scholarly journals Products of Chemoenzymatic Synthesis Representing MUC1 Tandem Repeat Unit with T-, ST- or STn-antigen Revealed Distinct Specificities of Anti-MUC1 Antibodies

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Yayoi Yoshimura ◽  
Kaori Denda-Nagai ◽  
Yoshie Takahashi ◽  
Izuru Nagashima ◽  
Hiroki Shimizu ◽  
...  
Keyword(s):  
Tandem Repeat ◽  
Repeat Unit ◽  
Structural Features ◽  
T Antigen ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serine Residue ◽  
Tn Antigen ◽  
Glycosylation Sites ◽  
Sialyl Tn Antigen ◽  
Cancer Diagnosis And Therapy

Abstract Anti-mucin1 (MUC1) antibodies have long been used clinically in cancer diagnosis and therapy and specific bindings of some of them are known to be dependent on the differential glycosylation of MUC1. However, a systematic comparison of the binding specificities of anti-MUC1 antibodies was not previously conducted. Here, a total of 20 glycopeptides including the tandem repeat unit of MUC1, APPAHGVTSAPDTRPAPGSTAPPAHGV with GalNAc (Tn-antigen), Galβ1-3GalNAc (T-antigen), NeuAcα2-3Galβ1-3GalNAc (sialyl-T-antigen), or NeuAcα2-6GalNAc (sialyl-Tn-antigen) at each threonine or serine residue were prepared by a combination of chemical glycopeptide synthesis and enzymatic extension of carbohydrate chains. These glycopeptides were tested by the enzyme-linked immunosorbent assay (ELISA) for their capacity to bind 13 monoclonal antibodies (mAbs) known to be specific for MUC1. The results indicated that anti-MUC1 mAbs have diverse specificities but can be classified into a few characteristic groups based on their binding pattern toward glycopeptides in some cases having a specific glycan at unique glycosylation sites. Because the clinical significance of some of these antibodies was already established, the structural features identified by these antibodies as revealed in the present study should provide useful information relevant to their further clinical use and the biological understanding of MUC1.

scholarly journals Polypeptide GalNAc-transferases, ST6GalNAc-transferase I, and ST3Gal-transferase I Expression in Gastric Carcinoma Cell Lines

2003 ◽  
Vol 51 (6) ◽  
pp. 761-771 ◽  
Author(s):  
Nuno T. Marcos ◽  
Andrea Cruz ◽  
Filipe Silva ◽  
Raquel Almeida ◽  
Leonor David ◽  
...  
Keyword(s):  
Cell Lines ◽  
Control Cell ◽  
T Antigen ◽  
Tn Antigen ◽  
Gastric Carcinoma Cell ◽  
Aberrant Expression ◽  
Peptide Epitopes ◽  
Gastric Cell ◽  
Sialyl Tn Antigen ◽  
Sialyl Tn

Mucin O-glycosylation in cancer is characterized by aberrant expression of immature carbohydrate structures leading to exposure of simple mucin-type carbohydrate antigens and peptide epitopes. Glycosyltransferases controlling the initial steps of mucin O-glycosylation are responsible for the altered glycosylation observed in cancer. We studied the expression in gastric cell lines of six UDP-GalNAc:polypeptide N-acetylgalactosaminyltransferases (GalNAc-T1, T2, T3, T4, T6, T11) that catalyze the initial key step in the regulation of mucin O-glycosylation, the transfer of GalNAc from UDP-GalNAc to serine and threonine residues. We also studied the expression of ST6GalNAc-I, the enzyme responsible for the synthesis of Sialyl-Tn antigen (NeuAcα2,6GalNAc) and the ST3Gal-I, the enzyme responsible for the synthesis of Sialyl-T antigen (NeuAcα2,3Galβ1,3GalNAc). This study was done using specific monoclonal antibodies, enzymatic assays, and RT-PCR. Our results showed that GalNAc-T1, -T2, and -T3 have an ubiquitous expression in all gastric cell lines, whereas GalNAc-T4, -T6, and -T11 show a restricted expression pattern. The immunoreactivity with MAb VU-2-G7 suggests that, apart from GalNAc-T4, another GalNAc transferase is involved in the glycosylation of the Thr in the PDTR region of the MUC1 tandem repeat. The expression of ST3Gal-I correlates with the expression of the Sialyl-T antigen in gastric cell lines and in the control cell lines studied. The expression of ST6GalNAc-I is low in gastric cell lines, in accordance with the low/absent expression of the Sialyl-Tn antigen.

