摘要:

Dendritic cells (DCs) loaded with tumor antigens have the potential to become a powerful tool for clinical cancer treatment. Recently, the authors showed that a tumor-specific immune response can be elicited in culture via stimulation with autologous renal tumor lysate (Tuly)–loaded DCs that were generated from cytokine-cultured adherent peripheral blood mononuclear cells (PBMCs). Here, the authors show that immunomodulatory DCs can be generated directly from nonfractionated bulk PBMC cultures. Kinetic studies of DC differentiation and maturation in PBMC cultures were performed by monitoring the acquisition of DC-associated molecules using fluorescence-activated cell sorting analysis to determine the percentage of positive immunostained cells and the mean relative linear fluorescence intensity (MRLFI). Compared with conventional adherent CD14+cultures, which have mostly natural killer, T, and B cells removed before cytokine culture, bulk PBMC cultures exhibited an early loss of CD14+cells (day 0 = 78.8%, day 2 = 29.6% versus day 0 = 74%, day 2 = 75%) with an increase in yield of mature DCs (CD19−CD83+) (day 5 = 17%, day 6 = 21%, day 7 = 22% versus day 5 = 11%, day 6 = 15%, day 7 = 23%). Although a comparable percentage of DCs expressing CD86+(B7-2), CD40+, and HLA-DR+were detected in both cultures, higher expression levels were detected in DCs derived from bulk culture (CD86 = MRLFI 3665.1 versus 2662.1 on day 6; CD40 = MRLFI 1786 versus 681.2 on day 6; HLA-DR = MRLFI 6018.2 versus 3444.9 on day 2). Cytokines involved in DC maturation were determined by polymerase chain reaction demonstrating interleukin-6 (IL-6), IL-12, interferon-gamma, granulocyte-macrophage colony-stimulating factor, and tumor necrosis factor-&agr; mRNA expression by bulk culture cells during the entire 9-day culture period. This same cytokine mRNA profile was not found in the conventional adherent DC culture. Autologous renal Tuly (30 &mgr;g protein/107PBMCs) enhanced human leukocyte antigen expression by DCs (class I = 7367.6 versus 4085.4 MRFLI; class II = 8277.2 versus 6175.7 MRFLI) and upregulated cytokine mRNAs levels. Concurrently, CD3+CD56−, CD3+CD25+, and CD3+TCR+cell populations increased and cytotoxicity against autologous renal cell carcinoma tumor target was induced. Specific cytotoxicity was augmented when cultures were boosted continuously with IL-2 (20 U/mL biological response modifier program) plus Tuly stimulation. These results suggest that nonadherent PBMCs may participate in enhancing DC maturation. Besides the simplicity of this culture technique, bulk DC cultures potentially may be used with the same efficiency as conventional purified DCs. Furthermore, bulk culture–derived DCs may be used directly in vivo as a tumor vaccine, or for further ex vivo expansion of co-cultured cytotoxic T cells to be used for adoptive immunotherapy.

ISSN:1524-9557    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

An interferon-&ggr; (IFN-&ggr;)-inducing molecule (OK-PSA) has been purified from OK-432 by an affinity chromatographic technique performed on cyanogen bromide-activated Sepharose 4B–bound TS-2 monoclonal antibody, which neutralizes IFN-&ggr;–inducing activity of OK-432. OK-PSA has striking anti-tumor activity in vivo and in vitro. In the current study, the liposomes were used to improve the delivery of the agent (OK-PSA) to effector cells and to increase the therapeutic effect. Significantly less OK-PSA encapsulated into liposomes (Lipo-OK-PSA) than OK-PSA alone (1/100 or less of OK-PSA alone) was required to induce IFN-&ggr;, tumor necrosis factor-&agr; (TNF-&agr;), TNF-&bgr;, interleukin-1&bgr; (IL-1&bgr;), natural killer, and lymphokine-activated killer activities by human peripheral blood mononuclear cells and mouse spleen cells. Furthermore, higher levels of these activities were detected in peripheral blood mononuclear cells and mouse spleen cells treated with Lipo-OK-PSA than in those treated with OK-PSA. All of these activities induced by Lipo-OK-PSA were almost completely neutralized by anti–asialo-GM1antibody and complement (p < 0.001). In in vivo experiments, Lipo-OK-PSA elicited striking anti-tumor activity on syngeneic Meth-A tumor-bearing and colon 26–bearing BALB/c mice and on salivary gland tumor–bearing nude mice far better than did OK-PSA. Furthermore, high levels of natural killer and lymphokine-activated killer activities and a significant increase in the number of cells positive for asialo-GM1, IFN-&ggr;, TNF-&agr;, or IL-1&bgr; were detected in the spleen cells derived from the animals given Lipo-OK-PSA compared with those given saline. These findings clearly indicate that OK-PSA plays an important role in the anti-tumor efficiency of OK-432, and that, for the most part, liposome encapsulation of this molecule markedly accelerates its effect mediated by asialo-GM1–positive cells (mainly natural killer cells).

