Browsing by Subject "nonhuman"

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Open Access
Adenosine A2A receptors intrinsically regulate CD8+ T cells in the tumor microenvironment
(American Association for Cancer Research Inc., 2014) Cekic, C.; Linden J.
Adenosine A2A receptor (A2AR) blockade enhances innate and adaptive immune responses. However, mouse genetic studies have shown that A2AR deletion does not inhibit the growth of all tumor types. In the current study, we showed that growth rates for ectopic melanoma and bladder tumors are increased in Adora2a-/- mice within 2 weeks of tumor inoculation. A2AR deletion in the host reduced numbers of CD8+ T cells and effector-memory differentiation of all T cells. To examine intrinsic functions in T cells, we generated mice harboring a T-cell-specific deletion of A2AR. In this host strain, tumor-bearing mice displayed increased growth of ectopic melanomas, decreased numbers of tumor-associated T cells, reduced effector-memory differentiation, and reduced antiapoptotic IL7Rα (CD127) expression on antigen-experienced cells. Intratumoral pharmacologic blockade similarly reduced CD8+ T-cell density within tumors in wild-type hosts. We found that A2AR-proficient CD8+ T cells specific for melanoma cells displayed a relative survival advantage in tumors. Thus, abrogating A2AR signaling appeared to reduce IL7R expression, survival, and differentiation of T cells in the tumor microenvironment. One implication of these results is that the antitumor effects of A2AR blockade that can be mediated by activation of cytotoxic T cells may be overcome in some tumor microenvironments as a result of impaired T-cell maintenance and effector-memory differentiation. Thus, our findings imply that the efficacious application of A2AR inhibitors for cancer immunotherapy may require careful dose optimization to prevent activation-induced T-cell death in tumors. ©2014 AACR.
Open Access
Antiangiogenic response after 70% hepatectomy and its relationship with hepatic regeneration and angiogenesis in rats
(2010) Dogrul, A.B.; Colakoglu, T.; Kosemehmetoglu, K.; Birben, E.; Yaman, E.; Gedikoglu G.; Abbasoglu O.
Background: The aim of this study was to evaluate the antiangiogenic response and its relation to regeneration and angiogenesis after 70% hepatectomy in a rat model. Methods: Sixty-four Wistar albino rats were included in the study. Animals were allocated into 8 groups (n = 8). After a 70% hepatectomy, liver regeneration, angiogenesis, and antiangiogenic response were evaluated in the remnant liver on days 0, 1, 2, 3, 5, 7, 10, and 14. Regeneration and angiogenesis were determined with immunoreactivity to proliferating cell nuclear antigen and vascular endothelial growth factor. Antiangiogenic response was evaluated by detecting collagen 18 m RNA with reverse transcriptase polymerase chain reaction. Results: We showed that liver regeneration peaked at day 1, whereas angiogenesis in the periportal and perisinusoidal areas reached their peak values on days 3 and 7, respectively. Both regeneration and angiogenic activity around perisinusoidal hepatocytes returned to basal activity on the day 10. Antiangiogenic response first appeared on day 5, reached a peak on day 10, and returned to basal values on day 14. Conclusion: Collagen18 mRNA expression is present in the normal liver during the regenerative process. We suggest that the stimulus that causes the cessation of regeneration process may come from hepatocytes, and collagen 18 produced by hepatocytes may modulate this event by inhibiting the angiogenesis. © 2010 Mosby, Inc. All rights reserved.
Open Access
Application of a customized pathway-focused microarray for gene expression profiling of cellular homeostasis upon exposure to nicotine in PC12 cells
(2004) Konu Ö.; Xu X.; Ma J.Z.; Kane J.; Wang J.; Shi, S.J.; Li, M.D.
