bluuebunny/crossref_metadata_2025 huggingface dataset:
How Much Is Investor Autonomy Worth?
Authors: Benartzi Shlomo , Thaler Richard H.
Published: March 2003

There is a worldwide trend towards defined contribution savings plans, where investors are often able to select their own portfolios. How much is this freedom of choice worth? We present retirement investors with information about the distribution of outcomes they could expect to obtain from the portfolios they picked for themselves, and the same information for the median portfolio selected by their peers. A majority of our survey participants actually prefer the median portfolio to the one they picked for themselves. We investigate various explanations for these findings and offer some evidence that the results are partly attributable to the fact that investors do not have well‐defined preferences.
Noise Trading, Costly Arbitrage, and Asset Prices: Evidence from Closed‐end Funds
Authors: Gemmill Gordon , Thomas Dylan C.
Published: March 2003

If arbitrage is costly and noise traders are active, asset prices may deviate from fundamental values for long periods of time. We use a sample of 158 closed‐end funds to show that noise‐trader sentiment, as proxied by retail‐investor flows, leads to fluctuations in the discount. Nevertheless, we reject the hypothesis that noise‐trader risk is the cause of the long‐run discount. Instead we find that funds which are more difficult to arbitrage have larger discounts, due to: (1) the censoring of the discount by the arbitrage bounds, and (2) the freedom of managers to increase charges when arbitrage is costly.
Why Do Managers Diversify Their Firms? Agency Reconsidered
Authors: Aggarwal Rajesh K. , Samwick Andrew A.
Published: March 2003

We develop a contracting model between shareholders and managers in which managers diversify their firms for two reasons: to reduce idiosyncratic risk and to capture private benefits. We test the comparative static predictions of our model. In contrast to previous work, we find that diversification is positively related to managerial incentives. Further, the link between firm performance and managerial incentives is weaker for firms that experience changes in diversification than it is for firms that do not. Our findings suggest that managers diversify their firms in response to changes in private benefits rather than to reduce their exposure to risk.
American Genotype Structures Decrease Dengue Virus Output from Human Monocytes and Dendritic Cells
Authors: Cologna Raymond , Rico-Hesse Rebeca
Published: March 2003

The dengue virus type 2 structures probably involved in human virulence were previously defined by sequencing the complete genome of both American and Southeast (SE) Asian genotype templates in patient serum (K. C. Leitmeyer et al., J. Virol. 73:4738-4747, 1999). We have now evaluated the effects of introducing a mutation in the envelope glycoprotein (E) gene and/or replacement of 5′- and 3′-nontranslated regions on dengue virus replication in human primary cell cultures. A series of chimeric infectious clones were generated containing different combinations of American and SE Asian genotype sequences. Some of the chimeric viruses had altered plaque morphology in mammalian cells; however, they replicated at similar rates in mosquito cells as measured by quantitative reverse transcription-PCR and plaque assay. Although susceptibility to virus infection varied from donor to donor in experiments using human macrophage and dendritic cells, we were able to measure consistent differences in viral RNA output per infected cell. Using this measurement, we demonstrated that the chimeric virus containing the E mutation had a lower virus output compared to the parental infectious clone. A larger reduction in virus output was observed for the triple mutant and the wild-type, American genotype virus from which chimeric inserts were derived. It appears that the three changes function synergistically, although the E mutation alone gives a lower output compared to the 5′- and 3′-terminal mutations. The data suggest that these changes may be responsible for decreased dengue virus replication in human target cells and for virulence characteristics during infection.
Possible Role of Dimerization in Human Immunodeficiency Virus Type 1 Genome RNA Packaging
Authors: Sakuragi Jun-Ichi , Ueda Shigeharu , Iwamoto Aikichi , Shioda Tatsuo
Published: March 2003

The dimer initiation site/dimer linkage sequence (DIS/DLS) region in the human immunodeficiency virus type 1 (HIV-1) RNA genome is suggested to play important roles in various steps of the virus life cycle. However, due to the presence of a putative DIS/DLS region located within the encapsidation signal region (E/psi), it is difficult to perform a mutational analysis of DIS/DLS without affecting the packaging of RNA into virions. Recently, we demonstrated that duplication of the DIS/DLS region in viral RNA caused the production of partially monomeric RNAs in virions, indicating that the region indeed mediated RNA-RNA interaction. We utilized this system to assess the precise location of DIS/DLS in the 5′ region of the HIV-1 genome with minimum effect on RNA packaging. We found that the entire lower stem of the U5/L stem-loop was required for packaging, whereas the region important for dimer formation was only 10 bases long within the lower stem of the U5/L stem-loop. The R/U5 stem-loop was required for RNA packaging but was completely dispensable for dimer formation. The SL1 lower stem was important for both dimerization and packaging, but surprisingly, deletion of the palindromic sequence at the top of the loop only partially affected dimerization. These results clearly indicated that the E/psi of HIV-1 is much larger than the DIS/DLS and that the primary DIS/DLS is completely included in the E/psi. Therefore, it is suggested that RNA dimerization is a part of RNA packaging, which requires multiple steps.
nef
Gene Is Required for Robust Productive Infection by Simian Immunodeficiency Virus of T-Cell-Rich Paracortex in Lymph Nodes
Authors: Sugimoto Chie , Tadakuma Kei , Otani Isao , Moritoyo Takashi , Akari Hirofumi , Ono Fumiko , Yoshikawa Yasuhiro , Sata Tetsutaro , Izumo Shuji , Mori Kazuyasu
Published: March 2003