scholarly journals Predictive value of preoperative serum sialyl tn antigen levels in prognosis of patients with gastric cancer

Cancer ◽  
1993 ◽  
Vol 72 (6) ◽  
pp. 1836-1840 ◽  
Author(s):  
Ikuo Takahashi ◽  
Yoshihiko Maehara ◽  
Tetsuya Kusumoto ◽  
Motofumi Yoshida ◽  
Yoshihiro Kakeji ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Predictive Value ◽  
Tn Antigen ◽  
Preoperative Serum ◽  
Sialyl Tn Antigen ◽  
Sialyl Tn

scholarly journals Crosslinked Recombinant-Ara h 1 Catalyzed by Microbial Transglutaminase: Preparation, Structural Characterization and Allergic Assessment

Foods ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 1508
Author(s):  
Yang Tian ◽  
Chenglong Liu ◽  
Wentong Xue ◽  
Zhongfu Wang
Keyword(s):  
Disulfide Bonds ◽  
Structural Changes ◽  
Structural Features ◽  
Microbial Transglutaminase ◽  
Enzyme Linked Immunosorbent Assay ◽  
Cross Linking ◽  
Intrinsic Structure ◽  
Ara H 1 ◽  
Molecular Forces ◽  
The One

As the one of the major allergens in peanut, the allergenicity of Ara h 1 is influenced by its intrinsic structure, which can be modified by different processing. However, molecular information in this modification has not been clarified to date. Here, we detected the influence of microbial transglutaminase (MTG) catalyzed cross-linking on the recombinant peanut protein Ara h 1 (rAra h 1). Electrophoresis and spectroscopic methods were used to analysis the structural changes. The immunoreactivity alterations were characterized by enzyme linked immunosorbent assay (ELISA), immunoblotting and degranulation test. Structural features of cross-linked rAra h 1 varied at different reaction stages. Hydrogen bonds and disulfide bonds were the main molecular forces in polymers induced by heating and reducing. In MTG-catalyzed cross-linking, ε-(γ-glutamyl) lysine isopeptide bonds were formed, thus inducing a relatively stable structure in polymers. MTG catalyzed cross-linking could modestly but significantly reduce the immunoreactivity of rAra h 1. Decreased content of conserved secondary structures led to a loss of protection of linear epitopes. Besides, the reduced surface hydrophobic index and increased steric hindrance of rAra h 1 made it more difficult to bind with antibodies, thus hindering the subsequent allergic reaction.

20 SIALYLTRANSFERASE GENE EXPRESSION IN GGTA1 KNOCKOUT PIGS

2016 ◽  
Vol 28 (2) ◽  
pp. 140
Author(s):  
G. A. Kim ◽  
J.-X. Jin ◽  
S. Lee ◽  
A. Oh ◽  
B. C. Lee
Keyword(s):  
Gene Expression ◽  
Somatic Cell ◽  
Real Time ◽  
Real Time Pcr ◽  
Internal Standard ◽  
Immune Rejection ◽  
Tn Antigen ◽  
Transgenic Pigs ◽  
Sialyl Tn Antigen ◽  
Sialyl Tn

