Anti-PD1 antibody enhances the anti-tumor efficacy of MUC1-MBP fusion protein vaccine via increasing Th1, Tc1 activity and decreasing the proportion of MDSC in the B16-MUC1 melanoma mouse model.

In previous studies, we have obtained a notable anti-tumor efficacy of the recombinant MUC1-MBP vaccine in the process of mouse B16-MUC1 melanoma treatment. However, the tumor cannot be eliminated completely. We found that the tumor inhibition rate decreased from 81.67% (five immunizations) to 43.67% (eight immunizations) after more than five immunizations, indicating persistent vaccine stimulation may activate immunosuppressive factors. In the present study, we revealed that programmed cell death 1 (PD1), an inhibitory molecule suppressing T cell function, expressed on splenic and tumor-infiltrating T cells were up-regulated by the vaccine. Therefore, to optimize the anti-tumor efficacy of the vaccine, we employed combination immunotherapy with MUC1-MBP vaccine and αPD1 (anti-PD1 antibody). Results showed that combination immunotherapy induced a more remarkable anti-tumor efficacy, the tumor clearance being increased to 80% from 20% which obtain by MUC1-MBP vaccine immunizations. To investigate the possible underlying mechanism, IFN-γ secretion and cytotoxic T lymphocyte (CTL) cytotoxicity were measured by enzyme-linked immunosorbent assay (ELISA) and xCELLigence real-time cell analyzer (RTCA) respectively. T cell subsets and immunosuppressive cells in the mouse spleen and tumor microenvironment were analyzed by FACS. Results showed that the proportion of splenic CD8+T cells and tumor infiltration was increased and the activity of CTL killing, T helper 1 (Th1), Type 1 CD8+T (Tc1) was enhanced, indicating that the anti-tumor efficacy enhanced by combination immunotherapy was mainly through boosting CD8+T cells mediated anti-tumor cellular immunity. Additionally, combination immunotherapy significantly decreased the splenic and tumor-infiltrating myeloid derived suppressor cells (MDSCs). These results demonstrated that combination immunotherapy with MUC1-MBP vaccine and αPD1 was capable to invoke a more potent anti-tumor immune response and provide a foundation for further research.

Dosagem sérica do marcador tumoral CA 15. 3 em cadelas portadoras de neoplasias mamárias pelo método de eletroquimioluminescência / Serum dosage of the tumor marker Ca 15. 3 in bitches presenting mammary neoplasia with the chemiluminescence method

The objective of the present study was to analyze the serum levels of the tumor marker Ca15.3 in healthy bitches and those with mammary neoplasms, correlating results with tumor type, clinical staging, time until presentation, and presence of ulceration and vascularization. For the study, 30 bitches with mammary tumors and 30 healthy bitches (control group) were selected. Histopathology was performed for identification of tumor type, and blood was collected for measurement of serum concentration of the marker via the chemiluminescence method using a commercial kit. A higher frequency of malignant neoplasms was observed (76.7%), with a higher quantity of carcinoma in mixed tumor (26.7%). Regarding serum concentration of the marker Ca15.3, there was no difference in serum values when comparing the means from bitches with neoplasia and healthy bitches, nor when comparing the other characteristics. The majority of results for serum concentration of Ca15.3, whether in bitches with neoplasia or in healthy bitches, was zero. It is concluded that the measurement of the marker Ca15.3 using the chemiluminescence method and commercial kits for humans did not offer significant results that would make this method or this marker a useful tool for patient monitoring and evaluation of the prognosis of bitches with mammary neoplasms.(AU)

Non-small cell lung cancer tumour antigen, MUC-1 peptide-loaded non-aggregated poly (lactide-co-glycolide) nanoparticles augmented cellular uptake in mouse professional antigen-presenting cells: optimisation and characterisation.

Aim: MUC-1 lipopeptide vaccine exhibited immense potential in the treatment of non-small cell lung cancer (NSCLC) in both preclinical and clinical trials. However, it lacks triggering of mucosal immunity at the site of action. Therefore, in present investigation, MUC-1 peptide-loaded poly(lactide-co-glycolide) nanoparticles (MUC-1 peptide-PLGA-NPs) and MUC-1 peptide-loaded poly(lactide-co-glycolide) non-aggregated nanoparticles (MUC-1 peptide-PLGA-NA-NPs) using Central Composite Design (CCD) were customised.Methods and Results: The mean particle size of MUC-1 peptide PLGA-NPs was estimated to be 176.7 ± 32.7 nm, significantly (p < 0.05) higher than 100.3 ± 24.3 nm of MUC-1 peptide-PLGA-NA-NPs. Furthermore, integrity and stability of MUC-1 were maintained in MUC-1 peptide PLGA-NA-NPs. MUC-1 peptide-PLGA-NA-NPs exhibited augmented cellular uptake in mouse RAW264.7 macrophages preferably by clathrin-mediated endocytosis pathway as compared to phagocytosis followed by MUC-1-peptide PLGA-NPs owing to size ≤100 nm, and spherical shape.Conclusion: MUC-1 peptide-PLGA-NA-NPs may be a potential candidate to study antitumor potential in xenograft model of NSCLC through inhalation route of administration.

