Response to high-altitude triggers in seasonal asthmatics on and off inhaled corticosteroid treatment.

Background: Due to the effects of climate change, winter sport enthusiasts will be increasingly forced to stay at higher altitudes. High altitude (HA) environmental factors such as cold temperature, physical exertion, and hypoxia with subsequent hypocapnia due to hyperventilation have been shown to induce bronchoconstriction. With bronchial asthma being highly prevalent, asthmatics also will be increasingly exposed to HA environment and might experience increasing symptoms. Methods: We analysed the effects of HA factors at around 2600 m a.s.l. (metres above sea level) on lung function in mild seasonal asthmatics while they were routinely off (January) and on (March, after start of lowland pollen season) low-dose inhaled corticosteroid (ICS) treatment (n = 10), and matched healthy controls (n = 11). Results: Without inhaled corticosteroid (ICS) treatment mean FEV1 in asthmatics was 230 ml lower after exercise at HA compared to low altitude (LA, p < 0.05), while in healthy controls there was no significant difference. This decrease was mainly induced by cold and exercise at HA. During ICS treatment, this decrease was prevented. Methacholine response was reduced at HA compared to LA. Conclusions: The decrease of FEV1 in response to a combination of hypoxia, cold, and exercise is prevented by ICS treatment in mild, seasonal asthmatics. However, the FEV1 response to high altitude factors was overall small.

Markers of Immune Cell Exhaustion as Predictor of Survival in Surgically-Treated Early-Stage NSCLC.

Background: Tumor tissue as well as regional lymph nodes are removed during curative surgery for early-stage non-small cell lung cancer (NSCLC). These tissues provide a unique snapshot of the immune cell composition at the time of surgery. We investigated the immune landscape in matched tumor tissue, tumor bearing (tb) and non-tumor bearing (ntb) N1 as well as N2 lymph nodes (LNs) in patients with NSCLC and its relation to survival. Methods: Internal hospital databases were screened for surgically treated NSCLC patients for whom tumor tissue, tbLNs as well as N1 and N2 ntbLNs were available. Clinical as well as demographic data were extracted from hospital records. Expression profiling of 770 immune-related genes was performed using the PanCancer IO 360 panel by NanoString Technologies. Results: We identified 190 surgically treated patients of whom 16 fulfilled inclusion criteria and had sufficient archived tissue. The Tumor Immune Dysfunction and Exclusion (TIDE) score in N1 tumor-free lymph nodes was associated with OS. TIM-3 expression was inversely correlated with TIDE scores in affected LNs, N1 and N2 ntbLNs. Levels of CD8 expression were significantly higher in TIDE High compared to TIDE Low patients. TIM-3 and PD-L1 were selected for the final model for OS in multivariate regression in more than one tissue. Conclusion: Levels of immune cell exhaustion markers may indicate a dysfunctional immune status and are associated with survival after curative surgery in NSCLC.

Consequences of the COVID-19 pandemic on lung cancer care and patient health in a German lung cancer center: results from a cross-sectional questionnaire.

