[Characterization of the novel HLA-A*24:191 allele and analysis of its MHC molecular modeling structure].

OBJECTIVE: To characterize a novel HLA allele, A*24:191, its DNA sequence, MHC modeling structure, and the possible influence of the amino-acid residue variations on the molecule. METHODS: The HLA sequence was determined by Luminex PCR-SSO and PCR-SBT. Its MHC molecular structure and the possible effects of the amino-acid residue variations were modeled and analyzed with Phyre2, RCSB PDB and HistoCheck software. RESULTS: The PCR-SBT revealed the novel A*24:191 differs from A*24:02 in exon 2 at position 256, 265, 270 with G>C, G>C, A>T. The MHC molecular structure prediction showed that, compared with A*24:02, the 62nd residue of A*24:191 changed from the acidic E to a neutral Q, both with the side chain extending outside the α helix pointing forward the groove, (Risler's score, R=2), the 65th changed from the smaller neutral G extending inside the helix to a basic R with a long-chain extending upward outside the helix (R=52), and the 66th changed from the basic K to a neutral N both with a long side chain extending inside the groove (R=31). The above residues are located on the α helix of the α 1 domain which constituting the side wall of the peptide-binding groove. The DSS Score=3.85. From the surface image of the molecule, it can be clearly seen that the variations of the properties, sizes and configurations of the residues caused significant changes in the shape of the surface structure of the α helix. CONCLUSION: It suggested that the residue variations are likely to change the peptide binding properties as well as the TCR and antibody binding characteristics of the molecule.

[Identification of a rare platelet-specific antigen HPA-10bw allele among ethnic Han Chinese population in Shandong].

OBJECTIVE: To study the polymorphism of human platelet antigen (HPA) system 10 among ethnic Han Chinese from Shandong, China so as to supplement the data of platelet donor bank in the region. METHODS: Peripheral blood samples of platelet donors from the region were genotyped for HPA-10 alleles by PCR-sequence specific primer (PCR-SSP) and direct sequencing. RESULTS: Among 1401 donors, a rare heterozygote carrier of HPA-10w (a+b+) was identified, which gave an allelic frequency of approximately 0.035%. CONCLUSION: The detection of rare HPA-10bw antigen allele among ethnic Han Chinese from Shandong is useful for the diagnosis and prevention of neonatal alloimmune thrombocytopenia and post-transfusion purpura in the region.

[Analysis on Polymorphism of Platelet Antigen Gene in Shandong Han Population].

OBJECTIVE: To study the Polymorphism of the human platelet antigen(HPA) gene 1-17 and human leukocyte antigen(HLA) gene-A and B locus in Shandong Han population. METHODS: A total of 962 samples from routine voluntary platelet donors were genotyped for HPA1-17 system and HLA-A site, B by PCR-SSP and PCR-SSOP respectively．Gene frequencies were calculated by counting. HPA1-17 and HLA genotype combinations were analyzed by Arelequin 3.5. RESULTS: The gene frequencies of HPA-la, -1b, HPA-2a, -2b, HPA-3a, -3b, HPA-4a, -4b, HPA-5a, -5b, HPA-6a, -6b, HPA-15a, -15b were 0.9918, 0.0082, 0.9419, 0.0592, 0.5841, 0.4174, 0.9969, 0.0031, 0.9892, 0.0108, 0.9835, 0.0175,0.5488 and 0.4512, respectively． The most common HPA genotype combination was HPA-(1, 2, 4, 5, 6, 7-14, 16, 17) aa-3ab-15ab (0.2048). Moreover, HLA-A*2(0.3094) and HLA-B*13(0.1513) showed the highest frequency in their respective locus. The most common HLA genotype combination was HLA-A*2-B*13(0.1397) . CONCLUSION: Distributions of HPA and HLA show high polymorphism in Shandong Han population. The ethnic and territorial difference of HPA distribution is also confirmed. It is imperative to establish local genetic database of volunteer platelet donors.

[Sequence analysis and 3D molecular structure simulation of a novel HLA allele B*51:159].