Utilizing VEGF165b mutant as an effective immunization adjunct to augment antitumor immune response.

Compelling evidence has shown that blocking VEGF via monoclonal antibodies may be beneficial in that it not only inhibits tumor angiogenesis but also reduces immune suppression and promotes T cell infiltration into tumors. Herein, we determined whether our recently generated VEGF165b mutant could be used as a co-immunization adjunct to augment the peptide cancer-vaccine- induced immune response in a mouse model of breast cancer. When co-immunized mVEGF165b with the peptide-based cancer vaccine (MUC1, a T-cell epitope dominant peptide vaccine from Mucin1), the VEGF antibody titers increased approximately 600,000-fold in mice. Moreover, the anti-VEGF antibody also reduced the frequency of regulatory T cells (Tregs) in both preventive and therapeutic scenarios. Mechanistically, the decrease of the Tregs population was associated with a remarkably increased MUC-1-specific IFN-γ-producing CD8+ T cells and anti-MUC1 humoral response. Finally, this combination co-immunization produced a superior antitumor response and significantly prolonged survival of tumor-bearing mice. In conclusion, our findings suggest that mVEGF165b may be an ideal immunization adjunct to enhance the immune efficacy of peptide-based tumor vaccines by overcoming immune tolerance.

Is mucin a determinant of peritoneal dissemination of gastrointestinal cancer? Analysis of mucin depletion in two preclinical models

Background. Mucinous gastrointestinal cancers may indicate a higher propensity for widespread peritoneal seeding than their non-mucinous counterparts. We hypothesized that mucin content of gastrointestinal cancer cells and tumors is an indicator of cell viability and a determinant of the peritoneal tumor burden and tested our hypothesis in relevant experimental models. Methods. MKN45 and LS174T models of human gastrointestinal cancer were treated with known mucin-depleting agents in vitro and in vivo, their mucin production was evaluated with Western blot immunohistochemistry, PAS staining and ELISA, and its correlation with cell viability and peritoneal tumor burden was analyzed. Results. A relationship was found between the viability of cancer cells and their mucin levels in vitro. In agreement, when treated animal models were categorized into low- and high-burden groups (based on the weight and number of the peritoneal nodules), tumoral mucin levels were found to be significantly higher in the latter group. Conclusions. Tumoral mucin is apparently among the factors that dictate the pattern and extent of the peritoneal spread of gastrointestinal cancer, where it allows for enhanced dissemination and redistribution. If further tested and validated, our hypothesis could lay the basis for the development of novel mucin-targeted strategies (AU)

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Enhanced synergistic anti-Lewis lung carcinoma effect of a DNA vaccine harboring a MUC1-VEGFR2 fusion gene used with GM-CSF as an adjuvant.

In order to achieve a synergistic effect on anti-tumour and anti-angiogenesis activity, we designed and constructed a DNA vaccine that expresses MUC1and VEGFR2 in the same reading frame. The aim of this study was to investigate the anti-tumour activity of this DNA vaccine. Furthermore, we also investigated the enhanced synergistic anti-Lewis lung carcinoma effect of this DNA vaccine by using GM-CSF as an adjuvant. A series of DNA plasmids encoding MUC1, VEGFR2, GM-CSF, and their conjugates were constructed and injected into mice intramuscularly (i.m.) followed by an electric pulse. The humoral and cellular immune responses after immunization were detected by enzyme-linked immunosorbent assay (ELISA) and enzyme-linked immunospot (ELISPOT), respectively. To evaluate the anti-tumour efficacy of these plasmids, murine models with MUC1-expressing tumours were generated. After injection into the tumour-bearing mouse model, the plasmid carrying the fusion gene of MUC1 and VEGFR2 showed stronger inhibition of tumour growth than the plasmid expressing MUC1 or VEGFR2 alone, which indicated that MUC1 and VEGFR2 could exert a synergistic anti-tumour effect. Furthermore, mice vaccinated with the combination of the GM-CSF expressing plasmid and the plasmid carrying the fusion gene of MUC1 and VEGFR2 showed an increased inhibition in the growth of MUC1-expressing tumours and prolonged mouse survival. These observations emphasize the potential of the synergistic anti-tumour and anti-angiogenesis strategy used in DNA vaccines, and the potential of the GM-CSF gene as an adjuvant for DNA vaccines, which could represent a promising approach for tumour immunotherapy.

