| 1. |
- Ragnarsson, Lotten, et al.
(författare)
-
Multiple myeloma cells are killed by syndecan-1-directed superantigen-activated T cells
- 2001
-
Ingår i: Cancer Immunology and Immunotherapy. - : Springer Science and Business Media LLC. - 0340-7004 .- 1432-0851. ; 50:7, s. 382-390
-
Tidskriftsartikel (refereegranskat)abstract
- Multiple myeloma (MM) is an incurable plasma cell/plasmablast malignancy with a great need for innovative treatment strategies. Since experimental immunotherapy with targeted superantigens (SAg) proved to be effective in other haematopoietic tumours, we investigated whether this would also hold true for MM. We used the bacterial SAg Staphylococcus enterotoxin A (SEA), a potent activator of T cell cytotoxicity by means of its binding to particular T cell receptor Vbeta sequences on effector cells and MHC class II molecules on target cells. To eliminate potentially unspecific binding via MHC class II, SEA was point mutated (SEAm). In a second step SEAm was genetically fused to protein A (PA), resulting in a fusion protein (PA-SEAm). This fusion protein was used together with four different plasma-cell-specific/associated mAbs to direct T cells towards 10 MM target cell lines. Three of these mAbs were directed against syndecan-1/CD138, known to be highly expressed on MM and plasma cells, but absent on other haematopoietic cells. All MM cell lines proved to be sensitive to SAg-activated T cell killing (15-50% lysis), as measured in a 51Cr-release assay. This effect was clearly mediated via the plasma-cell-reactive antibodies, as control antibodies only conferred a low background lysis. MM therapy based on targeted SAgs could in theory be hampered by dysfunctional T cells in MM patients. However, we show that T cells from MM patients and healthy controls responded equally well to activation by SAg.
|
|
| 2. |
- Carlsson, Björn, et al.
(författare)
-
Ex vivo stimulation of cytomegalovirus (CMV)-specific T cells using CMVpp65-modified dendritic cells as stimulators
- 2003
-
Ingår i: British Journal of Haematology. - : Wiley. - 0007-1048 .- 1365-2141. ; 121:3, s. 428-38
-
Tidskriftsartikel (refereegranskat)abstract
- Cytomegalovirus (CMV) infection is a dangerous complication in immunosuppressed individuals such as allogeneic stem cell transplant patients. CMV disease can be prevented by the early post-transplant transfer of donor-derived, CMV-directed, T cells. Fast and cost efficient methods to generate CMV-specific T cells are, therefore, warranted. The current study utilized peptide-pulsed and adenovirus-transduced dendritic cells (DC) to generate CMV-restricted T cells. After one stimulation with CMV pp65495-503 peptide-pulsed DC and three re-stimulations with peptide-pulsed monocytes, virtually all T cells were CD8+, expressed the relevant T cell receptor and exhibited high peptide-specific lytic activity. After only one stimulation, pp65495-503-restricted T cells could be sorted to a purity of higher than 95% and expanded up to 1000-fold in 2 weeks. This technique may prove useful for the rapid generation of large quantities of specific cytolytic T lymphocytes (CTL) for cell therapy. DC transduced with an adenoviral vector encoding the full-length pp65 protein (Adpp65) were able to simultaneously expand CTL against multiple epitopes of pp65. In addition, they activated CMV-specific CD4+ T-helper cells. This approach would stimulate multiple-epitope populations of pp65-specific T cells and could be made available to patients of any human leucocyte antigen (HLA) haplotype. DC transduced with adenoviral vectors to express full-length antigens may prove to be potent vaccines against viral pathogens and cancer.
|
|
| 3. |
- Carlsson, Björn, et al.
(författare)
-
Generation of cytotoxic T lymphocytes specific for the prostate and breast tissue antigen TARP
- 2004
-
Ingår i: The Prostate. - : Wiley. - 0270-4137 .- 1097-0045. ; 61:2, s. 161-170
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Expansion of cytotoxic T lymphocytes (CTL) directed against peptide epitopes from antigens that are specifically expressed by normal and neoplastic prostate epithelial cells has during the last years emerged as an interesting therapeutic approach to treat advanced prostate cancer. TCRgamma alternate reading frame protein (TARP) is a protein that in males is specifically expressed by normal prostate epithelial cells and prostate cancer cells. We have evaluated TARP for human leukocyte antigen (HLA)-A*0201-restricted peptides capable of triggering TARP-specific CTL. METHODS: Dendritic cells (DC) were pulsed either with synthetic peptides derived from the natural amino acid sequence of TARP or with cognate peptides having enhanced affinity for HLA-A*0201 due to an N-terminal anchor residue substitution. The peptide-pulsed DC were used to stimulate autologous T cells ex vivo. RESULTS: We were able to generate T cells against TARP(27-35) and TARP(4-13) and their mutated counterparts TARP(V28L)(27-35) and TARP(P5L)(4-13). The use of affinity-enhanced peptides resulted in the generation of T cells recognizing target cells displaying either wild-type or mutated peptide. We further show that TARP-specific T cells can be tetramer-sorted and subsequently expanded to large numbers by general T cell stimulation, with retained specificity and activity. Sorted and expanded T cells, obtained by stimulation with TARP(P5L)(4-13), exert moderate lysis of the TARP-expressing prostate cancer cell line, LNCaP, and breast cancer cell line, MCF-7, indicating that the TARP(4-13) epitope may be endogenously processed and presented by TARP-positive, HLA-A*0201-positive cells. CONCLUSIONS: Our findings suggest that synthetic TARP peptides, such as TARP(P5L)(4-13), may play a role in prostate and breast cancer immunotherapy.