ISSN:1524-9557    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

The role of major histocompatibility complex expression in cancer prognosis and pathogenesis is contradictory. The aim of the current study was to compare the expression of HLA class I molecules and of oncoproteins that may be sources of peptides presented by HLA class I antigens in non–small-cell lung cancer. For this purpose, the expression of HLA class I antigen and TAP-1 molecule (a transporter in the antigen-processing 1 transport protein) were studied with epidermal growth factor, receptor; c-erbB-2; episialin; wild-type and mutant p53; bcl-2 oncoprotein expression; and angiogenic factor expression (vascular endothelial growth factor and thymidine phosphorylase). The degree of lymphocytic stromal infiltration and of platelet-endothelial cell adhesion molecule–expressing lymphocytes was also studied. A strong association of c-erbB-2 and MUC1 (episialin) expression with HLA class I expression was observed (p = 0.005 and 0.009, respectively). Intense CD31-positive lymphocytic infiltration was also more frequent in HLA class I–positive cases (p = 0.05). Although there was no association of HLA class I expression with survival, loss of the HLA class I expression in MUC1 or c-erbB-2 overexpressing cases conferred a poorer clinical outcome (p = 0.04). Both c-erbB-2 and MUC1 are well-known targets of T-cell–mediated cytotoxicity and cell–cell or cell–matrix adhesion-regulating proteins. The authors provide evidence that the sequence of cell adhesion-disrupting oncoprotein expression, HLA class I induction, and enhanced epitope presentation followed by lymphocytic response is an important pathogenetic three-step sequence of events that define, in part, the clinical outcome in non–small-cell lung cancer.

ISSN:1524-9557    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

Tumor growth can increase the number of immature bone marrow-derived CD34+cells that exhibit natural suppressor (NS) activity toward T-cell function. Using a metastatic Lewis lung carcinoma (LLC-LN7) tumor model, these CD34+NS cells were shown to be present within the s.c. primary tumor tissue, but their levels declined after treatment with the inducer of myeloid cell differentiation, vitamin D3. Therefore, studies determined whether vitamin D3treatment to diminish the CD34+NS cell levels in LLC-LN7–bearing mice would enhance (a) intratumoral immune reactivity and (b) the antitumor activity of adoptive therapy consisting of tumor-reactive lymph node cells. The results showed that vitamin D3treatment alone increased the intratumoral CD8+cell content and the activity of the intratumoral infiltrate, as detected by production of interferon-&ggr; and expression of the p55 IL-2 receptor. Although vitamin D3treatment had no effect on the size of the primary tumor, it lessened the extent of tumor metastasis. Treating mice with the combination of vitamin D3and adoptive immunotherapy significantly reduced metastasis in mice with established tumors, and reduced both metastasis and locoregional recurrence after surgical excision of the primary tumor. These studies demonstrate that vitamin D3treatment increases intratumoral T-cell immune reactivity, and that coupling vitamin D3treatment to diminish levels of CD34+NS cells with adoptive immunotherapy enhances the effectiveness of the adoptively transferred tumor-reactive lymph node cells at limiting both metastasis and locoregional tumor recurrence.

ISSN:1524-9557    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

Synthetic peptides have raised a considerable interest in the fields of vaccines and immunotherapy. The authors previously introduced modifications into the peptide backbone of the H-2Kd-restricted epitope CW3. One of these pseudopeptides, C7, bound to Kdwith an affinity identical to the parent peptide and was recognized by T cells specific for the parent peptide. The authors now show that this analog has an increased resistance to trypsin and displays an extended half-life in serum. The authors further tested its immunogenicity both in vitro and in vivo and found that cytotoxic T lymphocytes (CTL) induced against the peptide analog recognize the parent peptide. Moreover, analysis of T-cell receptor rearrangements by Immunoscope software revealed that C7-induced CTL display the hallmarks of the response against the parental epitope CW3. Administration of the pseudopeptide into DBA/2 mice induces a protective immune response against a lethal challenge with tumor cells expressing the parent peptide. Therefore, modifications in the backbone of antigenic peptides can decrease protease susceptibility while preserving immunogenicity. Such peptide analogues may therefore prove useful for the development of new therapeutic tools aimed at eradicating pathogens or tumors.