Pre-clinical toxicity and immunogenicity evaluation of a MUC1-MBP/BCG anti-tumor vaccine.

Mucin 1 (MUC1), as an oncogene, plays a key role in the progression and tumorigenesis of many human adenocarcinomas and is an attractive target in tumor immunotherapy. Our previous study showed that the MUC1-MBP/BCG anti-tumor vaccine induced a MUC1-specific Th1-dominant immune response, simulated MUC1-specific cytotoxic T lymphocyte killing activity, and could significantly inhibit MUC1-expression B16 cells' growth in mice. To help move the vaccine into a Phase I clinical trial, in the current study, a pre-clinical toxicity and immunogenicity evaluation of the vaccine was conducted. The evaluation was comprised of a single-dose acute toxicity study in mice, repeat-dose chronic toxicity and immunogenicity studies in rats, and pilot toxicity and immunogenicity studies in cynomolgus monkeys. The results showed that treatment with the MUC1-MBP/BCG anti-tumor vaccine did not cause any organ toxicity, except for arthritis or local nodules induced by BCG in several rats. Furthermore, the vaccine significantly increased the levels of IFN-γ in rats, indicating that Th1 cells were activated. In addition, the results showed that the MUC1-MBP/BCG anti-tumor vaccine induced a MUC1-specific IgG antibody response both in rats and cynomolgus monkeys. Collectively, these data are beneficial to move the MUC1-MBP/BCG anti-tumor vaccine into a Phase I clinical trial.

Triple peptide vaccination as consolidation treatment in women affected by ovarian and breast cancer: Clinical and immunological data of a phase I/II clinical trial.

Vaccination with priming and expansion of tumour reacting T cells is an important therapeutic option to be used in combination with novel checkpoint inhibitors to increase the specificity of the T cell infiltrate and the efficacy of the treatment. In this phase I/II study, 14 high-risk disease-free ovarian (OC) and breast cancer (BC) patients after completion of standard therapies were vaccinated with MUC1, ErbB2 and carcinoembryonic antigen (CEA) HLA-A2+-restricted peptides and Montanide. Patients were subjected to 6 doses of vaccine every two weeks and a recall dose after 3 months. ECOG grade 2 toxicity was observed at the injection site. Eight out of 14 patients showed specific CD8+ T cells to at least one antigen. None of 4 patients vaccinated for compassionate use showed a CD8 activation. An OC patient who suffered from a lymph nodal recurrence, showed specific anti-ErbB2 CD8+ T cells in the bulky aortic lymph nodes suggesting homing of the activated T cells. Results confirm that peptide vaccination strategy is feasible, safe and well tolerated. In particular OC patients appear to show a higher response rate compared to BC patients. Vaccination generates a long-lasting immune response, which is strongly enhanced by recall administrations. The clinical outcome of patients enrolled in the trial appears favourable, having registered no deceased patients with a minimum follow-up of 8 years. These promising data, in line with the results of similar studies, the high compliance of patients observed and the favourable toxicity profile, support future trials of peptide vaccination in clinically disease-free patients who have completed standard treatments.

Phase I/II study exploring ImMucin, a pan-major histocompatibility complex, anti-MUC1 signal peptide vaccine, in multiple myeloma patients.

