Human allogeneic and murine xenogeneic dendritic cells are cytotoxic to human tumor cells via two distinct pathways.

Human monocyte-derived dendritic cells (DCs), stimulated with granulocyte-macrophage colony-stimulating factor and interleukin-4 for 1 week, major histocompatibility complex killed human tumor cells in 24-hour cytotoxicity assays. These immature DCs were >90% CD11c, major histocompatibility complex class II(+), but <1% were CD83(+) cells. Within 24 hours, these DCs ingested tumor membranes. The DC cells also lysed Jurkat lymphoma cells, but not Jurkat cells genetically knocked out of the Fas-associated death domain (FADD) or caspase-8. DC2.4, a cloned murine DC line, also displayed cytotoxicity toward U-251 cells, although these murine DCs were less potent than human DC. DC2.4 did not kill Jurkat cells, rat T9 glioma cells, or human Caco-2 colon cancer cells, suggesting that a unique receptor or ligand interaction exists between the DC and U-251 cells. This interaction was destroyed by the paraformaldehyde fixation of the tumor cells. Supernatants from the cultures of DC2.4 and tumor cells were analyzed by the Griess reaction for signs of nitric oxide (NO) production. Augmented NO production occurred in DC2.4/U-251 and DC2.4/Jurkat cultures but was not seen in the human DC/U-251 cultures. These studies suggest that DCs possess different mechanisms of tumoricidal activity.

Patient-specific vaccines derived from autologous tumor cell lines as active specific immunotherapy: results of exploratory phase I/II trials in patients with metastatic melanoma.

Seventy-four (74) patients with metastatic melanoma were treated with patient-specific vaccines derived from autologous tumor cell lines. Cryopreserved irradiated tumor cells were injected weekly for 3 weeks, then monthly for 5 months. At a median follow up >6 years, the median event-free survival (EFS) was 4.5 months, with 13 patients alive and progression free 6-12 years later. Median overall survival (OS) was 20.5 months, with 29% 5-year OS. Tumor response rate was 9% among the 35 patients with evaluable disease who received at least 3 injections. Better survival was observed for patients who had minimal rather than clinically evident metastatic disease at the time vaccine therapy was initiated (5-yr OS 47% vs. 13%; p < 0.0001), received granulocyte-macrophage colony-stimulating factor and/or interferon gamma as an adjuvant (5-yr EFS 26% vs. 0%; p < 0.0001) or received an average of <7 million cells for each of the first 3 injections, compared to those who received 7-11.9 million or >12 million cells per injection (5-yr EFS OS 35% vs. 24%; p = 0.041 and p = 0.034). There was a trend toward better EFS for those who had a positive delayed type hypersensitivity (DTH) reaction to an intradermal injection of 1 million irradiated tumor cells at baseline, or converted to positive after 3 injections, compared to those whose DTH remained negative (5-yr EFS 39% vs. 18%; p = 0.159). This treatment approach is feasible, produces minimal toxicity, and is associated with longterm survival in a significant proportion of patients.

Effects of IFN-gamma and interleukin-1beta on major histocompatibility complex antigen and intercellular adhesion molecule-1 expression by 9L gliosarcoma: relevance to its cytolysis by alloreactive cytotoxic T lymphocytes.

To enhance the efficacy of cellular immunotherapy for gliomas, we tested the concept of using proinflammatory cytokine treatment with interferon-gamma (IFN-gamma) or interleukin-1beta (IL-1beta) or both to render glioma cells more susceptible to cytolysis by alloreactive cytotoxic T lymphocytes (aCTL). The cytokines, separately or in combination, were able to upregulate major histocompatibility complex (MHC) class I antigen or intercellular adhesion molecule-1 (ICAM-1) on Fischer rat 9L gliosarcoma cells. 9L cells were incubated in vitro for 24, 48, or 72 h with varying concentrations of rat IFN-gamma (0-2000 U/ml) or recombinant human IL-1 (rHUIL-1) (0-1000 U/ml) or both. By 48 h, IFN-gamma (500 U/ml) maximally induced the percentage of positive expressing cells and the relative antigen density of MHC class I and ICAM-1 on 9L cells, whereas IL-1 induced only ICAM-1 expression. Simultaneous incubation of IL-1 with IFN-gamma did not further affect the induction of class I on 9L cells more than that achieved with IFN-gamma alone. 9L cells with upregulated MHC class I and ICAM-1 expression were more sensitive to lysis by aCTL in in vitro cytotoxicity assays, regardless of whether the precursor aCTL came from naive or from 9L-immunized rats. Furthermore, inhibition of 9L cytotoxicity in assays that included blocking antibodies to MHC class I or to ICAM-1 revealed that T cell receptor (TCR) interactions with MHC class I and that ICAM-1 interactions with lymphocyte function-associated-1 (LFA-1) antigen account for a portion of the glioma lysis by aCTL.

