-
NPJ Vaccines May 2021Natural and vaccine-induced SARS-CoV-2 immunity in humans has been described but correlates of protection are not yet defined. T cells support the SARS-CoV-2 antibody...
Natural and vaccine-induced SARS-CoV-2 immunity in humans has been described but correlates of protection are not yet defined. T cells support the SARS-CoV-2 antibody response, clear virus-infected cells, and may be required to block transmission. In this study, we identified peptide epitopes associated with SARS-CoV-2 T-cell immunity. Using immunoinformatic methods, T-cell epitopes from spike, membrane, and envelope were selected for maximal HLA-binding potential, coverage of HLA diversity, coverage of circulating virus, and minimal potential cross-reactivity with self. Direct restimulation of PBMCs collected from SARS-CoV-2 convalescents confirmed 66% of predicted epitopes, whereas only 9% were confirmed in naive individuals. However, following a brief period of epitope-specific T-cell expansion, both cohorts demonstrated robust T-cell responses to 97% of epitopes. HLA-DR3 transgenic mouse immunization with peptides co-formulated with poly-ICLC generated a potent Th1-skewed, epitope-specific memory response, alleviating safety concerns of enhanced respiratory disease associated with Th2 induction. Taken together, these epitopes may be used to improve our understanding of natural and vaccine-induced immunity, and to facilitate the development of T-cell-targeted vaccines that harness pre-existing SARS-CoV-2 immunity.
PubMed: 33986292
DOI: 10.1038/s41541-021-00331-6 -
Cancer Discovery Mar 2021Neoantigens are critical targets of antitumor T-cell responses. The ATLAS bioassay was developed to identify neoantigens empirically by expressing each unique...
Neoantigens are critical targets of antitumor T-cell responses. The ATLAS bioassay was developed to identify neoantigens empirically by expressing each unique patient-specific tumor mutation individually in , pulsing autologous dendritic cells in an ordered array, and testing the patient's T cells for recognition in an overnight assay. Profiling of T cells from patients with lung cancer revealed both stimulatory and inhibitory responses to individual neoantigens. In the murine B16F10 melanoma model, therapeutic immunization with ATLAS-identified stimulatory neoantigens protected animals, whereas immunization with peptides associated with inhibitory ATLAS responses resulted in accelerated tumor growth and abolished efficacy of an otherwise protective vaccine. A planned interim analysis of a clinical study testing a poly-ICLC adjuvanted personalized vaccine containing ATLAS-identified stimulatory neoantigens showed that it is well tolerated. In an adjuvant setting, immunized patients generated both CD4 and CD8 T-cell responses, with immune responses to 99% of the vaccinated peptide antigens. SIGNIFICANCE: Predicting neoantigens has progressed, but empirical testing shows that T-cell responses are more nuanced than straightforward MHC antigen recognition. The ATLAS bioassay screens tumor mutations to uncover preexisting, patient-relevant neoantigen T-cell responses and reveals a new class of putatively deleterious responses that could affect cancer immunotherapy design..
Topics: Animals; Antigens, Neoplasm; Biomarkers, Tumor; Cancer Vaccines; Cell Line, Tumor; Clinical Trials as Topic; DNA Mutational Analysis; Disease Models, Animal; Disease Progression; Genomics; Humans; Immunity, Cellular; Immunogenicity, Vaccine; Melanoma, Experimental; Mice; Mutation; Neoplasms; T-Lymphocytes; Treatment Outcome; Vaccination
PubMed: 33504579
DOI: 10.1158/2159-8290.CD-20-0377 -
Journal For Immunotherapy of Cancer Jan 2021Peptide vaccines designed to stimulate melanoma-reactive CD4 T cells can induce T cell and antibody (Ab) responses, associated with enhanced overall survival. We... (Clinical Trial)
Clinical Trial
BACKGROUND
Peptide vaccines designed to stimulate melanoma-reactive CD4 T cells can induce T cell and antibody (Ab) responses, associated with enhanced overall survival. We hypothesized that adding toll-like receptor 3 agonist polyICLC to an incomplete Freund's adjuvant (IFA) would be safe and would support strong, durable CD4 T cell and Ab responses. We also hypothesized that oral low-dose metronomic cyclophosphamide (mCy) would be safe, would reduce circulating regulatory T cells (T-regs) and would further enhance immunogenicity.
PARTICIPANTS AND METHODS
An adaptive design based on toxicity and durable CD4+ T cell immune response (dRsp) was used to assign participants with resected stage IIA-IV melanoma to one of four study regimens. The regimens included a vaccine comprising six melanoma peptides restricted by Class II MHC (6MHP) in an emulsion with IFA alone (Arm A), with IFA plus systemic mCy (Arm B), with IFA+ local polyICLC (Arm C), or with IFA+ polyICLC+ mCy (Arm D). Toxicities were recorded (CTCAE V.4.03). T cell responses were measured by interferon γ ELIspot assay ex vivo. Serum Ab responses to 6MHP were measured by ELISA. Circulating T-regs were assessed by flow cytometry.
