p.R180C mutation of glycosyltransferase B leads to B subgroup, an in vitro and in silico study

BACKGROUND AND OBJECTIVES

Dysfunctional glycosyltransferase A or B may lead to incomplete glycosylation of H antigen and atypical ABO blood group with weak A or B phenotypes, posing challenges for blood typing for transfusion.

MATERIALS AND METHODS

Serological studies and ABO gene analysis were performed. Flow cytometry was performed on HeLa cells transfected glycosyltransferase B expressing plasmids. Agglutination of transfected cells and total glycosyltransferase B transfer capacity were examined. Molecular dynamics simulations were used to explore possible dynamic conformational changes around the binding pocket.

RESULTS

We identified a mutation c.538C>T (p. R180C) of B allele in a Chinese donor and his father with ABw phenotype. In vitro expression study showed that mutation p.R180C, although not affecting expression of glycosyltransferase B, impaired H to B antigen conversion. The in silico analyses found that the residue Arg180 on the internal loop next to the entry of the binding pocket may have its long side chain salt-bridged with the highly flexible C-terminal carboxyl and contribute to the catalysis of H to B antigen conversion.

CONCLUSION

The p.R180C mutation impairs the conversion from H to B antigen and leads to weak B phenotype. Dynamic interaction between Arg180 and C-terminal of glycosyltransferase B may stabilize its binding with UDP-galactose and facilitate H/B antigen conversion.

A novel HLA class I allele: HLA-A*11:01:49

The HLA-A*11:01:49 allele differs from A*11:01:01:01 by one synonymous nucleotide substitution at position 837.

Characterization of the novel HLA-B*40:01:31 allele

The HLA-B*40:01:31 allele differs from B*40:01:01 by one nucleotide substitution at position 216.

A novel HLA-B allele: HLA-B*40:241

The HLA-B*40:241 allele differs from B*40:01:01 by 1 nucleotide substitution at position 691.

A novel HLA-B allele: HLA-B*40:242

The HLA-B*40:242 allele differs from B*40:54 by 1 nucleotide substitution at position 190.

Characterization of the novel HLA-DRB1*11:01:20 allele

The HLA- DRB1*11:01:20 allele differs from DRB1*11:01:01:01 by 1 nucleotide substitution at position 219.

The parthenogenetic development of porcine in vitro matured oocytes vitrified before or after electric activation

　　BACKGROUND: The highly efficient production of parthenogenetic embryos from vitrified porcine in vitro matured oocytes has become essential for biotechnology and biomedicine research.

OBJECTIVE

To investigate the survival and parthenogenetic development of oocytes vitrified before or after electric activation.

MATERIALS AND METHODS

The vitrified oocytes were parthenogenetically activated at 0, 0.5, 1, 2 and 4 h post warming (h.p.w.), and fresh oocytes were vitrified at 0, 0.5, 1, 2 and 4 h post electric activation (h.p.a.).

RESULTS

In comparison with non-vitrified oocytes, the rates of survival and activation of oocytes vitrified at 0.5, 1, 2 and 4 h.p.a. were similar, but the parameters in other vitrified groups significantly decreased. Parthenogenetic development in vitrified 0.5, 1, 2 and 4 h.p.a. groups was also significantly higher than that in other vitrified groups. Moreover, the total cell numbers of blastocysts were similar among all groups.

CONCLUSION

Porcine oocytes vitrified at 0.5-4 h h.p.a. showed acceptable survival and pronuclear formation, and a higher blastocyst yield could be obtained from these oocytes.

Identification of a novel HLA-DRB1*14 allele, HLA-DRB1*14:127:01, in a Chinese Individual

Two nucleotide changes in codon 77 (ACC → AAT) of HLA-DRB1*14:05:03 result in the allele, HLA-DRB1*14:127:01.

A novel HLA-B allele, HLA-B*13:69

HLA-B*13:69 allele differs from B*13:02:01 by one nucleotide substitution at position 628 from A to C.