OBJECTIVE: To identify a novel human leukocyte antigen (HLA) B allele in a Chinese Han individual and construct its three-dimensional structure. METHODS: The initial HLA genotyping was performed by PCR-sequence-based typing (PCR-SBT). The ambiguous allele was confirmed with single-strand DNA sequencing. The DNA sequence was analyzed to identify the difference between the novel allele and its closest matching allele. Finally, the three-dimensional molecular structure of the novel allele was constructed using a Swiss-Model. RESULTS: One allele of the subject at the HLA-B locus was B*44:03:01, whilst the other was a novel allele which differed from the closest matching allele B*51:01:01:01 by nucleotide (nt) 329 A to C in exon 2, resulting in an amino acid change at codon 86 (p.Asn86Thr). CONCLUSION: A novel HLA-B allele has been identified and officially named as HLA-B*51:159 by the WHO Nomenclature Committee for Factors of the HLA System. The three-dimensional structure of B*51:159 was simulated.

[Effects of Apheresis Platelets Treated with Vitamin B2 Photochemical Technology on the Release of White Blood Cells- and Platelet-Derived Cytokines during Storage].

OBJECTIVE: To investigate whether vitamin B2 photochemical pathogen reduction technology(PRT) treatment may lead to increase white cell- and platelet- derived cytokines release from platelets during storage. METHODS: Sixty milliliters of leukodepleted apheresis platelets were collected from 20 healthy donors, then were divided into 2 parts: one part (30 ml) remained untreated to serve as control, while the other part was treated with vitamin B2-UVB photo-chemical technology as experimental group. During 7 d of storage under standard blood bank conditions, platelet coun-ting (PC), platelet distribution width (PDW), mean platelet volume (MPV), white cell-derived cytokines (IL-1ß, IL-2, IL-6, IL-8, TNF-α and IFN-γ) and platelet-derived cytokines (CCL3, CCL5, TGF-ß-1 and PF4), P-selectin and phosphatidyl serine (PS) were analyzed on day 1, 3, 5 and 7 of storage, respectively. RESULTS: No signi-ficant differences were observed on PC, PDW and MPV between the experimental and control groups, respectively. The higher levels of platelet-derived cytokines were detected and reached a plateau after 5-7 days of storage, and the cyto-kines showed significant increase in experimental group compared with the control group. PS expression increased signi-ficantly in experimental group as compared with control group on day 3, 5 and 7 of storage, respectively. The accumula-tion of P-selectin was significant higher in experimental group than that in control group on day 5 and 7 of storage (P<0.05). The white cell-derived cytokines were not elevated by PRT treatment during 7 days of storage. CONCLUSION: The PRT-treated platelets are the main source of released cytokines during storage of PRT treatment. The levels of platelet-derived cytokines reach a plateau after 5-7 days of storage, most likely due to accelerated platelet activation and apoptosis.

[Analysis of HPA1-16 and HLA-A, B gene polymorphisms among ethnic Han population from Shandong].

OBJECTIVE: To study the polymorphisms of human platelet antigen (HPA) 1-16 and human leukocyte antigen (HLA)-A and -B loci among ethnic Han population from Shandong. METHODS: A total of 588 samples from platelet donors were genotyped for the above loci with sequence-specific primer PCR and sequence-specific oligonucleotide probe PCR. RESULTS: The frequencies of HPA-la, -1b, HPA-2a, -2b, HPA-3a, -3b, HPA-4a, -4b, HPA-5a, -5b, HPA-6a, -6b, HPA-15a, -15b were 0.9974, 0.0026, 0.9456, 0.0544, 0.5417, 0.4583, 0.9983, 0.0017, 0.9889, 0.0111, 0.9903, 0.0097, 0.5434 and 0.4583, respectively. The HPA-7-14 and HPA-16 showed no heterozygosity as the b allele was not detected in such loci. The most common genotypic combination for HPA was HPA-(1,4,7-14,16,17) aa-2aa-3ab-5aa -6aa-15ab (0.1820). HLA-A2 (0.3070) and HLA-B13 (0.1361) demonstrated the highest frequencies at their respective loci. CONCLUSION: The HPA and HLA loci are highly polymorphic among ethnic Hans from Shandong. The distribution of HPA polymorphisms also shows a great ethnic and territorial difference. It is important to construct regional database for the genotypes of HPA and HLA loci for platelet donors.

