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Cancer Discovery Jan 2016Weak and ineffective antitumor cytotoxic T lymphocyte (CTL) responses can be rescued by immunomodulatory mAbs targeting PD-1 or CD137. Using Batf3(-/-) mice, which are...
UNLABELLED
Weak and ineffective antitumor cytotoxic T lymphocyte (CTL) responses can be rescued by immunomodulatory mAbs targeting PD-1 or CD137. Using Batf3(-/-) mice, which are defective for cross-presentation of cell-associated antigens, we show that BATF3-dependent dendritic cells (DC) are essential for the response to therapy with anti-CD137 or anti-PD-1 mAbs. Batf3(-/-) mice failed to prime an endogenous CTL-mediated immune response toward tumor-associated antigens, including neoantigens. As a result, the immunomodulatory mAbs could not amplify any therapeutically functional immune response in these mice. Moreover, administration of systemic sFLT3L and local poly-ICLC enhanced DC-mediated cross-priming and synergized with anti-CD137- and anti-PD-1-mediated immunostimulation in tumor therapy against B16-ovalbumin-derived melanomas, whereas this function was lost in Batf3(-/-) mice. These experiments show that cross-priming of tumor antigens by FLT3L- and BATF3-dependent DCs is crucial to the efficacy of immunostimulatory mAbs and represents a very attractive point of intervention to enhance their clinical antitumor effects.
SIGNIFICANCE
Immunotherapy with immunostimulatory mAbs is currently achieving durable clinical responses in different types of cancer. We show that cross-priming of tumor antigens by BATF3-dependent DCs is a key limiting factor that can be exploited to enhance the antitumor efficacy of anti-PD-1 and anti-CD137 immunostimulatory mAbs.
Topics: Animals; Antibodies, Monoclonal; Basic-Leucine Zipper Transcription Factors; Cell Line, Tumor; Dendritic Cells; Humans; Immunotherapy; Lymphocyte Activation; Melanoma, Experimental; Mice; Mice, Transgenic; Programmed Cell Death 1 Receptor; Repressor Proteins; Tumor Necrosis Factor Receptor Superfamily, Member 9
PubMed: 26493961
DOI: 10.1158/2159-8290.CD-15-0510 -
Cellular & Molecular Immunology Nov 2015Previous studies have documented that selective delivery of protein antigens to cells expressing mannose receptor (MR) can lead to enhanced immune responses. We...
Previous studies have documented that selective delivery of protein antigens to cells expressing mannose receptor (MR) can lead to enhanced immune responses. We postulated that agents that influenced the MR expression level, and the activation and migration status of MR-expressing antigen presenting cells, would modulate immune responses to MR-targeted vaccines. To address this question, we investigated the effect of clinically used adjuvants in human MR transgenic (hMR-Tg) mice immunized with an MR-targeting cancer vaccine composed of the human anti-MR monoclonal antibody B11 fused with the oncofetal protein, human chorionic gonadotropin beta chain (hCGβ), and referred to as B11-hCGβ. We found that humoral responses to low doses of B11-hCGβ could be enhanced by prior administration of GM-CSF, which upregulated MR expression in vivo. However, co-administration of the Toll-like receptor (TLR) agonists, poly-ICLC and/or CpG with B11-hCGβ was required to elicit Th1 immunity, as measured by antigen-specific T-cell production of IFN-γ. The TLR agonists were shown to increase the number of vaccine-containing cells in the draining lymph nodes of immunized hMR-Tg mice. In particular, with B11-hCGβ and poly-ICLC, a dramatic increase in vaccine-positive cells was observed in the T-cell areas of the lymph nodes, compared to the vaccine alone or combined with GM-CSF. Importantly, the absence of the TLR agonists during the priming immunization led to antigen-specific tolerance. Therefore, this study provides insight into the mechanisms by which adjuvants can augment immune responses to B11-hCGβ and have implications for the rationale design of clinical studies combining MR-targeted vaccination with TLR agonists.
Topics: Animals; Antibodies, Monoclonal; Antigen-Presenting Cells; Cancer Vaccines; Carboxymethylcellulose Sodium; Chorionic Gonadotropin, beta Subunit, Human; Gene Expression Regulation; Granulocyte-Macrophage Colony-Stimulating Factor; Humans; Immunity, Cellular; Interferon-gamma; Lectins, C-Type; Lymph Nodes; Lymphocyte Count; Mannose Receptor; Mannose-Binding Lectins; Mice; Mice, Transgenic; Oligodeoxyribonucleotides; Poly I-C; Polylysine; Receptors, Cell Surface; Recombinant Fusion Proteins; Signal Transduction; T-Lymphocytes; Th1 Cells; Toll-Like Receptors
PubMed: 25345808
DOI: 10.1038/cmi.2014.100 -
Journal of Advanced Research Mar 2016Given the self nature of cancer, anti-tumor immune response is weak. As such, acute inflammation induced by microbial products can induce signals that result in...
