Denileukin Diftitox (ONTAK(®), DAB(389) IL-2) is a recombinant DNA-derived fusion protein depleting cells that express high-affinity IL-2 receptor. Important cell targets are CD4(+)CD25(+)Foxp3(+) regulatory T cells (T(reg)). Elimination of immunosuppressive T(reg) by Denileukin Diftitox may provide a way to modulate immune tolerance following stem cell transplantation. Here, we combined T(reg) depletion with a vaccination approach to induce donor-specific immune reactions. To investigate this approach we chose the mixed chimerism canine stem cell transplantation model which represents a high state of tolerance between two hematopoietic systems. The aim was therefore to induce a graft versus hematopoiesis effect thereby converting mixed to full donor chimerism. Dog leukocyte antigen identical siblings that had developed a stable mixed chimerism after non-myeloablative stem cell transplantation received a single dose of Denileukin Diftitox (18μg/kg, i.v.) followed by several cell-lysate vaccinations. Host peripheral blood mononuclear cell lysates combined with CpG-ODN, and Montanide(®) ISA 51 were locally applied. In vitro studies demonstrated that canine T(reg) are a target of Denileukin Diftitox. The suppression of T-cell proliferation by T(reg) was abolished by addition of Denileukin Diftitox (10nM). An increase of proliferation of median 300%(range: 200%-425%) was observed. No change in donor chimerism was observed after administration of Denileukin Diftitox and vaccination. This study highlights that application of Denileukin Diftitox resulted in a depletion of T(reg) followed by an increase of immune response in vitro. This effect could not be confirmed in vivo even if the immune system was stimulated by vaccinations.

[This corrects the article on p. e3508 in vol. 3.].

Imagining performing an action can induce false memories of having actually performed it-this is referred to as the imagination-inflation effect. Drawing on research suggesting that action observation-like imagination-involves action simulation, and thus creates matching motor representations in observers, we examined whether false memories of self-performance can also result from merely observing another person's actions. In three experiments, participants observed actions, some of which they had not performed earlier, and took a source-memory test. Action observation robustly produced false memories of self-performance relative to control conditions. The demonstration of this effect, which we refer to as observation inflation, reveals a previously unknown source of false memories that is ubiquitous in everyday life. The effect persisted despite warnings or instructions to focus on self-performance cues given immediately before the test, and despite elimination of sensory overlap between performance and observation. The findings are not easily reconciled with a source-monitoring account but appear to fit an account invoking interpersonal motor simulation.

HASH(0x26aafee0)

Targets that could improve the treatment of brain tumors remain important to define. This study of a transformation-associated isoform of alpha2-macroglobulin (A2M*) and its interaction with the low-density lipoprotein receptor-related protein-1 (LRP1) suggests a new mechanism for abrogating the malignant potential of astrocytoma cells. LRP1 bound A2M* found to be associated with an inhibition of tumor cell proliferation, migration, invasion, spheroid formation, and anchorage-independent growth. Transcriptional studies implicated effects on the Wnt/beta-catenin signaling pathway. Notably, LRP1 antibodies could phenocopy the effects of A2M*. Our findings suggest a pathway of tumor suppression in astrocytoma that might be tractable to therapeutic exploitation.

Background: The inhibition of nuclear factor (NF)-kappaB with nontoxic agents is a promising possible treatment approach that may inhibit tumor cell proliferation, counteract the prosurvival pathways that mediate resistance to cytotoxic therapy, and prevent tumor cell metastasis. Methods: An initial structure-activity relationship study of the NF-kappaB inhibitory activity of acetophenone-type compounds using electrophoretic mobility shift assay and Western blot analysis is presented. An in vitro cell invasion assay using DA3 cells, a murine breast cancer cell line, was conducted to model antimetastatic activity. Results: The carbonyl moiety is found to be the functional group responsible for inhibition of NF-kappaB, and a novel, more effective agent, 6,7-dihydroxy-3,4-dihydroisoquinoline, is postulated and confirmed. The compounds are characterized as active in the inhibition of both the canonical and noncanonical NF-kappaB signaling pathways. Lastly, 6,7-dihydroxy-3,4-dihydroisoquinoline is discovered to inhibit in vitro invasion in DA3 cells. Conclusion: 6,7-Dihydroxy-3,4-dihydroisoquionoline and its derivatives are presented as potential prototypes for a novel series of nontoxic antimetastatic agents that can be used in conjunction with current cancer therapeutic techniques.