BACKGROUND: The novel coronavirus SARS-CoV-2 has caused a global COVID-19 pandemic, leading to worldwide changes in public health measures. In addition to changes in the public sector (lockdowns, contact restrictions), hospitals modified care to minimize risk of infection and to mobilize resources for COVID-19 patients. Our study aimed to assess the impact of these measures on access to care and behaviour of patients with thoracic malignancies. METHODS: Thoracic oncology patients were surveyed in October 2020 using paper-based questionnaires to assess access to ambulatory care services and tumor-directed therapy during the COVID-19 pandemic. Additionally, behaviour regarding social distancing and wearing of face masks were assessed, as well as COVID-19 exposure, testing and vaccination. Results are presented as absolute and relative frequencies for categorical variables and means with standard deviation for numerical variables. We used t-test, and ANOVA to compare differences in metric variables and Chi2-test to compare proportions between groups. RESULTS: 93 of 245 (38%) patients surveyed completed the questionnaire. Respiration therapy and physical therapy were unavailable for 57% to 70% of patients during March/April. Appointments for tumor-directed therapy, tumor imaging, and follow-up care were postponed or cancelled for 18.9%, 13.6%, and 14.8% of patients, respectively. Patients reported their general health as mostly unaffected. The majority of patients surveyed did not report reducing their contacts with family. The majority reduced contact with friends. Most patients wore community masks, although a significant proportion reported respiratory difficulties during prolonged mask-wearing. 74 patients (80%) reported willingness to be vaccinated against SARS-CoV-2. CONCLUSIONS: This survey provides insights into the patient experience during the second wave of the COVID-19 pandemic in Munich, Germany. Most patients reported no negative changes to cancer treatments or general health; however, allied health services were greatly impacted. Patients reported gaps in social distancing, but were prepared to wear community masks. The willingness to get vaccinated against SARS-CoV-2 was high. This information is not only of high relevance to policy makers, but also to health care providers.

Effects of the NF-κB Pathway Agonist IL-1ß on Non-Small Cell Lung Cancer Cell Lines.

OBJECTIVE: Canakinumab is an interleukin (IL)-1ß inhibitory antibody. Recently, a large trial of canakinumab in cardiac patients described lower lung cancer incidence in patients treated with canakinumab compared to controls. This finding is the basis for ongoing clinical trials of canakinumab in lung cancer. To address the underlying mechanism, we established lung cancer co-cultures to investigate the interactions between lung cancer cells and immunocyte macrophages as related to the expression of IL-1ß and the effect of IL-1ß on the NF-κB pathway on lung cancer cells. METHODS: Lung cancer cell lines H838 and H1975 and macrophages were mono-cultured separately as control groups. Lung cancer cell lines and macrophages were co-cultured respectively in a ratio of 5:1 under the conditions of 37°C in a humidified atmosphere of 5% CO2 for seven days. Cell culture supernatants were collected at predetermined time points, and cell morphology was observed and photographed by microscopy. IL-1ß was detected by ELISA. H838 and H1975 cells were treated with PBS or IL-1ß for 24 hours. Cells were harvested and lysed, then analyzed in a proteome profiler array. RESULTS: Cells in co-cultures initially grew well. IL-1ß was almost undetectable in lung cancer cell lines and macrophage monoculture groups but was highly expressed in co-cultures after 24h and declined at the 7th day. In the H838 and H1975 co-culture group, the lung cancer cells occupied a great majority. IL-1ß activates the NF-κB pathway on H838 and H1975 cells. CONCLUSION: Our data showed that in a lung cancer co-culture incorporating lung cancer cells and macrophages lead to a higher expression of IL-1ß than monoculture. It is possible that such dynamic changes in IL-1ß expression may also occur in vivo in response to changes in the tumor microenvironment and interactions with immune cell populations. These interactions are likely important components to be considered when studying and modeling the expression of IL-1ß as a potential therapeutic target in lung cancer.

Systemic inflammation and pro-inflammatory cytokine profile predict response to checkpoint inhibitor treatment in NSCLC: a prospective study.

Treatment with single agent immune checkpoint inhibitors (ICIs) has tremendously changed second line therapy in NSCLC. However, there are still no reliable biomarkers predicting response and survival in this group of patients. PD-L1 revealed to be a correlating, but no perfect marker. Therefore, we sought to investigate in this prospective study, whether inflammation status and cytokine profile could serve as additional biomarkers guiding treatment decision for single agent ICIs in NSCLC. 29 stage IV NSCLC patients receiving single agent PD-1 checkpoint-inhibitor in second line were prospectively enrolled. Inflammatory scores and cytokine profiles (IL-6, IL-8, IL-10, IFN-γ and TNFα) have been obtained before treatment and at the time of the first staging. Cytokine profiles were correlated with response and survival. Patients with signs of pre-therapeutic inflammation (elevated, NLR, SII, IL-6, IL-8) showed significantly lower response to ICI treatment and reduced PFS. Contrary, elevated levels of IFN-γ revealed to characterize a subgroup of patients, who significantly benefits from ICI treatment. Furthermore, low systemic inflammation and high levels of IFN-γ characterized patients with long term-response to ICI treatment. Pre-therapeutic assessment of inflammation and cytokine profiles has the ability to predict response and survival in NSCLC patients treated with single agent ICIs.