Serum cytokines in metastatic melanoma patients treated with an autologous tumor vaccine.

Short-term autologous tumor vaccines were established and used to treat metastatic melanoma patients. Serum samples obtained prior to (week 0) and after three vaccinations (week 4) were assayed for interleukin (IL)-2, interferon (IFN)-gamma, IL-4, and IL-10. Results (mean +/- SD) for 30 patients who had matching serum samples obtained at weeks 0 and 4 were: week 0, IL-2, 122 +/- 320 pg/mL; IFN-gamma, 0.1 +/- 0.4 IU/mL; IL-4, 10.0 +/- 19 pg/mL; IL-10, 159 +/- 237 pg/mL; week 4: 119 +/- 308 for IL-2; 0.1 +/- 0.4 for IFN-gamma; 16 +/- 29 for IL-4, and 210 +/- 273 for IL-10. Medium conditioned by tumor cell lines demonstrated relatively low levels of secreted IL-10 (3.5 +/- 4.2 pg/106 cells/mL/96 hours), which would not account for the observed serum levels. In conclusion, the serum cytokine pattern from these patients suggests that the immune system is being modulated prior to and subsequent to vaccination.

Treatment of human solid malignancies with autologous activated lymphocytes and cimetidine: a phase II trial of the cancer biotherapy research group.

OBJECTIVE: The Cancer Biotherapy Research Group conducted a clinical trial to verify encouraging reports of antitumor activity of autolymphocyte therapy. PATIENTS AND METHODS: Patients with a variety of advanced solid malignancies underwent an initial leukapheresis procedure to collect about 5 x 10(9) autologous lymphocytes that were stimulated in vitro for 3 days with anti-CD3 monoclonal antibody in the presence of indomethicin and cis-retinoic acid to obtain media that was frozen in aliquots. This media contained significant amounts of tumor necrosis factor (TNF)-alpha, interleukin (IL)-1beta, interferon-gamma, and IL6, but no IL-2. Subsequently patients underwent up to 6 monthly leukaphereses to collect 2-5 x 10(9) autologous lymphocytes that were incubated in vitro for 6 days in the cryopreserved media containing autologous lymphokines, resulting in a cell population enriched for noncytotoxic T-helper lymphocytes. These were administered intravenously monthly for up to 6 months with daily oral cimetidine at a dose of 600 mg po qid, which was given throughout the treatment period. Tumor response was assessed every 2 months. RESULTS: There were 47 patients (25 women and 22 men) with a median age of 55 years (range 31-79). One hundred seventy four treatments were delivered and were well tolerated. A mean of 2.05 +/- 1.46 (range 0.82-12.8 x 10(9)) cells were infused. Eighty-five percent received two or more doses; 19% received six doses. Objective tumor responses were observed in 1/15 renal cell, 1/13 colorectal, 0/6 breast, 0/5 lung, 0/2 gastric, 0/2 sarcoma, 0/1 pancreas, 0/1 prostate, 0/1 melanoma, and 0/1 eccrine. Forty-three patients have died. Median survival was 8.8 months, 1-year survival 35%, and 2-year survival 15%. CONCLUSION: This complex treatment program was feasible. Infusion of these cells was well tolerated. Some antitumor activity was seen in patients with renal cell cancer and colorectal cancer.

Features associated with survival in metastatic melanoma patients treated with patient-specific dendritic cell vaccines.

