bluuebunny/crossref_metadata_2025_split huggingface dataset:
Identification of an HLA‐B7 serological variant and its characterization by sequencing based typing
Authors: Dunn P.P.J. , Carter V. , Dunn A. , Day S. , Fuggle S.V. , Ross J. , Cavanagh G. 
Published: March 2003

Abstract:We have identified an HLA‐B*07 variant allele, B*0716, in a Caucasoid cadaver kidney donor. The HLA class I type by polymerase chain reaction using sequence‐specific primers (PCR‐SSP) was A*01, 32; B*07, 08; Cw*07. Serological typing, using monoclonal and polyclonal anti‐HLA antisera, gave disparate results for the B antigens. Monoclonal antibodies identified B7 and B8 antigens but polyclonal antisera recognised only the B8 antigen. PCR using sequencing based typing (PCR‐SBT) confirmed the presence of both B*0703 and B*0801 alleles but with a mutation in one of the alleles. The HLA‐B*07 allele was isolated by allele‐specific PCR and was shown to have a mutation, G→T, at 292 in exon 2. This mutation changes codon 74, which encodes aspartic acid (GAC) present in all previously identified B*07 alleles, to tyrosine (TAC) in the variant. The serological results suggest that codon 74 is a crucial part of a B7 antigen‐specific epitope recognised by tissue typing polyclonal antisera ( Note).
Identification of the immunoreactive peptide sequence for AgSK1, an adenocarcinoma‐restricted antigen
Authors: Yasutomi J. , Koda K. , Saito N. , Nakajima N. , Nasoff M. , McKnight M. , Mukerjee S. , Gaskins C. , Chau P.C. , Glassy M.C. 
Published: March 2003

Acknowledgments:We would like to thank Jose Galindo and David Larocca for help during the initial phases of this work and to Minyi Gu, Soujan Wang and Janessa Molinari for expert technical assistance.Abstract:SK1, a human immunoglobulin M (IgM) monoclonal antibody was derived from regional nodal lymphocytes of a Dukes B colon carcinoma patient. The antigen recognized by the human monoclonal antibody (HuMab) SK1, termed AgSK1, was shown to be a two‐chain glycoprotein with an apparent molecular weight range of 42–46 kDa and preferentially expressed by human adenocarcinomas, particularly human gastrointestinal malignancies. To identify the gene encoding the AgSK1 antigenic epitope, a cDNA expression library constructed in λgt22A using mRNA from the colon carcinoma cell line HT29 was screened and one of the isolated clones encoding a 1.5‐kb cDNA, which showed strong immunoreactivity with HuMab SK1, was selected for further analysis. This clone consisted of an amino terminal open reading frame of 54 amino acids and the carboxyl terminal 20 amino acids of this protein coding region contained the antigenic epitope recognized by HuMab SK1.
Susceptible locus for obese type 2 diabetes mellitus in the 5′‐flanking region of the tumor necrosis factor‐α gene
Authors: Kamizono S. , Yamada K. , Seki N. , Higuchi T. , Kimura A. , Nonaka K. , Itoh K. 
Published: March 2003

Abstract:We have identified three novel polymorphisms in the promoter/enhancer region of the tumor necrosis factor (TNF)‐α gene. In this study we investigated the role of the polymorphisms in predisposition to Type 2 diabetes. The allele frequency of C→T substitution at −857 tended to be higher in obese patients with diabetes than in lean subjects with normal glucose tolerance (0.280 vs. 0.190). This tendency was due to a significantly higher ratio of −857T homozygotes in the obese patients with diabetes (15%) than in lean subjects with normal glucose tolerance (4%). There was no significant association between polymorphisms at positions −863 or −1,013, and diabetes. The homozygous −857T allele may be associated with genetic susceptibility to type 2 diabetes in obese subjects.
HLA‐DR51 expression failure caused by a two‐base deletion at exon 2 of a DRB5 null allele (DRB5*0110N) in a Spanish gypsy family
Authors: Balas A. , Ocon P. , Vicario J.L. , Alonso A. 
Published: March 2003