Role of the erythropoietin receptor in Lung Cancer cells: erythropoietin exhibits angiogenic potential.

Background: Recombinant human erythropoietin (rHuEPO), a hormone regulating the proliferation and differentiation of erythroid cells, is one of the prescription drugs used to treat cancer-associated anemia. However, administration of rHuEPO to cancer patients has been reported to be associated with decreased survival, and the mechanism by which it acts remains controversial. The present study aimed to investigate the expression of the EPO-receptor in lung cancer cell lines and whether rHuEPO treatment affected its growth and migration. Moreover, the angiogenic effects of rHuEPO were also explored in vivo. Methods: Expression of the EPO-receptor in lung cancer cell lines was measured by Western blotting and enzyme linked immunosorbent assays (ELISAs). Proliferation of the lung cancer cells was monitored in the presence of rHuEPO. Human umbilical vein endothelial cells (HUVECs) were used for tube formation assays in vitro, and transwell migration assays were performed to detect migration under rHuEPO treatment. Matrigel plug technology was employed to observe the angiogenic effects in both nude mice and Matrigel-containing lung cancer cell lines H838 or H1975. Microvessel density (MVD) was measured using CD31 Immunohistochemistry (IHC) staining. Results: EPO-receptor (EPO-R) was only detected in the cell lines H838 and H1339 by ELISA. However, the EPO-R protein was detected in all cell lines by Western blotting, which is in contradiction to the ELISA results. Proliferation and migration were not affected by rHuEPO treatment. However, rHuEPO promoted HUVEC tube formation in vitro and significantly induced the formation of new blood vessels in vivo. Furthermore, rHuEPO did not antagonize the inhibitory effects of Afatinib (epidermal growth factor receptor-tyrosine kinase inhibitor; EGFR-TKI) in simultaneous treatment with rHuEPO. In a 3D cell co-culture model, rHuEPO did not enhance the secretion of vascular endothelial growth factor (VEGF) in lung cancer cells or human lung fibroblast cell line MRC-5. Conclusions: We have shown that the role of EPO goes beyond erythropoiesis, also playing a strong role in angiogenesis by participating in new blood vessel formation in lung cancer models. Thus, rHuEPO may raise the risk of thrombosis and metastasis in vivo. Additionally, our results suggest that studies using commercially available EPO-R antibodies should be reexamined; some of these antibodies may not in fact recognize EPO-R.

Hedgehog Pathway Activation Might Mediate Pemetrexed Resistance in NSCLC Cells.

BACKGROUND/AIM: Resistance to chemotherapeutic agents is the main cause of reduced survival in non-small cell lung cancer (NSCLC) patients. The Hedgehog (HH) pathway has been shown to be crucial in cell development and survival. Activated in several types of cancer it might be a potent bypass mechanism mediating chemotherapy resistance. MATERIALS AND METHODS: HCC827 NSCLC cells were treated with sub-lethal doses of pemetrexed to produce pemetrexed resistance. RT-qPCR was performed to measure gene expression of HH pathway proteins. A cell growth assay was used to measure the impact of the HH-inhibitor Gant61 in naïve and chemoresistant cell lines. RESULTS: Pemetrexed resistant cells showed significantly increased expression of HH signaling genes (GLI1, GLI2, GLI3, PTCH1, SHH). Supporting these results, pemetrexed resistant cells treated with the HH inhibitor Gant61 showed reduced proliferation compared to naïve cells. CONCLUSION: HH pathway may play an important role in mediating pemetrexed resistance in NSCLC cells. Blocking the HH pathway may be a potential option to overcome this resistance.