Previously, a 54% 5-year survival was reported for metastatic melanoma patients treated with patient-specific vaccines consisting of autologous dendritic cells loaded with antigens from autologous proliferating tumor cells. This study attempted to determine which clinical and laboratory factors best explained long-term survival in this group of patients. Univariate analyses were used to identify factors associated with continuous survival after initiating vaccine therapy. Multivariate logistic regression was used to identify independent factors to classify survival at 3.5 years. Survivors were followed a minimum of 3.7 years (median: 5.7). Univariate analyses identified eight features associated with improved survival: Eastern Cooperative Oncology Group (ECOG) performance status (PS) of 0, no measurable disease at study entry, receiving 8 vaccinations, age <50 years, normal baseline lactate dehydrogenase, no history of visceral metastases, anergy to standard skin tests, and failure of interferon-gamma (IFN-γ) to induce apoptosis in autologous tumor cells. After examining 54 variables for which complete information was available over all patients, the best multivariate regression for survival at 3.5 years utilized six features: prior radiation therapy, younger age, male gender, ECOG PS 0, higher numbers of cells administered during the first 3 injections, and lower numbers of viable cells administered during the first 3 injections. This model correctly classified survival for 28 of 32 patients (87%) and death for 20 of 22 (91%). When features with incomplete information were included in the analysis, addition of IFN-γ-induced apoptosis (n=49) improved predictive accuracy to 27 of 29 (93%) for survival and 19 of 20 (95%) for death. Dependencies between variables were common, but these multivariate linear models yielded high classification accuracy for survival at 3.5 years and identified two features of the vaccine itself as being of independent significance.

Phase II trial of dendritic cells loaded with antigens from self-renewing, proliferating autologous tumor cells as patient-specific antitumor vaccines in patients with metastatic melanoma: final report.

UNLABELLED: Between January 2001 and September 2007, we treated 54 metastatic melanoma patients with patient-specific tumor cell vaccines consisting of dendritic cells (DCS), derived from their peripheral blood cells that were cultured in interleukin (IL)-4 and granulocyte macrophage colony-stimulating factor (GM-CSF), which had phagocytosed irradiated autologous tumor cells from a continuously proliferating, self-renewing, autologus tumor cell (TC) culture. The loaded DCs were injected subcutaneously in 500 microg of GM-CSF weekly x three, and then monthly for 5 months, for a total of up to 8 injections. The 34 men and 20 women had a median age of 50.5 years; 32 had M1c (visceral metastases and/or elevated lactate dehydrogenase) as their most advanced disease stage. Overall, 83% had received other systemic therapies, including interferon-alpha (n = 20), biochemotherapy (n = 19), GM-CSF (n = 19), chemotherapy (n = 16), IL-2 (n = 13), and other investigational vaccines (n = 7). Patients received an average of 7.4 vaccinations. Treatment was well-tolerated, with most patients experiencing only mild local pruritus and/or erythema. A positive delayed-type hypersensitivity reaction to purified autologous tumor cells was observed at baseline in only 1 of 54 patients, compared to 12 of 54 following vaccination (p = 0.001). The projected 5-year survival rate is an impressive 54% at a median follow-up of 4.5 years (range, 2.4-7.4) for the 30 surviving patients. This survival was superior to that observed following vaccination with irradiated TC in 48 melanoma patients in a previous trial (64 versus 31 months, p = 0.016). This patient-specific vaccine warrants further investigation, based on its safety and encouraging survival rates. ( CLINICAL TRIAL NUMBER: NCI-V01-1646).

Lack of elevation of serum S100B in patients with metastatic melanoma as a predictor of outcome after induction with an autologous vaccine of proliferating tumor cells and dendritic cells.

Serum levels of S100B and/or lactate dehydrogenase (LDH) are putative tumor markers in melanoma. Early changes in such markers may correlate with a positive immune response to vaccine therapy. In patients with metastatic melanoma, S100B and LDH serum levels were measured at baseline, and 1 week after 3 weekly subcutaneous injections of investigational, patient-specific vaccines consisting of autologous dendritic cells loaded with antigens from irradiated proliferating autologous tumor cells, and suspended in granulocyte macrophage colony-stimulating factor. There was a poor correlation between S100B and LDH levels at baseline (p = 0.324). Fourteen (14) patients with measurable disease had higher S100B (p = 0.0456) and LDH (p = 0.0013) levels than 31 patients who lacked measurable disease at that time. Fourteen (14) deceased patients (median survival, 13 months) had a mean baseline S100B of 0.62 mug/L (95% confidence interval [CI] 0.00-1.66) and LDH of 815 U/L (95% CI 222-1408); 31 surviving patients (median follow-up, 35.4 months) had mean S100B of 0.07 mug/L (95% CI 0.00-0.23; p = 0.006) and LDH of 442 U/L (95% CI 296-588; p = 0.002). Elevated baseline levels of LDH and S100B were each predictive of inferior progression-free survival (PFS) and overall survival (OS) (both p < 0.0001), but S100B was a better predictor for PFS than LDH. Changes in LDH between baseline and week 4 were not predictive of survival, but an increase in S100B predicted for inferior OS ( p = 0.039). Both LDH and S100B are predictive tumor markers in patients with metastatic melanoma. This is the first study to examine the changes in serum levels of LDH and S100B in response to an autologous tumor-cell vaccine.

