Engineering New Approaches to Cancer Vaccines

available in PMC 2016 August 01Recently, a number of promising approaches have been developed using synthetic chemistry, materials science, and bioengineering-based strategies to address challenges in the design of more effective cancer vaccines. At the stage of initial priming, potency can be improved by maximizing vaccine delivery to lymph nodes. Because lymphatic uptake from peripheral tissues is strongly size dependent, antigens and adjuvants packaged into optimally sized nanoparticles access the lymph node with much greater efficiency than unformulated vaccines. Once primed, T cells must home to the tumor site. Because T cells acquire the necessary surface receptors in the local lymph node draining the tissue of interest, vaccines must be engineered that reach organs, such as the lung and gut, which are common sites of tumor lesions but inaccessible by traditional vaccination routes. Particulate vaccine carriers can improve antigen exposure in these organs, resulting in greater lymphocyte priming. Immunomodulatory agents can also be injected directly into the tumor site to stimulate a systemic response capable of clearing even distal lesions; materials have been designed that entrap or slowly release immunomodulators at the tumor site, reducing systemic exposure and improving therapeutic efficacy. Finally, lessons learned from the design of biomaterial-based scaffolds in regenerative medicine have led to the development of implantable vaccines that recruit and activate antigen-presenting cells to drive antitumor immunity. Overall, these engineering strategies represent an expanding toolkit to create safe and effective cancer vaccines.United States. National Institutes of Health (CA174795)United States. National Institutes of Health (CA172164

Nanoparticulate STING agonists are potent lymph node–targeted vaccine adjuvants

Cyclic dinucleotides (CDNs) are agonists of stimulator of IFN genes (STING) and have potential as vaccine adjuvants. However, cyclic di-GMP (cdGMP) injected s.c. shows minimal uptake into lymphatics/draining lymph nodes (dLNs) and instead is rapidly distributed to the bloodstream, leading to systemic inflammation. Here, we encapsulated cdGMP within PEGylated lipid nanoparticles (NP-cdGMP) to redirect this adjuvant to dLNs. Compared with unformulated CDNs, encapsulation blocked systemic dissemination and markedly enhanced dLN accumulation in murine models. Delivery of NP-cdGMP increased CD8[superscript +] T cell responses primed by peptide vaccines and enhanced therapeutic antitumor immunity. A combination of a poorly immunogenic liposomal HIV gp41 peptide antigen and NP-cdGMP robustly induced type I IFN in dLNs, induced a greater expansion of vaccine-specific CD4[superscript +] T cells, and greatly increased germinal center B cell differentiation in dLNs compared with a combination of liposomal HIV gp41 and soluble CDN. Further, NP-cdGMP promoted durable antibody titers that were substantially higher than those promoted by the well-studied TLR agonist monophosphoryl lipid A and comparable to a much larger dose of unformulated cdGMP, without the systemic toxicity of the latter. These results demonstrate that nanoparticulate delivery safely targets CDNs to the dLNs and enhances the efficacy of this adjuvant. Moreover, this approach can be broadly applied to other small-molecule immunomodulators of interest for vaccines and immunotherapy.Bill & Melinda Gates FoundationRagon Institute of MGH, MIT and HarvardNational Institutes of Health (U.S.) (AI091693)National Institutes of Health (U.S.) (AI095109)National Cancer Institute (U.S.) (Koch Institute Support (Core) Grant P30-CA14051)National Institutes of Health (U.S.) (Ruth L. Kirschstein National Research Service Award 1F32CA180586)Hertz Foundation (Graduate Fellowship)National Science Foundation (U.S.). Graduate Research Fellowshi

Targeting small molecule drugs to T cells with antibody-directed cell-penetrating gold nanoparticles

