| 1. |
- Carlsson, Björn, 1975-
(författare)
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Adoptive T Cell Therapy of Viral Infection and Cancer : Ex vivo Expansion of Cytomegalovirus- and Prostate Antigen-specific T Cells
- 2005
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The main focus of my thesis has been to develop protocols for generating antigen-specific cytotoxic T lymphocytes (CTLs) and T helper cells (TH) for adoptive transfer to treat cytomegalovirus (CMV) disease and prostate cancer. CMV viremia is a severe complication in immunocompromised stem cell transplanted patients. Prostate cancer is a leading cause of death for men in Western countries. Although different in nature, CMV-infected cells and prostate cancer cells can both be eliminated through specific activation of the adaptive immune system. To generate CMV pp65-specific T cells, I utilized dendritic cells (DCs) modified with an HLA-A*0201/pp65495-503 peptide, a recombinant adenovirus coding for pp65, in vitro transcribed pp65 mRNA and a recombinant pp65 protein. Peptide stimulation yielded large numbers of peptide-specific CD8+ T cells with high lytic activity while adenovirus or mRNA stimulation resulted in the expansion of CTLs against multiple pp65 epitopes. The recombinant protein activated primarily CD4+ TH cells. Stimulation with DCs co-modified with pp65 mRNA and pp65 protein simultaneously generated both pp65-specific CTLs and TH cells. Such T cells would cover all pp65 epitopes while avoiding potential virus related biohazards. The mRNA/protein combinatory approach can be used to stimulate T cells ex vivo from virtually all stem cell donors for adoptive T cell transfer. I have identified two immunogenic HLA-A*0201-restricted peptide epitopes from the prostate tissue antigen TARP. Repeated stimulations with TARP peptide-pulsed DCs yielded up to 20% TARP-directed CD8+ T cells even when starting from undetectable frequencies (<0.01%). The T cells could be sorted to 99% purity and expanded 1000-fold with retained specificity and activity. We also detected TARP-directed CD8+ T cells in the blood of prostate cancer patients. Therefore, TARP seems to have potential as antigen in DC vaccination or adoptive T cell therapy of prostate cancer.
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| 2. |
- Carlsson, Björn, et al.
(författare)
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Characterization of human prostate and breast cancer cell lines for experimental T cell-based immunotherapy
- 2007
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Ingår i: The Prostate. - : Wiley. - 0270-4137 .- 1097-0045. ; 67:4, s. 389-395
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND. In order to develop experimental immunotherapy for prostate and breast cancer it is of outmost importance to have representative target cell lines that through human leukocyte antigen (HLA) class I molecules present relevant levels of peptides from tumor-associated antigens for cytotoxic T lymphocyte (CTL) recognition. METHODS. We sequenced the HLA-A and HLA-B loci of eight commonly used prostate and breast cancer cell lines and analyzed the surface expression of HLA-ABC, HLA-DR, CD40, CD80, CD86, and CD54 by flow cytometry. We also analyzed the cell lines for mRNA expression from 25 genes reported to be specifically or preferentially expressed by prostate cells. RESULTS. Among the analyzed cell lines we found that LNCaP, PC-346C and MCF-7 are HLA-A*0201 positive. However, the HLA-A2 expression level is low and only MCF-7 upregulates HLA-A2 in response to IFN-γ stimulation. MCF-7 also expresses high levels of CD54, which further improve its value as a CTL target cell line. On the other hand, LNCaP and PC-346C express 25 and 23 out of 25 prostate-related genes, respectively, while MCF-7 expresses 16 out of 25 genes. CONCLUSIONS. None of the analyzed prostate cancer cell lines are optimal CTL target cells. However, MCF-7 could in many cases be used as a complement to HLA-A*0201 positive prostate cancer cells. The LNCaP and PC-346C cell lines are rich sources of prostate-related antigens that may be valuable for cancer vaccine development.
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| 3. |
- Carlsson, Björn, et al.