ISSN:1524-9557    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

Although liposomal delivery of interleukin-2 (IL-2) and other cytokines improves their pharmacokinetics and biologic activity in vivo, there are no comparative functional studies of various liposomal formulations as cytokine carriers. In the present investigation, recombinant human IL-2 was encapsulated in two formulations of large (mean diameter 0.75–1.5 &mgr;m) multilamellar vesicles (MLV, referred to as conventional liposomes) or in small (mean diameter, 60 nm), unilamellar, long-circulating liposomes (referred to as sterically stabilized liposomes, SSL). The biologic activity of the liposomal formulations and of free IL-2 was tested in parallel in vitro and in mice. The main observations were as follows: (a) All the liposomal IL-2 (Lip-IL-2) formulations were more efficient than soluble IL-2 in stimulating spleen cell proliferation and lymphokine-activated killer (LAK) cell activation in vitro, particularly at low cytokine doses (1–100 CU/mL). (b) After i.v. injection, the circulation time of MLV-IL-2 and SSL-IL-2 was 7 and 17 times greater, respectively, than that of soluble IL-2. (c) In comparison with IL-2, all Lip-IL-2 formulations caused a marked increase in the leukocyte levels in blood, spleen, and peritoneal exudate, especially in those of myeloid origin (neutrophils, eosinophils, immature granulocytes, and macrophages). (d) Although SSL-IL-2 exhibited the longest circulation time, MLV-IL-2 was more potent in elevating leukocyte levels and in triggering LAK cell activity in vivo. (e) The route of Lip-IL-2 administration greatly affected the immunomodulatory activity in the various compartments. (f) MLV-IL-2 proved to be a much more efficient immunoadjuvant than free IL-2 for influenza subunit vaccines as well as for tumor cell vaccines. These findings lend support to our previous studies in which we demonstrated the superior immunomodulatory activity of liposomal IL-2, and suggest that cytokine pharmacokinetics, biodistribution, and pharmacodynamics are markedly influenced both by liposomal formulation and route of administration.

ISSN:1524-9557    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

To develop a T-cell-based therapy for carcinomas, the superantigen staphylococcal enterotoxin A (SEA) was supplied with tumor specificity by means of a recombinant fusion of the Fab fragment of the monoclonal antibody C242 recognizing human colorectal (CRC) and pancreatic carcinomas (PC). Using this Fab-SEA fusion protein (PNU-214565), potent cytotoxicity by activation of T cells can be obtained in the targeted area. Twenty-one patients with CRC and 3 with PC were treated with single, escalating doses of PNU-214565 to establish the maximum tolerated dose (MTD) and to define toxicities. The doses ranged from 0.01 ng/kg to 4.0 ng/kg with three patients at each dose level, except for the dose of 1.5 ng/kg with which six patients were treated because of dose-limiting toxicity. Adverse events (AE) were transient: 13 patients experienced mild to moderate fever. In one patient, a grade 3 fever was followed by a grade 2 hypotension. Other mild or moderate AEs were fatigue, nausea, vomiting, diarrhea, and abdominal pain. No significant hematological toxicity occurred. Immune activation was highly variable with strong activity in peripheral blood seen only in two patients at the dosage level 1.5 ng/kg. They showed pronounced elevations of interleukin-2 (IL-2), IL-6, tumor necrosis factor-&agr;, and interferon-&ggr;, 3–5 hours after the start of infusion. In one patient, IL-2 and IL-6 increased substantially (2,925 U/mL and 32,000 U/mL) concomitantly with grade 3 fever and transient grade 2 neutropenia, grade 2 lymphopenia, and grade 2 monocytopenia. In conclusion, a single 3-hour infusion of PNU-214565 could be safely administered up to 4 ng/kg. MTD was not determined. Instead, a repeat-dose trial was initiated starting at 0.5 ng/kg, considered safe in this trial, with the objective of defining the MTD.