The omega-3 index in patients with heart failure: A prospective cohort study.

BACKGROUND: Epidemiologic studies on the omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in heart failure are scarce, while one large intervention trial demonstrated a modest benefit. METHODS: This is a secondary analysis from the Interdisciplinary Network Heart Failure (INH) program. Patients hospitalized for systolic heart failure were enrolled and followed for 36 months. At baseline, whole blood samples from 899 patients were analyzed for fatty acid composition using a standardized analytical procedure (HS-Omega-3 Index®, O3-I). Associations of the O3-I with markers of heart failure severity, clinical characteristics, biomarkers, and mortality were analyzed. RESULTS: The mean O3-I was 3.7 ±â€¯1.0%. Patient mean age was 68 ±â€¯12 years (72% male, 43% in New York Heart Association (NYHA) class III or IV, mean LVEF 30 ±â€¯8%). During follow-up 258 patients (28.7%) died. After adjustment for potential confounders, the O3-I showed weak associations with uncured malignancy, end-systolic diameter of the left atrium, left ventricular end-diastolic and end-systolic diameters, and blood lipids and other laboratory parameters (all p < 0.05), but not with NYHA class, left ventricular ejection fraction, and the underlying cause of heart failure. The O3-I did not predict the 3-year mortality risk. CONCLUSIONS: Our results show a marked depletion of omega-3 fatty acids in patients hospitalized for decompensated heart failure (suggested target range 8-11%). Although the O3-I was associated with a panel of established risk indicators in heart failure, it did not predict mortality risk. CLINICAL TRIAL REGISTRATION: www.controlled-trials.com; ISRCTN23325295.

Trans-fatty acid levels in erythrocytes in Europe.

PURPOSE: High, but not low levels of trans-fatty acids (TFA) in erythrocytes are associated with increased mortality. Current erythrocyte TFA levels in Europe are not known. METHODS: TFA levels in samples submitted by physicians for erythrocyte omega-3 fatty acid analyses are reported, as analysed with a method (HS-Omega-3 Index®) previously used in pertinent prospective epidemiologic studies. From Germany, 6754 samples were included from 2008 through 2015, and 496 samples from 10 other European countries. RESULTS: In Germany, mean levels of C16:1n-7t, a marker for dairy and meat intake, decreased, as did mean levels of industrially produced (IP)-TFA, as did the percentage of individuals with IP-TFA > 1.04 %. Mean levels of IP-TFA in Austria and Switzerland were low before and after measures were taken to reduce them. Average levels of C16:1n-7t were low, and at levels associated with increased risk of death in previous studies. A limitation of our study is that samples were not obtained in a specific or representative manner. CONCLUSIONS: Levels of IP-TFA appear to be decreasing, as are those of ruminant-derived C16:1n-7t, a marker for dairy and meat intake. Few individuals had high levels of IP-TFA above a safe range, while many had low levels of C16:1n-7t. Our data argue against further action against TFA in the countries studied. More systematic biomarker-based studies are needed.

Interleukin-22 is elevated in lavage from patients with lung cancer and other pulmonary diseases.

BACKGROUND: Interleukin-22 (IL-22) is involved in lung diseases such as pneumonia, asthma and lung cancer. Lavage mirrors the local environment, and may provide insights into the presence and role of IL-22 in patients. METHODS: Bronchoscopic lavage (BL) samples (n = 195, including bronchoalveolar lavage and bronchial washings) were analysed for IL-22 using an enzyme-linked immunosorbent assay. Clinical characteristics and parameters from lavage and serum were correlated with lavage IL-22 concentrations. RESULTS: IL-22 was higher in lavage from patients with lung disease than in controls (38.0 vs 15.3 pg/ml, p < 0.001). Patients with pneumonia and lung cancer had the highest concentrations (48.9 and 33.0 pg/ml, p = 0.009 and p < 0.001, respectively). IL-22 concentration did not correlate with systemic inflammation. IL-22 concentrations did not relate to any of the analysed cell types in BL indicating a potential mixed contribution of different cell populations to IL-22 production. CONCLUSIONS: Lavage IL-22 concentrations are high in patients with lung cancer but do not correlate with systemic inflammation, thus suggesting that lavage IL-22 may be related to the underlying malignancy. Our results suggest that lavage may represent a distinct compartment where the role of IL-22 in thoracic malignancies can be studied.