The pathogenesis of AIDS virus infection in a nonhuman primate AIDS model was studied by comparing plasma viral loads, CD4
+
T-cell subpopulations in peripheral blood mononuclear cells, and simian immunodeficiency virus (SIV) infection in lymph nodes for rhesus macaques infected with a pathogenic molecularly cloned SIVmac239 strain and those infected with its
nef
deletion mutant (Δnef). In agreement with many reports, whereas SIVmac239 infection induced AIDS and depletion of memory CD4
+
T cells in 2 to 3 years postinfection (p.i.), Δnef infection did not induce any manifestation associated with AIDS up to 6.5 years p.i. To explore the difference in SIV infection in lymphoid tissues, we biopsied lymph nodes at 2, 8, 72, and 82 weeks p.i. and analyzed them by pathological techniques. Maximal numbers of SIV-infected cells (SIV Gag
+
, Env
+
, and RNA
+
) were detected at 2 weeks p.i. in both the SIVmac239-infected animals and the Δnef-infected animals. In the SIVmac239-infected animals, most of the infected cells were localized in the T-cell-rich paracortex, whereas in the Δnef-infected animals, most were localized in B-cell-rich follicles and in the border region between the paracortex and the follicles. Analyses by double staining of CD68
+
macrophages and SIV Gag
+
cells and by double staining of CD3
+
T cells and SIV Env
+
cells revealed that SIV-infected cells were identified as CD4
+
T cells in either the SIVmac239 or the Δnef infection. Whereas the many functions of Nef protein were reported from in vitro studies, our finding of SIVmac239 replication in the T-cell-rich paracortex in the lymph nodes supports the reported roles of Nef protein in T-cell activation and enhancement of viral infectivity. Furthermore, the abundance of SIVmac239 infection and the paucity of Δnef infection in the T-cell-rich paracortex accounted for the differences in viral replication and pathogenicity between SIVmac239 and the Δnef mutant. Thus, our in vivo study indicated that the
nef
gene enhances SIV replication by robust productive infection in memory CD4
+
T cells in the T-cell-rich region in lymphoid tissues.
Latency of Viral Expression In Vivo Is Not Related to CpG Methylation in the U3 Region and Part of the R Region of the Long Terminal Repeat of Bovine Leukemia Virus
Authors: Tajima Shigeru , Tsukamoto Masako , Aida Yoko
Published: March 2003

Bovine leukemia virus (BLV) is silent in most cells detectable in vivo, and the repression of its expression allows BLV to evade the host's immune response. In this study, we examined whether CpG methylation of DNA might be involved in the regulation of the expression of BLV in vivo. To investigate the effects of CpG methylation on the activity of the long terminal repeat (LTR) of BLV, we measured the transactivation activity of this region after treatment with the CpG methyltransferase
Sss
I by using a luciferase reporter system. The activity of methylated LTR was significantly lower than that of nonmethylated LTR. Therefore, we examined the extent of CpG methylation of the U3 region and part of the R region of the LTR in BLV-infected cattle and in experimentally BLV-infected sheep at various clinical stages by the bisulfite genomic sequencing method. We detected no or minimal CpG methylation at all stages examined in cattle and sheep, and our results indicate that CpG methylation probably does not participate in the silencing of BLV in vivo.
Polyprotein Processing Protease of African Swine Fever Virus: Purification and Biochemical Characterization
Authors: Rubio Daniel , Alejo Alí , Rodríguez Irene , Salas María L.
Published: March 2003

The purified recombinant African swine fever virus polyprotein processing protease cleaves the two GG-X sites in polyprotein pp62 with the same efficiency. Cleavage at the site that is first recognized in vivo is not a requisite for cleavage at the second site, suggesting the existence of mechanisms that control the ordered processing of the polyprotein during infection.
Fabrication of electroluminescent devices using Sr as an electron injection layer
Authors: Tanaka Kuniaki , Miyagawa Eijiro , Usui Hiroaki
Published: March 2003

Strontium (Sr) was evaporated on tris (8‐quinolinolato) aluminum (Alq) to form an electron injection layer for organic electroluminescence (EL) device. Chemical status of Sr was examined by x‐ray photoelectron spectroscopy (XPS). EL devices having the structure of ITO/PVCz:p‐TPD/Alq/Sr/Al were prepared and their luminance and lifetime were measured. It was found that EL characteristics could be improved by depositing metallic Sr layer at a deposition rate higher than 0.7 nm/s. XPS analysis showed that Sr interdiffuses into Alq when the Sr thickness exceeds 40 nm, which caused red shift of luminescence spectra by 10 nm. © 2003 Wiley Periodicals, Inc. Electron Comm Jpn Pt 2, 86(4): 36–41, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjb.1121
The second derivative of the dose–time–response surface as a measure of DNA repair kinetics in the comet assay
Authors: Kim Byung‐Soo , Park Jin Joo , Edler Lutz , Fournier Dietrich von , Haase Wulf , Sautter‐Bihl Marie‐Luise , Gotzes Florian , Thielmann Heinz Walter
Published: March 2003

The comet assay is a sensitive and rapid method for detecting DNA damage and repair of damage in individual cells. It has been widely used in genetic toxicology, environmental biomonitoring, molecular and human epidemiology and clinical investigations, since it was first introduced by Östling and Johanson in 1984 and independently modified by Singh et al. and Olive et al. There are still several issues that have to be resolved before the comet assay is accepted as a standard assay for detecting DNA damage/repair in a single cell. One of the major issues is the proper quantification of DNA repair kinetics. This article develops a new quantitative measure of the DNA repair kinetics which is represented in the dose–time–response surface. For measuring the DNA repair kinetics, we propose to use the second derivative, 2D, of the dose–time–response surface. This approach enables us to represent with a single number the DNA repair activity of cells exposed to ionizing radiation, by combining all the information in the experiment. The computation procedure includes the application of linear regression. In our application to the assessment of radiation sensitivity of patients we considered for the response four DNA damage parameters, i.e. the tail moment, the tail length, the tail DNA and the tail inertia for constructing the dose–time–response surface. Based on the data from 25 patients we observed that the second derivatives based on the tail moment and the tail DNA showed high correlation and that the tail inertia might express a somewhat different aspect of the DNA damage/repair. Copyright © 2003 John Wiley & Sons, Ltd.
Metabolic abnormalities (hypertension, hyperglycemia and overweight), lifestyle (high energy intake and physical inactivity) and endometrial cancer risk in a Norwegian cohort
Authors: Furberg Anne‐Sofie , Thune Inger
Published: March 2003