Generation of human innate immune responses towards membrane macrophage colony stimulating factor (mM-CSF) expressing U251 glioma cells within immunodeficient (NIH-nu/beige/xid) mice.

The response of human peripheral blood mononuclear cells (PBMC) to cloned human HLA-A2+ U251 glioma cells (U251-2F11/TK) expressing membrane macrophage colony stimulating factor (mM-CSF) was investigated in vitro and in vivo. Enriched human monocytes derived from cancer patients produced a respiratory burst following 20min of interaction with mM-CSF expressing U251 glioma cells. This respiratory burst response was not observed in the enriched human monocytes following similar exposure to the viral vector control U251 (U251-VV) cells. Reactive oxygen species such as H(2)O(2) and HOCl produced death of the U251 cells. The U251-2F11/TK cells failed to grow in severely compromised combined immunodeficient (NIH-bg-nu-xidBR) mice that were depleted of murine monocyte/macrophages then reconstituted with human HLA-A2+ PBMC. Reactive oxygen species (ROS) were produced by PBMC, both in vitro and in vivo in response tomM-CSF expressing U251 cells. U251-2F11/TK cells failed to form subcutaneous tumors in macrophage depleted mice reconstituted with human PBMC; whereas, progressive growth of such tumors was observed with the U251-VV cells. U251-2F11/TK tumors formed if the initial inoculums of PBMC were depleted of monocytes. From this work it can be concluded that mM-CSF transduced U251-2F11/TK glioma cells can safely stimulate human innate immune responses in vivo.

Human monocytes kill M-CSF-expressing glioma cells by BK channel activation.

In this study, human monocytes/macrophages were observed to kill human U251 glioma cells expressing membrane macrophage colony-stimulating factor (mM-CSF) via a swelling and vacuolization process called paraptosis. Human monocytes responded to the mM-CSF-transduced U251 glioma cells, but not to viral vector control U251 glioma cells (U251-VV), by producing a respiratory burst within 20 min. Using patch clamp techniques, functional big potassium (BK) channels were observed on the membrane of the U251 glioma cell. It has been previously reported that oxygen indirectly regulates BK channel function. In this study, it was demonstrated that prolonged BK channel activation in response to the respiratory burst induced by monocytes initiates paraptosis in selected glioma cells. Forced BK channel opening within the glioma cells by BK channel activators (phloretin or pimaric acid) induced U251 glioma cell swelling and vacuolization occurred within 30 min. U251 glioma cell cytotoxicity, induced by using BK channel activators, required between 8 and 12 h. Swelling and vacuolization induced by phloretin and pimaric acid was prevented by iberiotoxin, a specific BK channel inhibitor. Confocal fluorescence microscopy demonstrated BK channels co-localized with the endoplasmic reticulum and mitochondria, the two targeted organelles affected in paraptosis. Iberiotoxin prevented monocytes from producing death in mM-CSF-expressing U251glioma cells in a 24 h assay. This study demonstrates a novel mechanism whereby monocytes can induce paraptosis via the disruption of internal potassium ion homeostasis.

Establishment and characterization of a human primary prostate carcinoma cell line, HH870.

BACKGROUND: Development of new therapeutic modalities for human prostate carcinoma has been impeded by a lack of adequate in vitro and in vivo models. Most in vitro studies have been carried out using a limited number of human prostate cancer cell lines that are mostly derived from metastatic tumors sites or are immortalized. METHODS: Characterization of the prostate cancer cell line, HH870, included description of morphology, determination of doubling time, response to androgens, immunocytochemistry, and immunoblotting of proteins known to be associated with prostate carcinoma, karyotyping, fluorescence in situ hybridization (FISH), DNA profiling, and growth as xenograft in athymic rodents. RESULTS: HH870 expresses various epithelial marker antigens that correlate with known basic immunostaining profiles of prostate adenocarcinoma, although the cell line does not express PSA, PSMA, or PAP. HH870 exhibits complex chromosomal abnormalities and harbors no immortalizing HPV, BKV, JCV, and SV40 DNA. CONCLUSIONS: We report the successful establishment and characterization of a new long-term primary human prostate tumor cell line HH870.

