Weak D alleles in Japanese: a c.960G>A silent mutation in exon 7 of the RHD gene that affects D expression.

BACKGROUND AND OBJECTIVES: The molecular basis of the weak D phenotype has been investigated for many years, and more than 80 different alleles producing weak D phenotypes have been identified. Most alleles producing weak D phenotypes have a single missense mutation in exons corresponding to a transmembrane domain of the RhD polypeptide. We report here RHD alleles with single nucleotide mutations in Japanese accounting for weak expression of D antigen. METHODS: Seventy-five blood samples with a weak D phenotype were detected from 763 408 blood donors by standard serological methods. Forty-five of the 75 blood donors were available for RHD gene analysis by PCR and sequencing using genomic DNA and reticulocyte mRNA. Real-time PCR was performed to estimate the relative amounts of the RHD transcripts. RESULTS: We detected 16 different RHD alleles in the 45 individuals with weak D by nucleotide sequencing; 12 were newly identified. Thirty-two of the 45 individuals had an RHD allele with a single missense mutation, while the other 13 individuals had RHD with a c.960G>A silent mutation in exon 7. Red blood cells of these 13 individuals showed direct agglutination with anti-D at a strength of 3+ or less. Semi-quantitative analysis of the RHD transcripts by real-time PCR revealed that the cDNA samples with the c.960G>A mutation showed a significant increment of exon 7 skipping compared with the common RHD. CONCLUSION: Reduced expression of D antigen is caused not only by missense mutation of the RHD gene, but also by silent mutation that may affect splicing.

Estimation of the infectious viral load required for transfusion-transmitted human T-lymphotropic virus type 1 infection (TT-HTLV-1) and of the effectiveness of leukocyte reduction in preventing TT-HTLV-1.

BACKGROUND AND OBJECTIVES: The risk of transfusion-transmitted human T-lymphotropic virus type 1 infection (TT-HTLV-1) after prestorage leucocyte reduction (LR) remains unknown, as the proviral load in the blood component that would cause TT-HTLV-1 is undetermined. On the basis of the distribution of HTLV-1 proviral load among HTLV-1-sero-positive blood donors, we attempted to estimate the proviral load for transfusion-related infectivity. We also discuss the effectiveness of LR in preventing TT-HTLV-1. MATERIALS AND METHODS: The HTLV-1 proviral load in 300 HTLV-1-sero-positive blood donors was determined by real-time polymerase chain reaction analysis. The proviral load required for transfusion-related infectivity was estimated using historical TT-HTLV-1 frequency data from a retrospective study on patients who had received blood from HTLV-1-sero-positive blood donors and the distribution pattern of HTLV-1 proviral load among blood donors. RESULTS: HTLV-1 proviral loads ranged between < 0.01 and 25.0 copies per 100 leucocytes. Historical data showed TT-HTLV-1 frequency to be 80%. Assuming that 80% of the 300 sero-positive samples are infectious, it is estimated that the transfer of ≥ 9 × 10(4) cells containing the HTLV-1 provirus is required to establish TT-HTLV-1. CONCLUSION: The residual number of HTLV-1-infected cells after LR is substantially lower than the viral load necessary for TT-HTLV-1. LR therefore appears to be effective in minimizing the incidence of TT-HTLV-1.

Analysis of 66 patients definitive with transfusion-associated graft-versus-host disease and the effect of universal irradiation of blood.

