2 and rIL-12 stimulations. In addition, a positive correlation was found between surface CD56 expression and cytotoxic activity or IFN-γ mRNA gene expression. We revealed that the quantification of surface CD56 expression was applicable to the evaluation of cytotoxicity and IFN-γ production in activated NK cells. These results suggest that the measurement of surface CD56 expression represent an easy and rapidly reproducible technique to evaluate the activated state of NK cells and monitor NK cell activity in immunotherapy. J. Med. Invest. 63: 199-203, August, 2016.

The influence of NK cell-mediated ADCC: Structure and expression of the CD16 molecule differ among FcγRIIIa-V158F genotypes in healthy Japanese subjects.

NK cells express the CD16 (FcγRIIIa) receptor, which mediates antibody-dependent cellular cytotoxicity (ADCC), on their cell surface. Therefore, ADCC activity may be influenced by qualitative or quantitative changes in the CD16 molecule on NK cells. Responses to NK cell-mediated ADCC have been shown to depend on single nucleotide polymorphisms (SNPs) at FcγRIIIa amino acid position 158. However, a consensus has not yet been reached regarding differences in the structure and expression levels of the CD16 molecule among FcγRIIIa-V158F genotypes, which have not yet been adequately investigated in healthy Japanese individuals. We herein examined the influence of the FcγRIIIa polymorphism on ADCC, binding affinity of CD16 to the Fc region, FCGR3A gene expression, and cell-surface CD16 expression in healthy Japanese subjects. FcγRIIIa-V158F genotyping was performed for 101 subjects. The results obtained showed that all parameters analyzed increased in the order of V/V>V/F>F/F and were significantly higher in V/V subjects than in F/F subjects. Moreover, a positive correlation was observed between ADCC activity and binding affinity, FCGR3A transcript levels, and surface CD16 expression levels. These results suggest that the structure and expression of the CD16 molecule differs among FcγRIIIa-V158F genotypes, and the FcγRIIIa-V158F polymorphism may be represent a haplotype with other SNPs in regulatory regions in Japanese subjects.

[The relation between virus genotypes and coexisting surface antigen and antibody in patients with hepatitis B, and the development of preS region deletions].

In recent years, there has been renewed interest in hepatitis B virus (HBV) genotypes. Our previous data have shown the importance of in-frame deletions in the preS region in cases of coexisting hepatitis B surface antigen (HBsAg) and anti-hepatitis B surface antibody (HBsAb). The aim of the present study was to investigate the relation between HBV genotypes and coexisting HBsAg and HBsAb, preS deletion mutants. We investigated the HBV genotypes in 9 patients with coexisting HBsAg and HBsAb. Viral DNA was extracted from the patients' sera and the HBV S gene region was amplified by polymerase chain reaction (PCR). HBV genotypes were then investigated by restriction fragment length polymorphism(RFLP) analysis. All 9 cases were found to have genotype C. This result clearly indicates that the unique finding of coexisting HBsAg and HBsAb depends on the HBV genotype. After genotypic screening was performed for HBV-positive samples from randomly selected 60 cases. The results of the 60 cases we investigated showed 26 cases of genotype B (43.3%), 31 cases of genotype C (51.7%), 1 case of coexisting genotype B and C (1.7%), and 2 cases of other genotypes (3.3%). Of the 60 cases, 45 cases consisting of 21 with genotype B and 24 with genotype C were subject to direct DNA sequencing of PCR products in the preS region to determine the presence or absence of preS deletion mutants. PreS deletion mutants were found in a total of 7 of the 45 HBV cases that underwent sequencing(7/45; 15.6%), and 6 of these had genotype C (6/24 cases, 25.0%), whereas only 1 had genotype B (1/21 cases, 4.8%). These results demonstrate a greater frequency of preS deletion mutants with genotype C. Interestingly, many preS deletion mutants showed deletions at the same point, namely the amino terminal side of the preS2 region. These results indicate that the HBV genotype is involved in the molecular pathogenesis of hepatitis B.