Regulatory T-cell depletion does not prevent emergence of new CD25+ FOXP3+ lymphocytes after antigen stimulation in culture

BACKGROUND

The removal of human regulatory T (T(reg)) cells from a cellular product prior to the induction of a T-cell response has the potential to boost the total yield of antigen (Ag)-specific CD4(+) and CD8(+) T cells.

METHODS

We examined the effect of this manipulation on the generation of human anti-cytomegalovirus (CMV) T-cell responses. Furthermore, we examined the clonotypic composition of Ag-specific CD4(+)FOXP3(+) and CD4(+)FOXP3(-) T cells.

RESULTS

We found that the immunomagnetic depletion of CD25(+) cells had an unpredictable effect on outcome, with total yields of CMV-specific T cells either increasing or decreasing after the removal of these cells. The depletion of CD25(+) cells both removed a proportion of Ag-specific T cells and failed to eliminate a substantial population of T(reg) cells. Furthermore, using a novel T-cell receptor clonotyping technique, we found that Ag recognition induces the expression of FOXP3 in a proportion of specific T cells; these FOXP3-expressing Ag-specific CD4(+) and CD8(+) T cells were no longer capable of producing inflammatory cytokines.

DISCUSSION

The depletion of CD25(+) cells from the starting population has a variable effect on the total yield of Ag-specific T cells, a proportion of which invariably acquire FOXP3 expression and lose effector function.

CNTO 530: molecular pharmacology in human UT-7EPO cells and pharmacokinetics and pharmacodynamics in mice

CNTO 530 is a 58 kD antibody Fc domain fusion protein, created using Centocor's MIMETIBODY platform, that contains two EMP1 sequences as a pharmacophore. CNTO 530 has no sequence homology with EPO but acts as a novel erythropoietin receptor agonist. In UT-7(EPO) cells, CNTO 530 caused protein phosporylation of the erythropoietin receptor associated signaling pathway (Jak2, STAT5, AKT and ERK1/2). CNTO 530 also rescued these cells from apoptosis and mediated proliferation. In mice, pharmacokinetic analysis showed that CNTO 530 was slowly cleared from circulation with a t(1/2) approximately 40 h. Pharmacodynamic analysis in mice showed that a single sc dose of CNTO 530 caused a long-lived stimulation of erythropoiesis that translated into increases in red blood cell counts and hemoglobin values that were maintained for at least 28 d. In conclusion, CNTO 530 is a long-lived EPO-R agonist that stimulates erythropoiesis in a manner similar to epoetin-alpha. These data suggest that CNTO 530 may be an effective treatment of anemia in humans.

Regulation of bone-related genes expression by bone-like apatite in MC3T3-E1 cells

Bone-like apatite on HA/TCP ceramics sintered at 1,100 degrees C (HT1) and 1,200 degrees C (HT2) could be obtained via immersing substrates into simulated body fluid (SBF) for 3 days. When MC3T3-E1 preosteoblastic cells cultured on the surface of the bone-like apatite for 3 days, SEM observations revealed cell membrane features with secreted crystals very similar to in vivo bone formation during intramembranous ossification with a direct bone apposition on the ceramics. According to semi-quantitative RT-PCR method, mRNA expressions of osteocalcin (marker of late-stage differentiation) and type 1 collagen were increased in cultures with HT1S and HT2S when compared to HT1 and HT2 after cultured for 6 days. The results indicated that bone-like apatite had the ability to support the growth of osteoblast-like cells in vitro and to promote osteoblast differentiation by stimulating the expression of major phenotypic markers. Taken together, our findings will be helpful in understanding the mechanism of osteoinductivity of calcium phosphate ceramics and in constructing more appropriate biomimetic substrate.

