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Walter J Urba

Publications and source records attributed to Walter J Urba.

27 records · Page 2Linked to original sources
PubMed2002

CD28, TNF receptor, and IL-12 are critical for CD4-independent cross-priming of therapeutic antitumor CD8+ T cells.

Previously, we have shown that priming of therapeutic CD8(+) T cells in tumor vaccine-draining lymph nodes of mice vaccinated with GM-CSF secreting B16BL6 melanoma cells occurs independent of CD4 T cell help. In this study, we examined the contribution of the major costimulatory molecules, CD40 ligand (CD40L), CD80, and CD86, in the priming of CD8(+) T cells. Priming of therapeutic CD8(+) T cells by a GM-CSF-transduced tumor vaccine did not require CD40 and CD40L interactions, as therapeutic T cells could be generated from mice injected with anti-CD40L Ab and from CD40L knockout mice. However, costimulation via either CD80 or CD86 was required, as therapeutic T cells could be generated from mice injected with either anti-CD80 or anti-CD86 Ab alone, but administration of both Abs completely inhibited the priming of therapeutic T cells. Blocking experiments also identified that priming of therapeutic T cells in MHC class II-deficient mice required TNFR and IL-12 signaling, but signaling through CD40, lymphotoxin-betaR, or receptor activator of NF-kappaB was not essential. Thus, cross-priming of therapeutic CD8(+) T cells by a tumor vaccine transduced with GM-CSF requires TNFR, IL-12, and CD28 signaling.

Animals↗
PubMed2002

Development of antitumor immune responses in reconstituted lymphopenic hosts.

When naïve T cells reconstitute lymphopenic hosts, they transiently proliferate and differentiate into memory-like T cells. Here we report that tumor-specific T cells preferentially expand in tumor vaccine-draining lymph nodes after a melanoma vaccine given to RAG1 mice reconstituted with naïve T cells from normal mice. The percentage of tumor-specific Tc1 T cells detected by intracellular cytokine staining was increased approximately 4-fold in reconstituted lymphopenic hosts compared with normal hosts. Concomitantly, vaccination-induced Th1 T cells were also dramatically increased in vaccinated, reconstituted RAG1 hosts. T cells derived from reconstituted RAG1 hosts exhibited a higher level of melanoma-specific cytotoxicity in vitro. These cells were significantly more potent at mediating tumor regression in vivo after adoptive transfer into mice bearing established pulmonary metastases. Vaccination is best performed concomitantly with reconstitution; delayed vaccination resulted in T cells with less therapeutic activity.

Animals↗
PubMedDate not supplied

Adoptive cellular therapy with tumor vaccine draining lymph node lymphocytes after vaccination with HLA-B7/beta2-microglobulin gene-modified autologous tumor cells.

Adoptive immunotherapy with anti-CD3-expanded lymphocytes from lymph nodes draining alloantigen gene-modified autologous tumor vaccines is an effective treatment of poorly immunogenic murine tumors. This phase I/II study was performed to determine the feasibility and toxicity of combining ex vivo gene transfer of autologous tumor cells and adoptive immunotherapy with anti-CD3-expanded tumor vaccine draining lymph node lymphocytes (TVDLN) in patients with metastatic melanoma and renal cell cancer (RCC). To facilitate the generation of tumor-specific lymphocytes in the TVDLN, autologous tumor cells were modified by gene transfer ex vivo to express the alloantigen HLA-B7, a modification that has the potential to enhance the immunogenicity of the tumor cells. After vaccination with gene-modified tumor cells, patients' lymph nodes were harvested; TVDLN lymphocytes were activated and expanded ex vivo with anti-CD3 and interleukin-2 (IL-2), and adoptively transferred to patients in combination with systemic IL-2. Twenty patients, nine with melanoma and 11 with RCC were treated. Tumor was harvested successfully in all 20 patients. Ex vivo gene transfer was performed using lipofection with a lipid: DNA plasmid complex containing the genes for HLA-B7 and beta2-microglobulin. The mean expression of HLA-B7 by autologous tumor cells after gene transfer was 4.53% (range 0.3%-12.1%). Lymph nodes were harvested from all 20 patients with a mean of 53 x 107 and 60 x 107 cells obtained from the gene-modified and unmodified tumor vaccine sites, respectively. Successful expansion of adequate TVDLN was accomplished in 19 of 20 harvests of unmodified vaccines and in 18 of 20 gene-modified vaccines. No major toxicities were noted after vaccination with autologous tumor cells or adoptive transfer of ex vivo activated TVDLN lymphocytes. Typical IL-2-related toxicities were observed in all patients. No objective tumor regressions were observed. MHC class I restricted, tumor-specific cytokine secretion was observed in lymphocytes from TVDLN and the peripheral blood of vaccinated patients.