ImMucin, a 21-mer cancer vaccine encoding the signal peptide domain of the MUC1 tumour-associated antigen, possesses a high density of T- and B-cell epitopes but preserves MUC1 specificity. This phase I/II study assessed the safety, immunity and clinical response to 6 or 12 bi-weekly intradermal ImMucin vaccines, co-administered with human granulocyte-macrophage colony-stimulating factor to 15 MUC1-positive multiple myeloma (MM) patients, with residual or biochemically progressive disease following autologous stem cell transplantation. Vaccination was well tolerated; all adverse events were temporal grade 1 2 and spontaneously resolved. ImMucin vaccination induced a robust increase in γ-interferon (IFN-γ-producing CD4+ and CD8+ T-cells (≤80-fold), a pronounced population of ImMucin multimer CD8+ T-cells (>2%), a 9·4-fold increase in peripheral blood mononuclear cells proliferation and 6·8-fold increase in anti-ImMucin antibodies, accompanied with T-cell and antibody-dependent cell-mediated cytotoxicity. A significant decrease in soluble MUC1 levels was observed in 9/10 patients. Stable disease or improvement, persisting for 17·5-41·3 months (ongoing) was achieved in 11/15 patients and appeared to be associated with low-intermediate PDL1 (CD274) bone marrow levels pre- and post-vaccination. In summary, ImMucin, a highly tolerable cancerous vaccine, induces robust, diversified T- and B-cell ImMucin-specific immunity in MM patients, across major histocompatibility complex-barrier, resulting in at least disease stabilization in most patients.

Synthesis and immunological evaluation of self-adjuvanting MUC1-macrophage activating lipopeptide 2 conjugate vaccine candidates.

We describe herein the synthesis and immunological evaluation of self-adjuvanting mucin 1 (MUC1)-macrophage activating lipopeptide 2 (MALP2) (glyco)peptide vaccine candidates. Vaccine constructs were shown to induce high titres of class-switched IgG antibodies in C57BL/6 mice after four immunisations despite the lack of a helper T cell epitope.

Up to 15-year clinical follow-up of a pilot Phase III immunotherapy study in stage II breast cancer patients using oxidized mannan-MUC1.

BACKGROUND: Targeting antigens to dendritic cell receptors has recently become a popular approach to inducing effective immune responses against cancer antigens. Almost 20 years ago, however, we demonstrated that targeting the mannose receptor on macrophages and dendritic cells leads to strong cellular immune responses. We conducted numerous human clinical trials demonstrating the effectiveness of oxidized mannan-MUC1 (M-FP) in MUC1(+) adenocarcinoma patients. In one trial, the 5-8-year follow-up of breast cancer patients vaccinated with M-FP was published previously; we now report here the 12-15-year follow-up. Details regarding the preparation of the vaccine, inclusion and exclusion criteria, immunotherapy and follow-up schedule, were published previously. RESULTS: The follow-up at 12-15 years showed that the recurrence rate in patients receiving placebo was 60% (nine of 15). In those receiving immunotherapy (M-FP), the rate was 12.5% (two of 16). The time of recurrence in the placebo group ranged from 7 to 180 months (mean: 65.8 months) and in the two patients of the vaccine group, the recurrence appeared at 95 and 141 months (mean: 118 months) after surgery. These findings are statistically significant (p = 0.02 for survival and p = 0.009 for percentage of patients cancer-free). All patients injected with M-FP showed no evidence of toxic effects or signs of autoimmunity during the 12-15-year follow-up. DISCUSSION: The preliminary evidence indicates that M-FP is beneficial in the overall survival of early-stage breast cancer patients. This long-term clinical follow-up of patients strongly supports the necessity for a large Phase III study of direct M-FP injection in early-stage breast cancer patients, to evaluate immunotherapy as an adjuvant treatment for breast cancer.

The anti-chemoresistant effect and mechanism of MUC1 aptamer-miR-29b chimera in ovarian cancer.

OBJECTIVE: Currently, there are no effective therapies for advanced ovarian cancer. In this study, we aim to determine the anti-tumor effect of MUC1 aptamer-miR-29b chimera in xenograft ovarian cancer models and chemo-resistance tumor model and to further explore the associated mechanism. METHODS: Xenograft ovarian cancer animal models were established using OVCAR-3, OVCA420, and OVCAR-3-Taxol cancer cells. The chimera (Chi-29b) was delivered through intraperitoneal injections. Tumor growth was evaluated. Gene expression and PTEN methylation were measured. RESULTS: We demonstrated that intratumoral injection of Chi-29b chimera significantly inhibited the growth of xenograft OVCAR-3 tumors through downregulating PTEN methylation, subsequent PTEN expression, as well as downregulating MAPK 4 and IGF1 expressions. In contrast, Chi-29b inhibited tumor growth in OVCA420 tumors by downregulating MAPK 4 & 10 and IGF1 expression without affecting PTEN expression. Intraperitoneal injection of Chi-29b significantly increased apoptosis in paclitaxel-resistant OVCAR-3 cells and inhibited the growth of xenograft OVCAR-3-Taxol tumors. The anti-chemoresistant role of Chi-29b in OVCAR-3-Taxol tumors was associated with the activation of PTEN signaling and downregulation of MAPK 4 and 10 and IGF1 expression. CONCLUSION: Our study indicated that Chi-29b chimera can effectively exert an anti-tumor effect in xenograft tumor models and an anti-chemoresistant role through inhibiting cancer stem cell activation.