Competitive adsorption of bovine serum albumin and lysozyme on characterized calcium phosphates by polyacrylamide gel electrophoresis method

Characterizations of hydroxyapatite (HA), biphasic calcium phosphate (BCP) and beta tricalcium phosphate (beta-TCP) ceramic particles were carried out using X-ray diffusion (XRD), Scanning electron micrograph (SEM), Particle Sizer and Zeta potential analyzer. Competitive adsorption of bovine serum albumin (BSA) and lysozyme (LSZ) on the three calcium phosphates were investigated by polyacrylamide gel electrophoresis (PAGE) method. The results showed that HA, BCP and beta-TCP ceramic particles with irregular shapes and similar size distributions all had negative surface net charges in pH7.4 phosphate buffered saline (PBS) solution and exhibited alike behaviors of BSA and LSZ adsorption. LSZ had higher affinity for calcium phosphate ceramics than BSA and its adsorption on them didn't be almost influenced by the increasing of BSA concentration in the solution. Electrostatic interaction played an important role on the competitive adsorption of BSA and LSZ on the surface of calcium phosphate ceramic particles.

Controllable release of salmon-calcitonin in injectable calcium phosphate cement modified by chitosan oligosaccharide and collagen polypeptide

The aim of this research is to study the effect of the controlled releasing character of the salmon calcitonin (S-CT) loaded injectable calcium phosphate cement (CPC) modified by adding organic phase, chitosan oligosaccharide (CO) and collagen polypeptide (CP). The uniform design was used to determine the basic formulation with suitable injectable time for clinical application, and then the changes of the physical characters, the controlled releasing character of the modified CPC along with the ratio of the organic phase were also evaluated in vitro. The surface morphous of the modified CPC been implanted in the abdominal cavity or soaked into the serum of rat was also observed by scanning electron microscope (SEM). The result shows that a suitable formulation of modified CPC could be got, and the injectable time is 12 min, the compressive strength is 12 MPa, and the final setting time is 40 min. Comparing with the CPC without organic phase, the releasing rate of S-CT would increase along with the increase of the organic phase after 7th day. Therefore, a novel S-CT loaded bioactive injectable CPC for treating osteoporosis induced bone defect was obtained, and the release of the containing S-CT was controlled easily through adjusting the ratio of CO and CP.

P300 plays a role in p16(INK4a) expression and cell cycle arrest

As a cyclin-dependent kinase inhibitor, p16(INK4a) plays a key role in cell cycle progression and cellular differentiation, and its expression is frequently altered in human cancers through epigenetically mediated transcriptional silencing. In this report, we demonstrate that p300 was able to induce cell cycle arrest, and this process was reversed by p16(INK4a) silencing by RNA interference in HeLa cells. We also show that p300 was involved in activation of p16(INK4a) expression in 293T cells. Specifically, p300 cooperated with Sp1 to stimulate both p16(INK4a) promoter activity and mRNA expression. Co-immunoprecipitation and mammalian two-hybrid assays revealed that p300 and Sp1 formed a complex through interaction between the Q domain of p300 and the N-terminal domain of Sp1. The chromatin immunoprecipitation assays verified that p300 was recruited to p16(INK4a) promoter, and the histone acetyltransferase domain of p300 participated in p16(INK4a) activation through inducing hyperacetylation of histone H4 at p16(INK4a) gene. These data suggest that p300 plays a critical role in transcriptional regulation of p16(INK4a) and in cell cycle arrest.

Graph Abstraction in Real-time Heuristic Search

Real-time heuristic search methods are used by situated agents in applications that require the amount of planning per move to be independent of the problem size. Such agents plan only a few actions at a time in a local search space and avoid getting trapped in local minima by improving their heuristic function over time. We extend a wide class of real-time search algorithms with automatically-built state abstraction and prove completeness and convergence of the resulting family of algorithms. We then analyze the impact of abstraction in an extensive empirical study in real-time pathfinding. Abstraction is found to improve efficiency by providing better trading offs between planning time, learning speed and other negatively correlated performance measures.

Transformation, genomic instability and senescence mediated by platelet/megakaryocyte glycoprotein Ibalpha

GpIbalpha, a subunit of the von Willebrand factor receptor, functions during blood clotting to promote platelet adhesion and activation. GpIbalpha is widely expressed, is positively regulated by c-Myc and is essential for the promotion of c-Myc-mediated chromosomal instability. We now show that GpIbalpha is also a classical oncoprotein in which its deregulated expression leads to transformation, reduced growth factor requirements, increased resistance to apoptosis, and, in primary cells, p53-dependent senescence. Finally, GpIbalpha also promotes double-stranded DNA breaks, and induces profound nuclear dysmorphology, indicating that, in addition to its direct transforming function, it displays genotoxicity at several distinct levels. These findings identify novel functions for GpIbalpha and pathways through which c-Myc mediates transformation and global genomic destabilization.

