| 1. |
- Badn, Wiaam, et al.
(författare)
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Inhibition of Inducible Nitric Oxide Synthase Enhances Anti-tumour Immune Responses in Rats Immunized with IFN-gamma-Secreting Glioma Cells.
- 2007
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Ingår i: Scandinavian Journal of Immunology. - : Wiley. - 1365-3083 .- 0300-9475. ; 65:3, s. 289-297
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Tidskriftsartikel (refereegranskat)abstract
- Interferon gamma (IFN-gamma) has successfully been used in immunotherapy of different experimental tumours. Mechanistically, IFN-gamma has extensive effects on the immune system including release of nitric oxide (NO) by upregulation of the inducible nitric oxide synthase (iNOS). NO has putative immunosuppressive effects but could also play a role in killing of tumour cells. Therefore, the aim of the present study was to clarify whether inhibition of iNOS in rats immunized with glioma cells (N32) producing IFN-gamma (N32-IFN-gamma), could enhance the anti-tumour immune response. Initially, both a selective iNOS, L-N-6-(I-Iminoethyl)-L-lysine (L-NIL), and non-selective, N-nitro-L-arginine methyl ester (L-NAME), inhibitor of NOS were tested in vitro. After polyclonal stimulation with LPS and SEA, both L-NIL and L-NAME enhanced proliferation and production of IFN-gamma from activated rat splenocytes and this effect was inversely correlated to the production of NO. However, L-NIL had a broader window of efficacy and a lower minimal effective dose. When rats were immunized with N32-IFN-gamma), and administered NOS inhibitors by intraperitoneal (i.p.) mini-osmotic pumps, only splenocytes of rats treated with L-NIL, but not L-NAME, displayed an enhanced proliferation and production of IFN-gamma when re-stimulated with N32 tumour cells. Based on these findings, L-NIL was administered concurrently with N32-IFN-gamma cells to rats with intracerebral (i.c.) tumours resulting in a prolonged survival. These results show that inhibition of iNOS can enhance an IFN-gamma-based immunotherapy of experimental i.c. tumours implying that NO released after immunization has mainly immunosuppressive net effects.
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| 2. |
- C Johansson, Anna, et al.
(författare)
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Computerized image analysis as a tool to quantify infiltrating leukocytes : a comparison between high- and low-magnification images
- 2001
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Ingår i: Journal of Histochemistry and Cytochemistry. - 0022-1554. ; 49:9, s. 79-1073
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Tidskriftsartikel (refereegranskat)abstract
- The purpose of the present study was to establish a rapid and reproducible method for quantification of tissue-infiltrating leukocytes using computerized image analysis. To achieve this, the staining procedure, the image acquisition, and the image analysis method were optimized. Because of the adaptive features of the human eye, computerized image analysis is more sensitive to variations in staining compared with manual image analysis. To minimize variations in staining, an automated immunostainer was used. With a digital scanner camera, low-magnification images could be sampled at high resolution, thus making it possible to analyze larger tissue sections. Image analysis was performed by color thresholding of the digital images based on values of hue, saturation, and intensity color mode, which we consider superior to the red, green, and blue color mode for analysis of most histological stains. To evaluate the method, we compared computerized analysis of images with a x100 or a x12.5 magnification to assess leukocytes infiltrating rat brain tumors after peripheral immunizations with tumor cells genetically modified to express rat interferon-gamma (IFN-gamma) or medium controls. The results generated by both methods correlated well and did not show any significant differences. The method allows efficient and reproducible processing of large tissue sections that is less time-consuming than conventional methods and can be performed with standard equipment and software.(J Histochem Cytochem 49:1073-1079, 2001)
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| 3. |
- Cederberg, D., et al.
(författare)
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Antisecretory Factor May Reduce ICP in Severe TBI-A Case Series
- 2020
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Ingår i: Frontiers in Neurology. - : Frontiers Media SA. - 1664-2295. ; 11
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Tidskriftsartikel (refereegranskat)abstract
- Traumatic brain injury (TBI) constitutes a global epidemic. Overall outcome is poor, with mortality ranging from 10 to 70% and significant long-term morbidity. Several experimental reports have claimed effect on traumatic edema, but all clinical trials have failed. Antisecretory factor, an endogenous protein, is commercially available as Salovum (R), which is classified as a medical food by the European Union and has been proven effective in experimental trauma models. It has, however, previously not been tested in humans with severe TBI. We hereby report a case series of five adult patients with severe TBI, treated with Salovum. The objective of the intervention was to evaluate safety and, if possible, its effect on intracranial pressure and outcome. Patients received 1 g Salovum per kilo of body weight divided into six doses per 24 h. Each dose was administered through the nasogastric tube. Patients were scheduled for 5 days of treatment with Salovum. Intracranial pressure was controlled in all patients. In three of five patients, intracranial pressure could be controlled with Salovum and deep sedation (no barbiturates), except during periods of gastroparesis. Five of five patients had a favorable short-term outcome, and four of five patients had a favorable long-term outcome. No toxicity was observed. We conclude that at least three of the five treated patients experienced an effect of Salovum with signs of reduction of intracranial pressure and signs of clinical benefit. In order to validate the potential of antisecretory factor in TBI, a prospective, randomized, double-blind, placebo-controlled trial with Salovum has been initiated. Primary outcome for the trial is 30-day mortality; secondary outcomes are treatment intensity level, intracranial pressure, and number of days at the neurointensive care unit.