Possible association of killer cell immunoglobulin-like receptor genotypes and haplotypes with dry eye disease in a Han Chinese population.

PURPOSE: The objective of this study was to explore whether killer immunoglobulin-like receptor (KIR) genotypes and haplotypes are associated with dry eye disease (DED) in a Han Chinese population. METHODS: Polymerase chain reaction with sequence-specific primers (PCR-SSP) method was used to genotype KIR genes in 106 patients with DED and 220 healthy controls. RESULTS: Twenty-three KIR genotypes were observed in the DED patient and healthy control groups, ten of which had not been described previously. The genotype G and haplotype 4 were associated with increased risk of DED, and the odds ratio (OR) and 95% confidence interval (95% CI) were 2.58, 1.10-6.02 and 2.48, 1.31-4.69, respectively; while haplotype 2 appeared to have an inverse association with the disease (OR, 0.64; 95% CI, 0.44-0.92). Genotype B/B was also associated with increased risk of DED, and the OR and 95% CI were 2.35 and 1.09-5.10, respectively. KIR haplotypes A and B have distinctive centromeric (Cen) and telomeric (Tel) gene-content motifs, and Cen-B/B was associated with increased risk of DED (OR, 2.38; 95% CI, 1.03-5.49). However, all frequencies of these KIR genotypes and haplotypes were no longer statistically significant between the two groups after the Bonferroni correction was applied for multiple testing. CONCLUSIONS: There was a possible association between certain KIR genotypes and haplotypes with DED in a Han Chinese population. However, additional confirmation is required.

[Confirmation of 17 rare HLA alleles and prediction of their haplotypes].

OBJECTIVE: To confirm 17 rare HLA alleles detected during routine HLA typing and deduce their haplotypes. METHODS: Bi-allelic sequence-based typing and Luminex DNA PCR-SSOP assay were applied for the initial or repeat HLA typing, respectively. The rare HLA alleles were confirmed with mono-allelic sequence-based typing. Predicted haplotypes of the rare alleles were inferred based on the frequencies of HLA alleles and haplotypes in Han population. RESULTS: The authenticity of the total 17 rare HLA alleles was proven, and 18 predicted haplotypes associated with the rare alleles were recognized. A*11:12 and DRB1*13:19 were detected twice among unrelated individuals. CONCLUSION: Study of rare HLA alleles and predicted haplotype can provide useful information for donor searching and transplantation, and enrich polymorphisms of HLA in this population.

In vitro properties of apheresis platelet during extended storage in plasma treated with anandamide.

BACKGROUND: In China apheresis platelets (PLTs) are stored in plasma for only 5 days, resulting in PLT inventory pressures. Anandamide (ANA) was reported to be a potential agent to inhibit PLT apoptosis. The aim of this study was to evaluate the characteristics of extended storage PLTs in plasma treated with ANA in vitro. METHODS: Apheresis PLTs (n = 20) were prepared in plasma treated with ANA, and stored at 22 °C for up to 11 days. On day 1, 3, 5, 7, 9 and 11, PLTs were tested for PLT count, mean PLT volume (MPV), PLT distribution width (PDW), pH, pCO(2), pO(2), hypotonic shock response (HSR), phosphatidylserine (PS) exposure and soluble P-selectin content. RESULTS: PLTs stored in plasma with/without ANA didn't show significant differences during the first 5 days of storage. From the 7(th) day on, PLTs stored in plasma with ANA displayed significantly lower PS expression, soluble P-selectin content and higher HSR scores than those stored in plasma without ANA (P <0.05), respectively. CONCLUSION: The extended storage of PLTs in plasma treated with 0.5 µmol/l ANA showed better characteristics of the PLTs, compared with the control group, which was suggested to potentially alleviate the PLT storage lesion.

[Mechanism investigation of platelet apoptosis inhibition by N-Arachidonoylethanolamine].