|
|
| 4. |
- Cheng, Wing-Shing, et al.
(författare)
-
A novel TARP-promoter-based adenovirus against hormone-dependent and hormone-refractory prostate cancer
- 2004
-
Ingår i: Molecular Therapy. - : Elsevier BV. - 1525-0016 .- 1525-0024. ; 10:2, s. 355-364
-
Tidskriftsartikel (refereegranskat)abstract
- TARP (T cell receptor gamma-chain alternate reading frame protein) is a protein that in males is uniquely expressed in prostate epithelial cells and prostate cancer cells. We have previously shown that the transcriptional activity of a chimeric sequence comprising the TARP promoter (TARPp) and the PSA enhancer (PSAe) is strictly controlled by testosterone and highly restricted to cells of prostate origin. Here we report that a chimeric sequence comprising TARPp and the PSMA enhancer (PSMAe) is highly active in testosterone-deprived prostate cancer cells, while a regulatory sequence comprising PSAe, PSMAe, and TARPp (PPT) has high prostate-specific activity both in the presence and in the absence of testosterone. Therefore, the PPT sequence may, in a gene therapy setting, be beneficial to prostate cancer patients that have been treated with androgen withdrawal. A recombinant adenovirus vector with the PPT sequence, shielded from interfering adenoviral sequences by the mouse H19 insulator, yields high and prostate-specific transgene expression both in cell cultures and when prostate cancer, PC-346C, tumors were grown orthotopically in nude mice. Intravenous virus administration reveals both higher activity and higher selectivity for the insulator-shielded PPT sequence than for the immediate-early CMV promoter. Therefore, we believe that an adenovirus with therapeutic gene expression controlled by an insulator-shielded PPT sequence is a promising candidate for gene therapy of prostate cancer.
|
|
| 5. |
- Engstrand, Mats, et al.
(författare)
-
Cellular responses to cytomegalovirus in immunosuppressed patients : circulating CD8+ T cells recognizing CMVpp65 are present but display functional impairment
- 2003
-
Ingår i: Clinical and Experimental Immunology. - : Oxford University Press (OUP). - 0009-9104 .- 1365-2249. ; 132:1, s. 96-104
-
Tidskriftsartikel (refereegranskat)abstract
- The availability of tetrameric complexes of HLA class I molecules folded with immunodominant peptides makes it possible to utilize flow cytometry for rapid and highly specific visualization of virus specific CD8+ T cells. An alternate technique is to incubate whole blood with specific antigens and to subsequently detect and characterize responding T cells (e.g. by performing intracellular staining of interferon-gamma). By using an HLA-A2 tetramer construct folded with the same immunodominant CMV-peptide as that used for peptide pulsing, we monitored both the presence and functional capacity of CMV-specific CD8+ T cells. In addition T cell activation was assayed by determination of CD38 and CD69 expression. Twelve organ transplant patients and 31 healthy blood donors with latent CMV infection were investigated using CMV pp65 tetramer staining and intracellular staining of interferon-gamma after CMV pp65 peptide pulsing or CMV lysate pulsing. CMV-specific T cells were detected in similar absolute numbers as well as frequencies of T cells in the two groups investigated. However, the CMV-specific CD8+ T cells in immunosuppressed individuals showed a decreased functional response to the CMV-peptide, as evidenced by reduced interferon-gamma production when compared to healthy blood donors (19%; 42%, P < 0·005). In addition, CD38 expression was markedly higher in immunosuppressed patients compared to healthy blood donors (24%; 6%, P < 0·005). In a case report we demonstrate that reactivation of CMV can occur in an immunosuppressed patient with high number of CMV-specific T cells, but without functional capacity. Hence, these findings reflect impaired activation of cytotoxic T cells controlling latent CMV infection in immunosuppressed patients.
|
|
| 6. |
- Engstrand, Mats, et al.
