High-throughput simultaneous genotyping of human platelet antigen-1 to -16 by using suspension array.

BACKGROUND: Comprehensive and accurate detection of human platelet antigens (HPAs) plays a significant role in diagnosis and prevention of the platelet (PLT) alloimmune syndromes and ensuring clinical safety of patients undergoing PLT transfusion. The majority of the available methods are incapable of performing high-throughput simultaneous detection of HPA-1 to -16, and the accuracy of many methods needs to be further enhanced. STUDY DESIGN AND METHODS: We have developed a new HPA-genotyping method for simultaneous detection of HPA-1 to -16 based on suspension array technology. A total of 216 samples from Chinese Han donors in Xi'an were genotyped using the developed method, and all the samples again were genotyped using polymerase chain reaction (PCR) sequence-based typing (PCR-SBT), which is considered the gold standard. RESULTS: All 216 samples were successfully genotyped for HPA-1 to -16 using both our method and PCR-SBT. Results showed that the genotype and allele frequencies obtained using our method were fully consistent with those obtained using PCR-SBT. CONCLUSION: Our method provides accurate, high-throughput, and simultaneous genotyping of HPA-1 to -16 and will serve as the foundation for large-scale clinical genotyping of HPAs and for the establishment of an HPA-typed PLT donor registry.

Mac1+/Gr1+ cells contribute to transfusion-related acute lung injury.

Transfusion-related acute lung injury (TRALI) is a serious complication associated with blood transfusion and can cause transfusion associated fatalities. Both antibody dependent and non-dependent mechanisms are involved in TRALI, as proposed over the past years. Nonetheless, many details of the immune cells involved in TRALI, particularly the Mac1(+)/Gr1(+) cells from donors, are not fully understood yet. Here we used an in vitro transwell system and a mouse model to study the role of donor leukocytes, present in the donor material, in the occurrence of TRALI reactions. We found that there is a number of immature myeloid cells with Mac1(+)/Gr1(+) phenotype present in the red blood cell (RBC) products, when prepared by regular methods. We found that murine Mac1(+)/Gr1(+) cells from stored RBC products display an elevated MHC I and CD40 expression, as well as an enhanced tumor necrosis factor alpha(TNF-α), interlukin-6(IL-6) and macrophage inflammatory protein 2 (MIP-2) secretion. When tested in a transwell endothelial migration assay, Mac1(+)/Gr1(+) cells showed a significant capability to cross the endothelial barrier. In vivo investigation demonstrated that compared to the purified RBC transfusion, more murine Mac1(+)/Gr1(+) cells from the regular method produced RBC sequestered in the lung, which associated to shorter survival. Taken together, these data suggest that donor derived Mac1(+)/Gr1(+) cells can play a significant role in TRALI reactions, and that reduction of Mac1(+)/Gr1(+) cell number from RBC products is necessary to control the severity of TRALI reactions in clinic.

Green tea polyphenol epigallocatechin-3-gallate (EGCG) induced intermolecular cross-linking of membrane proteins.

Increasing evidence has demonstrated that EGCG possesses prooxidant potential in biological systems, including modifying proteins, breaking DNA strands and inducing the generation of reactive oxygen species. In the present study, the prooxidant effect of EGCG on erythrocyte membranes was investigated. SDS-PAGE and NBT-staining assay were utilized to detect the catechol-protein adducts that generated upon treating the membranes with EGCG. The results indicated that EGCG was able to bind covalently to sulfhydryl groups of membrane proteins, leading to the formation of protein aggregates with intermolecular cross-linking. We suggested that the catechol-quinone originated from the oxidation of EGCG acted as a cross-linker on which peptide chains were combined through thiol-S-alkylation at the C2- and C6-sites of the gallyl ring. EGC showed similar effects as EGCG on the ghost membranes, whereas ECG and EC did not, suggesting that a structure with a gallyl moiety is a prerequisite for a catechin to induce the aggregation of membrane proteins and to deplete membrane sulfhydryls. EDTA and ascorbic acid inhibited the EGCG-induced aggregation of membrane proteins by blocking the formation of catechol-quinone. The information of the present study may provide a fresh insight into the prooxidant effect and cytotoxicity of tea catechins.

Anti-HCV reactive volunteer blood donors distribution character and genotypes switch in Xi'an, China.

HCV is prevailed in the world as well as in China. Blood transfusion is one of the most common transmission pathways of this pathogen. Although data of HCV infection character were reported during the past years, anti-HCV reactive profile of China donors was not fully clear yet. Furthermore, infection progress was found related to the HCV genotype. Different genotype led to different efficacy when interferon was introduced into HCV therapy. Here we provided character data of HCV infection in China blood donors from the year of 2000 to 2009. The infection rate in local donors was lower than general population and descended from 0.80% to 0.40% or so in recent years. About 83% HCV strains were categorized into genotypes 1b and 2a. But 1b subtype cases climbed and 2a subtype cases decreased. The current study threw more light on HCV infection of blood donors in China, at least in the Northern region.