OBJECTIVE: To investigate the mechanism of N- Arachidonoylethanolamine (ANA) on inhibiting platelets (PLT) apoptosis under standard blood bank storage conditions. METHODS: Samples taken from collected apheresis PLT by the Amicus instrument were split into three parts. An aliquot of 0.5 µmol/L ANA were added to one part of storage PLT as the ANA group; an aliquot of 0.5 µmol/L ANA and 1 µmol/L SR141716 was added to the another part as the ANA + SR141716 group; and the third part without ANA and SR141716 as the control group. These samples were stored on a flat-bed shaker at (22 ± 2) °C for 7 days. The expression of phosphatidyl serine (PS) positive, phospho (p)-Akt, Akt, p-Bad, Bad, caspase-3, caspase-9, cytochrome C (Cyt-C) and BCL-XL interaction with Bak were detected. RESULTS: The rate of PLT PS positive in ANA group decreased significantly than that in control group[ (8.29 ± 1.44) % vs (14.24 ± 2.47) %, P<0.05]. The release of Cyt-C from mitochondria to cytosol in ANA group decreased significantly compared with control group[ (3.29 ± 1.44) % vs (15.24 ± 3.40) %, P<0.05]. Also the expressions of p-Akt and p-Bad in ANA group increased significantly than those in control group[ (71.33 ± 10.26) % vs (35.00 ± 6.00) %, P<0.05; (39.00 ± 9.64) % vs (10.33 ± 1.53) %, P<0.05, respectively]. Higher amounts of Bak protein were co-precipitated with BCL-XL in ANA group than that in control group (about 2.6 fold, P<0.05). The expressions of cleaved caspase- 9 and caspase- 3 in ANA group decreased significantly than those in control group[ (9.63 ± 1.47) % vs (23.24 ± 2.47) %, P<0.05; (6.30 ± 1.40) % vs (13.20 ± 2.50) %, P<0.05, respectively]. There were no significantly changes between ANA+SR141716 and control groups (P>0.05). CONCLUSION: ANA protected PLTs from apoptosis as a result of inhibiting the release of Cyt-C from mitochondria to cytosol by modifying the expressions of apoptosis-relative proteins.

[Identification of a novel HLA allele, HLA-DRB1*03:80, by sequencing-based typing].

This study was aimed to identify a novel HLA-DRB1 allele from a Chinese potential hemopoietic stem cell donor of Northeast China. A rare HLA-DRB1 allele was initially detected by Luminex PCR-SSO typing, then the sample was sequenced by sequence-based typing (SBT) and the alignments of sample's alleles was identified by single allele-specific sequencing strategy. The results revealed the existence of a new allele which differs from the closest matching allele DRB1*03:06 by a single nucleotide substitution at position 239, where C→G in exon 2, resulting in an amino acid exchange from Thr to Arg at codon 51. It is concluded that a novel allele has been confirmed and its name DRB1*03:80 is officially assigned by the WHO Nomenclature Committee in February 2012.

[Effects of N-Arachidonoylethanolamine on the quality of platelets stored in M-sol platelet preservative solution in vitro].