BACKGROUND: Transfusion-associated graft-versus-host disease (TA-GVHD) is a potentially fatal adverse reaction to blood transfusion. Although TA-GVHD was formerly considered to be rare and to occur only in immunocompromised patients, it was confirmed to occur even in immunocompetent patients in Japan, based on a definitive diagnostic test for TA-GVHD using highly polymorphic microsatellite repeat sequences. We clarify the clinical picture of TA-GVHD via definitive diagnosed cases and argue the validity of blood irradiation for TA-GVHD prevention. PATIENTS AND METHODS: Two-hundred and ninety patients who were suspected of having TA-GVHD and referred to us for diagnostic testing from October 1992 to August 1999 were analysed for the associated clinical characteristics and risk factors. Effects of universal irradiation were followed up until 2010. RESULTS: Sixty-six of the 290 study patients were diagnosed as having definite TA-GVHD by microsatellite DNA analysis. Regarding the symptoms of patients with definite TA-GVHD, a fever of over 38 °C, erythema and leucocytopenia were found in virtually all of these patients. Among patients in whom human leucocyte antigen (HLA) typing was carried out, TA-GVHD almost always developed in HLA heterozygous patients following the transfusion of HLA homozygous blood. TA-GVHD was reported significantly more frequently in older patients. In this study, TA-GVHD was caused by the transfusion of HLA one-way match blood stored for 14 days. CONCLUSION: No cases of TA-GVHD development have been confirmed since 2000, when the supply of irradiated blood products became widespread. No major problems have been encountered since the start of universal irradiation, more than 10 years ago.

Analysis of a questionnaire on adverse reactions to blood donation in Japan.

In 2007, the Japanese Red Cross Blood Center performed a large-scale questionnaire study of post-donation adverse reactions. The questionnaire was distributed to 98,389 donors, and the answers were returned by 55,231 (56.1%). In total, 2,877 (5.2%) complained of an adverse reaction. Assuming that there were no adverse reactions for the 46,150 donors who did not reply, the rate of adverse reaction can be speculated to be 2.8%. Our study strongly suggests that blood centers have long underestimated the risks of vaso-vagal reactions. Taking at least 6h of careful rest after donation would be a helpful counter measure.

HLA-A, -B, -DR haplotype frequencies in the Thai Stem Cell Donor Registry.

This study aimed to report antigen and haplotype frequencies (HFs) in the Thai Stem Cell Donor Registry (TSCDR). From 16,807 human leukocyte antigen (HLA)-A, -B, and -DR typed donors, 19 HLA-A, 41 HLA-B, and 13 HLA-DR antigens were found. HLA-A43, A80, B78, B82, B83, and DR18 were not observed. A total of 1921 haplotypes were estimated and 245 haplotypes were reliable and their cumulative HF was 75.74%. Similar to previous Thai subpopulation studies, the most common haplotypes were HLA-A33-B58-DR17 (4.54%), A2-B46-DR9 (4.11%), A33-B44-DR7 (2.85%), and A11-B75-DR12 (2.00%). To evaluate the probability in finding matched donors, from April 2002 to August 2008, 793 Thai patients were requested for unrelated stem cell donor searching. The number of patients with HLA-A, -B, -DR split matched donor found were 49%. Only 8% of the patients found matched donor within 1 month. However, high-resolution HLA-A, -B, -DR typing in TSCDR is suggested to accurately estimate HFs and evaluate the probability in finding a matched donor for patients in the future.

Role of anti-Nak(a) antibody, monocytes and platelets in the development of transfusion-related acute lung injury.

BACKGROUND AND OBJECTIVES: Transfusion-related acute lung injury (TRALI) is one of the most serious side-effects of transfusion. We report here the first two cases of TRALI caused by anti-Nak(a) (anti-CD36) antibody from a single blood donor. The aim of this study was to clarify the role of the anti-Nak(a) antibody in TRALI development. MATERIALS AND METHODS: Human lung microvascular endothelial cells were co-cultured with Nak(a)-positive monocytes and Nak(a)-positive platelets together with serum prepared from blood products of a TRALI-caused anti-Nak(a) antibody-carrying donor. Expressions of leukotriene B(4) (LTB(4)) and tumour necrosis factor alpha (TNF-alpha) in the co-culture supernatants were determined. RESULTS: The expressions of LTB(4) and TNF-alpha were found to be markedly increased, particularly in the presence of both Nak(a)-positive monocytes and platelets. The expressions of these mediators were almost completed within 4 h after the initiation of co-culture. Monocyte contribution seemed to be stronger than that of platelets. In the absence of human lung microvascular endothelial, no significant LTB(4) or TNF-alpha release was observed. CONCLUSION: Anti-Nak(a) antibody may be strongly implicated in lung microvascular endothelial dysfunctions that lead to TRALI in a monocyte- and platelet-dependent manner.