(författare)
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Simultaneous generation of cytomegalovirus-specific CD8+ and CD4+ T lymphocytes by use of dendritic cells comodified with pp65 mRNA and pp65 protein
- 2005
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Ingår i: Journal of Infectious Diseases. - : Oxford University Press (OUP). - 0022-1899 .- 1537-6613. ; 192:11, s. 1912-20
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Tidskriftsartikel (refereegranskat)abstract
- Cytomegalovirus (CMV) disease remains a severe complication in patients who have undergone transplantation. Viremia can be prevented and treated by the adoptive transfer of donor-derived CMV-directed T cells. To ensure long-term protection against CMV disease, it is important to transfer CMV antigen-specific T cells that represent both the CD8+ and the CD4+ subsets. In the present study, we used as stimulators dendritic cells (DCs) that were electroporated with in vitro-transcribed 5'-capped polyadenylated messenger RNA (mRNA) that encoded the CMV pp65 protein (i.e., pp65 mRNA). These DCs could efficiently activate CMV-directed CD8+ T cells, as assayed by tetramer staining, interferon- gamma production, and cytolytic activity. We also used DCs that were pulsed with a recombinant pp65 protein to activate CMV-directed CD4+ T cells. When DCs were comodified with pp65 mRNA and pp65 protein, large numbers of CMV-directed CD8+ and CD4+ T cells were generated simultaneously. The approach outlined in the present study can be adapted for a clinical protocol that circumvents potential virus-related biohazards and is available to all patients independently of their human leukocyte antigen haplotype.
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| 4. |
- Cheng, Wing-Shing, et al.
(författare)
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An oncolytic conditionally replicating adenovirus for hormone-dependent and hormone-independent prostate cancer
- 2006
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Ingår i: Cancer Gene Therapy. - 0929-1903 .- 1476-5500. ; 13:1, s. 13-20
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Tidskriftsartikel (refereegranskat)abstract
- The use of conditionally replicating adenoviruses offers an attractive complementary treatment strategy for localized prostate cancer. We have produced a replicating adenovirus, Ad[I/PPT-E1A], where E1A gene expression is controlled by a recombinant regulatory sequence designated PPT. The PPT sequence comprises a PSA enhancer, a PSMA enhancer and a T-cell receptor gamma-chain alternate reading frame protein promoter, and it is shielded from transcriptional interference from adenoviral backbone sequences by an H19 insulator. Ad[I/PPT-E1A] yields prostate-specific E1A protein expression, viral replication and cytolysis in vitro. Furthermore, Ad[I/PPT-E1A] considerably regresses the growth of subcutaneous LNCaP prostate cancer tumors in nude mice. Importantly, the viral replication and cytolytic effect of Ad[I/PPT-E1A] are independent of the testosterone levels in the prostate cancer cells. This may be beneficial in a clinical setting since many prostate cancer patients are treated with androgen withdrawal. In conclusion, Ad[I/PPT-E1A] may prove to be useful in the treatment of localized prostate cancer.
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| 5. |
- Cheng, Wing-Shing, 1974-
(författare)
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TARP Promoter-Based Prostate Cancer Gene Therapy : From Development to Application
- 2005
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Prostate cancer is one leading cause of cancer-related death among men in Western countries. The standard therapies for localized prostate cancer include radical prostatectomy and radiation therapy. Such measures are relatively effective in the short term, but many patients ultimately relapse. These patients may benefit from a combination of standard therapy and oncolytic virus therapy. My work aimed to develop viruses for this purpose.TARP is a protein that in males is specifically expressed in prostate epithelial and cancer cells. In my thesis, I characterized the TARP promoter and showed that TARP expression is regulated at the transcriptional level by testosterone through binding of the androgen receptor in the proximal TARP promoter. I further developed TARP promoter-based regulatory sequences for prostate-specific gene expression. A sequence comprising a PSA enhancer, a PSMA enhancer and the TARP promoter was constructed and designated PPT. An adenoviral vector containing the PPT sequence shielded from transcriptional interference by an H19 insulator showed high prostate-specific transcriptional activity in human cells both in the presence and absence of testosterone. However, in experimental murine prostate cancer the PPT sequence is not active. Therefore, a two-step transcriptional amplification (TSTA) system was used together with the PPT sequence to develop an adenovirus that confers prostate-specific transgene expression also in murine cells.I constructed a conditionally replicating adenovirus where the E1A gene expression is controlled by an H19 insulator-shielded PPT regulatory sequence, Ad[I/PPT-E1A]. This virus exhibited absolute prostate specificity in terms of E1A expression, viral replication and cytolysis in vitro and in vivo. Importantly, our virus is active both in the presence and absence of testosterone, which may prove beneficial for patients treated by hormonal withdrawal. Hopefully, my work will improve existing gene therapy strategies for prostate cancer and in the long term improve the prognosis for patients with prostate cancer.