First Report of Anthracnose Caused by Elsinoe ampelina on Muscadine Grapes (Vitis rotundifolia) in Northern Florida

Anthracnose of grapes is an economically devastating disease caused by Elsinoe ampelina (2). Warm, humid weather favors disease development, and therefore in the United States, it is generally restricted to grape-growing areas east of the Rocky Mountains. Vitis vinifera is highly susceptible to the disease, which is one of the principal factors preventing the development of an industry with this high-quality grape in the southeastern United States. Growers in this area produce local species-such as muscadine grapes (V. rotundifolia Michx.) and hybrids. Muscadine grapes are known for their resistance or "immunity" to many diseases found in bunch (Euvitis spp. Planch.) grape species (1). As yet, there has been no formal report of anthracnose or its causal agent on muscadine grapes. E. ampelina was detected on muscadine leaves for the first time in the experimental vineyard at the Center for Viticulture and Small Fruit Research during the summer of 2006. Approximately 40% of the 52 muscadine cultivars in the collection showed circular or irregular black spots typical of anthracnose mainly on young leaves and tendrils. However, no symptoms were observed on fruits, shoot tips, or any other plant part. To confirm the causal agent, infected leaves were surface sterilized with 75% ethanol, dipped in 2% sodium hypochlorite for 15 s, rinsed in distilled water, dissected into small 0.5-cm leaf discs, and plated on potato dextrose agar (PDA) and incubated at 28°C. Single-spore isolates were grown on PDA. Colonies were slow growing and appeared as dark red mounds with some mycelia. Conidia were cylindrical and hyaline with pointed ends consistent with previous reports for E. ampelina (2). The identity was also confirmed by using the following PCR primers to the 18S RNA: left primer; TCCGTAGGTGAACCTGCGGA and right primer; TCCTACCTGAT CCGAGGTCA designed on the basis of the alignment of E. ampelina sequences deposited in NCBI database. To fulfill Koch's postulates, symptoms were reproduced by artificial inoculation onto young muscadines (cv. Carlos) and bunch (cv. Cabernet Sauvignon) grapevines. A conidial suspension was prepared from single-conidial cultures, and three experimental vines of each species were sprayed with 0.5 ml of suspension (2 × 10⁵ conidia per ml), whereas three control plants were sprayed with distilled water. The plants were incubated in a moist chamber at 28°C with 16 h of light. The first typical symptoms appeared on V. vinifera 4 days postinoculation and on the muscadines 6 days postinoculation. To our knowledge, this is the first report confirming anthracnose disease on muscadine grapes. References: (1) J. Lu et al. Acta Hortic. 528:479, 2000. (2) R. C. Pearson and A. C. Gohen. Anthracnose. Pages 18-19 in: Compendium of Grape Diseases. The American Phytopathological Society. St. Paul, MN, 1994.

Mitochondrial myopathy associated with a novel mutation in mtDNA

A 6-year-old boy had progressive muscle weakness since age 4 and emotional problems diagnosed as Asperger syndrome. His mother and two older siblings are in good health and there is no family history of neuromuscular disorders. Muscle biopsy showed ragged-red and cytochrome coxidase (COX)-negative fibers. Respiratory chain activities were reduced for all enzymes containing mtDNA-encoded subunits, especially COX. Sequence analysis of the 22 tRNA genes revealed a novel G10406A base substitution, which was heteroplasmic in multiple tissues of the patient by RFLP analysis (muscle, 96%; urinary sediment, 94%; cheek mucosa, 36%; blood, 29%). The mutation was not detected in any accessible tissues from his mother or siblings. It appears that this mutation arose de novo in the proband, probably early in embryogenesis.

