Dendritic cell-based vaccines for cancer therapy.
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Animals↗
Biomedical subjects
J J Mulé
Publications and source records attributed to J J Mulé.
Augmentation of antitumor immune responses after adoptive transfer of bone marrow derived from donors immunized with tumor lysate-pulsed dendritic cells.
We demonstrated previously that tumor lysate-pulsed dendritic cells (TP-DC) could mediate a specific and long-lasting antitumor immune response against a weakly immunogenic breast tumor during early lymphoid reconstitution. The purpose of this study was to examine the potential therapeutic efficacy of bone marrow transplants from TP-DC-vaccinated donors. In 2 aggressive metastatic models, bone marrow transplantation with donor bone marrow cells from TP-DC-immunized mice mediated a tumor-specific immune response in the recipient, and this caused regressions of preexisting tumor metastases. After vaccination with TP-DC, donors harbored increased numbers of both activated CD4+ and CD8+ T-cell populations in the bone marrow. Adoptive transfer of T cells purified from the bone marrow of TP-DC-vaccinated mice led to a reduction in preestablished lung metastases, whereas depletion of T cells from bone marrow abolished this effect. By using T cells derived from the bone marrow of TP-DC-vaccinated major histocompatibility complex class I and class II knockout mice, the effector cells required for the observed antitumor effect were determined to be major histocompatibility complex class I-restricted CD8+ T cells. Additionally, the tumor burden in TP-DC-immunized transplant recipients could be reduced further by repetitive TP-DC immunizations after bone marrow transplantation. Collectively, these results demonstrate an important therapeutic role of bone marrow from TP-DC-immunized donors and raise the potential for this approach in patients with advanced cancer.
Adoptive Transfer↗
Tumor lysate-pulsed dendritic cells can elicit an effective antitumor immune response during early lymphoid recovery.
Dendritic cells (DC) can serve to immunize the newborn immune system to foreign antigen. In a lymphopenic environment, naive T cells undergoing homeostasis-driven proliferation can acquire increased sensitivity to antigen stimulation. Here, we evaluated the capacity of DC to effectively prime the host immune system to elicit antitumor effects in the setting of early lymphoid reconstitution after bone marrow transplantation (BMT). Indeed, bone marrow-derived, cytokine-driven DC pulsed with whole tumor lysates (TP-DC) could, early on, prime a specific and long-lasting antitumor immune response, which mediated the rejection of a lethal challenge of a weakly immunogenic breast tumor. In the therapeutic setting, TP-DC could also inhibit the growth of preexisting breast tumor metastases by repetitive immunizations initiated early after BMT. Spleen T cells obtained from mice immunized with TP-DC early after BMT showed a substantial increase in tumor-specific IFN-gamma production. Our findings demonstrate that it is possible to promote effective antitumor immunity in a defined lymphopenic environment through DC-based immunization.
Animals↗
The dynamics of the T-cell antitumor response: chemokine-secreting dendritic cells can prime tumor-reactive T cells extranodally.
Direct administration of dendritic cells (DCs) genetically modified to express secondary lymphoid tissue chemokine (SLC) into growing B16 melanoma could result in a substantial, sustained influx of T cells within the mass with only a transient increase in T-cell numbers in the draining lymph node (DLN). DCs were retained at the tumor site with only a very small percentage trafficking to the DLN. The T cells infiltrating the tumor mass expressed the activation marker CD25 within 24 h and developed IFN-gamma-secreting function within 7 days as tumor growth was inhibited. Similar results were obtained in lymphotoxin alpha-/- mice, which lacked peripheral lymph nodes. Our data demonstrate that effective T-cell priming can occur extranodally and result in measurable antitumor effects in vivo.
Adenoviridae↗
Vaccination of pediatric solid tumor patients with tumor lysate-pulsed dendritic cells can expand specific T cells and mediate tumor regression.