Interference with TRALI-causing anti-HLA DR alloantibody induction of human pulmonary microvascular endothelial cell injury by purified soluble HLA DR.

BACKGROUND AND OBJECTIVE: Antibodies to human leucocyte antigens (HLA) and human polymorphonuclear neutrophil (PMN) antigens are considered etiologic agents of transfusion-related acute lung injury (TRALI). The aim of this study was to clarify the role of anti-HLA DR antibodies in the pathophysiology of TRALI and the ability of purified soluble HLA DR (psHLA DR) to inhibit the release of cytokines in an in vitro model. MATERIALS AND METHODS: A coculture of human pulmonary microvascular endothelial cells (HMVEC) and monocytes in the presence of serum containing anti-HLA DR alloantibodies previously associated with cases of TRALI was used as an in vitro TRALI model. The release of leukotriene B(4) (LTB(4)) and tumour necrosis factor-alpha (TNF-alpha), the apoptosis of HMVECs were measured. RESULTS: The release of LTB(4) and TNF-alpha and apoptosis of HMVECs were observed in the model. The addition of psHLA DR markedly reduced the release of LTB(4) and TNF-alpha and inhibited apoptosis of HMVECs. CONCLUSION: These results support the critical role of anti-HLA DR alloantibodies in the pathogenesis of TRALI and suggest that the soluble HLA DR could inhibit TRALI development caused by anti-HLA DR alloantibodies.

Analysis of enhancer activity of a dinucleotide repeat polymorphism in the neurotrophin-3 gene and its association with bipolar disorder.

Growing evidence has implicated the possible involvement of neurotrophins in the pathogenesis of functional psychoses such as schizophrenia and bipolar disorder. Previous studies reported a significant association of a dinucleotide repeat polymorphism of the neurotrophin-3 (NTF3) gene with schizophrenia. The aims of the present study were to examine whether this polymorphism is associated with bipolar disorder and whether the polymorphic region has an enhancer/silencer effect on transcriptional activity in an allele-dependent manner. In an association analysis between the polymorphism and bipolar disorder in a Japanese sample of 88 patients and 98 controls matched for age, sex, and ethnicity, the distribution of alleles did not differ significantly between the two groups. pGL3-promoter luciferase reporter vectors containing the polymorphic region increased luciferase activity relative to empty pGL3-promoter vector in HeLa, IMR-32 (neuroblastoma) and Hs683 (glioma) cell lines; however, no significant difference was detected between alleles for either cell line. Our results suggest that the examined polymorphism has no major role in giving susceptibility to bipolar disorder. Although the polymorphic region may have an enhancer-like effect on transcriptional activity, we obtained no evidence for allele-dependent differential effects.

Molecular cloning and characterization of six novel isoforms of human Bim, a member of the proapoptotic Bcl-2 family.

Bim protein is one of the BH3-only proteins, members of the Bcl-2 family that have only one of the Bcl-2 homology regions, BH3. BH3-only proteins are essential initiators of apoptotic cell death. Thus far, three isoforms of Bim have been reported, i.e. Bim(EL), Bim(L) and Bim(S). Here we report the cloning and characterization of six novel isoforms of human Bim, designated as Bimalpha1, alpha2, and beta1-beta4, which are generated by alternative splicing. Unlike the three known isoforms, none of these novel isoforms contained a C-terminal hydrophobic region. Among the novel isoforms, only Bimalpha1 and alpha2 contained a BH3 domain and were proapoptotic, although less potent than the classical isoforms. These two isoforms localized, at least in part, in mitochondria when transiently expressed in HeLa cells as a green fluorescent protein-fused form. These results suggest that the BH3 domain is necessary for induction of apoptosis and mitochondrial localization but not sufficient for the full proapoptotic activity. While the classical isoforms were always predominantly expressed in transformed cells, expression profiles of bim isoforms were highly variable among normal tissues at least in humans, suggesting a tissue-specific transcriptional regulation of bim.