Since high energy intake, inactivity, hypertension and diabetes are linked to obesity and an unfavorable hormonal profile, we wanted to test whether energy intake, physical activity, blood pressure and serum glucose are related to the risk of endometrial cancer independent of the body mass index (BMI). A cohort of 24,460 women, aged 20–49 years, attended a Norwegian health screening twice during 1974–1981; they answered questions about diet, physical activity and chronic diseases, and their height, weight, blood pressure and non‐fasting serum glucose were measured. By the end of 1996, during 15.7 years of follow‐up, 130 cases of endometrial carcinomas were identified. The relative risks (RRs) for endometrial cancer were estimated in proportional hazards models including potentially confounding factors. Obese women (BMI ≥ 30 kg/m2) were at 2.6 times increased risk of endometrial cancer compared to normal weight women (BMI < 25 kg/m2) (RR = 2.57, 95%CI = 1.61–4.10). Among overweight women (BMI ≥ 25 kg/m2), non‐fasting serum glucose in the upper quartile vs. in the lower quartile was associated with a 2.4 times increase in risk (RR = 2.41, 95%CI = 1.08–5.37), whereas among obese women, blood pressure above 140/90 mmHg vs. below 140/90 mmHg in both surveys was associated with a 3.5 times increase in risk (RR = 3.47, 95%CI = 1.24–9.70). Especially in women younger than 50 years, high energy intake (5,044–6,401 kJ/day) conferred higher risk compared to low energy intake (< 4266 kJ/day) (RR = 3.40, 95%CI = 1.52–7.60). Increasing recreational activity tended to be protective. Among obese women with non‐sedentary jobs at both screenings, RR declined to 0.18 (95%CI = 0.05–0.62) as the level of sustained occupational activity increased (ptrend = 0.03). Our results suggest that inactivity and high energy intake are major risk factors for endometrial cancer independent of BMI, and that hypertension and relative hyperglycemia are significant markers of risk, especially among the heaviest women. © 2003 Wiley‐Liss, Inc.
Evidence of cross‐cultural invariance of the big five personality dimensions in work settings
Authors: Salgado Jesús F. , Moscoso Silvia , Lado Mario
Published: March 2003

This article explores the cross‐cultural invariance (construct validity) of two work‐related personality inventories based upon the Five Factor Model (the HPI and the IP/5F). The results show a good convergent and discriminant validity between scales that measure the Big Five personality dimensions. A factor analysis indicates that all personality scales load on the hypothesized Big Five dimensions. Some implications of these findings for the research and practice of personality measurement in personnel selection are discussed. Copyright © 2003 John Wiley & Sons, Ltd.
β2‐μ‐free HLA class I heavy chain levels in sera of healthy individuals. Lack of association with β2‐μ‐associated HLA class I heavy chain levels and HLA phenotype
Authors: Puppo F. , Bignardi D. , Contini P. , Hamby C.V. , Brenci S. , Lanza L. , Ghio M. , Scudeletti M. , Indiveri F. , Ferrone S.
Published: March 2003

We have applied a double‐determinant immune assay (DDIA) to measure soluble β2‐microglobulin (β2‐μ)‐free HLA class I heavy chains in serum. The mean concentration of β2‐μ‐free HLA class I heavy chains in serum from 120 healthy subjects was 0.21±0.24 μg/ml. The individual serum levels of β2‐μ‐free HLA class I heavy chains had a wide distribution, did not seem to be related with HLA phenotype, were stable over time and did not change with age. The serum levels of soluble β2‐μ‐free HLA class I heavy chains did not correlate with those of soluble β2‐μ‐associated HLA class I heavy chains, suggesting that their release is independently regulated. Three forms of soluble β2‐μ‐free HLA class I heavy chains, with apparent molecular masses of 44, 39 and 37–35 kD, respectively, circulate in human serum. These results provide a useful background to assess the serum level of soluble β2‐μ‐free HLA class I heavy chains in pathological conditions and to evaluate their putative immunoregulatory function.
A special report: histocompatibility testing guidelines for hematopoietic stem cell transplantation using volunteer donors *
Authors: Hurley C.K. , Wade J.A. , Oudshoorn M. , Middleton D. , Kukuruga D. , Navarrete C. , Christiansen F. , Hegland J. , Ren E.‐C. , Andersen I. , Cleaver S.A. , Brautbar C. , Raffoux C.
Published: March 2003