Preparation of an inoculum of Gluconacetobacter xylinus without mutants in shaken culture

AIMS

A high-quality inoculum of Gluconacetobacter xylinus is important to produce bacterial cellulose (BC), a versatile biomaterial. This work aims to develop a method of preparing an inoculum of this bacterium with high cell density and without mutants.

METHODS AND RESULTS

Inocula of G. xylinus ACCC 10220 without and with cellulase or carboxymethyl cellulose (CMC) were prepared in shaken culture. BC pellets and BC-negative mutants were present in the inoculum without additives but absent in the inoculum with additives. Based on BC weights statically produced in fresh BC-producing media initiated by different seed culture, the 24-h-shaken inoculum with 1·50% (w/v) CMC was the best because of high biomass and absence of mutants. The BC weights in fresh media inoculated by the 96-h-static inoculum and 24-h-shaken CMC inoculum at 7% (v/v) were 0·70 and 1·05 g l(-1) , respectively, implying significant difference (P < 0·01) in BC weights. However, structure properties of the two BC samples, including the crystallinity index, mass fraction of cellulose Iα , degree of polymerization (DP) and micromorphology were slightly different.

CONCLUSIONS

The 24-h-shaken CMC inoculum was the most suitable for a starter culture of BC.

SIGNIFICANCE AND IMPACT OF THE STUDY

A novel method of preparing G. xylinus inoculum in shaken culture was developed, featuring high biomass, absence of mutants and no BC entanglements. Cellulase or CMC added into the medium completely suppressed mutation of G. xylinus, and CMC facilitated to form colloidal BC with the low DP in shaken culture, indicating less BC stress to cells. These findings suggested the mutation could be induced by BC stress, and not by shear stress commonly accepted.

A novel HLA-B allele, HLA-B*56:40

HLA-B*56:40 allele differs from B*56:01:01:01 by one nucleotide substitution at position 874.

Identification of a novel HLA-B*40 allele, HLA-B*40:229, in a Chinese individual

The novel HLA-B*40:229 allele shows one nucleotide difference from B*40:02:01 in exon 2 at nucleotide position 97 (C → T).

Identification of a novel HLA-A*24 variant allele, A*24:02:60

HLA-A*24:02:60 allele differs from A*24:02:01:01 by one nucleotide substitution at nt 564 from C to T.

Identification of a novel HLA-B*40 allele, HLA-B*40:210, in a Chinese individual

The newly detected HLA-B*40:210 allele has two nucleotide changes in exon 2 compared to B*40:49 allele.