In vitro anti-tumour activity of alpha-galactosylceramide-stimulated human invariant Valpha24+NKT cells against melanoma.

alpha-galactosylceramide (KRN 7000, alpha-GalCer) has shown potent in vivo anti-tumour activity in mice, including against melanoma and the highly specific effect of inducing proliferation and activation of human Valpha24+NKT-cells. We hypothesized that human Valpha24+NKT-cells activated by alpha-GalCer might exhibit anti-tumour activity against human melanoma. To investigate this, Valpha24+NKT-cells were generated from the peripheral blood of patients with melanoma after stimulation with alpha-GalCer pulsed monocyte-derived dendritic cells (Mo-DCs). Valpha24+NKT-cells did not exhibit cytolytic activity against the primary autologous or allogeneic melanoma cell lines tested. However, proliferation of the melanoma cell lines was markedly suppressed by co-culture with activated Valpha24+NKT-cells (mean +/- SD inhibition of proliferation 63.9 +/- 1.3%). Culture supernatants of activated Valpha24+NKT-cell cultures stimulated with alpha-GalCer pulsed Mo-DCs exhibited similar antiproliferative activities against melanoma cells, indicating that the majority of the inhibitory effects were due to soluble mediators rather than direct cell-to-cell interactions. This effect was predominantly due to release of IFN-gamma, and to a lesser extent IL-12. Other cytokines, including IL-4 and IL-10, were released but these cytokines had less antiproliferative effects. These in vitro results show that Valpha24+NKT-cells stimulated by alpha-GalCer-pulsed Mo-DCs have anti-tumour activities against human melanoma through antiproliferative effects exerted by soluble mediators rather than cytolytic effects as observed against some other tumours. Induction of local cytokine release by activated Valpha24+NKT-cells may contribute to clinical anti-tumour effects of alpha-GalCer.

Activation of HIV-1-specific immune responses to an HIV-1 vaccine constructed from a replication-defective adenovirus vector using various combinations of immunization protocols.

We constructed a recombinant replication defective adenovirus vector containing the env gene (Ad-Bal) derived from macrophage-trophic HIV-1 (HIV-1 Bal). We then immunized mice with this vector using several administration routes and protocols, and examined the immune response. When the Ad-Bal viral vector (over 1 x 10(7) pfu) was injected subcutaneously, both humoral and cell-mediated immunities were induced. However, immune response induced by the Ad-Bal vector alone was weaker than that induced by the recombinant vaccinia viral vector. We then employed the following three immunization protocols: (l) DNA vaccination followed by immunization with the Ad-Bal; (2) vaccination using the Ad-Bal vector followed by DNA vaccination; and (3) DNA vaccination followed by Ad-Bal infection and passive transfer of dendritic cells (DCs) infected with the Ad-Bal. Among the three protocols, the last gave the strongest humoral and cell-mediated immunity. These results suggest that the combination of DNA vaccination, Ad-Bal vector infection and passive transfer of Ad-Bal-infected DCs can induce strong immunity against HIV-1 Bal.

Dendritic cells rapidly undergo apoptosis in vitro following culture with activated CD4+ Valpha24 natural killer T cells expressing CD40L.