The World Marrow Donor Association has formulated guidelines for establishing the extent and quality of histocompatibility testing for unrelated donor registries, umbilical cord blood banks, and transplant centers involved in international exchange of hematopoietic stem cells for allogeneic transplantation. Registry and cord blood bank guidelines suggest that, at a minimum, initial HLA typing should be performed for three HLA loci, HLA‐A, ‐B, and ‐DR, at low resolution/split antigen level. DNA‐based testing methods should be utilized for HLA‐DR typing. DNA‐based testing for HLA‐A and ‐B should replace serologic testing of new volunteer donors and cord blood units as robust protocols and reagents become available to the laboratories. Transplant center guidelines for typing of patient, family and to confirm the HLA types of potential unrelated donors should include, at the minimum, typing HLA‐A, B, and ‐DR loci using primarily DNA‐based testing methods at allele level resolution for DRB1 and low resolution/split antigen level for HLA‐A and ‐B. It is strongly recommended that the typing of a patient and the selected donor be performed using the same set of reagents, methodology, and interpretation criteria with fresh tissue samples to ensure HLA identity. Guidelines for laboratory accreditation, approaches to quality assurance and quality control for HLA testing, and suggestions for the format of the HLA database of donor types are also outlined.
Lack of association of MICA transmembrane region polymorphism and Behçet’s disease in Spain
Authors: González‐Escribano M.F. , Rodríguez M.R. , Aguilar F. , Alvarez A. , Sanchez‐Roman J. , Núñez‐Roldán A.
Published: March 2003

We have analyzed the distribution of the major histocompatibility complex (MHC) class I chain‐related gene A (MICA) transmembrane alleles among 58 Spanish patients with Behçet′s disease (BD) and in 194 ethnically matched healthy controls. The study included the characterization of A4, A5, A5.1, A6 “new” and “old” and A9 MICA‐TM alleles using polymerase chain reaction. As previously reported, the serological B51 specificity was increased among this BD patient group (36.25% vs. 19.6% in controls; P=0.009; OR=2.33). The MICA‐TM alleles A6 (“new” and “old”), in linkage disequilibrium with HLA‐B51 and HLA‐B14 respectively, were only slightly increased among patients (70.7% vs. 61.3% in controls; P=NS). We conclude that, in contrast to previous finding reporting a strong association of MICA‐TM genes and Behçet disease in Japanese patients, in our population HLA‐B51 is more closely associated to Behçet susceptibility than MICA‐TM genes. Finally, our data show that in Spain, as occurs in other populations, some MICA‐TM alleles exhibit strong linkage disequilibrium with certain alleles of the HLA‐B locus.
Periodontal attachment loss in HIV‐infected patients is associated with the major histocompatibility complex 8.1 haplotype (HLA‐A1,B8,DR3)
Authors: Price P. , Calder D.M. , Witt C.S. , Allcock R.J.N. , Christiansen F.T. , Davies G.R. , Cameron P.U. , Rogers M. , Baluchova K. , Moore C.B. , French M.A.
Published: March 2003

Periodontal attachment loss is mediated by overproduction of tumour necrosis factor (TNF) and interleukin (IL)‐1, and appears to have a genetic component. The 8.1 major histocompatibility complex (MHC) ancestral haplotype (HLA‐A1,B8,TNFA‐308(2),DR3) is associated with elevated TNF production and predisposes carriers to several autoimmune/immunopathological disorders, including rapid progression of HIV disease, but not early onset periodontal disease in healthy individuals. Rather a high proportion of subjects with severe periodontal disease carry allele 2 at IL‐1A−889 and IL‐1B+3953. We predicted that genetic associations may be different or clearer in HIV patients, as they often show elevated production of TNF and IL‐1 and periodontal attachment loss. Hence periodontal parameters and IL‐1 polymorphisms were assessed in HIV‐positive subjects expressing HLA‐B8 with or without other markers of the 8.1 haplotype. Of 16 HLA‐B8 subjects, 13 demonstrated elevated probing pocket depth and clinical attachment loss. The difference was statistically significant and did not correlate with smoking, age, CD4 T‐cell counts, HIV viral load or levels of dental plaque. As TNFA‐308 (allele 2) was present in four non‐B8 subjects who had minimal attachment loss, it may not mediate the effect of the 8.1 haplotype. Moreover, polymorphisms at IL‐1A−889 and IL‐1B+3953 did not significantly affect periodontal parameters. Thus a central MHC gene characteristic of the 8.1 haplotype was the clearest determinant of periodontal attachment loss in HIV‐infected individuals.xm
Alpha‐2 domain polymorphism and HLA class I peptide loading
Authors: Prilliman K.R. , Crawford D. , Hickman H.D. , Jackson K.W. , Wang J. , Hildebrand W.H.
Published: March 2003

Diversity within the class I HLA antigen binding groove is positioned to moderate the presentation of peptide ligands. Polymorphism is widely dispersed about the peptide binding groove, and unravelling the functional significance of a given polymorphism requires comparative analysis of peptides presented by class I subtypes differing at the position(s) in question. Previous studies have demonstrated that not all class I polymorphisms act equally, and to determine the impact of substitutions specifically located in the α2 domain, peptides purified from B*1501, B*1512, B*1510, and B*1518 were examined by pooled Edman sequencing and comparative mass spectrometric analysis. Molecule B*1512 differs from B*1501 at residues 166 (Glu to Asp) and 167 (Trp to Gly) of the α2 domain. The pooled motif and ion mass ligand maps for B*1512 tightly matched those of B*1501, demonstrating that the 166/167 polymorphism between B*1501 and B*1512 has little impact upon ligand presentation. Although the 166/167 polymorphism minimally affects peptide binding preferences, this polymorphism makes B*1512 and B*1501 quite distinct by serology. We then compared the B70 molecules B*1510 and B*1518. The two are almost indistinguishable by serology and differ only by an α2 polymorphism at 116. Comparative peptide mapping shows that a Tyr to Ser polymorphism at 116 drastically changes the ligands bound by B*1510 and B*1518; no overlaps could be found. Polymorphisms in α2 therefore vary from subtle to extreme in the manner by which they moderate ligand presentation, and serologic crossreactivity did not reflect the ligands presented by these B15 subtypes.
The CC‐chemokine receptor 5 (CCR5) is a marker of, but not essential for the development of human Th1 cells
Authors: Ødum N. , Bregenholt S. , Eriksen K.W. , Skov S. , Ryder L.P. , Bendtzen K. , Van Neerven R.J.J. , Svejgaard A. , Garred P.
Published: March 2003