Dendritic cells (DCs) have been shown to be a promising adjuvant for inducing immunity to cancer. We evaluated tumor lysate-pulsed DC in a Phase I trial of pediatric patients with solid tumors. Children with relapsed solid malignancies who had failed standard therapies were eligible. The vaccine used immature DC (CD14-, CD80+, CD86+, CD83-, and HLA-DR+) generated from peripheral blood monocytes in the presence of granulocyte/monocyte colony-stimulating factor and interleukin-4. These DC were then pulsed separately with tumor cell lysates and the immunogenic protein keyhole limpet hemocyanin (KLH) for 24 h and then combined. A total of 1 x 10(6) to 1 x 10(7) DC are administered intradermally every 2 weeks for a total of three vaccinations. Fifteen patients (ages 3-17 years) were enrolled with 10 patients completing all vaccinations. Leukapheresis yields averaged 2.8 x 10(8) peripheral blood mononuclear cells (PBMC)/kg, and DC yields averaged 10.9% of starting PBMC. Patients with neuroblastoma, sarcoma, and renal malignancies were treated without obvious toxicity. Delayed-type hypersensitivity (DTH) response was detected in 7 of 10 patients for KLH and 3 of 6 patients for tumor lysates. Priming of T cells to KLH was seen in 6 of 10 patients and to tumor in 3 of 7 patients as demonstrated by specific IFN-gamma-secreting T cells in unstimulated PBMCs. Significant regression of multiple metastatic sites was seen in 1 patient. Five patients showed stable disease, including 3 who had minimal disease at time of vaccine therapy and remain free of tumor with 16-30 months follow-up. Our results demonstrate that it is feasible to generate large numbers of functional DC from pediatric patients even in those highly pretreated and with a large tumor burden. The DC can be administered in an outpatient setting without any observable toxicity. Most importantly, we have demonstrated the ability of the tumor lysate/KLH-pulsed DC to generate specific T-cell responses and to elicit regression of metastatic disease.
Adolescent↗
Comparative analysis of necrotic and apoptotic tumor cells as a source of antigen(s) in dendritic cell-based immunization.
There is considerable controversy as to whether necrotic (lysate) or apoptotic tumor cells serve as the superior source of multiple tumor-associated antigens (TAAs) to pulse dendritic cells (DCs) for immunotherapeutic applications. Here, we show that standard procedures to induce apoptosis by UVB irradiation unequivocally result in a mixed population of viable, apoptotic, and necrotic tumor cells, necessitating additional purification. We used highly enriched apoptotic versus lysate of B16 melanoma cells to examine whether or not there are important distinctions between these two sources of TAAs for loading of DCs. Our results demonstrate that although some differences exist between the two forms of TAAs in expression of heat shock proteins, as well as production of interleukin-12 by pulsed DCs, their respective capacities to mature DCs phenotypically, as well as to elicit both effective immune priming and antitumor therapeutic efficacy in vivo when presented by DCs, are equivalent.
Animals↗
Enhancement of tumor lysate- and peptide-pulsed dendritic cell-based vaccines by the addition of foreign helper protein.
We have evaluated whether the addition of a foreign helper protein, keyhole limpet hemocyanin (KLH), can augment the efficacy of tumor lysate-pulsed dendritic cells and peptide-pulsed DC immunizations in vivo. Besides being used as a "surrogate antigen" in approaches to measure immunological response in cancer patients, KLH is also an immunogenic carrier protein to elicit T-cell help. Using the D5 subline of B16 melanoma, we demonstrate that DCs pulsed with both KLH and tumor lysate mediate enhanced immune priming and rejection of established metastases in vivo, which is dependent on host-derived T cells. Interleukin 2 augments the enhancement afforded by KLH, as measured by cure rates and overall survival, in the absence of autoimmune depigmentation. KLH added to DC immunizations markedly enhances tumor-specific T cell production of IFN-gamma. D5 melanoma exposed to similar levels of IFN-gamma results in substantial expression of MHC class I molecules. DCs pulsed with KLH and mouse tyrosinase-related protein-2 peptide results in enhanced reduction of B16 melanoma metastases; the effect is most pronounced in a setting where tyrosinase-related protein-2 peptide-pulsed DCs alone are completely ineffective. Collectively, these findings demonstrate that KLH addition to tumor antigen-pulsed DC immunizations can augment IFN-gamma production and enhance in vivo antitumor activity.
Adjuvants, Immunologic↗
Local administration of dendritic cells inhibits established breast tumor growth: implications for apoptosis-inducing agents.