Human milk mucin 1 and mucin 4 inhibit Salmonella enterica serovar Typhimurium invasion of human intestinal epithelial cells in vitro.

Many human milk glycans inhibit pathogen binding to host receptors and their consumption by infants is associated with reduced risk of disease. Salmonella infection is more frequent among infants than among the general population, but the incidence is lower in breast-fed babies, suggesting that human milk could contain components that inhibit Salmonella. This study aimed to test whether human milk per se inhibits Salmonella invasion of human intestinal epithelial cells in vitro and, if so, to identify the milk components responsible for inhibition. Salmonella enterica serovar Typhimurium SL1344 (SL1344) invasion of FHs 74 Int and Caco-2 cells were the models of human intestinal epithelium infection. Internalization of fluorescein-5-isothiocyanate-labeled SL1344 into intestinal cells was measured by flow cytometry to quantify infection. Human milk and its fractions inhibited infection; the inhibitory activity localized to the high molecular weight glycans. Mucin 1 and mucin 4 were isolated to homogeneity. At 150 µg/L, a typical concentration in milk, human milk mucin 1 and mucin 4 inhibited SL1344 invasion of both target cell types. These mucins inhibited SL1344 invasion of epithelial cells in a dose-dependent manner. Thus, mucins may prove useful as a basis for developing novel oral prophylactic and therapeutic agents that inhibit infant diseases caused by Salmonella and related pathogens.

MF59 formulated with CpG ODN as a potent adjuvant of recombinant HSP65-MUC1 for inducing anti-MUC1+ tumor immunity in mice.

MF59 is an oil-in-water emulsion adjuvant approved for influenza vaccines for human use in Europe. Due to its Th2 inducing properties, MF59 is seldom tested for cancer vaccines. In this study, MF59 formulated with a C-type CpG oligodeoxynucleotide (YW002) was tested for its Th1 adjuvant activity to induce immune responses to HSP65-MUC1, a recombinant fusion protein incorporating a mycobacterial heat shock protein (HSP65) and mucin 1, cell surface associated (MUC1) derived peptide. Combination of YW002 with MF59 (MF59-YW002) could confer a potent Th1 biasing property to the adjuvant, which enhanced the immunogenicity of HSP65-MUC1 to induce significantly higher levels of specific IgG2c, increased IFN-γ mRNA expression in splenocytes and the generation of antigen-specific cytotoxic T lymphocytes in mice. When prophylactically applied, MF59-YW002 adjuvant containing HSP65-MUC1 inhibited the growth of MUC1+ B16 melanoma and prolonged the survival of tumor-bearing mice. In contrast, adjuvant containing MF59 with HSP65-MUC1 in the absence of YW002, promoted the growth of MUC1+ B16 melanoma in mice. These results suggest that MF59 plus CpG oligodeoxynucleotide might be developed as an efficient adjuvant for tumor vaccines against melanoma, and possibly other tumors.

A phase I pilot trial of MUC1-peptide-pulsed dendritic cells in the treatment of advanced pancreatic cancer.

The objectives of this study were to assess the toxicity and immunological response induced by the intra-dermal (i.d.) administration of MUC1-peptide-pulsed dendritic cells (DCs) in advanced pancreatic cancer patients. Patients with recurrent lesions or metastasis after surgery, and immunohistochemistry positive for MUC1 were treated in cohorts that received 3-6 × 10(6) DCs i.d. for three or four vaccines. Each vaccine was composed of autologus DCs pulsed with MUC1-peptide. Peripheral blood mononuclear cells (PBMCs) that harvested 2 weeks after the second immunization were compared with PBMCs obtained before treatment for immunological response. Serial ELISPOT assays of PBMCs for antitumor reactivity were performed. Three patients received all four vaccines, and four patients received three vaccines. These patients were evaluable for toxicity and immunological monitoring. There were no grade 3 or 4 toxicities associated with the vaccines or major evidence of autoimmunity. Interferon-γ and granzyme B ELISPOT assay reactivity increased significantly in 2 of 7 patients (P < 0.05). The administration of MUC1-peptide-pulsed DCs is non-toxic and capable of inducing immunological response to tumor antigen MUC1 in advanced pancreatic cancer patients. Additional studies are necessary to improve tumor rejection responses.