The CC‐chemokine receptor 5 (CCR5) has recently been described as a surface marker of human T cells producing type 1 (Th1) cytokines. Here we confirm that CCR5 is expressed on human Th1 but not on Th2 T‐cell clones. Using intracellular cytokine staining, we show that allo‐antigen specific CD4+ T‐cell lines derived from a CCR5‐deficient individual (Δ32 allele homozygote) contain high numbers of both interferon γ (IFN‐γ) and interleukin (IL)‐2 producing cells, low numbers of IL‐10 producing cells and no IL‐4 or IL‐5 producing cells when stimulated with phorbol ester and ionomycin in vitro. These results were similar to those obtained from allo‐antigen specific CD4+ T‐cell lines derived from CCR5 expressing individuals. An enzyme‐linked immunoabsorbent assay (ELISA) confirmed that the Th1 cytokine‐positive cells from the CCR5‐deficient individual were able to produce equal amounts of cytokines when compared to T‐cell lines from CCR5‐expressing individuals. These results demonstrate that CCR5‐negative T cells display the same capacity of Th1 T‐cell differentiation as T cells derived from CCR5‐expressing individuals. Thus, CCR5 expression is not essential for differentiation of human Th1 T cells.
Identification of the null HLA‐A2 allele, A*0232N
Authors: Bunce M. , Procter J. , Dunn P.P.J. , Day S. , Ross J. , Welsh K.I.
Published: March 2003

We have identified a null HLA‐A*02 allele, HLA‐A*0232N, by using a combination of serology, flow cytometry, polymerase chain reaction using sequence‐specific primers (PCR‐SSP) and full‐length sequencing. The null HLA‐A2 allele was identified in an Asian individual originally typed by serology as an apparently homozygous HLA‐A3, B51. Subsequent genotyping by PCR‐SSP identified the genotype as HLA‐A*0201, *0301, B*51, Cw*1402. The serological type and lack of detectable HLA‐A2 was confirmed using monoclonal antibody typing reagents. Flow cytometry studies failed to identify any cell surface HLA‐A2 expression on the patient’s peripheral blood lymphocytes. Genotyping using a PCR‐SSP set designed to detect null alleles revealed the mutation had not been previously described. Full‐length sequencing of the allele identified an allele which was subsequently named HLA‐A*0232N. This allele is identical to HLA‐A*0201 except for a novel point mutation (T for C) at position 493 which creates a premature stop codon. The sequencing enabled the development of a monospecific A*0232N PCR‐SSP reaction which was used to screen 973 DNA samples: no further examples of A*0232N were identified.
Identification of the novel allele HLA‐B*1545: assessment of alloreactivity in case of mismatch with other B*15 alleles
Authors: Elsner H.‐A. , Blasczyk R.
Published: March 2003

The novel allele HLA‐B*1545, which has been serologically typed as B62, was identified in a male Caucasian. In the sequence analysis the new allele differs from B*1507 by nucleotide 419 which is located in exon 3. Its structure suggests that it may have originated by a point mutation or by gene conversion with a variety of HLA‐B alleles. At the protein level, the nucleotide substitution results in an amino acid exchange compared to B*1507 (Tyr116Ser). Due to probably substantial differences to B*1507 and the other B*15 variants with regard to peptide binding, a mismatch is likely to impair clinical outcome of bone marrow transplantation ( Note).
HLA‐B*4413 identified in a UK Caucasoid potential bone marrow donor
Authors: Cox S.T. , McWhinnie A. , Prokupek B. , Madrigal J.A. , Little A.‐M.
Published: March 2003

We describe a novel allele belonging to the B*44 allele group. HLA‐B*4413 was identified in a Caucasoid potential bone marrow donor from the Anthony Nolan Bone Marrow Trust register. Initial HLA typing of this donor revealed unusual serological reactivity. Further investigation was carried out by reference strand conformation analysis (RSCA) and sequence‐based typing (SBT) using DNA extracted from an Epstein‐Barr virus (EBV)‐transformed B‐cell line made from this donor (AMI005AN). In this individual, two B*44 alleles were revealed upon initial investigation: B*4409 and a previously unseen allele which has been named B*4413. B*4413 is identical to B*44031 except for a unique nucleotide substitution resulting in an amino acid difference at residue 61 in the α1 helix ( Note).
Routine HLA‐B genotyping with PCR‐sequence‐specific oligonucleotides (PCR‐SSO) detects eight new alleles: B*0807, B*0809, B*1551, B*3529, B*3532, B*4025, B*5304 and B*5508
Authors: Kennedy C.T. , Dodd R. , Le T. , Wallace R. , Ng G. , Greville W.D. , Kennedy A. , Taverniti A. , Moses J.H. , Clow N. , Watson N. , Dunckley H.
Published: March 2003

This paper describes eight new alleles (B*0807, B*0809, B*1551, B*3529, B*3532, B*4025, B*5304 and B*5508) that have been found by routine HLA‐B genotyping with sequence‐specific oligonucleotides (SSOs). All of the new alleles have variations which cause changes in residues that occur within antigen binding pockets and T‐cell recognition sites of the antigen. The new polymorphisms within these new alleles may affect the nature and specificity of peptide binding and cause differential T‐cell activation, which may have an affect in transplantation ( Note).
Limited plasticity in the recognition of peptide epitope variants by an alloreactive CTL clone correlates directly with conservation of critical residues and inversely with peptide length
Authors: García‐Peydró M. , Rognan D. , López de Castro J.A.
Published: March 2003