RESULTS
Forty-eight eligible participants were enrolled and treated. Early data on safety and dRsp favored enrollment on arm D. Total enrollment on Arms A-D were 3, 7, 6, and 32, respectively. Treatment-related dose-limiting toxicities (DLTs) were observed in 1/7 (14%) participants on arm B and 2/32 (6%) on arm D. None exceeded the 25% DLT threshold for early closure to enrollment for any arm. Strong durable T cell responses to 6MHP were detected ex vivo in 0%, 29%, 67%, and 47% of participants on arms A-D, respectively. IgG Ab responses were greatest for arms C and D. Circulating T-regs frequencies were not altered by mCy.
CONCLUSIONS
6MHP vaccines administered with IFA, polyICLC, and mCy were well tolerated. The dRsp rate for arm D of 47% (90% CI 32 to 63) exceeded the 18% (90% CI 11 to 26) rate previously observed with 6MHP in IFA alone. Vaccination with IFA+ polyICLC (arm C) also showed promise for enhancing T cell and Ab responses.
Topics: Administration, Metronomic; Administration, Oral; Antibodies; CD4-Positive T-Lymphocytes; Cancer Vaccines; Carboxymethylcellulose Sodium; Combined Modality Therapy; Cyclophosphamide; Female; Freund's Adjuvant; Humans; Lipids; Male; Melanoma; Neoplasm Staging; Poly I-C; Polylysine; T-Lymphocytes, Regulatory; Treatment Outcome; Vaccines, Subunit
PubMed: 33479025
DOI: 10.1136/jitc-2020-000934 -
Cancer Reports (Hoboken, N.J.) Mar 2022Active surveillance (AS) is the reference standard treatment for the management of low risk prostate cancer (PCa). Accurate assessment of tumor aggressiveness guides...
Unified model involving genomics, magnetic resonance imaging and prostate-specific antigen density outperforms individual co-variables at predicting biopsy upgrading in patients on active surveillance for low risk prostate cancer.
BACKGROUND
Active surveillance (AS) is the reference standard treatment for the management of low risk prostate cancer (PCa). Accurate assessment of tumor aggressiveness guides recruitment to AS programs to avoid conservative treatment of intermediate and higher risk patients. Nevertheless, underestimating the disease risk may occur in some patients recruited, with biopsy upgrading and the concomitant potential for delayed treatment.
AIM
To evaluate the accuracy of mpMRI and GPS for the prediction of biopsy upgrading during active surveillance (AS) management of prostate cancer (PCa).
METHOD
A retrospective analysis was performed on 144 patients recruited to AS from October 2013 to December 2020. Median follow was 4.8 (IQR 3.6, 6.3) years. Upgrading was defined as upgrading to biopsy grade group ≥2 on follow up biopsies. Cox proportional hazard regression was used to investigate the effect of PSA density (PSAD), baseline Prostate Imaging-Reporting and Data System (PI-RADS) v2.1 score and GPS on upgrading. Time-to-event outcome, defined as upgrading, was estimated using the Kaplan-Meier method with log-rank test.
RESULTS
Overall rate of upgrading was 31.9% (n = 46). PSAD was higher in the patients who were upgraded (0.12 vs. 0.08 ng/ml , p = .005), while no significant difference was present for median GPS in the overall cohort (overall median GPS 21; 22 upgrading vs. 20 no upgrading, p = .2044). On univariable cox proportional hazard regression analysis, the factors associated with increased risk of biopsy upgrading were PSA (HR = 1.30, CI 1.16-1.47, p = <.0001), PSAD (HR = 1.08, CI 1.05-1.12, p = <.0001) and higher PI-RADS score (HR = 3.51, CI 1.56-7.91, p = .0024). On multivariable cox proportional hazard regression analysis, only PSAD (HR = 1.10, CI 1.06-1.14, p = <.001) and high PI-RADS score (HR = 4.11, CI 1.79-9.44, p = .0009) were associated with upgrading. A cox regression model combining these three clinical features (PSAD ≥0.15 ng/ml at baseline, PI-RADS Score and GPS) yielded a concordance index of 0.71 for the prediction of upgrading.
CONCLUSION
In this study PSAD has higher accuracy over baseline PI-RADS score and GPS score for the prediction of PCa upgrading during AS. However, combined use of PSAD, GPS and PI-RADS Score yielded the highest predictive ability with a concordance index of 0.71.
Topics: Genomics; Humans; Image-Guided Biopsy; Magnetic Resonance Imaging; Male; Prostate-Specific Antigen; Prostatic Neoplasms; Retrospective Studies; Watchful Waiting
PubMed: 34931468
DOI: 10.1002/cnr2.1492 -
Vaccine Jan 2015Therapeutic interventions for HIV-1 that successfully augment adaptive immunity to promote killing of infected cells may be a requisite component of strategies to reduce...
Autologous aldrithiol-2-inactivated HIV-1 combined with polyinosinic-polycytidylic acid-poly-L-lysine carboxymethylcellulose as a vaccine platform for therapeutic dendritic cell immunotherapy.