Maintenance of cellular homeostasis is integral to appropriate regulation of cellular signaling and cell growth and division. In this study, we report the development and quality assessment of a pathway-focused microarray comprising genes involved in cellular homeostasis. Since nicotine is known to have highly modulatory effects on the intracellular calcium homeostasis, we therefore tested the applicability of the homeostatic pathway-focused microarray on the gene expression in PC-12 cells treated with 1 mM nicotine for 48 h relative to the untreated control cells. We first provided a detailed description of the focused array with respect to its gene and pathway content and then assessed the array quality using a robust regression procedure that allows for the exclusion of unreliable measurements while decreasing the number of false positives. As a result, the mean correlation coefficient between duplicate measurements of the arrays used in this study (control vs. nicotine treatment, three samples each) has increased from 0.974±0.017 to 0.995±0.002. Furthermore, we found that nicotine affected various structural and signaling components of the AKT/PKB signaling pathway and protein synthesis and degradation processes in PC-12 cells. Since modulation of intracellular calcium concentrations ([Ca2+]i) and phosphatidylinositol signaling are important in various biological processes such as neurotransmitter release and tissue pathogenesis including tumor formation, we expect that the homeostatic pathway-focused microarray potentially can be used for the identification of unique gene expression profiles in comparative studies of drugs of abuse and diverse environmental stimuli, such as starvation and oxidative stress. © 2003 Elsevier B.V. All rights reserved.
Open Access
Behavioural analyses of quinine processing in choice, feeding and learning of larval drosophila
(2012) El-Keredy, A.; Schleyer, M.; König, C.; Ekim, A.; Gerber, B.
Gustatory stimuli can support both immediate reflexive behaviour, such as choice and feeding, and can drive internal reinforcement in associative learning. For larval Drosophila, we here provide a first systematic behavioural analysis of these functions with respect to quinine as a study case of a substance which humans report as "tasting bitter". We describe the dose-effect functions for these different kinds of behaviour and find that a half-maximal effect of quinine to suppress feeding needs substantially higher quinine concentrations (2.0 mM) than is the case for internal reinforcement (0.6 mM). Interestingly, in previous studies (Niewalda et al. 2008, Schipanski et al 2008) we had found the reverse for sodium chloride and fructose/sucrose, such that dose-effect functions for those tastants were shifted towards lower concentrations for feeding as compared to reinforcement, arguing that the differences in dose-effect function between these behaviours do not reflect artefacts of the types of assay used. The current results regarding quinine thus provide a starting point to investigate how the gustatory system is organized on the cellular and/or molecular level to result in different behavioural tuning curves towards a bitter tastant. © 2012 El-Keredy et al.
Open Access
The bonobo genome compared with the chimpanzee and human genomes
(2012) Prüfer, K.; Munch, K.; Hellmann I.; Akagi, K.; Miller J.R.; Walenz, B.; Koren, S.; Sutton G.; Kodira, C.; Winer, R.; Knight J.R.; Mullikin J.C.; Meader, S.J.; Ponting, C.P.; Lunter G.; Higashino, S.; Hobolth, A.; Dutheil J.; Karakoç, E.; Alkan, C.; Sajjadian, S.; Catacchio, C.R.; Ventura, M.; Marques-Bonet, T.; Eichler, E.E.; André, C.; Atencia, R.; Mugisha L.; Junhold J.; Patterson, N.; Siebauer, M.; Good J.M.; Fischer, A.; Ptak, S.E.; Lachmann, M.; Symer, D.E.; Mailund, T.; Schierup, M.H.; Andrés, A.M.; Kelso J.; Pääbo, S.
Two African apes are the closest living relatives of humans: the chimpanzee (Pan troglodytes) and the bonobo (Pan paniscus). Although they are similar in many respects, bonobos and chimpanzees differ strikingly in key social and sexual behaviours, and for some of these traits they show more similarity with humans than with each other. Here we report the sequencing and assembly of the bonobo genome to study its evolutionary relationship with the chimpanzee and human genomes. We find that more than three per cent of the human genome is more closely related to either the bonobo or the chimpanzee genome than these are to each other. These regions allow various aspects of the ancestry of the two ape species to be reconstructed. In addition, many of the regions that overlap genes may eventually help us understand the genetic basis of phenotypes that humans share with one of the two apes to the exclusion of the other. © 2012 Macmillan Publishers Limited. All rights reserved.
Open Access
Chitosan polysaccharide suppress toll like receptor dependent immune response
(Turkish Society of Immunology, 2015) Tincer G.; Bayyurt, B.; Arıca, Y.M.; Gürsel İ.
