Amino-terminal extended peptide single-chain trimers are potent synthetic agonists for memory human CD8+ T cells

Upon Ag exposure, most memory T cells undergo restimulation-induced cell death. In this article, we describe a novel synthetic agonist, an N-terminal extended decamer peptide expressed as a single-chain trimer, the amino-terminal extended peptide MHC class I single-chain trimer (AT-SCT), which preferentially promotes the growth of memory human CD8(+) T cells with minimal restimulation-induced cell death. Using CMV pp65 and melanoma gp100 Ags, we observe the in vitro numerical expansion of a clonally diverse polyfunctional population of Ag-specific CD8(+) T cells from healthy individuals and vaccinated melanoma patients, respectively. Memory CD8(+) T cells stimulated with AT-SCT presented on MHC class I/II-null cells show reduced cytokine production, slower kinetics of TCR downregulation, and decreased cell death compared with native nonamer MHC class I single-chain trimer (SCT)-activated T cells. However, both ERK phosphorylation and cell cycle kinetics are identical in AT-SCT- and SCT-activated T cells. Probing of SCT and AT-SCT peptide-MHC complexes using fluorochrome-conjugated TCR multimers suggests that nonamer- and decamer-linked peptides may be anchored differently to the HLA-A2 peptide-binding groove. Our findings demonstrate that modified peptide-MHC structures, such as AT-SCT, can be engineered as T cell agonists to promote the growth and expansion of memory human CD8(+) T cells.     

Insulin-producing cells from human adipose tissue-derived mesenchymal stem cells detected by atomic force microscope

We successfully differentiated human adipose tissue-derived mesenchymal stem cells (haMSCs) into insulin-producing cells (IPCs) in vitro and did not use any insulin which might be absorbed by cells during in vitro culture. Expression of insulin gene was massively increased by 28,000-fold at day 12 compared with haMSCs (P < 0.05). IPCs could secrete insulin after glucose was stimulated. The higher the concentration of glucose, the more production of insulin was noted. We reported AFM images of IPCs for the first time. AFM images showed that the sizes of cells were similar to each other, and all IPC surface had a porous structure in the cytoplasm area. In sugar-free group, the size of holes was similar (diameter, 1,086.98 ± 156.70 nm; depth, 185.22 ± 52.14 nm). In higher sugar-stimulated group, there were more holes with bigger diameter and smaller depth. (diameter, 3,183.65 ± 2,229.18 nm; depth 109.42 ± 56.26 nm, P < 0.05). We found that the hole diameter and depth could change with the concentration of glucose in media. Concurrently, laser scanning confocal microscopy images indicated that cortical actin network beneath plasma membrane in IPCs was dense and continuous. After glucose stimulation, we found the actin web depolymerized and became discontinuous in IPCs. We speculated that diameter augmentation of holes located in the cytoplasm area in IPCs was one manifestation of excytosis increase.     

Long-term survival from adenocarcinoma of the esophagus after transthoracic and transhiatal esophagectomy

ABSTRACT: BACKGROUND: The effects of transthoracic or transhiatal esophagectomy on the long-term survival of patients who had adenocarcinoma of the esophagus were compared, as were factors applicable in preoperative stratification of patient treatment. METHODS: A cohort of 147 consecutive patients with adenocarcinoma of the esophagus was evaluated for esophagectomy between 1984 and 2000. The patients were followed prospectively and observed survival rates of patients with a transthoracic or transhiatal approach to esophagectomy were compared by standardized mortality ratio (SMR) and relative mortality ratio (RMR) using the expected survival of a matched Norwegian population. RESULTS: A R0 resection was performed by transthoracic (n = 33) or a transhiatal (n = 55) esophagectomy in 88 (60%) patients with a median age of 61 (range: 35-77) and 70 (42-88) years, respectively (P <0.001). Tumor stages and other possible risk factors were similar in the two groups. Transthoracic or transhiatal esophagectomy resulted in a median survival time of 20.5 (95% confidence interval (CI): 10.4-57.6) and 16.4 (10.6-28.7) months, respectively. The respective survival rates were 31.2% and 27.8% by 5 years, and 21.3% and 16.6% by 10 years with an overall RMR of 1.14 (P = 0.63). Median survival time in the absence or presence of lymph node metastases was 74.0 (95% CI: 17.5-166.4) and 10.7 (7.9- 14.9) months. The corresponding survival rates by 10 years with non-involved or involved nodes were 48.9% and 3.8% respectively (RMR 2.22, P = 0.007). Patients with a pT1-tumor were few and the survival rate was not very different from that of the general population (SMR = 1.7, 95% CI: 0.7-4.1). The median survival time of patients with a pT2-tumor was 30.4 (95% CI: 9.0-142) months and with a pT3-tumor 14 (9.2-16.4) months. The survival rates by 10 years among patients with a pT1 tumor were 57.0% (95% CI: 14.9-78.9), pT2 33.3% (11.8-52.2), and pT3 7.1% (1.9-15.5). The relative mortality for T3 stages compared to T1 stages was statistically significant (RMR = 3.22, P = 0.024). CONCLUSION: Transthoracic and transhiatal esophagectomy are both effective approaches for treatment of adenocarcinoma of the esophagus and survival of more than 10 years can be expected without adjuvant chemotherapy. However, increasing depth of tumor invasion and lymph node metastases reduce life expectancy.     