A comparison of tumor characteristics between ER+/PR+ and ER+/PR- breast tumors in Chinese women

21097

Background: Although breast caner patients with any one of the two sex hormone receptors positive can be treated with endocrine therapy, many clinical data showed that there was different response to endocrine therapy for patients with ER+/PR+ and with ER+/PR- tumors. The aim of this study was to find out the factors related to PR expression by comparing the ER+/PR+ tumors and ER+/PR- tumors clinically and biologically. Methods: Between January 1990 to August 2006, 5,191 female breast cancer patients with known ER/PR expression status who received operation in our hospital were enrolled onto this retrospective study. Clinical and biological features of 2,227 patients with ER+/PR+ tumors were compared with those of 909 patients with ER+/PR- tumors. χ2 test was used for univariate analysis and logistic regression for multivariate analysis. Disease-free survival (DFS) and overall survival (OS) was calculated using Kaplan-Meier analyses, and all statistical tests were two-sided. Results: The peak onset age of patients with ER+/PR+ tumors and ER+/PR- tumors was 50, and it was significantly higher than that of patients with ER- tumors, which is 48(P=0.001). Univariate analysis showed that ER+/PR- tumors were larger in size, had more lymph nodes of metastasis, were higher in tumor grade than ER+/PR+ tumors. Furthermore, the expression of ER and CathepsinD was significantly lower, and CerbB-2 expression was higher in ER+/PR- tumors than in ER+/PR+ tumors. Multivariate analysis indicated that positive PR expression was associated with the level of ER(OR=1.792, P=0.000), CathepsinD(OR=1.380, P=0.035)and CerbB-2(OR=0.639, P=0.007). DFS(P=0.004) and OS(P=0.009) were higher among patients with PR-expressing tumors than with PR- negative tumors. Conclusions: ER+/PR+ tumors and ER+/PR- tumors may have the same etiology which is different from that of ER- tumors. Because of low ER level and changes of the expression of CerbB-2 and CathepsinD, the tumors that lacked PR expression display more aggressive features and have worse prognosis. According to these differences, new target of therapy and endocrine regimen may provide the possibility of improving the response and prognosis of endocrine therapy for patients with ER+/PR- tumors.

No significant financial relationships to disclose.

Nijmegen breakage syndrome 1 (NBS1) gene polymorphism and chemotherapy-induced neutropenic fever in breast cancer patients

574

Background: Neutropenic fever (NF) is a serious complication of the chemotherapies given to breast cancer patients and often limits their use. Hence, identifying which patients are at increased risk to develop NF is very important. The NBS1 gene product is important for the repair of double-strand DNA breaks and is activated by chemotherapy. The objective of this study was to determine if genetic variations of NBS1 polymorphisms predict the risk of chemotherapy-induced NF in breast cancer patients. Methods: Blood from 306 newly diagnosed breast cancer patients treated with chemotherapy were prospectively collected on a study approved by the institutional review board. The relationship of chemotherapy administration (e.g. dose, timing) and growth factor use were correlated with the absolute neutrophil count (ANC) and NF development. For each patient, we assessed three polymorphisms (924T>C, 8360G>C, and 30537G>C) of NBS1 gene using polymerase chain reaction-restriction fragment length polymorphism method. Two-sided Chi-square test was used for univariate analysis and a multivariable logistical regression analysis was used to calculate odds ratios. Results: In total, 167 (55%) patients experienced ANC less than 1,000 cells/microliter (CIN1000) and 30 (10%) patients developed NF. For 8360G>C polymorphism, 9.7% of patients had a 8360CC variant genotype and these patients had increased risk of NF than the other genotypes (NF in CC 20.7% vs. in others 8.1%; Odds Ratio [OR] = 3.0; 95% confidence interval [CI] = 1.1 - 8.0, p = 0.034). In multivariable logistic regression model, 8360CC genotype (OR = 5.0, 95% CI = 1.6 - 16.1, p = 0.007) and growth factor support (OR = 19.6, 95% CI = 4.4 - 87.6, p < 0.001) were significantly associated with NF development. No genotypes of 924T>C and 30537G>C polymorphisms increased the risk of NF and there was no statistical association between the three NBS1 gene polymorphisms and CIN1000. Conclusions: Breast cancer patients with 8360CC variant polymorphism in NBS1 gene have increased risk in developing NF with systemic chemotherapy. Analysis of polymorphisms of NBS1 and other DNA repair genes could potentially help identify who will develop chemotherapy-induced bone marrow toxicities.