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| 4. |
- Siesjö, P, et al.
(författare)
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Increased proportion of CD8+ tumor responsive T cells after immunization with tum- versus tum+ rat glioma
- 1995
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Ingår i: Cellular Immunology. - : Elsevier BV. - 0008-8749. ; 165:2, s. 33-225
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Tidskriftsartikel (refereegranskat)abstract
- Previously established immunogenic (tum-) clones of an ENU (ethyl-N-nitrosourea)-induced rat glioma, N32, were compared to the original tumor concerning their capacity to induce T lymphocyte responses after in vivo immunization and in vitro restimulation of responder spleen cells in mixed lymphocyte tumor culture (MLTC) assays. Quite unexpectedly, original N32 (tum+) in vivo primed spleen cells proliferated to the same extent in vitro in response to tum+ stimulator cells as did tum- in vivo primed spleen cells. However, flow-cytometric analysis of parallel cultures showed a greatly increased proportion of CD3+CD8+ lymphocytes in the proliferating responder cell population from tum- immunized hosts, contrary to a CD3+CD4+ lymphocyte dominance after tum+ immunization. Although the original tum+ N32 tumor cells are not capable of inducing a clearly demonstrable isograft rejection response, they induce a strong T cell response readily detectable in MLTC assays. We propose that the increased CD8+ lymphocyte proliferation could be an essential feature of the isograft rejection response induced by tum- tumor variants. Possible mechanisms of the augmented CD8+ T cell response are discussed.
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| 5. |
- Smith, Karin E, et al.
(författare)
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Synergism between GM-CSF and IFNgamma: Enhanced immunotherapy in mice with glioma.
- 2007
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Ingår i: International Journal of Cancer. - : Wiley. - 0020-7136 .- 1097-0215. ; 120:1, s. 75-80
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Tidskriftsartikel (refereegranskat)abstract
- Glioblastoma multiforme is the most common malignant primary brain tumor and also one of the most therapy-resistant tumors. Because of the dismal prognosis, various therapies modulating the immune system have been developed in experimental models. Previously, we have shown a 37-70% cure in a rat glioma model where rats were peripherally immunized with tumor cells producing IFN. On the basis of these results, we wanted to investigate whether a combination of GM-CSF and IFN could improve the therapeutic effect in a mouse glioma model, GL261 (GL-wt). Three biweekly intraperitoneal (i.p.) immunizations with irradiated GM-CSF-transduced GL261 cells (GL-GM) induced a 44% survival in mice with intracranial glioma. While treatment of GL-wt and GL-GM with IFN in vitro induced upregulation of MHC I and MHC II on the tumor cells, it could not enhance survival after immunization. However, immunizations with GL-GM combined with recombinant IFN at the immunization site synergistically enhanced survival with a cure rate of 88%. Tumors from mice receiving only 1 immunization on Day 10 after tumor inoculation were sectioned on Day 20 for analysis of leukocyte infiltration. Tumor volume was reduced and the infiltration of macrophages was denser in mice immunized with GL-GM combined with IFN compared with that of both wildtype and nonimmunized mice. To our knowledge, this is the first study to demonstrate a synergy between GM-CSF and IFN in experimental immunotherapy of tumors, by substantially increasing survival as well as inducing a potent anti-tumor response after only 1 postponed immunization.
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| 6. |
- Visse, E, et al.
