196 research outputs found
Analysis of animal serum proteins using antisera against human analogous proteins: A study of immunological cross reaction between human and animal serum proteins
In the present rocket immunoelectrophoretic analysis commercially available antisera against human serum proteins were screened for their usability in the analysis of analogous proteins in a number of animal species.The result appears as a table which demonstrates to what extent antibodies raised against a human protein can be used in the quantitative and/or qualitative study of an analogous animal protein
Cancer associated auto-antibodies to MUC1 and MUC4 - A blinded case control study of colorectal cancer in UK Collaborative Trial of Ovarian Cancer Screening (UKCTOCS)
Recent reports suggest that autoantibodies directed to aberrantly glycosylated mucins, in particular MUC1 and MUC4, are found in patients with colorectal cancer. There is, however, limited information on the autoantibody levels prior to clinical diagnosis, and their utility in cancer screening in the general population. In this study, we have generated O-glycosylated synthetic MUC1 and MUC4 peptides in vitro, to mimic cancer associated glycoforms, and displayed these on microarrays. The assay's performance was tested through an initial screening of serum samples taken from patients at the time of colorectal cancer diagnosis and healthy controls. Subsequently the selected biomarkers were evaluated in a blinded nested case control study, using stored serum samples from among the 50,640 women randomised to the multimodal arm of the UKCTOCS, where women gave annual blood samples for several years. Cases were 97 postmenopausal women who developed colorectal cancer following recruitment, and were age-matched to 97 women without any history of cancer. MUC1-STn and MUC1-Core3 IgG autoantibodies identified cases with 8.2% and 13.4% sensitivity, respectively, at 95% specificity. IgA to MUC4-glycoforms were unable to discriminate between cases and controls in the UKCTOCS sera. Additional analysis was undertaken by combining the data of MUC1-STn and MUC1-Core3 with previously generated data on autoantibodies to p53 peptides, which increased the sensitivity to 32.0% at 95% specificity in the UKCTOCS set. These findings suggest that a combination of antibody signatures may have a role as part of a biomarker panel for the early detection of colorectal cancer
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High-efficiency genome editing via 2A-coupled co-expression of fluorescent proteins and zinc finger nucleases or CRISPR/Cas9 nickase pairs
Targeted endonucleases including zinc finger nucleases (ZFNs) and clustered regularly interspaced short palindromic repeats (CRISPRs)/Cas9 are increasingly being used for genome editing in higher species. We therefore devised a broadly applicable and versatile method for increasing editing efficiencies by these tools. Briefly, 2A peptide-coupled co-expression of fluorescent protein and nuclease was combined with fluorescence-activated cell sorting (FACS) to allow for efficient isolation of cell populations with increasingly higher nuclease expression levels, which translated into increasingly higher genome editing rates. For ZFNs, this approach, combined with delivery of donors as single-stranded oligodeoxynucleotides and nucleases as messenger ribonucleic acid, enabled high knockin efficiencies in demanding applications, including biallelic codon conversion frequencies reaching 30â70% at high transfection efficiencies and âź2% at low transfection efficiencies, simultaneous homozygous knockin mutation of two genes with âź1.5% efficiency as well as generation of cell pools with almost complete codon conversion via three consecutive targeting and FACS events. Observed off-target effects were minimal, and when occurring, our data suggest that they may be counteracted by selecting intermediate nuclease levels where off-target mutagenesis is low, but on-target mutagenesis remains relatively high. The method was also applicable to the CRISPR/Cas9 system, including CRISPR/Cas9 mutant nickase pairs, which exhibit low off-target mutagenesis compared to wild-type Cas9
Identification and evolution of a plant cell wall specific glycoprotein glycosyl transferase, ExAD
Extensins are plant cell wall glycoproteins that act as scaffolds for the deposition of the main wall carbohydrate polymers, which are interlocked into the supramolecular wall structure through intra- and inter-molecular iso-di-tyrosine crosslinks within the extensin backbone. In the conserved canonical extensin repeat, Ser-Hyp(4), serine and the consecutive C4-hydroxyprolines (Hyps) are substituted with an Îą-galactose and 1â5 β- or Îą-linked arabinofuranoses (Arafs), respectively. These modifications are required for correct extended structure and function of the extensin network. Here, we identified a single Arabidopsis thaliana gene, At3g57630, in clade E of the inverting Glycosyltransferase family GT47 as a candidate for the transfer of Araf to Hyp-arabinofuranotriose (Hyp-β1,4Araf-β1,2Araf-β1,2Araf) side chains in an Îą-linkage, to yield Hyp-Araf(4) which is exclusively found in extensins. T-DNA knock-out mutants of At3g57630 showed a truncated root hair phenotype, as seen for mutants of all hitherto characterized extensin glycosylation enzymes; both root hair and glycan phenotypes were restored upon reintroduction of At3g57630. At3g57630 was named Extensin Arabinose Deficient transferase, ExAD, accordingly. The occurrence of ExAD orthologs within the Viridiplantae along with itsâ product, Hyp-Araf(4), point to ExAD being an evolutionary hallmark of terrestrial plants and charophyte green algae
N-acetylgalactosaminyl transferase-3 is a potential new marker for non-small cell lung cancers
N-acetylgalactosaminyl transferase-3 (GalNAc-T3) is an enzyme involved in the initial glycosylation of mucin-type O-linked proteins. In the present study, we used immunohistochemistry to examine GalNAc-T3 expression in 215 surgically resected non-small cell lung cancers. We analysed the biological and clinical importance of GalNAc-T3 expression, especially with regard to its potential as a prognostic factor. We found that normal bronchial epithelial cells, bronchial gland cells, and alveolar pneumocytes showed cytoplasmic immunostaining for GalNAc-T3. Low expression of GalNAc-T3, observed in 93 of 215 tumours (43.4%), was found more frequently in tumours from smokers than those from nonsmokers (P=0.001), in squamous cell carcinomas than nonsquamous cell carcinomas (P<0.0001), and in moderately and poorly differentiated tumours than well differentiated tumours (P=0.0002). Multivariate logistic regression analysis showed that an association of low GalNAc-T3 expression with squamous cell carcinomas was the only one significant relationship of GalNAc-T3 expression with various factors (P<0.0001). Moreover, tumours losing GalNAc-T3 expression had a significantly higher Ki-67 labelling index than tumours retaining GalNAc-T3 expression (P=0.0003). Patients with low GalNAc-T3 expression survived a significantly shorter time than patients with high GalNAc-T3 expression in 103 pStage I non-small cell lung cancers (5-year survival rates, 58% and 78%, respectively; P=0.02 by log-rank test) as well as in 61 pStage I nonsquamous cell carcinomas (5-year survival rates, 63% and 85%, respectively; P=0.03). Low GalNAc-T3 expression was an unfavourable prognostic factor in pStage I non-small cell lung cancers (hazards ratio, 2.04; P=0.03), and in pStage I nonsquamous cell carcinomas (hazards ratio, 2.70; P=0.03). These results suggest that GalNAc-T3 is a new marker of non-small cell lung cancers with specificity for histology and prognosis
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