This study was purposed to investigate the effects of N-Arachidonoylethanolamine (ANA) on the quality of platelets (Plt) stored in Plt M-sol preservative solution at 22 ± 2°C. Samples taken from collecting apheresis Plt by the Amicus instrument and splited into two equal parts were stored in Plt M-sol preservative solution on a shaker at 22 ± 2°C. Different working concentrations of ANA (from 0.1 to 50 µmol/L) were then added into one part of stored Plt as the experimental group, the other without ANA was used as the control group. The viability of Plts stored at 22 ± 2°C for 7 days was evaluated by MTT colorimetric assay. The most effective concentration of ANA was selected and added to the subsequent experimental group. Plt count (BPC), mean Plt volume (MPV), Plt distribution width (PDW), phosphatidyl serine (PS) and soluble P-selectin were detected on the 1(st), 5(th), 7(th), 9(th) and 11(th) day of storage. The results showed that the most effective working concentration of ANA was 0.5 µmol/L, which showed significant increasing Plt viability (91.23 ± 5.44%) compared to the control group (62.54 ± 4.79%). Thus, ANA concentration at 0.5 µmol/L was choose to perform subsequent experiments. During 11 days of storage, the BPC, MPV and PDW were not changed significantly between the experimental group and control group, although there was decreasing trend in the BPC and increasing trends in MPV and PDW in the two groups. The rate of Plt PS positive was enhanced during the storage period: the rate of PS positive in experimental group increased from 7.69 ± 1.82% to 10.74 ± 1.78% while it in control group increased from 11.21 ± 2.03% to 15.37 ± 1.95%, with significant differences between the two groups (P < 0.05) on the 9(th) and 11(th) day of storage, respectively. Soluble P-selectin contents in experimental group on the 9(th) and 11(th) day of storage were 30.19 ± 2.03 ng/ml and 34.52 ± 2.64 ng/mL, respectively, while those in control group were 39.18 ± 2.66 ng/ml and 43.23 ± 2.58 ng/ml, respectively, with significant differences between the two groups (P < 0.05). It is concluded that the extended storage of Plt in M-sol treated with low concentration ANA can potentially alleviate Plt storage lesions.

[Identification of a novel HLA-A allele A*11:01:37 by sequence-based typing].

OBJECTIVE: To identify a novel HLA-A allele in a Chinese Han individual. METHODS: One mismatch was observed in HLA-A locus in HLA typing for CMDP donors using bi-allelic SBT kit. A confirmatory test for novel HLA allele was performed with mono-allelic SBT kit. RESULTS: The DNA sequence was confirmed to be a novel HLA-A allele. There was 1 nucleotide differed from the closest matching HLA-A*11:01:01 at position 393(G→A), which resulting a change from GGG to GGA at codon 107, led to a silent mutation, conserving the amino acid Gly. CONCLUSION: A novel HLA-A allele was confirmed and officially named HLA-A*11:01:37 (Genbank accession number, JN209962) by the WHO Nomenclature Committee for Factors of the HLA System in January 2012.

Transcriptional regulation of the one-carbon metabolism regulon in Saccharomyces cerevisiae by Bas1p.

The mechanisms mediating responses to glycine withdrawal in budding yeast were studied using a genome-wide profiling approach. A striking pattern of repressed expression of genes with an enrichment for those involved in one-carbon metabolism and AMP biosynthesis was revealed. Sequence analysis of the promoters for the most severely repressed genes identified a conserved sequence, TGACTC, a known binding site for the transcription factors Gcn4p and Bas1p. Loss of BAS1 abolished or significantly reduced the repression of these genes in response to glycine removal but this phenotype was much less apparent in the absence of BAS2 or GCN4. Addition of a Bas1p-LexA fusion protein to a strain with a LexAop-LacZ fusion showed a strong glycine effect both in a BAS2 and a bas2 background. A Bas1p-VP16 fusion protein activated expression in a bas1bas2 strain but no glycine effect was observed while a Bas1p-Bas2p fusion protein activated expression to a lesser extent with a slight stimulation by glycine. These results suggest that glycine affects Bas1p activation of transcription rather than DNA binding and that Bas2p is not required for this affect. Glycine withdrawal repressed many of the same genes as addition of adenine, a process known to be dependent on Bas1p. However, the glycine response is independent of adenine repression, because glycine regulation occurs normally in ade strains. We did not see any difference in the degree of stimulation by glycine in the presence or absence of adenine even in Ade+ strains. Glycine regulation was also found to be dependent on an intact SHM2 gene, which encodes cytoplasmic serine hydroxymethyltransferase. A reporter plasmid containing a DNA sequence from the GCV2 promoter which confers glycine regulation on heterologous genes was introduced into the yeast deletion set to screen for genes required for glycine regulation. A number of genes, including BAS1 were required for activation by glycine but only the SHM2 gene was required for repression in the absence of glycine. We also showed that regulation of the SHM2 promoter by glycine requires Bas1p but not Bas2p or Gcn4p using a beta-galactosidase reporter. The response of the promoter to glycine required an intact SHM2 gene but was restored in a shm2 strain by addition of formate to the medium.