Human Valpha24 natural killer T (Valpha24NKT) cells are activated by alpha-glycosylceramide-pulsed dendritic cells (DCs) in a CD1d-dependent and T-cell receptor-mediated manner. There are two major subpopulations of Valpha24NKT cells, CD4- CD8- Valpha24NKT and CD4+ Valpha24NKT cells. We have recently shown that activated CD4- CD8- Valpha24NKT cells have cytotoxic activity against DCs, but knowledge of the molecules responsible for cytotoxicity of Valpha24NKT cells is currently limited. We aimed to investigate whether CD4+ Valpha24NKT cells also have cytotoxic activity against DCs and to determine the mechanisms underlying any observed cytotoxic activity. We demonstrated that activated CD4+ Valpha24NKT cells [CD40 ligand (CD40L) -positive] have cytotoxic activity against DCs (strongly CD40-positive), but not against monocytes (weakly CD40-positive) or phytohaemagglutinin blast T cells (CD40-negative), and that apoptosis of DCs significantly contributes to the observed cytotoxicity. The apoptosis of DCs following culture with activated CD4+ Valpha24NKT cells, but not with resting CD4+ Valpha24NKT cells (CD40L-negative), was partially inhibited by anti-CD40L mAb. Direct ligation of CD40 on the DCs by the anti-CD40 antibody also induced apoptosis of DCs. Our results suggest that CD40-CD40L interaction plays an important role in the induction of apoptosis of DCs following culture with activated CD4+ Valpha24NKT cells. The apoptosis of DCs from normal donors, triggered by the CD40-CD40L interaction, may contribute to the homeostatic regulation of the normal human immune system, preventing the interminable activation of activated CD4+ Valpha24NKT cells by virtue of apoptosis of DCs.

Identification of novel single nucleotide substitutions in the NKp30 gene expressed in human natural killer cells.

Cytotoxicity of natural killer (NK) cells is regulated by a balance of signals from two kinds of NK receptors, activating receptors and inhibitory receptors. Natural cytotoxicity receptors (NCR) family, which consists of NKp30, NKp44 and NKp46, is a major human activating NK receptor. NKp30 has been mapped to the HLA class III region near tumor necrosis factor (TNF) family loci. We have analyzed the NKp30 gene of healthy Japanese and found two synonymous substitutions in the coding region, c.111G>A and c.156C>T, and also identified two single-nucleotide polymorphisms (SNPs) in the promotor region, -201G>A and -163G>C. Furthermore, it was confirmed that these polymorphisms of the NKp30 gene show strong linkage disequilibria with each other and with HLA-DRB1 or TNFA polymorphisms. Since susceptibilities to certain diseases were mapped near this region, the NKp30 polymorphisms could be useful genetic markers.

Guidelines for irradiation of blood and blood components to prevent post-transfusion graft-vs.-host disease in Japan.

The Japanese Red Cross analysed the results of questionnaires sent in 1993 regarding post-transfusion graft-vs.-host disease (PT-GVHD) from hospitals; the majority of patients with PT-GVHD in 1993 were transfused for cardiovascular or cancer surgery, and about 10 patients had died yearly from PT-GVHD in the following few years. The Japan Society of Blood Transfusion (JSBT) organized a subcommittee for the prevention of PT-GVHD, and issued a fourth version of guidelines for the irradiation of blood to prevent PT-GVHD. These guidelines recommended transfusion of irradiated blood for cardiosurgery, cancer surgery, elderly recipients and severe trauma, as well as congenital immunodeficient recipients, newborn infants and other immunocompromised patients. Also recommended was irradiation not only of blood within 72 h after collection but also of blood stored for 14 days. Reported PT-GVHD has diminished to a few cases in recent years.

Alpha-glycosylceramides enhance the antitumor cytotoxicity of hepatic lymphocytes obtained from cancer patients by activating CD3-CD56+ NK cells in vitro.

Alpha-glycosylceramides, such as alpha-galactosylceramide and alpha-glucosylceramide, induce antitumor immunity in various murine cancer models. In the murine hepatic metastasis model, V alpha 14 TCR+NK1.1+ T cells, which accumulate preferentially in the liver, are considered to play a key role in the induction of antitumor immunity by alpha-glycosylceramides. We recently reported that V alpha 24 TCR+ NKT cells, the human homologues of murine V alpha 14 TCR+NK1.1+ cells, are rarely seen among freshly isolated human hepatic lymphocytes. Therefore, it is important to examine whether alpha-glycosylceramides also enhance the antitumor cytotoxicity of human hepatic lymphocytes, as they have been shown to do in murine systems, to determine the usefulness of alpha-glycosylceramides in cancer immunotherapy in humans. Here, we show that alpha-glycosylceramides greatly enhance the cytotoxicity of human hepatic lymphocytes obtained from cancer patients against the tumor cell lines, K562 and Colo201, in vitro. The direct effector cells of the elicited cytotoxicity were CD3-CD56+ NK cells. Even though V alpha 24 TCR+NKT cells proliferated remarkably in response to alpha-glycosylceramides, they did not contribute directly to the cytotoxicity. Our observations strongly suggest the potential usefulness of alpha-glycosylceramides for immunotherapy of liver cancer in humans based on their ability to activate CD3-CD56+ NK cells in the liver.