Interactions among Lung Cancer Cells, Fibroblasts, and Macrophages in 3D Co-Cultures and the Impact on MMP-1 and VEGF Expression.

In vitro cell-based models of lung cancer are frequently employed to study invasion and the mechanisms behind metastasis. However, these models often study only one cell type with two-dimensional (2D) monolayer cell cultures, which do not accurately reflect the complexity of inflammation in vivo. Here, a three-dimensional (3D) cell co-culture collagen gel model was employed, containing human lung adenocarcinoma cells (HCC), human lung fibroblast cells (MRC-5), and macrophages. Cell culture media and cell images were collected, and matrix metalloproteinase-1 (MMP-1) and vascular endothelial growth factor (VEGF) production was monitored under different cell culture conditions. We found that simulating hypoxia and/or serum starvation conditions induced elevated secretion of VEGF in the 3D co-culture model in vitro, but not MMP-1; the morphology of HCC in the 2D versus the 3D co-culture system was extremely different. MMP-1 and VEGF were secreted at higher levels in mixed cell groups rather than mono-culture groups. Therefore, incorporating lung cancer cells, fibroblasts, and macrophages may better reflect physiological metastasis mechanisms compared to mono-culture systems. Tumour stromal cells, macrophages, and fibroblast cells may promote invasion and metastasis, which also provides a new direction for the design of therapies targeted at destroying the stroma of tumor tissues.

Concomitant gemcitabine therapy negatively affects DC vaccine-induced CD8(+) T-cell and B-cell responses but improves clinical efficacy in a murine pancreatic carcinoma model.

BACKGROUND: Multiple studies have shown that dendritic cell (DC)-based vaccines can induce antitumor immunity. Previously, we reported that gemcitabine enhances the efficacy of DC vaccination in a mouse model of pancreatic carcinoma. The present study aimed at investigating the influence of gemcitabine on vaccine-induced anti-tumoral immune responses in a syngeneic pancreatic cancer model. MATERIALS AND METHODS: Subcutaneous or orthotopic pancreatic tumors were induced in C57BL/6 mice using Panc02 cells expressing the model antigen OVA. Bone marrow-derived DC were loaded with soluble OVA protein (OVA-DC). Animals received gemcitabine twice weekly. OVA-specific CD8(+) T-cells and antibody titers were monitored by FACS analysis and ELISA, respectively. RESULTS: Gemcitabine enhanced clinical efficacy of the OVA-DC vaccine. Interestingly, gemcitabine significantly suppressed the vaccine-induced frequency of antigen-specific CD8(+) T-cells and antibody titers. DC migration to draining lymph nodes and antigen cross-presentation were unaffected. Despite reduced numbers of tumor-reactive T-cells in peripheral blood, in vivo cytotoxicity assays revealed that cytotoxic T-cell (CTL)-mediated killing was preserved. In vitro assays revealed sensitization of tumor cells to CTL-mediated lysis by gemcitabine. In addition, gemcitabine facilitated recruitment of CD8(+) T-cells into tumors in DC-vaccinated mice. T- and B-cell suppression by gemcitabine could be avoided by starting chemotherapy after two cycles of DC vaccination. CONCLUSIONS: Gemcitabine enhances therapeutic efficacy of DC vaccination despite its negative influence on vaccine-induced T-cell proliferation. Quantitative analysis of tumor-reactive T-cells in peripheral blood may thus not predict vaccination success in the setting of concomitant chemotherapy.