(författare)
-
Characterization of CMVpp65-specific CD8+ T lymphocytes using MHC tetramers in kidney transplant patients and healthy participants
- 2000
-
Ingår i: Transplantation. - : Ovid Technologies (Wolters Kluwer Health). - 0041-1337 .- 1534-6080. ; 69:11, s. 2243-2250
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Cytomegalovirus (CMV) is a ubiquitous herpesvirus that infects 50-90% of individuals in different populations. After primary infection, the virus persists latently in myeloid cells under the control of specific T-cells. Reactivation of CMV infection may cause lethal organ dysfunction and is frequently seen in immunosuppressed individuals. CD8+ cytotoxic T-cells (CTL) have a primary role in suppressing CMV reactivation, and the dominating CTL response is directed against pp65. METHODS: MHC tetramers, that is, complexes between HLA class I (or class II) molecules and antigenic peptides conjugated to fluorochromes allow the direct visualization of antigen-specific receptor-carrying T-cells using flow cytometry. We constructed a novel MHC tetramer for identification of CMVpp65-specific CD8+ T-cells using HLA-A2 molecules folded with the immunodominant NLVPMVATV peptide. RESULTS: The A2/pp65 tetramer specifically stained CMV-directed T-cell lines, and sorted cells showed CMV-specific cytotoxicity. High proportions (0.1-9%) of the CD8+ T-cells were A2/pp65 tetramer+ in healthy HLA-A2+ CMV carriers and in immunosuppressed kidney transplant patients with latent infection. Patients with reactivated CMV infection exhibited up to 15% A2/pp65 tetramer+ cells, which seemed to correlate with CMV load over time. A2/pp65 tetramer+ cells expressed T-cell activation markers. CONCLUSIONS: The construction of a novel A2/pp65 MHC tetramer enabled the design of a rapid and precise flow cytometric method allowing quantitative and qualitative analysis of CMV-specific T-cells. The number of A2/pp65 tetramer binding CTLs in blood may prove to be clinically relevant in assessing the immune response to CMV.
|
|
| 7. |
- Eriksson, Britt-Marie, et al.
(författare)
-
Circulating soluble vascular cell adhesion molecule-1 and intercellular adhesion molecule-1 in immunocompetent and renal transplant patients:correlation with cytomegalovirus disease and renal function
- 2001
-
Ingår i: Scandinavian Journal of Infectious Diseases. - : Informa UK Limited. - 0036-5548 .- 1651-1980. ; 33:5, s. 350-354
-
Tidskriftsartikel (refereegranskat)abstract
- The plasma levels of the soluble adhesion molecules, soluble vascular cell adhesion molecule-1 (sVCAM-1) and intercellular adhesion molecule-1 (sICAM-1), were measured before and after transplantation in 26 renal transplant recipients, and in 173 longitudinally collected samples in 17 of the patients. The patients were carefully monitored for the presence of cytomegalovirus (CMV) infection and rejection. Forty healthy blood donors and 12 otherwise healthy subjects with symptomatic primary CMV infections served as controls. During CMV disease, plasma levels of sVCAM-1 and sICAM-1 were elevated in both renal transplant patients and otherwise healthy subjects with CMV disease. The sVCAM-1 levels were strongly elevated before transplantation in renal transplant recipients and correlated with creatinine levels. Increased sVCAM-1 levels were also registered during rejection episodes. CMV disease, per se, is associated with markedly increased levels of sVCAM-1 and sICAM-1. There is also a correlation of sVCAM-1 levels with serum creatinine levels. Thus, the presence of CMV infection and renal function are factors that must be considered in further studies of soluble adhesion molecules.
|
|
| 8. |
- Loskog, Angelica, et al.