Background: Xenotransplantation using pigs as donor species carries a risk for the activation of latent porcine herpesviruses and potential transmission to the human recipient. The porcine lymphotropic herpesviruses (PLHV-1,-2,-3) are widespread in domestic pigs and closely related to the human gammaherpesviruses, Epstein-Barr virus and Kaposi sarcoma herpesvirus, causing lymphoproliferative disorders. PLHV-1 has been associated with a porcine post-transplantation lymphoproliferative disorder (PTLD), affecting miniature swine after experimental transplantation. In human xenotransplantation, PLHV might be transferred to the transplant recipient and cause PTLD or related diseases. The elimination of PLHV from donor pigs is therefore necessary, and requires the availability of nucleic-acid- and antibody-based detection methods. Methods: The N- and C-terminal parts (gB1 and gB2) of the glycoprotein B gene of PLHV-1,-2 and -3 were cloned and expressed in Escherichia coli. Antisera were raised in mice. PLHV PCR was performed as published earlier. Results: An ELISA was developed, using recombinant glycoprotein B of PLHV-1 as the antigen, and used for the analysis of groups of pigs, differing by age and origin. Seropositivity ranged from 38%(piglets) to 90%(gilts) and 100%(breeding sows, miniature pigs and pigs for slaughter). In comparison, PCR products of PLHV were found in the blood of 0 to 80% of the pig groups. Additionally, a group of 12 piglets was tested repeatedly after birth until the age of 156 days. A decline of antibodies was found during the first 3 weeks after birth, followed by a rise in most pigs during the weeks thereafter. PLHV PCR products in the blood were only observed later than 3 weeks after birth. Conclusion: Newborn pigs may be passively protected by maternal antibodies against PLHV infection during the first 3 weeks post partum. The rise of antibody titers thereafter and the appearance of PLHV sequences in the blood possibly indicates de novo infection by contact to the infected mother sow. The PLHV-ELISA may aid in breeding PLHV-free pigs.

Clinical studies demonstrated the efficacy of Coenzyme Q_{10}(CoQ_{10}) as an adjuvant therapeutic in cardiovascular diseases, mitochondrial myopathies and neurodegenerative diseases. More recently, expression profiling revealed that Coenzyme Q_{10}(CoQ_{10}) influences the expression of several hundred genes. To unravel the functional connections of these genes, we performed a text mining approach using the Genomatix BiblioSphere. We identified signalling pathways of G-protein coupled receptors, JAK/STAT, and Integrin which contain a number of CoQ_{10} sensitive genes. Further analysis suggested that IL5, thrombin, vitronectin, vitronectin receptor, and C-reactive protein are regulated by CoQ_{10} via the transcription factor NFkappaB1. To test this hypothesis, we studied the effect of CoQ_{10} on the NF$\kappa$B1-dependent pro-inflammatory cytokine TNF-alpha. As a model, we utilized the murine macrophage cell lines RAW264.7 transfected with human apolipoprotein E3 (apoE3, control) or pro-inflammatory apoE4. In the presence of 2.5 muM or 75 muM CoQ_{10} the LPS-induced TNF-alpha response was significantly reduced to 73.3 +/- 2.8% and 74.7 +/- 8.9% in apoE3 or apoE4 cells, respectively. Therefore, the in silico analysis as well as the cell culture experiments suggested that CoQ_{10} exerts anti-inflammatory properties via NFkappaB1-dependent gene expression.