IL-12 responsiveness and expression of IL-12 receptor in human peripheral blood monocyte-derived dendritic cells.

We analyzed the expression of IL-12Rbeta1 and IL-12Rbeta2 and the role of IL-12 in the activation of monocyte-derived dendritic cells (DCs) via IL-12Rbeta1-mediated signaling events. Flow cytometric analysis revealed that IL-12Rbeta1 was expressed in T cells, Con A blasts, and monocyte-derived DCs, but not in monocytes, while its transcript was detected in all of these cell types. Transcriptional expression of IL-12Rbeta2 was observed in T cells, Con A blasts, and monocyte-derived DCs, but not monocytes. The ligation of DCs as well as Con A blasts by IL-12 induced the production of GM-CSF, IL-1beta, IL-6, TNF-alpha, and IFN-gamma at the transcription levels. Furthermore, stimulation of DCs with IL-12 induced IL-12p40 transcript, but not IL-12p35 transcript, whereas this stimulation caused the expressions of both transcripts in Con A blasts. Stimulation of DCs with IL-12 caused a tyrosine phosphorylation of several intracellular proteins, and the pattern of these events were distinct from those of IL-12-stimulated Con A blasts. IL-12 also induced tyrosine phosphorylation of IL-12Rbeta1 as well as recruitment of several tyrosine-phosphorylated proteins to IL-12Rbeta1 in DCs and Con A blasts. Receptor engagement of DCs as well as Con A blasts by IL-12 resulted in activation of Janus kinase 2 and Tyk2 kinases and Stat3 and Stat4 transcription factors and the association of these proteins to IL-12Rbeta1. Stimulation with IL-12 caused a tyrosine phosphorylation and enzymatic activity of a family of mitogen-activated protein kinases, p38mapk. These results suggest that IL-12 acts directly on DCs to induce their functional activation via IL-12Rbeta1-mediated signaling events.

Protein binding of a DRPLA family through arginine-glutamic acid dipeptide repeats is enhanced by extended polyglutamine.

Dentatorubral-pallidoluysian atrophy (DRPLA) is one of the hereditary neurodegenerative disorders caused by expansion of CAG/glutamine repeats. To investigate the normal function of the DRPLA gene and the pathogenic mechanism of neuron death in specific areas of the brain, we isolated and analyzed a gene that shares a notable motif with DRPLA, arginine-glutamic acid (RE) dipeptide repeats. The gene isolated, designated RERE, has an open reading frame of 1566 amino acids, of which the C-terminal portion has 67% homology to DRPLA, whereas the N-terminal portion is distinctive. RERE also contains arginine-aspartic acid (RD) dipeptide repeats and putative nuclear localization signal sequences, but no polyglutamine tracts. RERE is expressed at a low level in most tissues examined. Immunoprecipitation and in vitro binding assays demonstrate that the DRPLA and RERE proteins bind each other, for which one of the RE repeats has a primary role, and extended polyglutamine enhances the binding. With engineered constructs fused with a tag, the RERE protein localized predominantly in the nucleus. Moreover, when RERE is overexpressed, the distribution of endogenous DRPLA protein alters from the diffused to the speckled pattern in the nucleus so as to co-localize with RERE. More RERE protein is recruited into nuclear aggregates of the DRPLA protein with extended polyglutamine than into those of pure polyglutamine. These results reveal a function for the DRPLA protein in the nucleus and the RE repeat in the protein-protein interaction.