Although self‐restricted T cells are peptide‐specific and can distinguish among closely related ligands, they have some flexibility in the recognition of sequence variants of their natural peptide epitopes. Alloreactive cytotoxic T lymphocytes (CTL) can recognize specific peptides bound to the allo‐major histocompatibility complex (MHC) molecule, but their plasticity in the recognition of related peptide variants has not been properly defined. The anti‐B*2705 alloreactive CTL 27S69 specifically recognizes a natural octamer ligand of HLA‐B*2705. In this study, we tested the recognition of a nested set of epitope variants by this CTL clone. Although none of these peptides was recognized equally as the natural epitope, two of the peptide variants were recognized with only slightly decreased efficiency. Peptide sensitization assays showed that CTL recognition of epitope variants correlated directly with conservation of two non‐anchor residues that were critical for recognition of the natural epitope, and inversely with peptide length. Molecular modeling of the peptide variants complexed with B*2705 provided a rational explanation for their differential recognition. Location of the two critical peptide residues at the right three‐dimensional space favored efficient recognition by CTL 27S69. The negative effect of increasing peptide length on recognition was due to the bigger bulging surface between the two critical residues, which precluded for optimal interaction with the specific T‐cell receptors (TCR). Our results demonstrate that an alloreactive CTL has a degree of plasticity in the recognition of peptide epitope variants that is comparable to that of peptide‐specific self‐restricted CTL, and define the structural features determining crossreaction among related peptides.
HLA‐DQ/human CD4‐restricted immune response to cockroach allergens in transgenic mice
Authors: Papouchado B.G. , Chapoval S.P. , Marietta E.V. , Weiler C.R. , David C.S.
Published: March 2003

We investigated the immune response to the German cockroach (Blattella germanica), and one of its major antigens, Blattella germanica group 5 (Bla g 5), in a double‐transgenic, double‐knockout mouse expressing human HLA‐DQ8, HLA‐DQ6 and CD4 molecules in the absence of mouse class II and mouse CD4. Transgenic mice were primed and challenged with CR extract or individual synthetic peptides representing Bla g 5. Strong T‐cell responses to CR extract were detected in both HLA‐DQ/hCD4+ transgenic mice. The responses were two times lower in mice expressing HLA‐DQ molecule in the context of mouse CD4. Under similar treatment, no responses were found in the double‐knockout Aβ°/mCD4° mice and in mice expressing human CD4 molecule alone. HLA‐DQ/hCD4+ mice produced primarily interleukin (IL)‐5, IL‐10, and IL‐13. Minimal amounts of IL‐4 were detected only in HLA‐DQ6/hCD4+ mice. Interferon (IFN)‐γ production was low in both transgenic mouse, suggesting a predominantly T‐helper 2 (Th2)‐type response. Cockroach allergen extract immunized HLA‐DQ8/hCD4+ mice recognized only one of the 20 peptides of Bla g 5 while HLA‐DQ6/hCD4+ mice responded primarily to three peptides. Primed with individual peptides, both HLA‐DQ/hCD4+ mice responded maximally to peptides 10 (residues 91–110) and 17 (residues 161–180). In addition, HLA‐DQ6/hCD4+ mice responded to peptide 16 (residues 151–170). Thus, peptides 10 and 17 contained the major HLA‐DQ‐restricted hCD4+ T‐cell epitopes and could be recognized by both HLA‐DQ8 and HLA‐DQ6 transgenic mice. Transgenic mice represent a new tool for investigating the immune responses to cockroach allergen. Our results suggest that therapeutic strategies aimed at developing antagonist peptides might be a useful treatment (immunotherapy) for allergic asthma.
The relationship between HLA‐B45 and B*5002 in the five major U.S. population groups
Authors: Kosman C. , Steiner N. , Pulyaeva H. , Mitton W. , Slack R. , Hartzman R.J. , Ng J. , Hurley C.K.
Published: March 2003

The antigen encoded by B*5002 differs in sequence from that encoded by B*5001 only at amino acid residue 167 (consensus tryptophan vs. serine) which results in B45 serologic reactivity. To search for B*5002, the frequencies of alleles encoding the serologically defined B45 antigen were determined by sequence‐based typing in 5 major U.S. populations: Caucasians, African Americans, Asians/Pacific Islanders, Hispanics, and Native Americans. The percent of serologically defined B45‐positive individuals in the 5 populations ranged from 0.7–9.0%. Thirty‐two B45‐positive individuals were randomly chosen, when available, for sequence‐based typing from each ethnic group from a database of 82,979 consecutively typed unrelated individuals. The B*5002 allele was most prevalent in Hispanic (22%) and Caucasian (9%) individuals, while conspicuously absent in African Americans. In addition, a new allele associated with the B45 antigenic specificity, B*4502, has been identified from an African American individual of Middle Eastern descent. In light of the continuing need to reconcile differences between relationships determined by the sequence homologies among alleles and relationships based on the serologic determinants carried by allelic products when determining the level of HLA match for hematopoietic stem cell transplantation, it is suggested that B*5002 be recognized individually from other B*50 alleles when reporting HLA‐B typings for clinical purposes.
DRB3 alleles with variations in the annealing sites of commonly used amplification primers
Authors: Coquillard G.J. , Tang T.F. , Steiner N. , Perlee L. , Ng J. , Hartzman R. , Hurley C.K.
Published: March 2003