Therapeutic interventions for HIV-1 that successfully augment adaptive immunity to promote killing of infected cells may be a requisite component of strategies to reduce latent cellular reservoirs. Adoptive immunotherapies utilizing autologous monocyte-derived dendritic cells (DCs) that have been activated and antigen loaded ex vivo may serve to circumvent defects in DC function that are present during HIV infection in order to enhance adaptive immune responses. Here we detail the clinical preparation of DCs loaded with autologous aldrithiol-2 (AT-2)-inactivated HIV that have been potently activated with the viral mimic, Polyinosinic-polycytidylic acid-poly-l-lysine carboxymethylcellulose (Poly-ICLC). HIV is first propagated from CD4+ T cells from HIV-infected donors and then rendered non-replicative by chemical inactivation with aldrithiol-2 (AT-2), purified, and quantified. Viral inactivation is confirmed through measurement of Tat-regulated β-galactosidase reporter gene expression following infection of TZM-bl cells. In-process testing for sterility, mycoplasma, LPS, adventitious agents, and removal of AT-2 is performed on viral preparations. Autologous DCs are generated and pulsed with autologous AT-2-inactivated virus and simultaneously stimulated with Poly-ICLC to constitute the final DC vaccine product. Phenotypic identity, maturation, and induction of HIV-specific adaptive immune responses are confirmed via flow cytometric analysis of DCs and cocultured autologous CD4+ and CD8+ T cells. Lot release criteria for the DC vaccine have been defined in accordance with Good Manufacturing Practice (GMP) guidelines. The demonstrated feasibility of this approach has resulted in approval by the FDA for investigational use in antiretroviral (ART) suppressed individuals. We discuss how this optimized DC formulation may enhance the quality of anti-HIV adaptive responses beyond what has been previously observed during DC immunotherapy trials for HIV infection.
Topics: 2,2'-Dipyridyl; AIDS Vaccines; Adaptive Immunity; CD4-Positive T-Lymphocytes; CD8-Positive T-Lymphocytes; Carboxymethylcellulose Sodium; Cell Line; Dendritic Cells; Disulfides; HIV Infections; HIV-1; Humans; Immunotherapy, Adoptive; Poly I-C; Polylysine; Virus Inactivation; beta-Galactosidase
PubMed: 25444812
DOI: 10.1016/j.vaccine.2014.10.054 -
International Journal of Molecular... Feb 2021NSCLC (non-small cell lung cancer) is a leading cause of cancer-related deaths worldwide. Clinical trials showed that Hiltonol, a stable dsRNA representing an advanced...
NSCLC (non-small cell lung cancer) is a leading cause of cancer-related deaths worldwide. Clinical trials showed that Hiltonol, a stable dsRNA representing an advanced form of polyI:C (polyinosinic-polycytidilic acid), is an adjuvant cancer-immunomodulator. However, its mechanisms of action and effect on lung cancer have not been explored pre-clinically. Here, we examined, for the first time, how a novel Hiltonol cocktail kills NSCLC cells. By retrospective analysis of NSCLC patient tissues obtained from the tumor biobank; pre-clinical studies with Hiltonol alone or Hiltonol cocktail [Hiltonol+anti-IL6+AG490 (JAK2 inhibitor)+Stattic (STAT3 inhibitor)]; cytokine analysis; gene knockdown and gain/loss-of-function studies, we uncovered the mechanisms of action of Hiltonol. We demonstrated that Hiltonol kills the cancer cells and suppresses the metastatic potential of NSCLC through: (i) upregulation of pro-apoptotic Caspase-9 and Caspase-3, (ii) induction of cytosolic cytochrome , (iii) modulation of pro-inflammatory cytokines (GRO, MCP-1, IL-8, and IL-6) and anticancer IL-24 in NSCLC subtypes, and (iv) upregulation of tumor suppressors, PKR (protein kinase R) and OAS (2'5' oligoadenylate synthetase). In silico analysis showed that Lys296 of PKR and Lys66 of OAS interact with Hiltonol. These Lys residues are purportedly involved in the catalytic/signaling activity of the tumor suppressors. Furthermore, knockdown of PKR/OAS abrogated the anticancer action of Hiltonol, provoking survival of cancer cells. Ex vivo analysis of NSCLC patient tissues corroborated that loss of PKR and OAS is associated with cancer advancement. Altogether, our findings unraveled the significance of studying tumor biobank tissues, which suggests PKR and OAS as precision oncological suppressor candidates to be targeted by this novel Hiltonol cocktail which represents a prospective drug for development into a potent and tailored therapy for NSCLC subtypes.
Topics: 2',5'-Oligoadenylate Synthetase; A549 Cells; Antineoplastic Agents, Immunological; Antineoplastic Combined Chemotherapy Protocols; Binding Sites; Carboxymethylcellulose Sodium; Carcinoma, Non-Small-Cell Lung; Cell Line, Tumor; Cell Movement; Cell Proliferation; Cell Survival; Cyclic S-Oxides; Gene Expression Regulation, Neoplastic; Humans; Interleukin-6; Lung Neoplasms; Models, Molecular; Poly I-C; Polylysine; Tumor Microenvironment; Tyrphostins; eIF-2 Kinase
PubMed: 33562773
DOI: 10.3390/ijms22041626 -
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