(författare)
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Immunohistochemical analysis of glioma-infiltrating leucocytes after peripheral therapeutic immunization with interferon-gamma-transfected glioma cells
- 2000
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Ingår i: Cancer Immunology and Immunotherapy. - : Springer Science and Business Media LLC. - 1432-0851 .- 0340-7004. ; 49:3, s. 142-151
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Tidskriftsartikel (refereegranskat)abstract
- We have shown previously that rejection of preinduced rat brain tumours is possible following therapeutic immunizations with interferon-gamma (IFN gamma)-transfected glioma cells (N32-IFN gamma). In the present study we have used the same model to evaluate whether quantitative differences in tumour-infiltrating lymphocytes can be detected between animals receiving therapeutic immunizations with either IFN gamma-transfected glioma cells, wild-type glioma cells or no treatment. Since leucocyte transpedesis into the tumour can be anticipated to depend on the state of vascularization, we have mapped the development of microvessels in the tumour in parallel with the leucocyte infiltration. Our results show that microvessels start to form at day 7 and then gradually increase in number and size, indicating the establishment of an extensive vascularization by day 24. Leucocyte infiltration displays a biphasic pattern after tumour grafting. We have therefore studied the infiltration kinetics after an early immunization (1 day after intracerebral isografting) and compared the effects with those of a late immunization (10 days after intracerebral isografting) with N32-IFN gamma or wild-type N32. Our results show (1) an early infiltration of granulocytes 3 days after isografting; (2) a T-cell-receptor-positive (TCR+) T-cell infiltration starting on day 10; (3) a macrophage infiltration starting on day 13; (4) a CD8+ cell infiltration starting on day 13. The proportions of TCR+ T cells, CD8+ cells and natural killer cells differs significantly between animals immunized with N32-IFN gamma and those receiving wild-type N32, when analysed 14 days after immunization at day 10. This difference can only be detected when animals are immunized at later stages of tumour growth. We propose that this could depend on an early-immunization-independent leucocyte infiltration during tumour establishment. This has to be considered when evaluating studies of leucocyte infiltration in experimental tumours.
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| 7. |
- Visse, E, et al.
(författare)
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Regression of intracerebral rat glioma isografts by therapeutic subcutaneous immunization with interferon-gamma, interleukin-7, or B7-1-transfected tumor cells
- 1999
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Ingår i: Cancer Gene Therapy. - : Springer Science and Business Media LLC. - 0929-1903 .- 1476-5500. ; 6:1, s. 37-44
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Tidskriftsartikel (refereegranskat)abstract
- Progress in the definition of the roles of various costimulators and cytokines in determining the type and height of immune responses has made it important to explore genetically altered tumor cells expressing such molecules for therapeutic immunizations. We have studied the effect of therapeutic subcutaneous (s.c.) immunizations on the growth of preexisting intracerebral brain tumor isografts in the rat. Transfectant glioma cell clones expressing either rat interferon-gamma (IFN-gamma), rat interleukin-7 (IL-7), or rat B7-1 were selected. After irradiation (80 Gy) the clones were used for immunization (administered in up to four s.c. doses in a hind leg over 14-day intervals starting 1 day after the intracranial isografting of the parental tumor). Significant growth inhibition of the intracerebral parental tumors was induced by transfectants expressing IFN-gamma and IL-7, respectively. The strongest effect was observed with IFN-gamma-expressing cells, resulting in cures in 37% of the males and in 100% of the females. Immunization with IL-7 had a similar, strong initial effect, with significantly prolonged survival in the majority of the rats but a lower final cure rate (survival for >150 days). The B7-1-expressing tumor clones induced cures in seven of eight female rats; however, no cures were seen in the male rats. It was also shown that the B7-1-expressing cells were themselves strongly immunogenic in female rats, requiring high cell numbers to result in a progressively growing tumor upon s.c. isografting; this was not the case in male rats. As a whole, the results imply that despite the unfavorable location of intracerebral tumors, therapeutic s.c. immunizations with certain types of genetically altered tumor cells can induce complete regressions with permanent survival and without gross neurological or other apparent signs of brain damage. The present results demonstrate complete regressions when immunizations are initiated shortly after intracranial isografting, when the intracerebral tumor is small.
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| 8. |
- Visse, Edward, et al.
(författare)
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The MAP kinases are differently utilized by CD28 and CD2 adhesion pathways in superantigen-activated Jurkat T cells
- 2003
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Ingår i: Biological Research. - 0717-6287. ; 36:2, s. 263-278
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Tidskriftsartikel (refereegranskat)abstract
- To mimic the two-signal requirements for T cell activation mediated by ligands, we exposed the superantigens SEA or SEE (signal 1) to T cells incubated with HLA-DR/LFA-3 or HLA-DR/137-1-CHO transfected cells (signal 2). LFA-3 costimulation was able to induce T cell proliferation as well as IFN-gamma and IL-4 production at similar levels as in cells induced by B7-1. Analysis of the CD28RE of the IL-2 promoter showed specific transcription factor recruitment at the CD28RE element upon induction by B7-1/SEE. Further functional Studies with an IL-2 enhancer-promoter carrying either wild type or mutated versions of the CD28RE site revealed that this element is necessary for full activation upon B7-1 costimulation. While both CD28/B7-1 and CD2/LFA-3 costimulation resulted in the up-regulation of IL-4 and IFN-gamma promoters, IL-2 promoter activity and production of IL-2 were only seen after B7-1 costimulation. However, contrary to what has been previously proposed, we show that costimulation with either B7-1 or LFA-3 further enhanced the ERK-2 activity and strongly activated the p38 MAPK pathway, but only B7-1 costiniulation induced high levels of JNK-1 activity. These data Suggest that the differential effect of CD28 vs. CD2 can be related to the difference in the ability of the two pathways to induce JNK-1 activity.
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