Objectives: Chitosan is a widely used vaccine or anti-cancer delivery vehicle. In this study, we investigated the immunomodulatory effect of chitosan/pIC nanocomplexes on mouse immune cells. Materials and methods: Proliferative and cytotoxic features of chitosan were tested via CCK-8 assay on RAW 264. 7. IL-1β production was assessed via ELISA from PEC supernatants. TNF-α, and NO induction from chitosan treated RAW cells detected by ELISA and Griess assay, respectively. mRNA message levels of TLRs and cytokines on macrophages in response to chitosan/pIC nanocomplex treatments were evaluated by RT-PCR. Results: Results revealed that chitosan is non-toxic to cells, however, proliferative capacities of macrophages were reduced by chitosan administration. Mouse PECs treated with chitosan, led to NLRP3 dependent inflammasome activation as evidenced by dose-dependent IL-1β secretion. Chitosan/pIC nanocomplexes did not improve immunostimulatory action of pIC on RAW cells, since TNF-α and NO productions remained unaltered. Expression levels of several TLRs, CXCL-16 and IFN-α messages from mouse splenocytes were down regulated in response to chitosan/pIC nanocomplex treatment. Conclusion: Our results revealed that chitosan is an anti-proliferative and inflammasome triggering macromolecule on immune cells. Utilization of chitosan as a carrier system is of concern for immunotherapeutic applications. © 2015 Turkish Journal of Immunology.
Open Access
Chitosan scaffolds with BMP-6 loaded alginate microspheres for periodontal tissue engineering
(2012) Soran, Z.; Aydin, R.S.T.; Gumusderelioglu, M.
The aim of this study is to develop an effective growth factor releasing scaffold-microsphere system for promoting periodontal tissue engineering. Bone morphogenetic protein-6 (BMP-6)-loaded alginate microspheres in narrow size distribution were produced by optimising electrospraying conditions. The addition of these microspheres to chitosan gels produced a novel scaffold in which not only the pore sizes and interconnectivity were preserved, but also a controlled release vehicle was generated. Loading capacity was adjusted as 50ng or 100ng BMP-6 for each scaffold and the controlled release behaviour of BMP-6 from chitosan scaffolds was observed during seven days. Cell culture studies were carried out with rat mesenchymal stem cells derived from bone marrow in three groups; chitosan scaffolds, chitosan scaffolds containing BMP-6-loaded alginate microspheres and chitosan scaffolds with free BMP-6 in culture medium. Results showed that controlled delivery of BMP-6 from alginate microspheres has a significant effect on osteogenic differentiation. © 2012 Informa UK Ltd All rights reserved.
Open Access
The cholesterol transporter ABCG1 links cholesterol homeostasis and tumour immunity
(Nature Publishing Group, 2015) Sag, D.; Cekic, C.; Wu, R.; Linden J.; Hedrick, C.C.
ATP-binding cassette transporter G1 (ABCG1) promotes cholesterol efflux from cells and regulates intracellular cholesterol homeostasis. Here we demonstrate a role of ABCG1 as a mediator of tumour immunity. Abcg1-/- mice have dramatically suppressed subcutaneous MB49-bladder carcinoma and B16-melanoma growth and prolonged survival. We show that reduced tumour growth in Abcg1-/- mice is myeloid cell intrinsic and is associated with a phenotypic shift of the macrophages from a tumour-promoting M2 to a tumour-fighting M1 within the tumour. Abcg1-/- macrophages exhibit an intrinsic bias towards M1 polarization with increased NF-κB activation and direct cytotoxicity for tumour cells in vitro. Overall, our study demonstrates that the absence of ABCG1 inhibits tumour growth through modulation of macrophage function within the tumour, and illustrates a link between cholesterol homeostasis and cancer. © 2015 Macmillan Publishers Limited. All rights reserved.
Open Access
Compound Hertzian chain model for copper-carbon nanocomposites' absorption spectrum
(2011) Kokabi, A.; Hosseini, M.; Saeedi, S.; Moftakharzadeh, A.; Vesaghi, M.A.; Fardmanesh, M.
The infrared range optical absorption mechanism of carbon-copper composite thin layer coated on the diamond-like carbon buffer layer has been investigated. By consideration of weak interactions between copper nanoparticles in their network, optical absorption is modelled using their coherent dipole behaviour induced by the electromagnetic radiation. The copper nanoparticles in the bulk of carbon are assumed as a chain of plasmonic dipoles, which have coupling resonance. Considering nearest neighbour interactions for this metallic nanoparticles, surface plasmon resonance frequency (ω 0) and coupled plasmon resonance frequency (ω 1) have been computed. The damping rate against wavelength is derived, which leads to the derivation of the optical absorption spectrum in terms of ω 0 and ω 1. The dependency of the absorption peaks to the particle size and the particle mean spacing is also investigated. The absorption spectrum is measured for different Cu-C thin films with various Cu particle size and spacing. The experimental results of absorption are compared with the obtained analytical ones. © 2011 The Institution of Engineering and Technology.