Importance of human leukocyte antigen (HLA) class I and II alleles on the risk of multiple sclerosis

Multiple sclerosis (MS) is a complex disease of the central nervous system of unknown etiology. The human leukocyte antigen (HLA) locus on chromosome 6 confers a considerable part of the susceptibility to MS, and the most important factor is the class II allele HLA-DRB1*15:01. In addition, we and others have previously established a protective effect of HLA-A*02. Here, we genotyped 1,784 patients and 1,660 healthy controls from Scandinavia for the HLA-A, HLA-B, HLA-C and HLA-DRB1 genes and investigated their effects on MS risk by logistic regression. Several allele groups were found to exert effects independently of DRB1*15 and A*02, in particular DRB1*01 (OR = 0.82, p = 0.034) and B*12 (including B*44/45, OR = 0.76, p = 0.0028), confirming previous reports. Furthermore, we observed interaction between allele groups: DRB1*15 and DRB1*01 (multiplicative: OR = 0.54, p = 0.0041; additive: AP = 0.47, p = 4 × 10(-06)), DRB1*15 and C*12 (multiplicative: OR = 0.37, p = 0.00035; additive: AP = 0.58, p = 2.6 × 10(-05)), indicating that the effect size of these allele groups varies when taking DRB1*15 into account. Analysis of inferred haplotypes showed that almost all DRB1*15 bearing haplotypes were risk haplotypes, and that all A*02 bearing haplotypes were protective as long as they did not carry DRB1*15. In contrast, we found one class I haplotype, carrying A*02-C*05-B*12, which abolished the risk of DRB1*15. In conclusion, these results confirms a complex role of HLA class I and II genes that goes beyond DRB1*15 and A*02, in particular by including all three classical HLA class I genes as well as functional interactions between DRB1*15 and several alleles of DRB1 and class I genes.     

Wnt signaling and neural stem cells: caught in the Wnt web

Wnt proteins have now been identified as major physiological regulators of multiple aspects of stem cell biology, from self-renewal and pluripotency to precursor cell competence and terminal differentiation. Neural stem cells are the cellular building blocks of the developing nervous system and provide the basis for continued neurogenesis in the adult mammalian central nervous system. Here, we outline the most recent advances in the field about the critical factors and regulatory networks involved in Wnt signaling and discuss recent findings on how this increasingly intricate pathway contributes to the shaping of the developing and adult nervous system on the level of the neural stem cell. Funding: We wish to apologize to those whose work is not included due to the length constraints on the review. Work in the Lie lab is supported by the European Young Investigator Award Program of the European Science Foundation and grants of the Deutsche Forchungsgemeinschaft (LI 858/5-1), the European Union (Marie Curie Excellence Team Award and Marie Curie International Reintegration Grant), and the Bavarian Research Network “Adult Neural Stem Cells” FORNEUROCELL.     

小麦开花后不同器官中硝酸还原酶和谷氨酰胺合成酶的活性比较

小麦开花后各器官的硝酸还原酶和谷氨酰胺合成酶均具有一定的活性,旗叶中硝酸还原酶和谷氨酰胺合成酶活性最高。开花后旗叶和根系硝酸还原酶和谷氨酰胺合成酶活性逐渐降低,颗壳和籽粒中硝酸还原酶和谷氨酰胺合成酶活性先升高,达到最大值后又降低。     

Genetic Variations in the Antibody Response in Young Bulls

Considerable evidence for the existence of a direct genetic control of the immune response has been presented during recent years. Experimental work with rodents are the main basis for this evidence. The first study on genetic variations in the antibody response was carried out by Gorer & Schütze (1938). Later Cinader (1960) published detailed considerations about the specificity and inheritance of the antibody response. In mice it has been demonstrated that a few dominant immune response (Ir) genes determine the ability to produce antibodies against certain specific antigens (McDevitt & Tyan 1968). The magnitude of the response is probably under the influence of polygenes, which are not associated with Ir genes. This theory is supported by selection for high and low antibody production in mice (Biozzi et al. 1972).