Immune response to fused core protein of hepatitis C virus and truncated tetanus toxin peptides in mice.

Because no vaccine or effective therapy is available, thousands of people with HCV have died in recent years. Cytotoxic T lymphocytes (CTLs) play a critical role in the host cellular immune response against HCV. CTL epitopes in HCV core protein have been identified and used in vaccine development. T helper epitopes could promote cytokine secretion and antibody production to fight HCV. Tetanus toxin, an immunogen with many T helper epitopes, was once used in HBV therapeutic vaccine design. Here, eukaryotic and prokaryotic expression vectors were constructed to express truncated fragments of tetanus toxin and core genes of HCV. HLAA2.1 transgenic mice were inoculated with a recombinant plasmid vehicle with these two heterogenic gene fragments, and this augmented the titres of antibody against HCV. Antigen-specific lymphocyte proliferation, Th1 and Th2 cytokine levels and the number of lysed cells were markedly increased in the combined immunization group compared to controls. These findings provide new insights into a potential role for T helper epitopes from tetanus toxin combined with protein from the HCV core gene, which has numerous CTL epitopes. This design strategy may aid in the development of new vaccines against HCV.

Hepatitis B virus genotypes and evolutionary profiles from blood donors from the northwest region of China.

Hepatitis B virus (HBV) is prevalent in China and screening of blood donors is mandatory. Up to now, ELISA has been universally used by the China blood bank. However, this strategy has sometimes failed due to the high frequency of nucleoside acid mutations. Understanding HBV evolution and strain diversity could help devise a better screening system for blood donors. However, this kind of information in China, especially in the northwest region, is lacking. In the present study, serological markers and the HBV DNA load of 11 samples from blood donor candidates from northwest China were determined. The HBV strains were most clustered into B and C genotypes and could not be clustered into similar types from reference sequences. Subsequent testing showed liver function impairment and increasing virus load in the positive donors. This HBV evolutionary data for China will allow for better ELISA and NAT screening efficiency in the blood bank of China, especially in the northwest region.

[A comparative study on the properties of trichosanthin before and after site-directed PEGylation].

OBJECTIVE: To construct PEGylated trichosanthin (TCS) mutein and analyze its bioactivities, immunogenicity, acute toxicity, and pharmacokinetics. METHODS: The potential antigenic determinant site YFF81-83 in the molecule of TCS was selected to undergo site-directed mutagenesis. Thus, a TCS mutein named TCS(YFF81-83ACS) was constructed and expressed in Escherichia coli of the line BL21 (DE3). Wild TCS (wTCS), TCSY(FF81-83ACS), and PEGylated TCS(YFF81-83ACS) (PEG- TCS(YFF81-83ACS)) of different concentrations were incubated with the supercoiled plasmid pUC19 to detect the DNAse activity, mixed with rabbit reticulocyte lysate to detect the ribosome inactivation activity, subcutaneously injected into 6 mice respectively to measure the serum IgG and IgE levels, intravenously injected into mice to observe the toxicity, and intravenously injected into SD rats to observe its -plasma half-life. RESULTS: The DNAse activity of the PEG-TCS(YFF81-83ACS) was similar to that of the wTCS. The ribosome inactivation activity of the PEG-TCS(YFF81-83ACS) was 1/9-1/8 of that of the wTCS (P < 0.05). The serum IgE and IgG levels of the PEG-TCS(YFF81-83ACS) were both significantly lower than those of the wTCS (both P < 0.05). The LD50 of the PEG-TCS(YFF81-83ACS) was 1.8 times that of the wTCS (P < 0.05). The mean residence time and plasma half-life of the PEG-TCS(YFF81-83ACS) were significantly increased and its plasma clearance was significantly decreased (all P < 0.05). CONCLUSION: Site-directed mutagenesis and PEGylation of TCS provide a new approach for reconstructing TCS.

Fixed rate of blood component improves the survival rate of patients in massive transfusion.

The aim of this study was to examine the manner in which varying proportions of serum and red blood cells (RBC) in massive blood transfusion affect the survival rates of patients with severe blood loss. Massive transfusion (MT) was determined as receiving ≥10 units of red blood cells in 24 h. The electronic medical records and blood transfusion information for the period January, 2002 to December, 2011 of patients with MT were examined. Moreover, we calculated the ratio of blood components and examined their correlation with survival. In total, 1,658 patients underwent MT during the period 2002-2011, with an overall of 28,030 units RBC, accounting for 2.8% of the total blood transfusion. In conclusion, fixing blood-component ratios has the potential to help improve survival rate in MT.