Open Access
Copy number variation of individual cattle genomes using next-generation sequencing
(2012) Bickhart, D.M.; Hou, Y.; Schroeder, S.G.; Alkan C.; Cardone, M.F.; Matukumalli L.K.; Song J.; Schnabel, R.D.; Ventura M.; Taylor J.F.; Garcia J.F.; Van Tassell, C.P.; Sonstegard, T.S.; Eichler, E. E.; Liu G.E.
Copy number variations (CNVs) affect a wide range of phenotypic traits; however, CNVs in or near segmental duplication regions are often intractable. Using a read depth approach based on next-generation sequencing, we examined genome - wide copy number differences among five taurine (three Angus, one Holstein, and one Hereford) and one indicine (Nelore) cattle. Within mapped chromosomal sequence, we identified 1265 CNV regions comprising ∼55.6-Mbp sequence-476 of which (~38%) have not previously been reported. We validated this sequence-based CNV call set with array comparative genomic hybridization (aCGH), quantitative PCR (qPCR), and fluorescent in situ hybridization (FISH), achieving a validation rate of 82% and a false positive rate of 8%. We further estimated absolute copy numbers for genomic segments and annotated genes in each individual. Surveys of the top 25 most variable genes revealed that the Nelore individual had the lowest copy numbers in 13 cases (∼52%, χ 2 test; P-value <0.05). In contrast, genes related to pathogen- and parasite-resistance, such as CATHL4 and ULBP17, were highly duplicated in the Nelore individual relative to the taurine cattle, while genes involved in lipid transport and metabolism, including APOL3 and FABP2, were highly duplicated in the beef breeds. These CNV regions also harbor genes like BPIFA2A (BSP30A) and WC1, suggesting that some CNVs may be associated with breed-specific differences in adaptation, health, and production traits. By providing the first individualized cattle CNV and segmental duplication maps and genome-wide gene copy number estimates, we enable future CNV studies into highly duplicated regions in the cattle genome. © 2012 by Cold Spring Harbor Laboratory Press.
Open Access
Development of a thulium (Tm:YAP) laser system for brain tissue ablation
(2011) Bilici, T.; Mutlu, S.; Kalaycioglu H.; Kurt, A.; Sennaroglu, A.; Gulsoy, M.
In this study, a thulium (Tm:YAP) laser system was developed for brain surgery applications. As the Tm:YAP laser is a continuous-wave laser delivered via silica fibers, it would have great potential for stereotaxic neurosurgery with highest local absorption in the IR region. The laser system developed in this study allowed the user to set the power level, exposure time, and modulation parameters (pulse width and on-off cycles). The Tm:YAP laser beam (200-600 mW, 69-208 W/cm 2) was delivered from a distance of 2 mm to cortical and subcortical regions of ex-vivo Wistar rat brain tissue samples via a 200-μm-core optical fiber. The system performance, dosimetry study, and ablation characteristics of the Tm:YAP laser were tested at different power levels by maximizing the therapeutic effects and minimizing unwanted thermal side-effects. The coagulation and ablation diameters were measured under microscope. The maximum ablation efficiency (100 × ablation diameter/coagulation diameter) was obtained when the Tm:YAP laser system was operated at 200 mW for 10 s. At this laser dose, the ablation efficiency was found to be 71.4% and 58.7% for cortical and subcortical regions, respectively. The fiber-coupled Tm:YAP laser system in hence proposed for the delivery of photothermal therapies in medical applications. © 2011 Springer-Verlag London Ltd.
Open Access
Differential effects of nitrogen and sulfur deprivation on growth and biodiesel feedstock production of Chlamydomonas reinhardtii
(2012) Cakmak, T.; Angun P.; Demiray, Y.E.; Ozkan, A.D.; Elibol, Z.; Tekinay, T.