We sought to develop a nanoparticle vehicle that could efficiently deliver small molecule drugs to target lymphocyte populations. The synthesized amphiphilic organic ligand-protected gold nanoparticles (amph-NPs) were capable of sequestering large payloads of small molecule drugs within hydrophobic pockets of their ligand shells. These particles exhibit membrane-penetrating activity in mammalian cells, and thus enhanced uptake of a small molecule TGF-β inhibitor in T cells in cell culture. By conjugating amph-NPs with targeting antibodies or camelid-derived nanobodies, the particles' cell-penetrating properties could be temporarily suppressed, allowing targeted uptake in specific lymphocyte subpopulations. Degradation of the protein targeting moieties following particle endocytosis allowed the NPs to recover their cell-penetrating activity in situ to enter the cytoplasm of T cells. In vivo, targeted amph-NPs showed 40-fold enhanced uptake in CD8+ T cells relative to untargeted particles, and delivery of TGF-β inhibitor-loaded particles to T cells enhanced their cytokine polyfunctionality in a cancer vaccine model. Thus, this system provides a facile approach to concentrate small molecule compounds in target lymphocyte populations of interest for immunotherapy in cancer and other diseases.Massachusetts Institute of Technology. Institute for Soldier Nanotechnologies (Contract W911NF-13-D-0001)Melanoma Research AllianceNational Cancer Institute (U.S.) (David H. Koch Institute for Integrative Cancer Research at MIT. (Support (Core) Grant P30-CA14051)National Institutes of Health (U.S.) (Grant CA174795)National Institutes of Health (U.S.) (Grant CA172164)Horizon 2020 Framework Programme (European Commission). FutureNanoNeeds Projec

Targeting dendritic cells to accelerate T-cell activation overcomes a bottleneck in tuberculosis vaccine efficacy

The development of a tuberculosis (TB) vaccine that induces sterilizing immunity to Mycobacterium tuberculosis infection has been elusive. Absence of sterilizing immunity induced by TB vaccines may be due to delayed activation of mucosal dendritic cells (DCs), and subsequent delay in antigen presentation and activation of vaccine-induced CD4[superscript +] T-cell responses. Here we show that pulmonary delivery of activated M. tuberculosis antigen-primed DCs into vaccinated mice, at the time of M. tuberculosis exposure, can overcome the delay in accumulation of vaccine-induced CD4[superscript +] T-cell responses. In addition, activating endogenous host CD103[superscript +] DCs and the CD40–CD40L pathway can similarly induce rapid accumulation of vaccine-induced lung CD4[superscript +] T-cell responses and limit early M. tuberculosis growth. Thus, our study provides proof of concept that targeting mucosal DCs can accelerate vaccine-induced T-cell responses on M. tuberculosis infection, and provide insights to overcome bottlenecks in TB vaccine efficacy.National Institutes of Health (U.S.) (grant HL105427)National Institutes of Health (U.S.) (grant AI127172)United States. Army Research Office. Institute for Soldier Nanotechnologies (contract W911NF-13-D-0001)Howard Hughes Medical Institute (Investigator

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Engineering immunity : enhancing T Cell vaccines and combination immunotherapies for the treatment of cancer

Thesis: Ph. D., Massachusetts Institute of Technology, Department of Biological Engineering, 2017.Cataloged from PDF version of thesis.Includes bibliographical references (pages 127-140).Checkpoint blockade with antibodies against CTLA-4 or PD-1 has demonstrated that an endogenous adaptive immune response can be stimulated to elicit durable tumor regressions in metastatic cancer, but these dramatic responses are confined to a minority of patients¹-³. This outcome is likely due in part to the complex network of immunosuppressive pathways present in advanced tumors, which necessitates the development of novel therapeutics and combination immunotherapies to generate a counter-directed network of pro-immunity signals⁴-⁸. In Chapters 2 and 3 of this thesis, we describe methods for enhancing T cell priming against tumor antigens via covalent modification of molecular vaccines to enhance lymphatic drainage, serum stability, or cytosolic access to improve presentation on MHC class I. In Chapter 4, we demonstrate a combination immunotherapy that recruits a diverse set of innate and adaptive effector cells, enabling robust elimination of large tumor burdens that to my knowledge have not previously been curable by treatments relying on endogenous immunity. Maximal anti-tumor efficacy required four components: a tumor antigen targeting antibody, an extended half-life IL-2⁹, anti-ƯPD-1, and a powerful T-cell vaccine¹⁰. This combination elicited durable cures in a majority of animals, formed immunological memory in multiple transplanted tumor models, and induced sustained tumor regression in an autochthonous BRraf[superscript V600E]/Pten[superscript -/-] melanoma model. Finally, in Chapter 5, we show preliminary data on combination immunotherapies used to treat antigenically heterogeneous tumors. Taken together, these data define design criteria for enhancing the immunogenicity of molecular vaccines and elucidate essential characteristics of combination immunotherapies capable of curing a majority of tumors in experimental settings typically viewed as intractable."During my doctorate by the John and Fanny Hertz Foundation Fellowship (specifically the Wilson Talley Hertz Fellowship), the NSF Graduate Research Fellowship Program, and the Siebel Scholarship"--Page 141. "This thesis work was supported in part by the Koch Institute Support (core) grant P30-CA14051 from the National Cancer Institute, the US National Institutes of Health (NIH) grant CA174795, the Bridge Project partnership between the Koch Institute for Integrative Cancer Research and the Dana Farber-Harvard Cancer Center (DF-HCC), the V Foundation, the Ragon Institute, and the Howard Hughes Medical Institute"--Page 141.by Kelly D. Moynihan.Ph. D