Growth inhibition and apoptosis induction of human umbilical vein endothelial cells by apogossypolone.

AIMS AND BACKGROUND: Prostate cancer is one of the most common malignant tumors in the male reproductive system, which causes the second most cancer deaths of males, and control of angiogenesis in prostate lesions is of obvious importance. This study assessed the effect of apogossypolone (ApoG2) on proliferation and apoptosis of human umbilical vein endothelial cells (HUVECs). SUBJECTS AND METHODS: HUVECs were treated with different concentrations of ApoG2. The survival rate of HUVECs were determined by MTT assay. Utrastructural changes of HUVECs were assessed with transmission electron microscopy. Apoptosis in HUVECs was analyzed by flow cytometry and cell migration by Boyden chamber assay. Matrigel assays were used to quantify the development of tube-like networks. RESULTS: ApoG2 significantly inhibited HUVEC growth even at 24 h (P<0.05). The inhibitory effect of ApoG2 is more obvious as the concentration and the culture time increased (P<0.05). These results indicate that ApoG2 inhibits the proliferation of HUVECs in a time- and concentration-dependent manner with increase of the apoptosis rate. Besides, ApoG2 reduced the formation of total pseudotubule length and network branches of HUVECs. CONCLUSIONS: The results suggest that ApoG2 inhibits angiogenesis of HUVECs by growth inhibition and apoptosis induction.

[Studies on the killing effect of gamma ray irradiated peripheral blood mononuclear cells combined with (-)-gossypol on human prostate cancer LNCaP cells].

AIM: To observe the killing effect of irradiated peripheral blood mononuclear cells (PBMCs) at low dose combined with (-)-gossypol on cultured human prostate cancer LNCaP cells. METHODS: Human PBMCs were irradiated by gamma ray at 1 gray, the irradiation dose rate was 17 Gy/min. The experiments were divided into control group (LNCaP cells only), LNCaP cells with irradiated and non-irradiated PBMCs co-culture groups, (-)-gossypol treatment group, irradiated PBMCs and (-)-gossypol co-treatment group. Acridine orange/ethidium bromide (AO/EB) staining and MTT method were used to observe the killing effect of PBMCs and/or (-)-gossypol. RESULTS: The killing activity of irradiated PBMCs group and (-)-gossypol treatment group were obviously increased and were higher than that of non-irradiated group (P < 0.05). The killing activity of combined group was much higher than that of irradiated group and ApoG2 treatment group (P < 0.01). CONCLUSION: Irradiated PBMCs at low dose combined with (-)-gossypol can enhance the anti-tumor effects obviously.

Inhibition of proliferation of prostate cancer cell line, PC-3, in vitro and in vivo using (-)-gossypol.

We investigated the antiproliferative activity of (-)-gossypol on the human prostate cancer cell line PC3 in vitro and in vivo to elucidate its potential molecular mechanisms. Cell growth and viability were evaluated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, and cell apoptosis was detected by flow cytometry, terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL) and electron microscopy. Expression of proliferating cell nuclear antigen (PCNA), Bcl-2, CD31, caspase-3 and caspase-8 in tumour tissue was determined by immunohistochemistry. The drug concentration that yielded 50% cell inhibition (IC(50) value) was 4.74 microg mL(-1). In the PC-3 tumour xenograft study, (-)-gossypol (> 5 mg kg(-1)) given once a day for 7 days significantly inhibited tumour growth in a dose-dependent manner. Immunohistochemical analysis revealed that (-)-gossypol enhanced caspase-3 and caspase-8 expression and decreased the expression of PCNA, Bcl-2 and CD31 in tumour tissues. It suggested that cell apoptosis and inhibition of angiogenesis might contribute to the anticancer action of (-)-gossypol.

Apogossypolone, a novel inhibitor of antiapoptotic Bcl-2 family proteins, induces autophagy of PC-3 and LNCaP prostate cancer cells in vitro.

Limited treatment options are available for aggressive prostate cancer. Gossypol has been reported to have a potent anticancer activity in many types of cancer. It can increase the sensitivity of cancer cells to alkylating agents, diminish multidrug resistance and decrease metastasis. Whether or not it can induce autophagy in cancer cells has not yet been determined. Here we investigated the antiproliferative activity of apogossypolone (ApoG2) and (-)-gossypol on the human prostate cancer cell line PC3 and LNCaP in vitro. Exposure of PC-3 and LNCaP cells to ApoG2 resulted in several specific features characteristic of autophagy, including the appearance of membranous vacuoles in the cytoplasm and formation of acidic vesicular organelles. Expression of autophagy-associated LC3-II and beclin-1 increased in both cell lines after treatment. Inhibition of autophagy with 3-methyladenine promoted apoptosis of both cell types. Taken together, these data demonstrated that induction of autophagy could represent a defense mechanism against apoptosis in human prostate cancer cells.