Biodiesel production from microalgae is a promising approach for energy production; however, high cost of its process limits the use of microalgal biodiesel. Increasing the levels of triacylglycerol (TAG) levels, which is used as a biodiesel feedstock, in microalgae has been achieved mainly by nitrogen starvation. In this study, we compared effects of sulfur (S) and nitrogen (N) starvation on TAG accumulation and related parameters in wild-type Chlamydomonas reinhardtii CC-124 mt(-) and CC-125 mt(+) strains. Cell division was interrupted, protein and chlorophyll levels rapidly declined while cell volume, total neutral lipid, carotenoid, and carbohydrate content increased in response to nutrient starvation. Cytosolic lipid droplets in microalgae under nutrient starvation were monitored by three-dimensional confocal laser imaging of live cells. Infrared spectroscopy results showed that relative TAG, oligosaccharide and polysaccharide levels increased rapidly in response to nutrient starvation, especially S starvation. Both strains exhibited similar levels of regulation responses under mineral deficiency, however, the degree of their responses were significantly different, which emphasizes the importance of mating type on the physiological response of algae. Neutral lipid, TAG, and carbohydrate levels reached their peak values following 4 days of N or S starvation. Therefore, 4 days of N or S starvation provides an excellent way of increasing TAG content. Although increase in these parameters was followed by a subsequent decline in N-starved strains after 4 days, this decline was not observed in S-starved ones, which shows that S starvation is a better way of increasing TAG production of C. reinhardtii than N starvation. © 2012 Wiley Periodicals, Inc.
Open Access
Effect of double growth factor release on cartilage tissue engineering
(2013) Ertan, A.B.; Yilgor P.; Bayyurt, B.; Çalikoǧlu, A.C.; Kaspar Ç.; Kök F.N.; Kose G.T.; Hasirci V.
The effects of double release of insulin-like growth factor I (IGF-I) and growth factor β1 (TGF-β1) from nanoparticles on the growth of bone marrow mesenchymal stem cells and their differentiation into cartilage cells were studied on PLGA scaffolds. The release was achieved by using nanoparticles of poly(lactic acid-co-glycolic acid) (PLGA) and poly(N-isopropylacrylamide) (PNIPAM) carrying IGF-I and TGF-β1, respectively. On tissue culture polystyrene (TCPS), TGF-β1 released from PNIPAM nanoparticles was found to have a significant effect on proliferation, while IGF-I encouraged differentiation, as shown by collagen type II deposition. The study was then conducted on macroporous (pore size 200-400μm) PLGA scaffolds. It was observed that the combination of IGF-I and TGF-β1 yielded better results in terms of collagen type II and aggrecan expression than GF-free and single GF-containing applications. It thus appears that gradual release of a combination of growth factors from nanoparticles could make a significant contribution to the quality of the engineered cartilage tissue. © 2011 John Wiley & Sons, Ltd.
Open Access
Herpes simplex virus 1 amplicon vector-mediated siRNA targeting epidermal growth factor receptor inhibits growth of human glioma cells in vivo
(2005) Saydam O.; Glauser, D.L.; Heid I.; Turkeri G.; Hilbe, M.; Jacobs, A.H.; Ackermann, M.; Fraefel, C.
In primary glioblastomas and other tumor types, the epidermal growth factor receptor (EGFR) is frequently observed with alterations, such as amplification, structural rearrangements, or overexpression of the gene, suggesting an important role in glial tumorigenesis and progression. In this study, we investigated whether posttranscriptional gene silencing by vector-mediated RNAi to inhibit EGFR expression can reduce the growth of cultured human gli36 glioma cells. To "knock down" EGFR expression, we have created HSV-1-based amplicons that contain the RNA polymerase III-dependent H1 promoter to express double-stranded hairpin RNA directed against EGFR at two different locations (pHSVsiEGFR I and pHSVsiEGFR II). We demonstrate that both pHSVsiEGFR I and pHSVsiEGFR II mediated knock-down of transiently transfected full-length EGFR or endogenous EGFR in a dose-dependent manner. The knock-down of EGFR resulted in the growth inhibition of human glioblastoma (gli36-luc) cells both in culture and in athymic mice in vivo. Cell cycle analysis and annexin V staining revealed that siRNA-mediated suppression of EGFR induced apoptosis. Overall HSV-1 amplicons can mediate efficient and specific posttranscriptional gene silencing. Copyright © The American Society of Gene Therapy.
Open Access
Identification of novel neutralizing single-chain antibodies against vascular endothelial growth factor receptor 2
(2011) Erdag, B.; Koray Balcioglu, B.; Ozdemir Bahadir, A.; Serhatli, M.; Kacar O.; Bahar, A.; Seker, U.O.S.; Akgun, E.; Ozkan, A.; Kilic, T.; Tamerler, C.; Baysal, K.