Abstract:Here we describe a new HLA class II null allele at the DRB5 gene. Serologic HLA typing of a Spanish gypsy family rendered the following paternal haplotype: A2‐Cblk‐B52‐Bw4‐DR15‐DQ5. However, DNA typing demonstrated the presence of a DRB5 gene in the haplotype DRB1*1502‐DRB5*0102‐DQB1*05031. Complete DRB5 cDNA sequencing revealed a DRB5*0102 allele with a deletion of two nucleotides at exon 2 (239–240) in codon 80. This change generates a frame shift leading to a stop codon at position 86, and could explain the lack of DR51 protein at the cell surface. This is the second DRB5 null allele described together with DRB5*0108N, raising the number of HLA alleles with an expression disorder ( Note).
A PCR‐SSP method to specifically select HLA‐A*0201 individuals for immunotherapeutic studies
Authors: Gatz S.A. , Pohla H. , Schendel D.J. 
Published: March 2003

Abstract:HLA‐A*0201 is an important restriction element for peptide presentation to T cells in disease and cancer. Mutation studies and analyses using cytotoxic T lymphocytes have shown the functional relevance of subtype‐specific differences in HLA‐A2 molecules for peptide binding and T‐cell receptor recognition. Therefore, many immunotherapeutic studies need to accurately select HLA‐A*0201‐positive individuals. We designed an easy, robust approach based on the polymerase chain reaction using sequence‐specific primers (PCR‐SSP) to specifically distinguish A*0201‐positive individuals from other HLA‐A2 subtypes described to date. The first step includes reactions that give information whether the sample donor is HLA‐A2 and, if so, whether the individual is homozygous or heterozygous for HLA‐A2. Further, it is determined whether the sample has an HLA‐A*0209 or an HLA‐A*0201 sequence at the corresponding position in exon 4. Samples that may contain an HLA‐A*0201 allele according to the results of this first step are subtyped in a second step nested PCR. Here the strategy is focussed on the discrimination of HLA‐A*0201 from the other subtypes by considering divergent nucleotide positions in two ways. One SSP combination amplifies the HLA‐A*0201 sequence while a corresponding SSP combination specifically amplifies the subtype or group of subtypes differing from HLA‐A*0201 at this position. Thus, at relevant polymorphic nucleotide positions the HLA‐A*0201 sequence is both directly and indirectly confirmed. This strategy strongly enhances the reliability of the subtyping and allows better verification of HLA‐A*0201‐positive patient selection for clinical studies ( Note).
HLA‐B*0811: another example of a single point substitution of the HLA‐B*0801 allele
Authors: Magira E. , Beznik‐Cizman B. , Monos D. 
Published: March 2003

Acknowledgments:This work was supported in part by office of Naval Research cooperative agreement # N‐00014‐96‐2‐0016 to the National Marrow Donor Program and by funding from the E.B. Foerderer Fund of the Children’s Hospital of Philadelphia to D.M.Abstract:The described alle HLA‐B*0811 is of Caucasoid origin. Most likely it derived from a point mutation of the B*0801 allele at position 559, where an adenine was converted to guanine. This position corresponds to codon 163 and resulted in an amino acid change from threonine to alanine. This substitution may influence both, T‐cell interactions and/or peptide binding ( Note).
Effect of asymmetric modification on the conformation of ascidiacyclamide analogs
Authors: Asano A. , Minoura K. , Yamada T. , Numata A. , Ishida T. , Doi M. , Katsuya Y. , Mezaki Y. , Sasaki M. , Taniguchi T. , Nakai M. , Hasegawa H. , Terashima A. 
Published: March 2003