Progression of pancreatic adenocarcinoma is significantly impeded with a combination of vaccine and COX-2 inhibition.

With a 5-year survival rate of <5%, pancreatic cancer is one of the most rapidly fatal malignancies. Current protocols for the treatment of pancreas cancer are not as effective as we desire. In this study, we show that a novel Mucin-1 (MUC1)-based vaccine in combination with a cyclooxygenase-2 inhibitor (celecoxib), and low-dose chemotherapy (gemcitabine) was effective in preventing the progression of preneoplastic intraepithelial lesions to invasive pancreatic ductal adenocarcinomas. The study was conducted in an appropriate triple transgenic model of spontaneous pancreatic cancer induced by the KRAS(G12D) mutation and that expresses human MUC1 as a self molecule. The combination treatment elicited robust antitumor cellular and humoral immune responses and was associated with increased apoptosis in the tumor. The mechanism for the increased immune response was attributed to the down-regulation of circulating prostaglandin E(2) and indoleamine 2, 3,-dioxygenase enzymatic activity, as well as decreased levels of T regulatory and myeloid suppressor cells within the tumor microenvironment. The preclinical data provide the rationale to design clinical trials with a combination of MUC1-based vaccine, celecoxib, and gemcitabine for the treatment of pancreatic cancer.

Characterization of the MUC1.Tg/MIN transgenic mouse as a model for studying antigen-specific immunotherapy of adenomas.

A bigenic MUC1.Tg/MIN mouse model was developed by crossing Apc/(MIN/+) (MIN) mice with human MUC1 transgenic mice to evaluate MUC1 antigen-specific immunotherapy of intestinal adenomas. The MUC1.Tg/MIN mice developed adenomas at a rate comparable to that of MIN mice and had similar levels of serum MUC1 antigen. A MUC1-based vaccine consisting of MHC class I-restricted MUC1 peptides, a MHC class II-restricted pan-helper peptide, unmethylated CpG oligodeoxynucleotide and GM-CSF caused flattening of adenomas and significantly reduced the number of large adenomas. Immunization was successful in generating a MUC1-directed immune response evidenced by increased MUC1 peptide-specific anti-tumor cytotoxicity and IFN-gamma secretion by lymphocytes.

MUC1-specific immune therapy generates a strong anti-tumor response in a MUC1-tolerant colon cancer model.

A MUC1-based vaccine was used in a preclinical model of colon cancer. The trial was conducted in a MUC1-tolerant immune competent host injected with MC38 colon cancer cells expressing MUC1. The vaccine included: MHC class I-restricted MUC1 peptides, MHC class II-restricted pan-helper-peptide, unmethylated CpG oligodeoxynucleotide, and granulocyte macrophage-colony stimulating factor. Immunization was successful in breaking MUC1 self-tolerance, and in eliciting a robust anti-tumor response. The vaccine stimulated IFN-gamma-producing CD4(+) helper and CD8(+) cytotoxic T cells against MUC1 and other undefined MC38 tumor antigens. In the prophylactic setting, immunization caused complete rejection of tumor cells, while in the therapeutic regimen, tumor burden was significantly reduced.

Multistep process through which adenoviral vector vaccine overcomes anergy to tumor-associated antigens.

Our goal in the present work was to characterize the multiple steps involved in overcoming the anergy that exists in tumor hosts to tumor-associated antigen (TAA). Our studies showed that the subcutaneous injection of the Ad-sig-TAA/ecdCD40L vector resulted in secretion of the TAA/ecdCD40L protein for at least 10 days from infected cells. Binding of the TAA/ecdCD40L protein to dendritic cells (DCs) resulted in the induction of CCR-7 chemokine receptor expression and cytokine release. This was followed by migration of the DCs to regional lymph nodes. Tetramer staining, enzyme-linked immunospot (ELISPOT) assay, and cytotoxicity assay all showed that the Ad-sig-TAA/ecdCD40L vector increased the levels of splenic CD8(+) T cells specific for the 2 TAAs (human MUC1 [hMUC1] and HPV E7) tested. Vaccination with the Ad-sighMUC1/ecdCD40L vector suppressed the growth of hMUC1 antigen-positive tumor cells in 100% of the test mice that were previously anergic to the hMUC1 antigen. These data suggest that Ad-sig-TAA-ecd/ecdCD40L vector injections may be of value in treating the many epithelial malignancies in which TAA-like hMUC1 is overexpressed.