Human vascular endothelial growth factor (VEGF) and its receptor (VEGFR-2/kinase domain receptor [KDR]) play a crucial role in angiogenesis, which makes the VEGFR-2 signaling pathway a major target for therapeutic applications. In this study, a single-chain antibody phage display library was constructed from spleen cells of mice immunized with recombinant human soluble extracellular VEGFR-2/KDR consisting of all seven extracellular domains (sKDR D1-7) to obtain antibodies that block VEGF binding to VEGFR-2. Two specific single-chain antibodies (KDR1.3 and KDR2.6) that recognized human VEGFR-2 were selected; diversity analysis of the clones was performed by BstNI fingerprinting and nucleotide sequencing. The single-chain variable fragments (scFvs) were expressed in soluble form and specificity of interactions between affinity purified scFvs and VEGFR-2 was confirmed by ELISA. Binding of the recombinant antibodies for VEGFR-2 receptors was investigated by surface plasmon resonance spectroscopy. In vitro cell culture assays showed that KDR1.3 and KDR2.6 scFvs significantly suppressed the mitogenic response of human umbilical vein endothelial cells to recombinant human VEGF 165 in a dose-dependent manner, and reduced VEGF-dependent cell proliferation by 60% and 40%, respectively. In vivo analysis of these recombinant antibodies in a rat cornea angiogenesis model revealed that both antibodies suppressed the development of new corneal vessels (p < 0.05). Overall, in vitro and in vivo results disclose strong interactions of KDR1.3 and KDR2.6 scFvs with VEGFR-2. These findings indicate that KDR1.3 and KDR2.6 scFvs are promising antiangiogenic therapeutic agents. © 2011 International Union of Biochemistry and Molecular Biology, Inc.
Open Access
In vitro biocompatibility of plasma-aided surface-modified 316L stainless steel for intracoronary stents
(Institute of Physics Publishing, 2010) Bayram, C.; Mizrak, A.K.; Aktürk, S.; Kurşaklioǧlu H.; Iyisoy, A.; Ifran, A.; Denkbaş, E.B.
316L-type stainless steel is a raw material mostly used for manufacturing metallic coronary stents. The purpose of this study was to examine the chemical, wettability, cytotoxic and haemocompatibility properties of 316L stainless steel stents which were modified by plasma polymerization. Six different polymeric compounds, polyethylene glycol, 2-hydroxyethyl methacrylate, ethylenediamine, acrylic acid, hexamethyldisilane and hexamethyldisiloxane, were used in a radio frequency glow discharge plasma polymerization system. As a model antiproliferative drug, mitomycin-C was chosen for covalent coupling onto the stent surface. Modified SS 316L stents were characterized by water contact angle measurements (goniometer) and x-ray photoelectron spectroscopy. C1s binding energies showed a good correlation with the literature. Haemocompatibility tests of coated SS 316L stents showed significant latency (t-test, p < 0.05) with respect to SS 316L and control groups in each test. © 2010 IOP Publishing Ltd.
Open Access
Induction of potent protection against acute and latent herpes simplex virus infection in mice vaccinated with dendritic cells
(2013) Ghasemi, M.; Erturk, M.; Buruk, K.; Sonmez, M.
Background aims. Dendritic cells (DCs) are the most potent antigen presenting cells of the immune system and have been under intense study with regard to their use in immunotherapy against cancer and infectious disease agents. In the present study, DCs were employed to assess their value in protection against live virus challenge in an experimental model using lethal and latent herpes simplex virus (HSV) infection in Balb/c mice. Methods. DCs obtained ex vivo in the presence of granulocyte-macrophage colony-stimulating factor and interleukin-4 were loaded with HSV-1 proteins (DC/HSV-1 vaccine). Groups of mice were vaccinated twice, 7 days apart, via subcutaneous, intraperitoneal or intramuscular routes with DC/HSV-1 and with mock (DC without virus protein) and positive (alum adjuvanted HSV-1 proteins [HSV-1/ALH]) control vaccines. After measuring anti-HSV-1 antibody levels in blood samples, mice were given live HSV-1 intraperitoneally or via ear pinna to assess the protection level of the vaccines with respect to lethal or latent infection challenge. Results. Intramuscular, but not subcutaneous or intraperitoneal, administration of DC/HSV-1 vaccine provided complete protection against lethal challenge and establishment of latent infection as assessed by death and virus recovery from the trigeminal ganglia. It was also shown that the immunity was not associated with antibody production because DC/HSV-1 vaccine, as opposed to HSV-1/ALH vaccine, produced very little, if any, HSV-1-specific antibody. Conclusions. Overall, our results may have some impact on the design of vaccines against genital HSV as well as chronic viral infections such as hepatitis B virus, hepatitis C virus and human immunodeficiency virus. © 2013, International Society for Cellular Therapy.