Dendritic cells (DCs) can efficiently acquire foreign antigen(s) from apoptotic cells and induce MHC class I-restricted, antigen-specific CTLs. An accumulation of DCs within solid tumor masses in situ has been associated indirectly with a more favorable prognosis. Therefore, DCs may offer an efficient means for triggering immune responses within tumors, particularly in those masses containing significant apoptosis. We examined whether delivery of DCs could, alone, impact on the progressive growth of a tumor with a relatively high apoptotic index. We detected significant early apoptosis within the mass of a s.c. growing murine MT-901 breast carcinoma. DCs could efficiently engulf MT-901 tumor apoptotic cells in vitro. Intratumoral injections of syngeneic but not allogeneic DCs resulted in significant inhibition of MT-901 tumor growth. Histological examination of the tumor revealed intense mononuclear cell infiltration during and after DC injections. Tumor growth inhibition was relatively radiosensitive and dependent on host-derived CD8+ T cells. The baseline level of tumor apoptosis could be increased substantially by tumor necrosis factor alpha administration, leading to a greater DC-mediated antitumor effect. The antitumor effect could also be enhanced by first pulsing DCs with the foreign helper protein, keyhole limpet hemocyanin, prior to intratumoral delivery and combining it with the systemic administration of interleukin 2. Splenocytes from treated animals showed heightened levels of specific CTL activity and production of cytokines. The level of in situ tumor apoptosis appears to play a critical role in DC-mediated antitumor effects. The potential implication of these findings in DC-based tumor therapy strategies is discussed.
Animals↗
Immune evasion by muscle-specific gene expression in dystrophic muscle.
Muscle tissue from Duchenne muscular dystrophy patients and the Dmd(mdx/mdx) (hereafter referred to as mdx) mouse is characterized by an abundance of necrotic myofibers and infiltrating macrophages. Both features may provide additional stimulus to the immune response directed against novel antigens, such as those delivered by gene therapy vectors. It has previously been shown that the immune evasion achieved by adeno-associated virus in healthy muscle fails in one model of muscular dystrophy. Here, we examined the immune response to adenoviral vectors and their transgenes in normal and mdx mice. We found that mdx mouse muscles contain 20 times more macrophages and 7 times more dendritic cells than healthy muscles. This higher professional antigen-presenting cell content results in a stronger immune response to antigens that can be directly presented by those cells, including viral antigens and constitutively expressed transgene products. However, we did not detect a significant immune response to beta-galactosidase expressed specifically in muscle, even at high expression levels. This result suggests that cross-presentation is not more effective in mdx mouse muscle, and that targeted vectors and tissue-specific promoters may be useful tools for evasion of the immune response in dystrophic muscle.
Adenoviridae↗
Dendritic cells genetically engineered to express IL-4 inhibit murine collagen-induced arthritis.
Dendritic cells (DCs) are specialized antigen-presenting cells that migrate from the periphery to lymphoid tissues, where they activate and regulate T cells. Genetic modification of DCs to express immunoregulatory molecules would provide a new immunotherapeutic strategy for autoimmune and other diseases. We have engineered bone marrow-derived DCs that express IL-4 and tested the ability of these cells to control murine collagen-induced arthritis (CIA), a model for rheumatoid arthritis in which Th1 cells play a critical role. IL-4-transduced DCs inhibited Th1 responses to collagen type II in vitro. A single injection of IL-4-transduced DCs reduced the incidence and severity of CIA and suppressed established Th1 responses and associated humoral responses, despite only transient persistence of injected DCs in the spleen. In contrast, control DCs and IL-4-transduced T cells or fibroblastic cells failed to alter the course of the disease. The functional effects correlated well with the differential efficiency of DC migration from various sites of injection to lymphoid organs, especially the spleen. The ability of splenic T cells to produce IL-4 in response to anti-CD3 was enhanced after the administration of IL-4-transduced DCS: These results support the feasibility of using genetically modified DCs for the treatment of autoimmune disease.
Animals↗
How much help does a vaccine-induced T-cell response need?
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Adjuvants, Immunologic↗
Gene-modified dendritic cells for use in tumor vaccines.