It is considered that GGTA1 knockout (KO) pig production via somatic cell NT would overcome the problem of immune rejection after xenotransplantation. It is reported that although GGTA KO mice showed only a mild increase in sialyltransferase gene expression, GGTA1 deficiency in pig could increase the sialyltransferase activities, non-Gal epitope expression, consequently may raise non-Gal xenoantigenicity. Therefore, in the present study we investigated whether the expression level of Sia-containing glycoconjugate mRNA in transgenic pigs could be affected by knocking out the GGTA1 gene. Besides GGTA1 KO pigs, double genes overexpressing pigs (2TG) and GGTA1 KO with double genes overexpressing (KO+2TG) pigs were produced by somatic cell NT. For the present study, fibroblasts were isolated from wild-type pigs without gene modification, 2TG, GGTA1 KO, and KO+2TG pig. The GAPDH gene was used as an internal standard to normalise the real-time PCR (RT-qPCR) analysis reaction efficiency and to quantify mRNA in pigs-derived fibroblast. The expression levels were compared between them (RT-qPCR) in triplicate for each sample. Oligonucleotide primers for real-time PCR were designed for Hanganutziu-Deicher antigen (ST3Gal1–4, ST6Gal1) and Sialyl-Tn antigen (ST6GalNac1, ST6GalNac2, and ST6GalNac6) analysis. For statistical analysis, one-way ANOVA with Dunn’s multiple comparison test were used. The mRNA expression of GGTA1 KO and KO+2TG pig derived fibroblasts cells genes showed that ST3Gal1, ST3Gal2, ST3Gal3, and ST6Gal1 gene expression were significantly up-regulated compared to the wild and 2TG pigs (P < 0.05). However, ST3Gal4, Sialyl-Tn antigen including ST6GalNac1, ST6GalNac2, and ST6GalNac6 in KO+2TG pigs were not different compared with the wild pigs (P > 0.05), whereas only GGTA1 KO pigs showed significantly higher expressions than wild, 2TG, and KO+2TG pigs (P < 0.05). These results demonstrated that GGTA KO pig-derived cells exhibit a higher Hanganutziu-Deicher antigen on glycoprotein and glycolipid than controls, and KO+2TG pig exhibit no differences when compared with GGTA1 KO pig, indicating that they do not act as an immune antigen in xenograft. Overall, the increase in glycosyltransferase expression suggests a corresponding increase in the cell surface sialyation in GGTA KO pig cells. For xenotransplantation, KO+2TG pigs were more preferable because of absence of immune rejection for Sia-containing glycoconjugate on glycoprotein and glycolipid than GGTA KO pigs. This study was supported by the Ministry of Trade, Industry and Energy (#10048948), Korea IPET (#114059–3), Research Institute for Veterinary Science, TS Corporation, and the BK21 plus program.

scholarly journals Recruitment of Replication Protein A by the Papillomavirus E1 Protein and Modulation by Single-Stranded DNA

2004 ◽  
Vol 78 (4) ◽  
pp. 1605-1615 ◽  
Author(s):  
Yueh-Ming Loo ◽  
Thomas Melendy
Keyword(s):  
Dna Replication ◽  
Protein A ◽  
Replication Protein A ◽  
T Antigen ◽  
Replication Protein ◽  
Enzyme Linked Immunosorbent Assay ◽  
Physical Interaction ◽  
Single Stranded Dna ◽  
Ssdna Binding ◽  
Papillomavirus Dna

ABSTRACT With the exception of viral proteins E1 and E2, papillomaviruses depend heavily on host replication machinery for replication of their viral genome. E1 and E2 are known to recruit many of the necessary cellular replication factors to the viral origin of replication. Previously, we reported a physical interaction between E1 and the major human single-stranded DNA (ssDNA)-binding protein, replication protein A (RPA). E1 was determined to bind to the 70-kDa subunit of RPA, RPA70. In this study, using E1-affinity coprecipitation and enzyme-linked immunosorbent assay-based interaction assays, we show that E1 interacts with the major ssDNA-binding domain of RPA. Consistent with our previous report, no measurable interaction between E1 and the two smaller subunits of RPA was detected. The interaction of E1 with RPA was substantially inhibited by ssDNA. The extent of this inhibition was dependent on the length of the DNA. A 31-nucleotide (nt) oligonucleotide strongly inhibited the E1-RPA interaction, while a 16-nt oligonucleotide showed an intermediate level of inhibition. In contrast, a 10-nt oligonucleotide showed no observable effect on the E1-RPA interaction. This inhibition was not dependent on the sequence of the DNA. Furthermore, ssDNA also inhibited the interaction of RPA with papillomavirus E2, simian virus 40 T antigen, human polymerase alpha-primase, and p53. Taken together, our results suggest a potential role for ssDNA in modulating RPA-protein interactions, in particular, the RPA-E1 interactions during papillomavirus DNA replication. A model for recruitment of RPA by E1 during papillomavirus DNA replication is proposed.

Different Levels of Sialyl-Tn Antigen Expressed on MUC16 in Patients With Endometriosis and Ovarian Cancer

2012 ◽  
Vol 22 (4) ◽  
pp. 531-538 ◽  
Author(s):  
Kaoru Akita ◽  
Shuhei Yoshida ◽  
Yuzuru Ikehara ◽  
Sayumi Shirakawa ◽  
Munetoyo Toda ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Tn Antigen ◽  
Sialyl Tn Antigen ◽  
Different Levels ◽  
Sialyl Tn
Sign in / Sign up

Export Citation Format

Share Document