First Report of Tomato mottle mosaic virus Infection of Pepper in China

Tomato mottle mosaic virus (ToMMV), a tentative member in genus Tobamovirus, was first reported from a greenhouse tomato sample collected in Mexico in 2013 (2). In August 2013, foliar mottle, shrinking, and necrosis were observed on pepper plants in several vegetable greenhouses of Lhasa, Tibet Autonomous Region, China. Seven symptomatic samples were collected and tested by dot-blot ELISA with antisera against Cucumber mosaic virus, Tobacco mosaic virus (TMV), Cucumber green mottle mosaic virus, Tomato spotted wilt virus, Turnip mosaic virus, and Broad bean wilt virus 2 (kindly provided by Dr. Xueping Zhou of Zhejiang University, China) (3). One of the bell pepper (Capsicum annuum var. grossum) samples reacted with the TMV antibody. Rod-shaped virus particles 300 nm in length were observed in this sample under electron microscopy. The results suggested that a tobamovirus closely related to TMV might be a causal agent. Total nucleic acids were then extracted from all seven samples using a CTAB method (1) and tested by RT-PCR using a pair of tobamovirus degenerate primers, TobamoF (GCWAAGGTKGTWYTBGTRGAYGG) and TobamoR (GTAATTGCTATTGDGTWCCWGC). These two primers were designed according to a conserved region of the TMV, Tomato mosaic virus, and ToMMV genomes (nt 2551-3433 of ToMMV genome [KF477193]). An amplicon of approximately 880 bp was obtained only from the TMV-positive sample. The amplicon was cloned and sequenced (GenBank Accession No. KJ605653). NCBI BLAST search showed that it shared the highest identity (99%) with ToMMV (KF477193), and shared the sequence homology of 82% to Tomato mosaic virus (AF332868) and 77% to TMV (V01408). The results indicated that the symptomatic pepper was infected with ToMMV. To investigate the distribution and incidence of ToMMV, 313 samples of symptomatic pepper, tomato, pumpkin, cucumber, radish, Chinese cabbage, broad bean, pea, and kidney bean samples were collected from 65 fields in Yunnan Province and Tibet Autonomous Region, and tested in RT-PCR with ToMMV-specific primers ToMMVF (AGAGAGATGGCGATAGGTTAAC, identical to nt 830-851 of ToMMV genome, GenBank Accession No. KF477193) and ToMMVR (CTGCAGTCATAGGATCTACTTC, complementary to nt1849-1828). The virus was detected in three tabasco peppers (C. frutescens) from Yunnan and one bell pepper plant from Tibet, suggesting that ToMMV has a restricted host range and is not common in these two regions. To our knowledge, this is the first report of natural infection of ToMMV in peppers as well as in China. References: (1) R. Li et al. J. Virol. Methods 154:48, 2008. (2) R. Li et al. Genome Announc. 1(5):e00794-13, 2013. (3) Y. Xie et al. Virol. J. 10:142, 2013.

Correlated energy-spread removal with space charge for high-harmonic generation

We study the effect of longitudinal space charge on the correlated energy spread of a relativistic high-brightness electron beam that has been density modulated for the emission of coherent, high-harmonic radiation. We show that, in the case of electron bunching induced by a laser modulator followed by a dispersive chicane, longitudinal space charge forces can act to strongly reduce the induced energy modulation of the beam without a significant reduction in the harmonic bunching content. This effect may be optimized to enhance the output power and overall performance of free-electron lasers that produce coherent light through high-gain harmonic generation. It also increases the harmonic number achievable in these devices, which are otherwise gain-limited by the induced energy modulation from the laser.

A new human leukocyte antigen class I allele: HLA-A*11:125

HLA-A*11:125 allele differs from A*11:01:01 by one nucleotide substitution at nt 140 from T to C.

Non-viral FoxM1 gene delivery to hepatocytes enhances liver repopulation

Hepatocyte transplantation as a substitute strategy of orthotopic liver transplantation is being studied for treating end-stage liver diseases. Several technical hurdles must be overcome in order to achieve the therapeutic liver repopulation, such as the problem of insufficient expansion of the transplanted hepatocytes in recipient livers. In this study, we analyzed the application of FoxM1, a cell-cycle regulator, to enhance the proliferation capacity of hepatocytes. The non-viral sleeping beauty (SB) transposon vector carrying FoxM1 gene was constructed for delivering FoxM1 into the hepatocytes. The proliferation capacities of hepatocytes with FoxM1 expression were examined both in vivo and in vitro. Results indicated that the hepatocytes with FoxM1 expression had a higher proliferation rate than wild-type (WT) hepatocytes in vitro. In comparison with WT hepatocytes, the hepatocytes with FoxM1 expression had an enhanced level of liver repopulation in the recipient livers at both sub-acute injury (fumaryl acetoacetate hydrolase (Fah)^–/– mice model) and acute injury (2/3 partial hepatectomy mice model). Importantly, there was no increased risk of tumorigenicity with FoxM1 expression in recipients even after serial transplantation. In conclusion, expression of FoxM1 in hepatocytes enhanced the capacity of liver repopulation without inducing tumorigenesis. FoxM1 gene delivered by non-viral SB vector into hepatocytes may be a viable approach to promote therapeutic repopulation after hepatocyte transplantation.