Open Access
MAb 6D5 against proteins overexpressed in hepatocellular carcinoma cell lines
(2007) Yagci, T.
[No abstract available]
Open Access
MST1 is a multifunctional caspase-independent inhibitor of androgenic signaling
(2011) Cinar, B.; Collak F.K.; Lopez, D.; Akgul, S.; Mukhopadhyay, N.K.; Kilicarslan, M.; Gioeli, D.G.; Freeman, M.R.
The MST1 serine - threonine kinase, a component of the RASSF1-LATS tumor suppressor network, is involved in cell proliferation and apoptosis and has been implicated in cancer. However, the physiologic role of MST1 in prostate cancer (PCa) is not well understood. Here, we investigated the possibility of a biochemical and functional link between androgen receptor (AR) and MST1 signaling. We showed that MST1 forms a protein complex with AR and antagonizes AR transcriptional activity as shown by coimmunoprecipitation (co-IP), promoter reporter analysis, and molecular genetic methods. In vitro kinase and site-specific mutagenesis approaches indicate that MST1 is a potent AR kinase; however, the kinase activity of MST1 and its proapoptotic functions were shown not to be involved in inhibition of AR. MST1 was also found in AR - chromatin complexes, and enforced expression of MST1 reduced the binding of AR to a well-characterized, androgen-responsive region within the prostate-specific antigen promoter. MST1 suppressed PCa cell growth in vitro and tumor growth in mice. Because MST1 is also involved in regulating the AKT1 pathway, this kinase may be an important new link between androgenic and growth factor signaling and a novel therapeutic target in PCa. ©2011 AACR.
Open Access
Myeloid expression of adenosine a2A receptor suppresses T and NK cell responses in the solid tumor microenvironment
(American Association for Cancer Research Inc., 2014) Cekic, C.; Day, Y.-J.; Sag, D.; Linden J.
High concentrations of adenosine in tumor microenvironments inhibit antitumor cytotoxic lymphocyte responses. Although T cells express inhibitory adenosine A2A receptors (A2AR) that suppress their activation and inhibit immune killing of tumors, a role for myeloid cell A2ARs in suppressing the immune response to tumors has yet to be investigated. In this study, we show that the growth of transplanted syngeneic B16F10 melanoma or Lewis lung carcinoma cells is slowed in Adora2af/f-LysMCre+/- mice, which selectively lack myeloid A2ARs. Reduced melanoma growth is associated with significant increases in MHCII and IL12 expression in tumor-associated macrophages and with >90% reductions in IL10 expression in tumor-associated macrophages, dendritic cells (DC), and Ly6C+ or Ly6G+ myeloid-derived suppressor cells (MDSC). Myeloid deletion of A2ARs significantly increases CD44 expression on tumor-associated T cells and natural killer (NK) cells. Depletion of CD8+ T cells or NK cells in tumor-bearing mice indicates that both cell types initially contribute to slowing melanoma growth in mice lacking myeloid A2A receptors, but tumor suppression mediated by CD8+ T cells is more persistent. Myeloid-selective A2AR deletion significantly reduces lung metastasis of melanomas that express luciferase (for in vivo tracking) and ovalbumin (as a model antigen). Reduced metastasis is associated with increased numbers and activation of NK cells and antigen-specific CD8+ T cells in lung in filtrates. Overall, the findings indicate that myeloid cell A2ARs have direct myelosuppressive effects that indirectly contribute to the suppression of T cells and NK cells in primary and metastatic tumor microenvironments. The results indicate that tumor-associated myeloid cells, including macrophages, DCs, and MDSCs all express immunosuppressive A2ARs that are potential targets of adenosine receptor blockers to enhance immune killing of tumors. ©2014 AACR.