Adult↗
PubMedDate not supplied

Immune effects of escalating doses of granulocyte-macrophage colony-stimulating factor added to a fixed, low-dose, inpatient interleukin-2 regimen: a randomized phase I trial in patients with metastatic melanoma and renal cell carcinoma.

Previous studies in cancer patients demonstrated that granulocyte-macrophage colony-stimulating factor (GM-CSF) upregulated the interleukin (IL)-2 receptor on T lymphocytes and monocytes suggesting that subsequently administered IL-2 would produce greater immune effects. The authors treated 21 patients with metastatic renal cell carcinoma and melanoma on a randomized phase I study to test this hypothesis. All 21 patients received a fixed dose of IL-2 (72,000 IU/kg every 8 hours for 5 days) administered intravenously as an inpatient. Patients were randomized to receive IL-2 alone or in combination with GM-CSF at a dose of 125 or 250 mcg/m /d (Sargramostim; Immunex Corporation, WA, U.S.A.) daily for 7 days by subcutaneous injection starting on day 1, the day before IL-2 treatment. The results from this study demonstrated that GM-CSF did not worsen the toxicities produced by IL-2 alone. Grade 3 confusion occurred in four patients, three who received IL-2 alone. No partial or complete tumor responses were seen. Assays of serum soluble IL-2 receptor (sIL2R) and neopterin, measures of T cell and monocyte activation, respectively, demonstrated a significant increase in sIL2R but not neopterin, 24 hours after the first dose of GM-CSF. In combination with IL-2, the higher dose of GM-CSF (250 mcg/m ) produced higher sIL2R levels on days 3 and 7 than the 125-mcg/m dose of GM-CSF or IL-2 alone. Although neopterin levels did not increase after 1 day of GM-CSF, the addition of IL-2 resulted in a significantly increased neopterin level on day 3 at the higher dose of GM-CSF. On day 7, neopterin levels in all three groups were similarly increased over baseline. Ten days after treatment, neopterin levels had returned to normal, but sIL2R levels remained markedly increased (12 fold) over baseline in the higher GM-CSF dose group. The authors conclude that 1) monocyte activation was not significantly enhanced by 1 day of GM-CSF treatment; 2) the 250-mcg/m GM-CSF dose plus IL-2 produced superior T cell activation compared with a lower dose of GM-CSF plus IL-2 or to IL-2 alone; and 3) the combination of GM-CSF and IL-2 was safe and tolerable but was not associated with any clinical responses.

Aged↗
PubMedDate not supplied

Identification of tumor-specific antibodies in patients with breast cancer vaccinated with gene-modified allogeneic tumor cells.

Thirty HLA-A2 women with metastatic breast cancer received up to 14 vaccinations with MDA-MB-231-CD80, an HLA-A2 allogeneic breast cancer cell line, which had been lipofected with the cDNA for the CD80 costimulatory molecule. Tumor cells were administered with BCG or GM-CSF as an adjuvant. Sera obtained before and after vaccination were analyzed for antibodies to tumor cell lysate, MUC1, HER2/neu and p53. Since the cell line was grown in fetal bovine serum (FBS), sera were also analyzed for antibodies to FBS. Eighteen of 24 patients for whom sera were available exhibited anti-FBS activity at baseline. Eleven of these 18 patients and all six patients without baseline anti-FBS activity showed an increased titer after vaccination. The anti-FBS activity required that serum samples be absorbed in excess FBS to detect specific antibodies to tumor cell lysate. A two-fold increase in the titer of IgG specific to tumor cell lysate was observed in 6 patients. Eight of 24 patients made an antibody response to HER-2/neu, four of 24 to MUC1 and one of 24 to p53. Although antibody production to a variety of tumor cell-associated antigens was detected our results suggest that a whole cell vaccine comprising a CD80-transfected allogeneic breast cancer cell line with adjuvant BCG or GM-CSF was not a reliable method to induce significant antibody responses in women with advanced breast cancer.

Aged↗
PubMedDate not supplied

Immunological monitoring of patients with melanoma after peptide vaccination using soluble peptide/HLA-A2 dimer complexes.