No significant financial relationships to disclose.

The rule of mortality risk in young women (≤35 years) with primary breast cancer

21098

Background: The prognosis of young women (=35 years) is poorer than that of women over 35 years, which may indicate that they bear different biologic characteristics. However, such data is still not available at home and abroad as the rule of mortality risk in young women and its distinction from that in women over 35 years. We sought to investigate the clinical characteristics, prognosis and the rule of mortality risk in young women (=35 years) with primary breast cancer. Methods: We performed a retrospective study of 2331 female unilateral breast cancer patients undergoing surgery in our hospital from January 1990 to October 2005.They were divided into two groups with the cut-off of 35 years. Selection criteria included complete data on the following: age, tumor size, axillary nodal status, estrogen receptor (ER) status, menopausal status.Overall survival curve was estimated by Kaplan-Meier method and annual mortality hazard by hazard function. Their clinicopathologic indices, overall survival curve and annual mortality hazard were analyzed. Results: There was statistical significance between =35 years and >35 years group in terms of tumor size( P =0.0231), axillary nodal status( P <0.001) and estrogen receptor status( P =0.064). 10-year overall survival was 72% and 79% ( P = 0.0081), respectively, for =35 years and >35 years group. Although annual mortality hazard curve for both groups showed double-peaked pattern, there also exist some differences. Mortality surges for =35 years patients appeared earlier than those for >35 years counterparts. Moreover, =35 years group showed a minor increase between double peaks, which cannot be found in >35 years group. Conclusions: Between the two groups, different tumor biology leads to the discrepancy of overall survival and mortality pattern, which might indicate distinct principles and measures in the follow-up and treatment for young patients to provide the possibility of improving the therapeutic effect and reducing the mortality hazard.

No significant financial relationships to disclose.

A phase II study of FolateImmune (EC90 with GP1–0100 adjuvant followed by EC17) with low dose cytokines interleukin-2 (IL-2) and interferon-α (IFN-α) in patients with refractory or metastatic cancer

13516

Background: FolateImmune is a folate-receptor (FR)-targeted immunotherapy that induces an immune response against tumor cells by marking them with a folate-hapten conjugate. The conjugate is specifically designed to target FR, which is over-expressed in a variety of cancers. FolateImmune therapy is comprised of a vaccine fluorescein conjugate (EC90), an adjuvant (GP-0100), and a folate-hapten conjugate (EC17). Patients (pts) receive a series of subcutaneous (SQ) injections of EC90 vaccine to stimulate the production of antibodies to the fluorescein-hapten, followed by SQ injections of EC17, which forms a molecular bridge between the tumor cell and the endogenous circulating anti-fluorescein IgG antibody. This is thought to initiate an Fc-mediated immune response leading to antibody-dependent cellular cytotoxicity and/or phagocytosis. IL-2 and IFN are utilized at low doses (7 MIU and 3 MIU, respectively) to further promote an immune response. The Phase Ib objective is to determine the safety of EC90 vaccine/EC17 folate-targeted therapy in combination with IL-2 and IFN. The previous phase I trial explored the safety of FolateImmune without cytokines. Methods: This phase 1b safety study treated eligible patients with FolateImmune therapy at dose levels of 1.2 mg EC90 and EC17 of 0.3 mg/kg. Results: As of Jan 2, 2007, all patients have tolerated therapy without significant toxicity. Grade 1–2 toxicity included: chills, fever, and nausea. One patient has had a minor response and continues on study. Laboratory studies revealed decline in circulating FR+ cells. Of 6 pts enrolled, 5 had a pathologic classification of renal cell cancer (RCC). Conclusion: Preliminary data suggest that FolateImmune therapy, with the addition of low dose cytokines, may be administered in a safe and well-tolerated manner. Phase II trials are planned for RCC.

No significant financial relationships to disclose.