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| 6. |
- Dzojic, Helena, 1978-
(författare)
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Adenovirus-mediated CD40 Ligand Immunotherapy of Prostate and Bladder Cancer
- 2007
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Cancer immunotherapy aims at reversing the immunosuppressive tumor environment and enhancing anti-tumor immunity. This thesis comprises studies on murine models for prostate (TRAMP-C2) and bladder (MB49) cancer with the aim to explore if the introduction of an adenoviral vector expressing CD40 ligand (AdCD40L) can induce anti-tumor immune responses.We show in subcutaneous mouse models that AdCD40L treatment suppresses tumor growth. Bladder cancer is known to secrete immunosuppressive IL-10 which may inhibit T cell function. We show that introducing AdCD40L into mouse bladder tumors inhibits IL-10 production and reverses immunosuppression. AdCD40L-transduced mouse prostate cancer cells showed caspase activation and reduced cell viability. Vaccination with CD40L-modified prostate cancer cells induces anti-tumor responses and protects mice against rechallenge with native TRAMP-C2 cells. In order to enhance AdCD40L therapy, we explored the possibility of combining it with the histone deacetylase inhibitor FK228, also known as depsipeptide. We show that FK228 upregulates coxsackie and adenovirus receptor expression and thereby enhances adenoviral-mediated CD40L expression in both murine and human prostate cancer cells. Increasing amounts of FK228 or AdCD40L reduces prostate cancer cell viability, while the combined treatment gives at least an additive therapeutic effect. Moreover, we show that AdCD40L transduction of prostate cancer cells induces endogenous CD40 expression and sensitize them for CD40L-mediated therapy.In order to conduct prostate-specific gene therapy, prostate-specific promoters can be used to drive transgene expression. However, there are no reports on prostate-specific promoters that are transcriptionally active in mouse cells. Here we show that by using the two-step transcription activation system (TSTA), we can enhance the activity of a recombinant human promoter sequence and obtain activity in mouse prostate cancer cells as well. This finding paves the way for future studies of prostate-specific gene therapy in immunocompetent mouse models.
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| 7. |
- Dzojic, Helena, et al.
(författare)
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Adenovirus-Mediated CD40 Ligand Therapy Induces Tumor Cell Apoptosis and Systemic Immunity in the TRAMP-C2 Mouse Prostate Cancer Model
- 2006
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Ingår i: The Prostate. - : Wiley. - 0270-4137 .- 1097-0045. ; 66:8, s. 831-838
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The interaction between CD40 ligand (CD40L) and CD40 on antigen presenting cells is essential for the initiation of antigen-specific T-cell responses, whereas CD40L stimulation of CD40+ tumor cells can induce cellular apoptosis. We investigated the anti-tumor effects induced by CD40L gene transfer into the mouse prostate adenocarcinoma cell line TRAMP-C2, both in vitro and in vivo. METHODS: TRAMP-C2 cells were transduced with an adenoviral vector encoding CD40L (AdCD40L). The induced expression of co-stimulatory molecules and cell viability was analyzed. AdCD40L-transduced TRAMP-C2 cells were used in prophylactic vaccination studies, while therapeutic studies were performed using peritumoral injections of AdCD40L. RESULTS: AdCD40L yielded reduced TRAMP-C2 cell viability and induced apoptosis in vitro. Vaccination with CD40L-expressing TRAMP-C2 cells induced anti-tumor immunity and peritumoral AdCD40L injections induced tumor growth suppression. CONCLUSIONS: Our observations highlight the therapeutic potential of using AdCD40L as a monotherapy or in combination with conventional chemotherapy or novel therapies (e.g., oncolytic viruses). The use of AdCD40L offers an attractive option for future clinical trials.