Abstract P6-06-35: Invasive lobular cancer versus mixed invasive lobular cancer with invasive ductal cancer: 20 year outcomes at one institution

Introduction: Conflicting reports exist regarding characteristics and outcomes of patients with only invasive lobular carcinoma (ILC) and mixed invasive lobular and ductal carcinoma (ILC/IDC). The purpose of this project is to report experience of 20 year cohort at one institution.

Methods: Patients diagnosed with ILC between 1990 and 2010 were divided into two groups: ILC alone and ILC/IDC. Patient demographics, history, diagnosis and treatment modalities, and outcomes were captured. Chi-square, log-rank, and Wilcoxon rank sums tests were utilized for statistical analysis. P &lt; 0.05 was considered significant.

Results: In 189 AJCC Stage I-III patients, ILC was identified in 149 (79%) and ILC/IDC in 39 (21%). ILC stage was I, II, III in 46 (31%), 57 (41%), 32 (21%) ILC, and ILC/IDC was 17 (44%), 16 (41%), 4 (10%). Median age (range) at diagnosis was 64 (31-88) for ILC and 64 (35-84) years for ILC/IDC (p = 0.78). Median largest tumor diameter was 22 (range 1-100) in ILC, and 20 (range 2-110) mm in ILC/IDC (p = 0.97). Seventy-eight (52%) and 20 (51%) were diagnosed with ILC and ILC/IDC clinically, and 58 (39%) and 15 (38%) were diagnosed with ILC and ILC/IDC radiographically (p = 0.96). Treatment modalities were mastectomy and breast conservation therapy in 82(55%) and 67(45%) of patients with ILC, 18 (46%) and 21 (54%) of patients with ILC/IDC (p = 0.32). In 136 (91%) ILC and 33 (85%) ILC/IDC patients who had nodal evaluation/excision, 59 (43%) ILC and 12 (36%) ILC/IDC patients presented with positive nodal status. ER, PR, and HER2 status were positive in 132 (89%), 104 (70%), 7 (5%) ILC, and 29 (74%), 26 (67%), 3 (8%) ILC/IDC patients respectively (p = 0.02, p = 0.85, p = 0.17).

Median (range) follow-up for ILC was 6.1 (&lt; 1-22.3), and 8.0 (1.72-17.7) years for ILC/IDC (p = 0.03). At the time of analysis, 43(29%) patients with ILC, and 11(28%) patients with ILC/IDC had expired (p = 0.94). Median (range) follow-up for patients who were alive at time of analysis was 6.8 (&lt;1-20.7) years for ILC, and10.1 (2.3-17.7) years for ILC/IDC (p = 0.06). Time to first recurrence was 3.23 (0.8-17.0) years in ILC, and 5.2 (2.9-9.3) years in ILC/IDC (p = 0.20). Recurrence was identified in 33(22%) ILC: 15(46%) locoregional and18 (54%) distant disease. Similarly, recurrence was found in 7 (20%) ILC/IDC patients: 4 locoregional and 3 distant. Most locoregional recurrences, 12/15 (80%), occurred in the ipsilateral breast in ILC, and 3/4 (75%) in ILC/IDC (p = 0.82). Five years disease free survival rates were 76% ILC and 85% for ILC/IDC, and 10 years rates were 63% for ILC and 67% for ILC/IDC (p = 0.4941). Overall survival estimates at 5 years were 84% for ILC and 92% for ILC/IDC, and at 10 years were 65% for ILC and 74% for ILC/IDC (p = 0.52).

Conclusion: While basic demographics and survival patterns did not differ statistically between ILC and ILC/IDC, pure ILC histology tends to carry a higher risk of recurrence, as well as worse disease free and overall survival compared to ILC/IDC. ILC histology was more likely to be ER positive, present with advanced stage, and recur in the ipsilateral breast than the contralateral breast.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P6-06-35.