Dendritic cells (DCs) are potent antigen-presenting cells capable of priming activation of naive T cells. Because of their immunostimulatory capacity, immunization with DCs presenting tumor antigens has been proposed as a treatment regimen for cancer. The results from translational research studies and early clinical trials point to the need for improvement of DC-based tumor vaccines before they become a more broadly applicable treatment modality. In this regard, studies suggest that genetic modification of DCs to express tumor antigens and/or immunomodulatory proteins may improve their capacity to promote an antitumor response. Because the DC phenotype is relatively unstable, nonperturbing methods of gene transfer must be employed that do not compromise viability or immunostimulatory capacity. DCs expressing transgenes encoding tumor antigens have been shown to be more potent primers of antitumor immunity both in vitro and in animal models of disease; in some measures of immune priming, gene-modified DCs exceeded their soluble antigen-pulsed counterparts. Cytokine gene modification of DCs has improved their capacity to prime tumor antigen-specific T cell responses and promote antitumor immunity in vivo. Here, we review the current status of gene-modified DCs in both human and murine studies. Although successful results have been obtained to date in experimental systems, we discuss potential problems that have already arisen and may yet be encountered before gene-modified DCs are more widely applicable for use in human clinical trials.
Animals↗
Dendritic cells: at the clinical crossroads.
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Animals↗
Tumor vaccine strategies that employ dendritic cells and tumor lysates: experimental and clinical studies.
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Adjuvants, Immunologic↗
Potentiation of immunologic responsiveness to dendritic cell-based tumor vaccines by recombinant interleukin-2.
PURPOSE: Dendritic cells (DC) can elicit potent immune responses to tumors through their capacity to efficiently process and present tumor-associated antigens. In a variety of animal tumor models, vaccines based on tumor lysate-pulsed DC (TP-DC) have been shown to effectively immunize against lethal tumor challenges as well as to treat established growing tumors at skin and organ sites. The antitumor effects elicited by TP-DC-based vaccines in vivo have been shown to be mediated by tumor-specific proliferative, cytotoxic, and cytokine-secreting host-derived T cells. Because of the critical involvement of T cells in the antitumor immune response, we have been investigating whether the systemic administration of recombinant interleukin (IL)-2 can enhance the therapeutic efficacy of TP-DC-based tumor vaccines. MATERIALS AND METHODS: Immunization with TP-DC plus IL-2 administration was evaluated to determine if this combination could enhance protective immunity toward a weakly immunogenic sarcoma (MCA-207) and a poorly immunogenic subline (D5) of the B16 melanoma and mediate therapeutic rejection of established tumors in C57BL/6 (B6) mouse models. RESULTS: We have demonstrated in our murine models that the addition of IL-2 at relatively nontoxic doses can markedly augment the antitumor activity of TP-DC-based tumor vaccine therapies against both a weakly immunogenic sarcoma and a poorly immunogenic melanoma. Animals treated with the combination exhibited significantly greater protection from tumor-cell challenge, significantly greater regression of established tumors, and significantly longer mean survival time than with either TP-DC or IL-2 therapy alone. The mechanism operative in vivo appears to involve the enhancement of immune T-cell function. CONCLUSION: These preclinical studies demonstrate the potential of this novel treatment strategy and support the rationale for planned phase I/II clinical trials of TP-DC-based vaccines plus IL-2 in patients with advanced melanoma and colorectal cancer.
Animals↗
Systemic administration of interleukin 2 enhances the therapeutic efficacy of dendritic cell-based tumor vaccines.
We have reported previously that murine bone marrow-derived dendritic cells (DC) pulsed with whole tumor lysates can mediate potent antitumor immune responses both in vitro and in vivo. Because successful therapy was dependent on host immune T cells, we have now evaluated whether the systemic administration of the T cell stimulatory/growth promoting cytokine interleukin-2 (IL-2) could enhance tumor lysate-pulsed DC-based immunizations to further promote protective immunity toward, and therapeutic rejection of, syngeneic murine tumors. In three separate approaches using a weakly immunogenic sarcoma (MCA-207), the systemic administration of nontoxic doses of recombinant IL-2 (20,000 and 40,000 IU/dose) was capable of mediating significant increases in the potency of DC-based immunizations. IL-2 could augment the efficacy of tumor lysate-pulsed DC to induce protective immunity to lethal tumor challenge as well as enhance splenic cytotoxic T lymphocyte activity and interferon-gamma production in these treated mice. Moreover, treatment with the combination of tumor lysate-pulsed DC and IL-2 could also mediate regressions of established pulmonary 3-day micrometastases and 7-day macrometastases as well as established 14- and 28-day s.c. tumors, leading to either significant cure rates or prolongation in overall survival. Collectively, these findings show that nontoxic doses of recombinant IL-2 can potentiate the antitumor effects of tumor lysate-pulsed DC in vivo and provide preclinical rationale for the use of IL-2 in DC-based vaccine strategies in patients with advanced cancer.