Given the self nature of cancer, anti-tumor immune response is weak. As such, acute inflammation induced by microbial products can induce signals that result in initiation of an inflammatory cascade that helps activation of immune cells. We aimed to compare the nature and magnitude of acute inflammation induced by toll-like receptor ligands (TLRLs) on the tumor growth and the associated inflammatory immune responses. To induce acute inflammation in tumor-bearing host, CD1 mice were inoculated with intraperitoneal (i.p.) injection of Ehrlich ascites carcinoma (EAC) (5 × 10(5) cells/mouse), and then treated with i.p. injection on day 1, day 7 or days 1 + 7 with: (1) polyinosinic:polycytidylic (poly(I:C)) (TLR3L); (2) Poly-ICLC (clinical grade of TLR3L); (3) Bacillus Calmette Guerin (BCG) (coding for TLR9L); (4) Complete Freund's adjuvant (CFA) (coding for TLR9L); and (5) Incomplete Freund's Adjuvant (IFA). Treatment with poly(I:C), Poly-ICLC, BCG, CFA, or IFA induced anti-tumor activities as measured by 79.1%, 75.94%, 73.94%, 71.88% and 47.75% decreases, respectively in the total number of tumor cells collected 7 days after tumor challenge. Among the tested TLRLs, both poly(I:C) (TLR3L) and BCG (contain TLR9L) showed the highest anti-tumor effects as reflected by the decrease in the number of EAc cells. These effects were associated with a 2-fold increase in the numbers of inflammatory cells expressing the myeloid markers CD11b(+)Ly6G(+), CD11b(+)Ly6G(-), and CD11b(+)Ly6G(-). We concluded that Provision of the proper inflammatory signal with optimally defined magnitude and duration during tumor growth can induce inflammatory immune cells with potent anti-tumor responses without vaccination.
PubMed: 26966565
DOI: 10.1016/j.jare.2015.06.001 -
Brain, Behavior, and Immunity Aug 2015Maternal infection during pregnancy increases the risk for neurodevelopmental disorders in offspring. Rodent models have played a critical role in establishing maternal...
Maternal infection during pregnancy increases the risk for neurodevelopmental disorders in offspring. Rodent models have played a critical role in establishing maternal immune activation (MIA) as a causal factor for altered brain and behavioral development in offspring. We recently extended these findings to a species more closely related to humans by demonstrating that rhesus monkeys (Macaca mulatta) prenatally exposed to MIA also develop abnormal behaviors. Here, for the first time, we present initial evidence of underlying brain pathology in this novel nonhuman primate MIA model. Pregnant rhesus monkeys were injected with a modified form of the viral mimic polyI:C (poly ICLC) or saline at the end of the first trimester. Brain tissue was collected from the offspring at 3.5 years and blocks of dorsolateral prefrontal cortex (BA46) were used to analyze neuronal dendritic morphology and spine density using the Golgi-Cox impregnation method. For each case, 10 layer III pyramidal cells were traced in their entirety, including all apical, oblique and basal dendrites, and their spines. We further analyzed somal size and apical dendrite trunk morphology in 30 cells per case over a 30 μm section located 100±10 μm from the soma. Compared to controls, apical dendrites of MIA-treated offspring were smaller in diameter and exhibited a greater number of oblique dendrites. These data provide the first evidence that prenatal exposure to MIA alters dendritic morphology in a nonhuman primate MIA model, which may have profound implications for revealing the underlying neuropathology of neurodevelopmental disorders related to maternal infection.
Topics: Animals; Behavior, Animal; Brain; Carboxymethylcellulose Sodium; Cell Shape; Female; Macaca mulatta; Male; Neurons; Poly I-C; Polylysine; Pregnancy; Prenatal Exposure Delayed Effects
PubMed: 25816799
DOI: 10.1016/j.bbi.2015.03.009 -
Oncoimmunology Jun 2013Toll-like receptor 3 (TLR3) agonists have been extensively used as adjuvants for anticancer vaccines. However, their immunostimulatory effects and precise mechanisms of...