New HLA alleles are often identified initially from observing uncommon patterns found in low‐resolution typing performed via polymerase chain reaction using sequence‐specific oligonucleotide probes (PCR‐SSOP). Recently, the HLA‐DR oligotyping analysis of two Caucasian, one Caucasian/American Indian and two African American individuals resulted in the identification of three novel DRB3 alleles. Using DRB‐specific primer sets commonly employed in amplification‐based typing, all four individuals were originally characterized as DRB3 negative. Direct sequencing identified DRB3*0104 (variation at codon 8, T CG instead of T
TG), and DRB3*0101202 (variation at intron (−13), G instead of C). One individual appeared to carry a DR52‐associated DRB1 allele without an associated DRB3 allele. Lack of conservation at the junction of intron 1 and exon 2 of the DRB3 gene suggests that commonly used DRB‐specific primer sets may need to be modified.
Intercellular adhesion molecule‐1 (ICAM‐1) K469E polymorphism: no association with type 1 diabetes among Finns
Authors: Nejentsev S. , Laine A.‐P. , Simell O. , Ilonen J.
Published: March 2003

The intercellular adhesion molecule‐1 (ICAM‐1) has an important role in the process of lymphocyte migration and activation, and is supposed to be involved in the pathogenesis of type 1 diabetes. We studied A/G (K469E) polymorphism of the ICAM‐1 gene in 218 type 1 diabetes patients and 212 controls from Finland and found no association. We then studied transmission of the ICAM‐1 alleles in 102 Finnish families using a transmission disequilibrium test (TDT). Alleles A and G were transmitted to the affected offspring in 50% each. Stratification by the HLA‐DQB1‐DQA1 genotypes, sex and age at onset did not reveal association. Our data demonstrate that in the Finnish population K469E polymorphism of the ICAM‐1 gene is not associated with type 1 diabetes.
Definition of peptide binding motifs amongst the HLA‐A*30 allelic group
Authors: Krausa P. , Münz C. , Keilholz W. , Stevanovic S. , Jones E.Y. , Browning M. , Bunce M. , Rammensee H.‐G. , McMichael A.
Published: March 2003

HLA class I molecules present endogenously processed peptide ligands for surveillance by the T‐cell receptor. This potentially immunogenic surface of HLA and peptide is a consequence of the polymorphism found within the HLA molecule and its preference for ligand binding together with peptide conformation within the binding groove. To investigate the relation between the polymorphic differences between some closely related HLA alleles and their effect on peptide preference, transfectants were established, each containing one of four allelic variants of HLA‐A*30. Peptides from all four transfectants were eluted, and both individual ligands and peptide pools were sequenced. The data shows two distinct peptide motifs which distinguish A*3001 from the other three known A*30 variants. Differences in preferences at minor positions within the peptide sequence were noted between A*3002, A*3003 and A*3004, providing additional evidence of the implications of sequence polymorphism to HLA function.
Identification of tumor antigen‐specific cytotoxic T lymphocytes cross‐recognizing allogeneic major histocompatibility class I molecules
Authors: Fleischhauer K. , Gattinoni L. , Lietti G. , Zino E. , Bordignon C. , Traversari C.
Published: March 2003

Adoptive immunotherapy of cancer utilizes tumor antigen‐specific cytotoxic T lymphocytes (CTL) as mediators of a targeted anti‐tumor effect. In this study, we show that such CTL can be able to cross‐recognize allogeneic major histocompatibility complex (MHC) molecules in a phenomenon of molecular mimicry. A self histo‐leukocyte antigen (HLA) A*0201‐restricted CTL specific for peptide MT27‐35 from the human differentiation antigen Melan‐A/MART‐1 was shown to cross‐recognize allogeneic A*0220 molecules which differ from syngeneic A*0201 for a single amino acid substitution at position 66 of the antigen‐binding groove. A*0220 molecules were recognized on a variety of human cells of different histological origin but not on COS‐7 cells. A second self‐A*0201‐restricted CTL, specific for peptide D10/6‐271 encoded by the tumor‐specific DAM‐gene family, was shown to cross‐recognize allogeneic B*3701 molecules which differ from syngeneic A*0201 by 32 amino acids in the peptide antigen‐binding cleft. B*3701 molecules were recognized on a variety of cell types including COS‐7 cells. These data raise new safety issues for clinical trials of cancer immunotherapy using adoptive transfer of in vitro generated, allogeneic CTL with specific anti‐tumor activity.
A study on the polymorphism of human MHC class I‐related MR1 gene and identification of an MR1‐like pseudogene
Authors: Parra‐Cuadrado J.F. , Navarro P. , Mirones I. , Setién F. , Oteo M. , Martínez‐Naves E.
Published: March 2003

Human MR1 is a recently discovered, ubiquitously transcribed gene very similar to the HLA class I loci and of unknown function. Mouse and rat MR1 sequences have also been described showing high similarity with the human gene. The goal of this work was to investigate if human MR1 was polymorphic. We have found that DNA sequences of MR1‐specific polymerase chain reaction (PCR) products obtained from samples of diverse ethnic origin were invariant except in one case in which two silent mutations were detected. We also found an MR1‐like sequence displaying significant differences with the previously described, the most remarkable of which is a STOP codon in the α2 domain indicating that is a pseudogene.
Unexpected Bw4 and Bw6 reactivity patterns in new alleles
Authors: Voorter C.E.M. , Van Der Vlies S. , Kik M. , Van Den Berg‐Loonen E.M.
Published: March 2003