(författare)
-
Adenovirus CD40 Ligand Gene Therapy Counteracts Immune Escape Mechanisms in the Tumor Microenvironment
- 2004
-
Ingår i: Journal of Immunology. - 0022-1767 .- 1550-6606. ; 172:11, s. 7200-7205
-
Tidskriftsartikel (refereegranskat)abstract
- Tumors exhibit immune escape properties that promote their survival. These properties include modulation of Ag presentation, secretion of immunosuppressive factors, resistance to apoptosis, and induction of immune deviation, e.g., shifting from Th1- to Th2-type responses. These escape mechanisms have proven to hamper several immunotherapeutic strategies, and efforts need to be taken to revert this situation. We have studied the immunological effects of introducing CD40 ligand (CD40L), a potent dendritic cell activation molecule, into the tumor micromilieu by adenoviral gene transfer. For this purpose, a murine bladder cancer model (MB49) was used in C57BL/6 mice. The MB49 cells are known to induce IL-10 in the tumor environment. IL-10 potently inhibits the maturation of dendritic cells and thereby also the activation of CTLs. In this paper we show that CD40L immunogene therapy suppresses IL-10 and TGF-beta production (2-fold decrease) and induces a typical Th1-type response in the tumor area (200-fold increase in IL-12 production). The antitumor responses obtained were MB49 cell specific, and the cytotoxicity of the stimulated CD8(+) cells could be blocked by IL-10. Adenovirus CD40L therapy was capable of regressing small tumors (five of six animals were tumor free) and inhibiting the progression of larger tumors even in the presence of other escape mechanisms, such as apoptosis resistance. Furthermore, CD40L-transduced MB49 cells promoted the maturation of dendritic cells (2-fold increase in IL-12) independently of IL-10. Our results argue for using adenovirus CD40L gene transfer, alone or in combination with other modalities, for the treatment of Th2-dominated tumors.
|
|
| 9. |
- Loskog, Angelica, et al.
(författare)
-
Human urinary bladder carcinomas express adenovirus attachment and internalization receptors
- 2002
-
Ingår i: Gene Therapy. - : Springer Science and Business Media LLC. - 0969-7128 .- 1476-5462. ; 9:9, s. 547-553
-
Tidskriftsartikel (refereegranskat)abstract
- The use of adenoviral vectors as potent gene delivery systems requires expression of the Coxsackievirus/adenovirus receptor (CVADR) on the target cell surface. This receptor is important for virus attachment to the cell surface. For effective internalization of the vector into the target cell the integrins alpha(v)beta(3) and/or alpha(v)beta(5) are needed. Since there have been reports of loss of CVADR in bladder cancer cell lines, we wanted to investigate the expression of this receptor in bladder carcinoma biopsies. Surgical biopsies, as well as five human bladder cancer cell lines, were analyzed for expression of CVADR, the integrins alpha(v)beta(3) and alpha(v)beta(5) and MHC class I. Further, we studied the ability to transduce these cell lines using adenoviral vectors. Immunohistochemistry revealed that all biopsies (27/27) were positive for CVADR. Some variation in expression was evident, and superficially growing tumors stained more strongly than invasive ones. Most human tumors expressed the integrin alpha(v)beta(5) (14/24), whereas integrin alpha(v)beta(3) was less frequently seen (3/20). The established cell lines were efficiently transduced with adenoviral vectors, and transduction could be reduced with anti-CVADR antibodies. The abundance of appropriate viral receptors on tumor biopsy cells is a further argument for using adenoviral vectors in gene therapy of bladder cancer.
|
|
| 10. |
- Loskog, Angelica, et al.
(författare)
-
In vitro activation of cancer patient-derived dendritic cells by tumor cells genetically modified to express CD154
- 2002
-
Ingår i: Cancer Gene Therapy. - 0929-1903 .- 1476-5500. ; 9:10, s. 846-853
-
Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: Triggering of CD40 on antigen-presenting cells via its ligand CD154 is an important event in the initial phase of an immune response against cancer cells. In this study, we investigated the effects of adenoviral CD154 immunomodulatory gene therapy on the activation of human dendritic cells (DCs) in a well-defined in vitro system. EXPERIMENTAL DESIGN: Human bladder cancer cell lines and tumor cells from patients with renal cell carcinoma (RCC) were transduced with Ad-CD154 vectors or control vectors. Activation of human in vitro generated DCs after coculture with transduced tumor cells was analyzed. Therapeutic efficacy and cytotoxic T-lymphocyte (CTL) activity were assessed in a subcutaneous (s.c.) murine bladder cancer model. RESULTS: Human bladder cancer cell lines expressing CD154 showed a decreased growth rate, increased apoptosis, and modulated expression of molecules important for recognition by cytotoxic lymphocytes. Further, CD154-expressing allogeneic bladder tumor cell lines and autologous tumor cells from patients with renal cell cancer induced maturation of DCs and stimulated IFN-gamma production from lymphocytes cocultured with mature DCs. In vivo studies showed that CD154 gene therapy was highly effective in wild-type mice but only minimally effective in nude mice. Consequently, strong tumor-specific CTL activity was detected in mice vaccinated with tumor cells expressing CD154. CONCLUSIONS: Using tumor cell lines as well as patient-derived material, we could show that tumor cells expressing CD154 efficiently induce maturation and activation of DCs as well as activation of lymphocytes. Our murine in vivo studies demonstrate that lymphocytes contribute to the observed antitumor effect in a s.c. bladder tumor model. These studies should stimulate CD154 gene therapy approaches for the treatment of urologic malignancies.
|
|