Abstract: Ascidiacyclamide (ASC), cyclo(‐Ile1‐Oxz2‐d‐Val3‐Thz4‐)2 (Oxz=oxazoline and Thz=thiazole) has a C2‐symmetric sequence, and the relationships between its conformation and symmetry have been studied. In a previous study, we performed asymmetric modifications in which an Ile residue was replaced by Gly, Leu or Phe to disturb the symmetry [Doi et al. (1999) Biopolymers49, 459–469]. In this study, the modifications were extended. The Ile1 residue was replaced by Gly, Ala, aminoisobutyric acid (Aib), Val, Leu, Phe or d‐Ile, and the d‐Val3 residue was replaced by Val. The structures of these analogs were analyzed by X‐ray diffraction, 1H NMR and CD techniques. X‐Ray diffraction analyses revealed that the [Ala1], [Aib1] and [Phe1]ASC analogs are folded, whereas [Val1]ASC has a square form. These structures are the first examples of folded structures for ASC analogs in the crystal state and are similar to the previously reported structures of [Gly1] and [Phe1]ASC in solution. The resonances of amide NH and Thz CH protons linearly shift with temperature changes; in particular, those of [Aib1], [d‐Ile1] and [Val3]ASCs exhibited a large temperature dependence. DMSO titration caused nonlinear shifts of proton resonances for all analogs and largely affected [d‐Ile1] and [Val3]ASCs. A similar tendency was observed upon the addition of acetone to peptide solutions. Regarding peptide concentration changes, amide NH and Thz CH protons of [Gly1]ASC showed a relatively large dependence. CD spectra of these analogs indicated approximately two patterns in MeCN solution, which were related to the crystal structures. However, all spectra showed a similar positive Cotton effect in TFE solution, except that of [Val3]ASC. In the cytotoxicity test using P388 cells, [Val1]ASC exhibited the strongest activity, whereas the epimers of ASC ([d‐Ile1] and [Val3]ASCs), showed fairly moderate activities.
Insights into the determinants of β‐sheet stability: 1H and 13C NMR conformational investigation of three‐stranded antiparallel β‐sheet‐forming peptides
Authors: Santiveri C.M. , Rico M. , Jiménez M.A. , Pastor M.T. , Pérez‐Payá E. 
Published: March 2003

Abstract: In a previous study we designed a 20‐residue peptide able to adopt a significant population of a three‐stranded antiparallel β‐sheet in aqueous solution (de Alba et al. [1999]Protein Sci.8, 854–865). In order to better understand the factors contributing to β‐sheet folding and stability we designed and prepared nine variants of the parent peptide by substituting residues at selected positions in its strands. The ability of these peptides to form the target motif was assessed on the basis of NMR parameters, in particular NOE data and 13Cα conformational shifts. The populations of the target β‐sheet motif were lower in the variants than in the parent peptide. Comparative analysis of the conformational behavior of the peptides showed that, as expected, strand residues with low intrinsic β‐sheet propensities greatly disfavor β‐sheet folding and that, as already found in other β‐sheet models, specific cross‐strand side chain–side chain interactions contribute to β‐sheet stability. More interestingly, the performed analysis indicated that the destabilization effect of the unfavorable strand residues depends on their location at inner or edge strands, being larger at the latter. Moreover, in all the cases examined, favorable cross‐strand side chain–side chain interactions were not strong enough to counterbalance the disfavoring effect of a poor β‐sheet‐forming residue, such as Gly.
A strategy for managing fungal infections in haematopoietic stem cell transplantation
Authors: Donnelly J.P. 
Published: March 2003

Abstract:As more indications continue to be found for allogeneic haematopoietic transplantation, more patients are at risk for invasive fungal infectious diseases (IFID), particularly candidiasis and aspergillosis. Risk factors for disease are becoming better defined and diagnostic methods have improved considerably. In addition, there is now international agreement that three elements form the basis for defining IFID (host factors, clinical evidence, and mycological results), that imaging is acceptable for diagnosing disease, and that indirect tests such as antigen detection are also adequate mycological proof of cause. There are also more drugs available and still more to come, offering the potential for selective prophylaxis as well as preemptive and specific therapy, as well as for flexible administration. Hence, all the elements are in place for designing and testing an effective and economically sound strategy for dealing with IFID.
Comparative analysis of three genetic modifications designed to inhibit human serum‐mediated cytolysis
Authors: Costa Cristina , Zhao Lisa , Decesare Stephanie , Fodor William L. 
Published: March 2003

AbstractHyperacute rejection (HAR) remains a critical immunologic hurdle in the development of xenogeneic organs for human transplantation. Strategies that simultaneously eliminate both natural antibody reactivity and complement activation on the xenogeneic cell surface may be the best approach to achieve clinical application of xenogeneic vascularized organ transplantation. We have developed multiple lines of genetically manipulated mice to evaluate the combination of different genetic approaches aimed at inhibiting antibody and complement‐mediated cell lysis. We utilized transgenic mice expressing the human complement inhibitor, CD59, the human 1,2‐fucosyltransferase (H‐transferase, HT) and the α1,3‐galactosyltransferase (α1,3‐GT) knock‐out mouse line (Gal KO). Our data show that expression of hCD59 in combination with HT expression or the null phenotype of α1,3‐GT are equally effective at preventing human serum‐mediated cytolysis. Interestingly, the triple combination affords no additional protective effect. Therefore, coexpression of HT and a complement inhibitor is the most immediate strategy to genetically engineer transgenic pigs to be used as xenogeneic donors.
Continued production of xenoimmune antibodies 6–8 years after clinical transplantation of fetal pig islet‐like cell‐clusters
Authors: Lindeborg E. , Kumagai‐Braesch M. , Tibell A. , Möller E. 
Published: March 2003