Intracavitary placement of autologous lymphokine-activated killer (LAK) cells after resection of recurrent glioblastoma.

This study was performed to obtain safety and survival data for patients with histologically confirmed recurrent glioblastoma multiforme (GBM) who received intralesional lymphokine-activated killer (LAK) cells following surgery. LAK cells were generated by incubating peripheral blood mononuclear cells with interleukin-2 for 3 to 5 days in vitro. Forty patients with pathologic confirmation of GBM at surgery had placement of autologous LAK cells into the tumor cavity. The 23 men and 17 women had a median age of 48 years (range 21-76). The median interval from the original diagnosis of glioma to LAK treatment was 10.9 months. Patients received an average of 2.0 +/- 1.0 x 10(9) LAK cells, with viability of 91 +/- 6.8%. Treatment was well tolerated; there was one death within 60 days. At a median follow-up of 2.3 years, median survival post-LAK was 9.0 months; 1-year survival was 34%. Gender, age, location of tumor, LAK cell lytic activity, number of cells implanted, and inclusion of interleukin-2 at cell instillation were not correlated with outcome. Median survival from the date of original diagnosis for 31 patients who had GBM at initial diagnosis was 17.5 months versus 13.6 months for a control group of 41 contemporary GBM patients (p2 = 0.012). This treatment is safe and feasible. The median survival rates are higher than reported in most published series of patients who underwent reoperation for recurrent GBM. A randomized trial would be needed to establish therapeutic benefit.

Gamma interferon transduced 9L gliosarcoma. Cytokine gene therapy and its relevance to cellular therapy with alloreactive cytotoxic T lymphocytes.

In earlier studies, we demonstrated that intratumoral infusions of alloreactive cytotoxic T lymphocytes (aCTL), sensitized to the major histocompatibility complex (MHC) antigens of the host, effectively retarded the intracranial growth of Fischer 9L gliosarcoma. We further demonstrated that continuous in vitro exposure to gamma-interferon (gammaIFN) upregulates MHC on 9L gliosarcoma cells and that they were better targets of anti-Fischer aCTL. We hypothesized that the efficacy of cellular therapy with aCTL could be further improved by in situ transduction of the tumor with retroviral vectors coding for gammaIFN, which would generate continuous secretion of the cytokine and maintain upregulated MHC expression by the tumor cells. 9L gliosarcoma and Herpes simplex virus thymidine kinase (tk) transductants of those cells were transduced with a retrovirus carrying the murine gammaIFN gene. By limiting dilution, clones of these cells, designated 9Lgamma 7, 9Lgamma tk8, and 9Lgamma tk10, which produced similar levels of gammaIFN (383-411 ng gammaIFN/10(6) cells/24 h) were isolated. The production of gammaIFN by one clone, 9Lgamma 7, was stable when monitored over 6 weeks in vitro. The clones also demonstrated upregulated MHC class I expression, and the tk-transduced clones maintained their sensitivity to ganciclovir. Compared to the wildtype cells, 9Lgamma 7 had approximate 6- and 1.5-fold increases in the relative antigen densities of MHC I and II, respectively. Addition of exogenous gammaIFN to 9Lgamma 7 cultures did not significantly increase the MHC expression. In cytotoxicity assays, 9Lgamma 7 cells, or 9Lgamma 7 incubated with exogenous gammaIFN, were better targets of aCTL than the parental 9L cells. The growth rate of 9Lgamma-transduced cells was decreased compared to the wildtype cells both in vitro and in vivo. Proliferation studies with transwell plated 9L, 9Lgamma 7, and 9Lgamma tk10 cells in various combinations revealed that the secreted cytokine itself caused a decrease in proliferation. However, the transduced cells exhibited a much reduced growth rate, which likely was a consequence of redirected metabolic activity of the cells. In vivo growth of the 9L and 9Lgamma 7 tumors in rat brains given identical inoculums similarly demonstrated significantly reduced 9Lgamma 7 tumor volumes at various timepoints, indicative of slower growth of the gammaIFN-producing tumors.