Toll-like receptor 3 (TLR3) agonists have been extensively used as adjuvants for anticancer vaccines. However, their immunostimulatory effects and precise mechanisms of action in the presence of antineoplastic monoclonal antibodies (mAbs) have not yet been evaluated. We investigated the effect of TLR3 agonists on cetuximab-mediated antibody-dependent cellular cytotoxicity (ADCC) against head and neck cancer (HNC) cells, as well as on dendritic cell (DC) maturation and cross-priming of epidermal growth factor receptor (EGFR)-specific CD8 T cells. The cytotoxic activity of peripheral blood mononuclear cells (PBMCs) or isolated natural killer (NK) cells expressing polymorphic variants (at codon 158) of the Fcγ receptor IIIa (FcγIIIa) was determined in Cr release assays upon incubation with the TLR3 agonist poly-ICLC. NK cell stimulation was measured based on activation and degranulation markers, while DC maturation in the presence of poly-ICLC was assessed using flow cytometry. The DC-mediated cross priming of EGFR-specific CD8 T cells was monitored upon in vitro stimulation with tetramer-based flow cytometry. TLR3-stimulated, unfractionated PBMCs from HNC patients mediated robust cetuximab-dependent ADCC, which was abrogated by NK-cell depletion. The cytolytic activity of TLR3-stimulated NK cells differed among cells expressing different polymorphic variants of FcγRIIIa, and NK cells exposed to both poly-ICLC and cetuximab expressed higher levels of CD107a and granzyme B than their counterparts exposed to either stimulus alone. Poly-ICLC plus cetuximab also induced a robust upregulation of CD80, CD83 and CD86 on the surface of DCs, a process that was partially NK-cell dependent. Furthermore, DCs matured in these conditions exhibited improved cross-priming abilities, resulting in higher numbers of EGFR-specific CD8 T cells. These findings suggest that TLR3 agonists may provide a convenient means to improve the efficacy of mAb-based anticancer regimens.
PubMed: 23894722
DOI: 10.4161/onci.24677 -
Frontiers in Immunology 2019Myeloid Derived suppressor cells (MDSCs) play a key role in the progression and recurrence of human malignancies and in restraining the efficacy of adjuvant therapies....
The Reversal of Immune Exclusion Mediated by Tadalafil and an Anti-tumor Vaccine Also Induces PDL1 Upregulation in Recurrent Head and Neck Squamous Cell Carcinoma: Interim Analysis of a Phase I Clinical Trial.
Myeloid Derived suppressor cells (MDSCs) play a key role in the progression and recurrence of human malignancies and in restraining the efficacy of adjuvant therapies. We have previously shown that Tadalafil lowers MDSCs and regulatory T cells (Treg) in the blood and in the tumor, primes a tumor specific immune response, and increases the number of activated intratumoral CD8T cells in patients with primary Head and Neck Squamous Cell Carcinoma (HNSCC). However, despite these important immune modulatory actions, to date no clinically significant effects have been reported following PDE5 inhibition. Here we report for the first time interim results of our ongoing phase I clinical trial (NCT02544880) in patients with recurrent HNSCC to evaluate the safety of and immunological effects of combining Tadalafil with the antitumor vaccine composed of Mucin1 (MUC1) and polyICLC. The combined treatment of Tadalafil and MUC1/polyICLC vaccine was well-tolerated with no serious adverse events or treatment limiting toxicities. Immunologically, this trial also confirms the positive immunomodulation of Tadalafil in patients with recurrent HNSCC and suggests an adjuvant effect of the anti-tumor vaccine MUC1/polyICLC. Additionally, image cytometry analysis of scanned tumors indicates that the PDE5 inhibitor Tadalafil in conjunction with the MUC1/polyICLC vaccine effectively reduces the number of PDL1macrophages present at the tumor edge, and increases the number of activated tumor infiltrating T cells, suggesting reversion of immune exclusion. However, this analysis shows also that CD163 negative cells within the tumor upregulate PDL1 after treatment, suggesting the instauration of additional mechanisms of immune evasion. In summary, our data confirm the safety and immunologic potential of PDE5 inhibition in HNSCC but also point to PDL1 as additional mechanism of tumor evasion. This supports the rationale for combining checkpoint and PDE5 inhibitors for the treatment of human malignancies.