Abstract: We have monitored the humoral immune responses of 10 type I diabetic patients, xenotransplanted with fetal porcine islet‐like cell clusters for up to 8 years after xenotransplantation. We investigated the immunoglobulin subclass distribution as well as specificity differences of xenoreactive antibodies. Hemagglutintion tests, using pig erythrocytes, showed that some patients maintained higher titers of xenoreactive IgM antibodies during the entire follow up period, compared with pretransplant levels. In microcytotoxicity tests all but one patient tested showed higher than pretransplant levels of cytotoxic antibodies against pig peripheral blood mononuclear cells (PBMC) 6–8 years after transplantation. Levels of Galα1,3Gal specific antibodies, were also high. Antibody dependent cellular cytotoxicity (ADCC) activity against a Galα1,3Gal expressing human B cell line was detected in four patients while ADCC reactivity against adult pig islet cells was detected in only two patients, 6–8 years after transplantation. Immune sera collected 30 days and 1 year after transplantation showed positive staining of adult pig islet cells in fluoromicroscopy whereas sera from later time points did not.Western blot experiments showed that some patients had IgG1 antibodies reactive against epitopes on pig cells other than Galα1,3Gal, while xenoreactive IgM and IgG2 antibodies mainly reacted with Galα1,3Gal‐containing epitopes as shown by absorption experiments.These results show that patients continue to produce higher than pretransplant levels of IgM and IgG2 xenospecific antibodies against Galα1,3Gal for extended time periods following xenotransplantation. Some patients also produce xenoreactive IgG1 antibodies directed against non‐Galα1,3Gal epitopes.
Multivalent Galα1,3Gal‐substitution makes recombinant mucin–immunoglobulins efficient absorbers of anti‐pig antibodies
Authors: Liu Jining , Weintraub Andrej , Holgersson Jan 
Published: March 2003

Liu J, Weintraub A, Holgersson J. Multivalent Galα1,3Gal‐substitution makes recombinant mucin–immunoglobulins efficient absorbers of anti‐pig antibodies. Xenotransplantation 2003; 10: 149–163. © Blackwell Munksgaard, 2003Hyperacute organ xenograft rejection can be prevented by removing anti‐pig antibodies by extracorporeal absorption prior to transplantation. A novel recombinant absorber of anti‐pig antibodies was developed by fusing the cDNA encoding the extracellular part of a mucin‐type protein, P‐selectin glycoprotein ligand‐1, with an antibody Fc fragment cDNA, which upon coexpression with the porcine α1,3 galactosyltransferase carried the xenogeneic epitope, Galα1,3Gal (Liu J., Qian Y., Holgersson J., Transplantation 1997, 63, 1673–1682). The biochemical characterization of the mucin/Ig and its absorption efficacy compared with that of porcine thyroglobulin and Galα1,3Gal‐conjugated beads are reported. The carbohydrate portion of the mucin/Ig constituted 43% of its molecular weight and the majority of the Galα1,3Gal epitopes were O‐linked as assessed by sodium dodecyl sulfate‐polyacrylamide gel electrophoresis and Western blotting following N‐glycosidase F digestion. Gas chromatography–mass spectrometry of reduced and acetylated saccharides released by α‐galactosidase treatment revealed that the fusion protein carried approximately 140 mol of terminal, α‐linked galactose per mole protein. Based on the reduction in pig aortic endothelial cell cytotoxicity, Galα1,3Gal‐substituted mucin/Igs on agarose beads were, on a carbohydrate molar basis, shown to be approximately 20 times more efficient than agarose‐conjugated pig thyroglobulin, and approximately 5000 and 30 000 times more efficient than Galα1,3Gal‐substituted agarose and macroporous glass beads, respectively. Structural features of the mucin backbone and its carbohydrate core saccharide chains determine the structural context, spatial orientation and spacing of Galα1,3Gal epitopes and are likely to explain the superior absorption efficacy of the recombinant mucin‐type chimera.
The liver as a crucial organ in the first line of host defense: the roles of Kupffer cells, natural killer (NK) cells and NK1.1 Ag+ T cells in T helper 1 immune responses
Authors: Seki Shuhji , Habu Yoshiko , Kawamura Toshihiko , Takeda Kazuyoshi , Dobashi Hiroshi , Ohkawa Takashi , Hiraide Hoshio 
Published: March 2003