To facilitate the immunologic monitoring of a peptide vaccine trial, a novel, empty dimeric HLA-A2 molecule (A2 dimer) that could be loaded with peptides was produced. The dimer comprises the extracellular domain of HLA-A2 noncovalently linked to a fusion protein consisting of human beta2-microglobulin joined to the human IgG1 Fc domain. Peptide-loaded dimer complexes were used to assess the function of peptide-specific T cells. HLA-A2 gp100 peptide dimers stimulated interferon (IFN)-gamma production by the gp100-specific TIL-1520 cell line. Gp100/A2 dimer stimulation in combination with intracellular cytokine staining was used to analyze peptide-specific T-cell responses in patients with melanoma after vaccination with the modified gp100: 209-2M peptide in adjuvant. Titration analysis of the amount of peptide-loaded dimer required to stimulate gp100-specific T cells was used to estimate the functional avidity of effector/memory CD8+ T lymphocytes. The number of peptide-specific T cells detected in the peripheral blood of vaccinated patients using this assay was comparable to the number determined by staining with fluoresceinated gp100: 209-2M HLA-A2 tetramers. IFN-gamma production by T cells was comparable after stimulation with peptide-pulsed dimers, T2 cells, or autologous dendritic cells. Peptide-loaded A2 dimers could also be used directly to stimulate T cells in the ELISPOT assay.

Animals↗
PubMedDate not supplied

Efficacy of GM-CSF-producing tumor vaccine after docetaxel chemotherapy in mice bearing established Lewis lung carcinoma.

In this report, we evaluated the efficacy of a GM-CSF-producing tumor vaccine given before and after docetaxel in mice bearing established lung tumors. Mice bearing established 3LL tumors were treated with docetaxel and tumor vaccines transduced with either control or GM-CSF adenoviral vectors. Docetaxel (5-20 mg/kg) treatment alone had only a minimal effect on growth of established 3LL tumors in vivo, although docetaxel was cytotoxic to 3LL cells in vitro. When mice bearing established 3LL tumors were pretreated with docetaxel followed by vaccination with irradiated GM-CSF- transduced 3LL tumor cells, significant tumor regression and prolonged survival were observed compared with chemotherapy alone. Delaying docetaxel treatment until after tumor vaccination abrogated the vaccine's anti-tumor effects. Mice that survived treatment were able to resist a lethal rechallenge of 3LL tumor cells. Memory CTL specific for an epitope (MUT-1) derived from 3LL were detected in surviving mice. Docetaxel induced a mild lymphodepletion in mice, both CD4 and CD8 subsets were reduced in LN and spleens. Interestingly, docetaxel also diminished the number of memory CD8+ T cells (CD122+) and possible CD4+ CD25+ Foxp3+ natural Treg cells. Docetaxel treatment did not affect antigen-driven proliferation of naive T cells but significantly promoted survival of activated T cells. Thus, augmentation of vaccine induced antitumor immunity in docetaxel-treated mice primarily due to the enhanced survival of antigen-experienced T cells.

Adenoviridae↗
PubMedDate not supplied

Anti-OX40 (CD134) administration to nonhuman primates: immunostimulatory effects and toxicokinetic study.

The immune-stimulatory properties of anti-CD134 (OX40) antibodies have been well documented in rodents, including their ability to enhance antitumor immunity. In this study, an anti-OX40 antibody (Ab) known to costimulate monkey T cells in vitro, was infused into rhesus macaque monkeys during immunization with the simian immunodeficiency virus protein, gp130. The draining lymph nodes from immunized monkeys treated with anti-OX40 were enlarged compared with immunized monkeys injected with mouse Ig. Anti-OX40-treated monkeys had increased gp130-specific Ab titers, and increased long-lived T-cell responses, compared with controls. There were no overt signs of toxicity in the anti-OX40-treated monkeys. The encouraging immune-stimulatory effects led to the good manufacturing practice production of an anti-OX40 Ab for clinical trials in cancer patients. A detailed toxicology study was performed with anti-OX40 in nonhuman primates. Three groups of 8 monkeys received anti-OX40 at 1 of 3 dose levels (0.4, 2.0, and 10 mg/kg) and a control group received saline. No clinical toxicity was observed, but acute splenomegaly and enlarged gut-associated lymph nodes were observed in the anti-OX40-treated animals; splenomegaly and lymphadenopathy resolved by day 28. These studies demonstrate the immune-stimulatory properties and safety of anti-OX40 in primates and provide a strong scientific rationale to pursue clinical trials in humans.

Adjuvants, Immunologic↗