The hedgehog pathway inhibitor GDC-0449 alters intracellular Ca2+ homeostasis and inhibits cell growth in cisplatin-resistant lung cancer cells.

AIM: Cisplatin resistance is an important issue in lung cancer. We aimed at investigating if the Hedgehog pathway inhibitor GDC-0449 is effective in cisplatin-resistant cells and if it alters intracellular Ca(2+)-homeostasis. MATERIALS AND METHODS: The cytoplasmatic ([Ca(2+)](cyto)) and endoplasmatic ([Ca(2+)])(ER) Ca(2+) concentration of HCC (adeno carcinoma of the lung) and H1339 (small cell lung carcinoma) cells were measured with the calcium indicator dye Fura-2 AM. The expression of the inositol-1,4,5-trisphosphate receptor (IP(3)R) and sarco/endoplasmic reticulum Ca(2+)-ATPase (SERCA) were analyzed using western blot analysis. RESULTS: GDC-0449 inhibited cell growth in cisplatin-naïve and -resistant cells. In both cell types, GDC-0449 increased [Ca(2+)](cyto) and reduced endoplasmatic [Ca(2+)](ER). Cisplatin failed to considerably alter Ca(2+) homeostasis in resistant cells. The effects of GDC-0449 on intracellular Ca(2+) homeostasis were not mediated by an altered expression of IP(3)R or SERCA. CONCLUSION: GDC-0449 alters intracellular Ca(2+) homeostasis and inhibits cell growth in cisplatin-resistant lung cancer cells.

Dendritic cell-based vaccination of patients with advanced pancreatic carcinoma: results of a pilot study.

BACKGROUND AND AIMS: Dendritic cell (DC)-based vaccination can induce antitumor T cell responses in vivo. This clinical pilot study examined feasibility and outcome of DC-based tumor vaccination for patients with advanced pancreatic adenocarcinoma. METHODS: Tumor lysate of patients with pancreatic carcinoma was generated by repeated freeze-thaw cycles of surgically obtained tissue specimens. Patients were eligible for DC vaccination after recurrence of pancreatic carcinoma or in a primarily palliative situation. DC were generated from peripheral blood mononuclear cells (PBMC), loaded with autologous tumor lysate, stimulated with TNF-α and PGE(2) and injected intradermally. All patients received concomitant chemotherapy with gemcitabine. Disease response was the primary endpoint. Individual immunological responses to DC vaccination were analyzed by T cell-based immunoassays using pre- and post-vaccination samples of non-adherent PBMC. RESULTS: Twelve patients received DC vaccination and concomitant chemotherapy. One patient developed a partial remission, and two patients remained in stable disease. Median survival was 10.5 months. No severe side effects were observed. Tumor-reactive T cells could be detected prior to vaccination. DC vaccination increased the frequency of tumor-reactive cells in all patients tested; however, the degree of this increase varied. To quantify the presence of tumor-reactive T cells, stimulatory indices (SI) were calculated as the ratio of proliferation-inducing capacity of lysate-loaded versus -unloaded DC. The patient with longest overall survival of 56 months had a high SI of 6.49, indicating that the presence of a pre-vaccination antitumor T cell response might be associated with prolonged survival. Five patients survived 1 year or more. CONCLUSION: DC-based vaccination can stimulate an antitumoral T cell response in patients with advanced or recurrent pancreatic carcinoma receiving concomitant gemcitabine treatment.

Combined use of toll-like receptor agonists and prostaglandin E(2) in the FastDC model: rapid generation of human monocyte-derived dendritic cells capable of migration and IL-12p70 production.