Topics: B7-H1 Antigen; Biomarkers; Cancer Vaccines; Combined Modality Therapy; Gene Expression Regulation, Neoplastic; Humans; Immunohistochemistry; Immunomodulation; Kaplan-Meier Estimate; Myeloid-Derived Suppressor Cells; Neoplasm Staging; Squamous Cell Carcinoma of Head and Neck; Tadalafil; Treatment Outcome
PubMed: 31214178
DOI: 10.3389/fimmu.2019.01206 -
Antiviral Research Mar 2017Hiltonol, (Poly IC:LC), a potent immunomodulator, is a synthetic, double-stranded polyriboinosinic-polyribocytidylic acid (poly IC) stabilized with Poly-L-lysine and...
Hiltonol, (Poly IC:LC), a potent immunomodulator, is a synthetic, double-stranded polyriboinosinic-polyribocytidylic acid (poly IC) stabilized with Poly-L-lysine and carboxymethyl cellulose (LC). Hiltonol was tested for efficacy in a lethal SARS-CoV-infected BALB/c mouse model. Hiltonol at 5, 1, 0.5 or 0.25 mg/kg/day by intranasal (i.n.) route resulted in significant survival benefit when administered at selected times 24 h prior to challenge with a lethal dose of mouse-adapted severe acute respiratory syndrome coronavirus (SARS-CoV). The infected BALB/c mice receiving the Hiltonol treatments were also significantly effective in protecting mice against weight loss due to infection (p < 0.001). Groups of 20 mice were dosed with Hiltonol at 2.5 or 0.75 mg/kg by intranasal instillation 7, 14, and 21 days before virus exposure and a second dose was given 24 h later, prophylactic Hiltonol treatments (2.5 mg/kg/day) were completely protective in preventing death, and in causing significant reduction in lung hemorrhage scores, lung weights and lung virus titers. Hiltonol was also effective as a therapeutic when give up to 8 h post virus exposure; 100% of the-infected mice were protected against death when Hiltonol was administered at 5 mg/kg/day 8 h after infection. Our data suggest that Hiltonol treatment of SARS-CoV infection in mice leads to substantial prophylactic and therapeutic effects and could be used for treatment of other virus disease such as those caused by MERS-CoV a related coronavirus. These properties might be therapeutically advantageous if Hiltonol is considered for possible clinical use.
Topics: Adjuvants, Immunologic; Administration, Intranasal; Animals; Carboxymethylcellulose Sodium; Disease Models, Animal; Immunomodulation; Interferon Inducers; Lung; Mice; Mice, Inbred BALB C; Poly I-C; Polylysine; Severe acute respiratory syndrome-related coronavirus; Severe Acute Respiratory Syndrome; Survival Analysis
PubMed: 27956136
DOI: 10.1016/j.antiviral.2016.12.007 -
Journal of Neuro-oncology Dec 2016Recurrent high-grade gliomas (HGGs) of childhood have an exceedingly poor prognosis with current therapies. Accordingly, new treatment approaches are needed. We...
Antigen-specific immunoreactivity and clinical outcome following vaccination with glioma-associated antigen peptides in children with recurrent high-grade gliomas: results of a pilot study.
Recurrent high-grade gliomas (HGGs) of childhood have an exceedingly poor prognosis with current therapies. Accordingly, new treatment approaches are needed. We initiated a pilot trial of vaccinations with peptide epitopes derived from glioma-associated antigens (GAAs) overexpressed in these tumors in HLA-A2+ children with recurrent HGG that had progressed after prior treatments. Peptide epitopes for three GAAs (EphA2, IL13Rα2, survivin), emulsified in Montanide-ISA-51, were administered subcutaneously adjacent to intramuscular injections of poly-ICLC every 3 weeks for 8 courses, followed by booster vaccines every 6 weeks. Primary endpoints were safety and T-cell responses against the GAA epitopes, assessed by enzyme-linked immunosorbent spot (ELISPOT) analysis. Treatment response was evaluated clinically and by magnetic resonance imaging. Twelve children were enrolled, 6 with glioblastoma, 5 with anaplastic astrocytoma, and one with malignant gliomatosis cerebri. No dose-limiting non-CNS toxicity was encountered. ELISPOT analysis, in ten children, showed GAA responses in 9: to IL13Rα2 in 4, EphA2 in 9, and survivin in 3. One child had presumed symptomatic pseudoprogression, discontinued vaccine therapy, and responded to subsequent treatment. One other child had a partial response that persisted throughout 2 years of vaccine therapy, and continues at >39 months. Median progression-free survival (PFS) from the start of vaccination was 4.1 months and median overall survival (OS) was 12.9 months. 6-month PFS and OS were 33 and 73 %, respectively. GAA peptide vaccination in children with recurrent malignant gliomas is generally well tolerated, and has preliminary evidence of immunological and modest clinical activity.