Summary: The liver remains a hematopoietic organ after birth and can produce all leukocyte lineages from resident hematopoietic stem cells. Hepatocytes produce acute phase proteins and complement in bacterial infections. Liver Kupffer cells are activated by various bacterial stimuli, including bacterial lipopolysaccharide (LPS) and bacterial superantigens, and produce interleukin (IL)‐12. IL‐12 and other monokines (IL‐18 etc.) produced by Kupffer cells activate liver natural killer (NK) cells and NK1.1 Ag+ T cells to produce interferon‐g and thereby acquire cytotoxicity against tumors and microbe‐infected cells. These liver leukocytes and the T helper 1 immune responses induced by them thus play a crucial role in the first line of defense against bacterial infections and hematogenous tumor metastases. However, if this defense system is inadequately activated, shock associated with multiple organ failure takes place. Activated liver NK1.1 Ag+ T cells and NK cells also cause hepatocyte injury. NK1.1 Ag+ T cells and another T‐cell subset with an intermediate T‐cell receptor, CD122+CD8+ T cells, can develop independently of thymic epithelial cells. Liver NK cells and NK1.1 Ag+ T cells physiologically develop in situ from their precursors, presumably due to bacterial antigens brought from the intestine via the portal vein. NK cells activated by bacterial superantigens or LPS are also probably involved in the vascular endothelial injury in Kawasaki disease.
Structure–function relationships of complement receptor type 1
Authors: Krych‐Goldberg Malgorzata , Atkinson John P. 
Published: March 2003

Summary:Human complement receptor type 1 (CR1) is a large, multifunctional glycoprotein which is a member of the regulators of complement activation family. Like other members of this family, it is composed mainly of tandemly arranged modules, each about 60–70 amino acids long, known as complement control protein repeats (CCPs). Each domain folds independently and contains a hydrophobic core wrapped in β sheets. These domains mediate interactions with C3/C4‐derived fragments. CR1 is the most versatile inhibitor of both classical and alternative pathway C3 and C5 convertases due to its decay‐accelerating activity and co‐factor activity for C3b/C4b cleavage. Moreover, CR1 plays a major role in immune complex clearance due to its high affinity for C3b and C4b. CR1 is an excellent model to study structure–function relationships because its functions are mediated by two distinct but highly homologous sites, each composed of three CCPs. CR1 derivatives carrying just one active site were used to define critical sequences/amino acids. This was achieved by testing functional profiles of the proteins carrying a mutated active site produced by substituting peptides/amino acids with their counterparts from the other site. These mutated proteins, of which we analyzed over 100, permitted the fine mapping of the functional sites. CR1 on primate erythrocytes varies in size. In most cases it is smaller and has fewer active sites than does human CR1. This variation was used to determine that increased copy number (3,000 to 20,000 versus 300 for human CR1) compensates for a smaller size. Moreover, studies of primate CR1 led to the finding that subtle differences in the critical areas, as compared to human sites, produce active sites with a broader functional repertoire. These alterations ensure that short CR1 forms possess similar biologic activities to the large CR1 forms. There is much interest in producing therapeutic agents to inhibit unwanted complement activation. Based on these structure–function analyses, smaller and more potent complement inhibitors derived from CR1 can be produced.This work was supported by National Institutes of Health grant AI41592.
Kinetic perspectives of T cell antigen receptor signaling
Authors: Iwashima Makio 
Published: March 2003

Summary:T‐cell activation consists of multiple layers of signaling events. Interleukin‐2 production is of interest for many, since its expression determines a critical difference between partial and full T‐cell activation. To achieve full activation of T cells, it is necessary for the T‐cell antigen receptor (TCR) to be engaged for an extended period of time. However, why extended stimulation is required for full T‐cell activation is not understood at the molecular level. In this review, orchestrated events of TCR signal transduction will be analyzed in a kinetic manner and connected toward the understanding of the mechanism of T‐cell activation. Based on recent results, a model of the mechanism that dictates the threshold between partial and full T‐cell activation is proposed.