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| 8. |
- Dzojic, Helena, et al.
(författare)
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Two-step amplification of the human PPT sequence provides specific gene expression in an immunocompetent murine prostate cancer model
- 2007
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Ingår i: Cancer Gene Therapy. - : Springer Science and Business Media LLC. - 0929-1903 .- 1476-5500. ; 14:3, s. 233-240
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Tidskriftsartikel (refereegranskat)abstract
- The recombinant prostate-specific PPT sequence comprises a prostate-specific antigen enhancer, a PSMA enhancer and a TARP promoter. It is transcriptionally active in human prostate cancer cells both in the presence and absence of testosterone. However, in experimental murine prostate cancer, it has no detectable transcriptional activity. Herein, we describe that the PPT sequence in combination with a two-step transcriptional amplification (TSTA) system becomes active also in murine prostate cancer cells. An adenovirus with TSTA-amplified PPT-controlled expression of the luciferase reporter gene, Ad[PPT/TSTA-Luc], has up to 100-fold higher prostate-specific transcriptional activity than a non-amplified PPT-based adenovirus, Ad[PPT-Luc], in human cells. In addition, Ad[PPT/TSTA-Luc] confers prostate-specific transgene expression in murine cells, with an activity that is approximately 23% of Ad[CMV-Luc] in the transgenic adenocarcinoma of the mouse prostate (TRAMP)-C2 cells. Moreover, to visualize luciferase expression in living mice a charge-coupled device camera was used. Ad[PPT/TSTA-Luc] yielded approximately 30-fold higher transgene expression than Ad[PPT-Luc] in LNCaP tumor xenografts. Importantly, Ad[PPT/TSTA-Luc] also showed activity in murine TRAMP-C2 tumors, whereas Ad[PPT-Luc] activity was undetectable. These results highlight that the recombinant PPT sequence is active in murine prostate cancer cells when augmented by a TSTA system. This finding opens up for preclinical studies with prostate-specific therapeutic gene expression in immunocompetent mice.
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| 9. |
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| 10. |
- Essand, Magnus, et al.
(författare)
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Identification and characterization of a novel splicing variant of vesicular monoamine transporter 1
- 2005
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Ingår i: Journal of Molecular Endocrinology. - : Bioscientifica. - 0952-5041 .- 1479-6813. ; 35:3, s. 489-501
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Tidskriftsartikel (refereegranskat)abstract
- Vesicular monoamine transporter 1 (VMAT1) is an integral protein in the membrane of secretory vesicles of neuroendocrine and endocrine cells that allows the transport of biogenic monoamines, such as serotonin, from the cytoplasm into the secretory vesicles. The full-length VMAT1 transcript is produced from 16 exons. We have identified and characterized an alternatively spliced form of VMAT1 that lacks exon 15, the next to last exon of VMAT1. The new form was therefore denoted VMAT1Delta15. Exon 15 does not contain an even multiple of three nucleotides. As a consequence, there is a shift of reading frame, and exon 16 is translated in an alternative reading frame, yielding a novel protein with a shorter and unrelated C-terminus compared with the native VMAT1 protein. VMAT1 and VMAT1Delta15 mRNAs are simultaneously expressed in normal and neoplastic neuroendocrine cells of the GI tract. However, VMAT1 expression is always higher than VMAT1Delta15 expression. We prove that VMAT1Delta15 is not localized in large, dense core vesicles as the native form but in the endoplasmic reticulum. Furthermore, while VMAT1 can take up serotonin, VMAT1Delta15 cannot, indicating different functions for the two forms of VMAT1.
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