Topics: Adolescent; Antigens, Neoplasm; Brain Neoplasms; Carboxymethylcellulose Sodium; Child; Child, Preschool; Female; Glioma; Humans; Immunotherapy, Active; Infant; Inhibitor of Apoptosis Proteins; Interleukin-13 Receptor alpha1 Subunit; Male; Peptides; Pilot Projects; Poly I-C; Polylysine; Receptor, EphA2; Receptors, Interleukin-13; Survivin; Treatment Outcome; Young Adult
PubMed: 27624914
DOI: 10.1007/s11060-016-2245-3 -
Veterinary Immunology and... Mar 1988Natural killer (NK) cell activity in the peripheral blood lymphocytes (PBL) of newborn piglets, normally negligible, was stimulated by in vitro treatment with porcine...
Natural killer (NK) cell activity in the peripheral blood lymphocytes (PBL) of newborn piglets, normally negligible, was stimulated by in vitro treatment with porcine type I interferon (IFN), and the NK activity of PBL from weaned piglets was augmented by the same treatment. Binding of the PBL to the PK-15 targets used in the single cell cytotoxicity assay for NK activity was not affected by age or by IFN treatment. When newborn piglets were treated with a single intravenous dose at 2 days of age of 0.5 mg/kg of polyinosinic:polycytidylic acid complexed with poly-L-lysine and carboxymethylcellulose (poly ICLC), a synthetic IFN inducer, their IFN levels peaked at 6 h post-induction, and NK activity in their PBL peaked at 24 h post-induction at the level normally found in weaned piglets. The NK activity then declined until 7 days post-induction, when it increased again in a similar manner to that in untreated control piglets. Target-binding of the PBL was not affected by poly ICLC treatment of the piglets. Newborn piglets treated with poly ICLC and subsequently exposed to infection with transmissible gastroenteritis (TGE) virus showed a delay in onset of clinical signs of TGE compared with untreated control piglets. It was concluded that NK cells in newborn piglets can be activated by treatment of the piglets with poly ICLC, and that the presence of active NK cells is associated with some increase in resistance to challenge with TGE virus.
Topics: Animals; Animals, Newborn; Carboxymethylcellulose Sodium; Cytotoxicity, Immunologic; Gastroenteritis, Transmissible, of Swine; Interferon Inducers; Killer Cells, Natural; Lymphocyte Activation; Methylcellulose; Poly I-C; Polylysine; Swine; Transmissible gastroenteritis virus
PubMed: 2838948
DOI: 10.1016/0165-2427(88)90053-0 -
Journal of Immunology (Baltimore, Md. :... Aug 2015Nonlive vaccine platforms that induce potent cellular immune responses in mucosal tissue would have broad application for vaccines against infectious diseases and...
Nonlive vaccine platforms that induce potent cellular immune responses in mucosal tissue would have broad application for vaccines against infectious diseases and tumors. Induction of cellular immunity could be optimized by targeted activation of multiple innate and costimulatory signaling pathways, such as CD40 or TLRs. In this study, we evaluated immune activation and elicitation of T cell responses in nonhuman primates after immunization with peptide Ags adjuvanted with an agonistic anti-CD40Ab, with or without the TLR3 ligand poly IC:LC. We found that i.v. administration of the anti-CD40Ab induced rapid and transient innate activation characterized by IL-12 production and upregulated costimulatory and lymph node homing molecules on dendritic cells. Using fluorescently labeled Abs for in vivo tracking, we found that the anti-CD40Ab bound to all leukocytes, except T cells, and disseminated to multiple organs. CD4(+) and CD8(+) T cell responses were significantly enhanced when the anti-CD40Ab was coadministered with poly IC:LC compared with either adjuvant given alone and were almost exclusively compartmentalized to the lung. Notably, Ag-specific T cells in the bronchoalveolar lavage were sustained at ∼5-10%. These data indicate that systemic administration of anti-CD40Ab may be particularly advantageous for vaccines and/or therapies that require T cell immunity in the lung.
Topics: Adjuvants, Immunologic; Animals; Antibodies; Bronchoalveolar Lavage Fluid; CD4-Positive T-Lymphocytes; CD40 Antigens; CD8-Positive T-Lymphocytes; Carboxymethylcellulose Sodium; Cell Differentiation; Dendritic Cells; Humans; Immunity, Cellular; Interleukin-12; Lung; Lymphocyte Activation; Macaca mulatta; Poly I-C; Polylysine; Respiratory Mucosa; Vaccination; Vaccines
PubMed: 26123354
DOI: 10.4049/jimmunol.1500078