The Bw4 and Bw6 epitopes were the first HLA‐B differences to be recognized by serological methods. Since then 44 serological groups have been identified and more than 250 alleles assigned by molecular typing methods. In general each serological HLA‐B group is associated with the presence of either the Bw4 or the Bw6 epitope. There are several exceptions to this rule. Four alleles, B*4601, *7301, *5503 and *1806, show no serological reactivity with either Bw4 or Bw6. Although the Bw6 motif at residues 77–83 is present in these alleles the Bw6 epitope is modified by a valine at residue 76. One or more alleles from the B8, B40 and B62 groups are identified as Bw4 positive, whereas all others are Bw6 positive. In the groups B27, B44 and B47 several alleles are found to be Bw6 positive, while the majority is Bw4 positive. Histocompatibility testing of dialysis patients and their families revealed the serological presence of an unexpected Bw4 epitope associated with B18 in one patient and B56 in another. Allele‐specific amplification and sequencing of exons 2 and 3 of these HLA‐B alleles revealed the presence of the Bw4 sequence motif for both. The new alleles were assigned B*1809 and B*5607, respectively. In 2 other patients the presence of a new B*07 allele was determined by sequence based typing. Although the new allele, B*0715, showed the Bw6 sequence motif at positions 77 to 83, a substitution of amino acid 76 from glutamic acid to valine was identified. This change resulted in an aberrant Bw6 serological reaction pattern.
Increased diversity within the HLA‐B*07 group: identification of the two novel alleles B*0709 and B*0710
Authors: Elsner H.‐A. , Blasczyk R.
Published: March 2003

The identification of the two novel alleles, HLA‐B*0709 and B*0710, is described. B*0709 differs from B*07021 by a nucleotide exchange at position 419 (A>C) which is located in exon 3. At the protein level the nucleotide exchange results in an amino acid residue difference (Tyr116Ser). The other newly detected allele, B*0710, differs from B*07021 by a nucleotide exchange at position 272 (A>G) which is located in exon 2. This nucleotide exchange also leads to an amino acid substitution (Tyr67Cys). The allogeneic potential in case of mismatch with other alleles of the B*07 group at bone marrow transplantation was assessed. The peptide motifs between B*0709 and B*0711 may be very similar and thus the alloreactive potential in case of mismatch may be low. In contrast, mismatches of B*0709 and B*0710 with other B*07 alleles are likely to stimulate alloreactive T cells ( Note).
Molecular, serological and genetic studies on two new HLA‐DRB1 alleles – HLA‐DRB1*0704 and HLA‐DRB1*1507
Authors: Darke C. , Guttridge M.G. , Street J. , Thompson J. , Thomas M.
Published: March 2003

Acknowledgments:

We thank ROS and LJM for their help and interest in this work and Dr Helen Bass, from our laboratory, for the production of EBV‐transformed B‐cell lines. The financial support of the British Bone Marrow Donor Appeal is gratefully acknowledged.

Two new HLA‐DRB1 alleles (DRB1*0704 and DRB1*1507) were detected during routine polymerase chain reaction (PCR)‐based typing of two Caucasoid bone marrow panel donors due to apparent DRB1*“blanks” being associated with unexpected DRB4, DRB5 and DQB1 alleles. HLA‐DRB1*0704 differed from DRB1*0701 by five consecutive nucleotides at positions 217 to 221 of exon 2 encoding two amino acids substitutions of tyrosine to asparagine at codons 77 and valine to tyrosine at codon 78. DRB1*1507 differed from DRB1*1501 by a single nucleotide at position 127 encoding an amino acid substitution of phenylalanine to tyrosine at codon 47. Their specificities were unequivocally assigned by serology as HLA‐DR7 and DR15, respectively, and family and population studies allowed their likely HLA‐A,B,C,DR,DQ and complement (Bf, C4A, C4B) bearing haplotypes to be identified. No further examples were found in 19,113 HLA‐DR,DQ typed donors from the Welsh Bone Marrow Donor Registry indicating that both these alleles have a phenotype frequency of <0.01% and a gene frequency of <0.00003 (Note).
Tubal versus uterine placentation: similar HLA‐G expressing extravillous cytotrophoblast invasion but different maternal leukocyte recruitment
Authors: Pröll J. , Bensussan A. , Goffin F. , Foidart J.‐M. , Berrebi A. , Le Bouteiller P.
Published: March 2003

The nonclassical HLA‐G class I gene is expressed by extravillous cytotrophoblast that invades decidua in uterine pregnancy, suggesting that it may contribute to the immunological mechanisms that protect the fetus against maternal alloimmune response and/or pathogen infections. We first addressed the question of whether HLA‐G expression was dependent on maternal tissue environment by comparing uterine and ectopic tubal pregnancies. Using HLA‐G‐specific mAb on placental cryosections, we found by immunohistochemistry that all subtypes of extravillous cytotrophoblast similarly expressed HLA‐G in pregnant tubes, demonstrating that its expression was independent of the site of implantation. We next compared by immunohistochemistry the phenotype of maternal leukocytes recruited in both pregnant tissues. In contrast to decidua, pregnant tubes were characterized firstly, by the lack of natural killer (NK) cells and of cells expressing CD94 receptor specific for HLA‐E, secondly, by a prominent increase of CD8+ T cells, dendritic cells, and macrophages, the latter co‐expressing the LIR1/ILT2 killer immunoglobulin‐like receptor (KIR), and finally, by the presence of cells expressing LIR2/ILT4 KIR or BY55 NK receptors, known to bind to HLA‐G. Such cell types may favor a unique innate defense in pregnant tubes. These observations also suggest that trophoblast HLA‐G expression does not influence the recruitment of particular maternal leukocytes in pregnant tissues.
Two new HLA DPB1 alleles identified by sequence‐based typing: DPB1*8201 and DPB1*8301
Authors: Voorter C.E.M. , Tilanus M.G.J. , Van Den Berg‐Loonen E.M.
Published: March 2003

Two new HLA DPB1 alleles were identified by sequence‐based typing and are reported. Both alleles differ from DPB1*0402 by a single nucleotide: DPB1*8201 has a difference at position 359 (codon 91) leading to an amino acid change from arg to his, making this position a new polymorphic site; DPB1*8301 has a difference at position 280 (codon 65) changing the amino acid from ile to phe ( 1).