Animals↗
Induction of tumor antigen-specific immunity in vivo by a novel vaccinia vector encoding safety-modified simian virus 40 T antigen.
BACKGROUND: Evidence that simian virus 40 (SV40) is associated with human mesotheliomas, osteosarcomas, and brain tumors suggests that a recombinant vaccine directed against lethal cancers expressing SV40 T antigen (Tag) could have clinical utility. To address this potential need, we designed a novel vaccinia virus construct that encodes an SV40 Tag in which oncogenic domains were excluded and immunogenic domains were preserved. We named this recombinant construct vaccinia-encoding safety-modified SV40 Tag (vac-mTag). METHODS: Purified vac-mTag was characterized by DNA sequencing, reverse transcription-coupled polymerase chain reaction, western blot analysis, and immunocytochemical techniques. Induction of Tag-specific immunity was examined by cytolytic T-cell assays, and the efficacy of vac-mTag in protecting animals against Tag-expressing tumors and in treating pre-established microscopic tumors was evaluated in vac-mTag-immunized BALB/c mice. RESULTS: The immune response elicited by vac-mTag in C57BL/6 and BALB/c mice included an SV40 Tag-specific cytolytic T-lymphocyte activity against syngeneic (identical genetic background) SV40 Tag-expressing tumor targets. Immunization of mice with a single dose of vac-mTag resulted in potent protection against subsequent challenge with a lethal mouse cancer expressing SV40 Tag. In addition, single-dose vac-mTag immunization coadministered with interleukin 2 produced a possible therapeutic effect against a preadministered microscopic (but lethal) burden of Tag-expressing tumor cells in vivo. CONCLUSION: vac-mTag induces an effective immune response in mice that is specific for a tumor-associated antigen. This response protects against a lethal tumor challenge and results in a possible therapeutic effect against Tag-expressing tumors in vivo. Thus, vac-mTag provides a new avenue for the development of therapies for human cancers thought to be associated with SV40.
Antineoplastic Agents↗
Murine dendritic cells pulsed with whole tumor lysates mediate potent antitumor immune responses in vitro and in vivo.
The highly efficient nature of dendritic cells (DC) as antigen-presenting cells raises the possibility of uncovering in tumor-bearing hosts very low levels of T cell reactivity to poorly immunogenic tumors that are virtually undetectable by other means. Here, we demonstrate the in vitro and in vivo capacities of murine bone marrow-derived, cytokine-driven DC to elicit potent and specific anti-tumor responses when pulsed with whole tumor lysates. Stimulation of naive spleen-derived T cells by tumor lysate-pulsed DC generated tumor-specific proliferative cytokine release and cytolytic reactivities in vitro. In addition, in two separate strains of mice with histologically distinct tumors, s.c. injections of DC pulsed with whole tumor lysates effectively primed these animals to reject subsequent lethal challenges with viable parental tumor cells and, important to note, also mediated significant reductions in the number of metastases established in the lungs. Tumor rejection depended on host-derived CD8(+) T cells and, to a lesser extent, CD4(+) T cells. Spleens from mice that had rejected their tumors contained specific precursor cytotoxic T lymphocytes. The use of whole tumor lysates as a source of tumor-associated antigen(s) for pulsing of DC circumvents several limitations encountered with other methods as well as provides certain distinct advantages, which are discussed. These data serve as rationale for our recent initiation of a phase I clinical trial of immunization with autologous tumor lysate-pulsed DC in adult and pediatric cancer patients.
Animals↗