ISSN:1524-9557    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

Relapse after high-dose chemotherapy is the main cause of therapeutic failure in patients with metastatic breast cancer. Adoptive immunotherapy with interleukin-2 (IL-2) plus activated natural killer cells may eliminate residual disease without excessive toxicity. The authors sought to determine if immunotherapy immediately after transplantation would affect engraftment and the toxicity associated with transplantation. Fifteen consecutive patients with metastatic breast cancer were allocated to three cohorts. Cohort 1 (five patients) received high-dose cyclophosphamide, thiotepa, and carboplatin (CTCb) followed by peripheral blood stem cell infusion and granulocyte colony-stimulating factor at 10 &mgr;g/kg. Cohort 2 (five patients) received in addition rhIL-2 (2 × 106IU/m2/day) for 4 days intravenously via continuous infusion after peripheral blood stem cell infusion. In cohort 3 (five patients), peripheral blood stem cell transplant was followed by infusion of autologous activated NK cells and rhIL-2 (2 × 106IU/m2/day) for 4 days (via continuous intravenous infusion). Generation of activated NK cells was possible in all patients in cohort 3. All patients has successful engraftment. Median time to absolute neutrophil count more than 0.5 × 109/L was 8 days (range, 8 to 11 days) in cohort 1, 9 days (range, 7 to 11 days) in cohort 2, and 9 days (range, 8 to 9 days) in cohort 3. Median time until the platelet count was more than 20 × 109/L was 14 days (range, 9 to 22 days) in cohort 1, 11 days (range, 6 to 14 days) in cohort 2, and 12 days (range, 11 to 21 days) in cohort 3. All patients developed neutropenic fevers, but the overall toxicity associated with the infusion of IL-2 (cohort 2) or IL-2 plus activated NK cells (cohort 3) did not differ from that observed in cohort 1. Complete responses were achieved in one patient in cohort 1, in two patients in cohort 2, and in one patient in cohort 3. In conclusion, post-transplant adoptive immunotherapy with activated NK cells plus IL-2 is feasible, well tolerated, and does not adversely affect engraftment.

ISSN:1524-9557    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

The association of adoptive immunotherapy (AI) and radiotherapy has been shown to be effective in the control of residual intrathoracic disease, while having no systemic advantages, in patients operated on for locally advanced non–small-cell lung cancer (NSCLC). The potential synergy of coupling immunotherapy and chemotherapy has been emphasized in several tumors including NSCLC. The aim of this work was to determine the feasibility and activity of a combined therapeutic program, including AI, chemotherapy, and radiotherapy in patients who had undergone incomplete resections for NSCLC. In a phase II trial, 13 patients received the combined treatment. AI was given from week 4 after surgery until week 8. Concurrent chemo-(cisplatin and etoposide)-radiotherapy (60 Gy) was given from week 9 to week 14. Twenty eligible patients received chemoradiotherapy only and were used as a nonrandomized concomitant group for merely descriptive purposes. At 9-month follow-up, 10 of the 13 patients had progression of disease and the study was stopped. Progression-free survival and survival were similar to those of the chemoradiotherapy group. The present study showed that the sequence of immunotherapy followed by chemotherapy is not effective as adjuvant treatment in patients operated on for stage III NSCLC, at least when used according to the adopted schedule.

ISSN:1524-9557    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

Immunization with tumor-specific–associated antigen—pulsed dendritic cells has proved to be efficacious in various animal models and is being evaluated for the treatment of cancer in humans. Use of dendritic cells pulsed with specific peptides or transfected with tumor-associated antigen genes has been a focused area of investigation for inducing potent tumor and viral immune responses. In this study, the authors demonstrate transgene expression, including the lacZ and MART-1 genes, in dendritic cells infected with adenoviral constructs. These transiently transduced dendritic cells, derived from melanoma patients' monocytes cultured with granulocyte-macrophage colony-stimulating factor and interleukin-4, express the transgene and can stimulate patients' CD8+T cells to elicit an antitumor immune response comparable to dendritic cells loaded with a defined peptide. These cytotoxic T lymphocytes were able to recognize both known and unknown tumor-associated antigen epitopes and exhibited cytolytic activity against HLA-matched tumor cells expressing the antigen. The ability to induce tumor-specific cytotoxic T lymphocytes in vitro using gene-modified dendritic cells that transiently express tumor-associated antigens demonstrates the potential use of these antigen-presenting cells for developing in vivo cancer vaccines.

ISSN:1524-9557    

出版商:OVID    

年代:2000

数据来源: OVID