Phenotypical maturation, IL-12p70 production and migration upon chemokine receptor CCR7 ligation are currently proposed as requirements for the use of human monocyte-derived dendritic cells (DC) in antitumoral vaccination. We have previously described a short-term protocol for DC generation from monocytes including stimulation with TNF-alpha, IL-1beta and PGE(2) (FastDC). These "conventional" FastDC are mature, migrate in response to CCR7 ligation and effectively stimulate autologeous T cells in vitro, but are deficient in IL-12p70 production. Here, conventional FastDC were compared to FastDC activated with different TLR ligands. High levels of IL-12p70 were induced by combined activation of FastDC with TLR4 and TLR7/8 ligands. IL-12 secretion could be maximized by additional T cell-derived stimulation. However, TLR-stimulated FastDC failed to migrate upon CCR7 ligation, independent of additional activation with CD40 ligand and IFN-gamma. The presence of PGE(2) during TLR ligation fully restored migratory capacity of FastDC, but left IL-12p70 production and activation of tumor antigen-specific cytotoxic T cells unaffected, challenging previous findings obtained with standard 7-day monocyte-derived DC. The FastDC model thus not only represents an effective tool for antitumoral vaccination, but may also provide novel insights into human DC biology.

IFN-alpha promotes definitive maturation of dendritic cells generated by short-term culture of monocytes with GM-CSF and IL-4.

Dendritic cells (DC) generated in vitro have to be viable and phenotypically mature to be capable of inducing T cell-mediated immunity after in vivo administration. To facilitate optimization of DC-based vaccination protocols, we investigated whether the cytokine environment and the mode of activation affect maturation and survival of DC derived from monocytes by a short-term protocol. Monocytes cultured for 24 h with granulocyte macrophage-colony stimulating factor and interleukin-4 were stimulated with proinflammatory mediators for another 36 h to generate mature DC. Additional activation with CD40 ligand and interferon (IFN)-gamma increased viability of DC and promoted definitive maturation as defined by maintenance of a mature phenotype after withdrawal of cytokines. Addition of IFN-alpha to DC cultures prior to stimulation further enhanced definitive maturation: IFN-alpha-primed DC expressed high levels of costimulatory molecules and CC chemokine receptor 7 (CCR7) up to 5 days after cytokine withdrawal. Compared with unprimed DC, IFN-alpha-primed DC displayed equal capacity to migrate upon CCR7 ligation and to prime antigen-specific T helper cell as well as cytolytic T cell responses. In conclusion, we show that optimal maturation and survival of monocyte-derived DC require multiple activation signals. Furthermore, we identified a novel role for IFN-alpha in DC development: IFN-alpha priming of monocytes promotes definitive maturation of DC upon activation.

FastDC derived from human monocytes within 48 h effectively prime tumor antigen-specific cytotoxic T cells.

Previously, we have shown that dendritic cells (DCs) with full T-cell stimulatory capacity can be derived from human monocytes after 48 h of in vitro culture (FastDC). Compared to a standard 7-day protocol, this new strategy not only reduces the time span and the amount of recombinant cytokines required, but may also resemble DC development in vivo more closely. Using a melanoma antigen model, we show here that FastDC prime CTL responses against tumor antigens as effectively as standard monocyte-derived DCs (moDCs). FastDC and moDCs derived from monocytes of HLA-A2(+) donors were loaded with the melanoma-associated, HLA-A(*)0201-restricted peptide Melan-A and cocultured with autologous CD3(+) T cells. After two weekly restimulations with freshly prepared, peptide-loaded FastDC or moDCs, binding of CD8(+) T cells to fluorescently labeled MHC-I/Melan-A-peptide complexes and intracellular cytokine staining revealed that the two DC preparations had an equal capacity to prime Melan-A-specific, IFN-gamma producing CD8(+) T cells. CTLs derived from cocultures with FastDC lysed Melan-A-loaded T2 cells even more effectively than CTLs primed by moDCs. Comparative analysis also revealed that FastDC possess an equal capacity to migrate in response to the chemokine receptor CCR-7 ligand 6Ckine. Importantly, DCs can be generated with higher yield and purity using the FastDC-protocol. The reliability and efficacy of this new strategy for DC development from monocytes may facilitate clinical investigation of DC-based tumor immunotherapy.