Roles for Innate Immunity in Combination Immunotherapies

Immunity to infectious agents involves a coordinated response of innate and adaptive immune cells working in concert, with many feed-forward and regulatory interactions between both arms of the immune system. In contrast, many therapeutic strategies to augment immunity against tumors have focused predominantly on stimulation of adaptive immunity. However, a growing appreciation of the potential contributions of innate immune effectors to antitumor immunity, especially in the context of combination immunotherapy, is leading to novel strategies to elicit a more integrated immune response against cancer. Here we review antitumor activities of innate immune cells, mechanisms of their synergy with adaptive immune responses against tumors, and discuss recent studies highlighting the potential of combination therapies recruiting both innate and adaptive immune effectors to eradicate established tumors.National Institutes of Health (U.S.) (CA174795)National Cancer Institute (U.S.) (David H. Koch Institute for Integrative Cancer Research at MIT. Grant P30-CA14051)Bridge ProjectV Foundation for Cancer ResearchRagon Institute of MGH, MIT and HarvardHertz FoundationNational Science Foundation (U.S.) (Graduate Research Fellowship)Thomas and Stacey Siebel Foundation (Scholarship

Radiation-enhanced delivery of systemically administered amphiphilic-CpG oligodeoxynucleotide

Along with vaccines and checkpoint blockade, immune adjuvants may have an important role in tumor immunotherapy. Oligodeoxynucleotides containing unmethylated cytidyl guanosyl dinucleotide motifs (CpG ODN) are TLR9 ligands with attractive immunostimulatory properties, but intratumoral administration has been required to induce an effective anti-tumor immune response. Following on recent studies with radiation-targeted delivery of nanoparticles, we examined enhanced tumor-specific delivery of amphiphile-CpG, an albumin-binding analog of CpG ODN, following systemic administration 3 days after tumor irradiation. The combination of radiation and CpG displayed superior tumor control over either treatment alone. Intravital imaging of fluorescently labeled amphiphilic-CpG revealed increased accumulation in irradiated tumors along with decreased off-target accumulation in visceral organs. Within 48 h after amphiphile-CpG administration, immune activation could be detected by increased Granzyme B and Interferon gamma activity in the tumor as well as in circulating monocytes and activated CD8+T cells. Using radiotherapy to enhance the targeting of CpG to tumors may help advance this once promising therapy to clinical relevance. Keywords: CpG oligodeoxynucleotides; Ionizing radiation; Immune adjuvant; Enhanced permeability and retention; Cancer therapeutic efficac

High-throughput quantitation of inorganic nanoparticle biodistribution at the single-cell level using mass cytometry

Inorganic nanoparticles (NPs) are studied as drug carriers, radiosensitizers and imaging agents, and characterizing nanoparticle biodistribution is essential for evaluating their efficacy and safety. Tracking NPs at the single-cell level with current technologies is complicated by the lack of reliable methods to stably label particles over extended durations in vivo. Here we demonstrate that mass cytometry by time-of-flight provides a label-free approach for inorganic nanoparticle quantitation in cells. Furthermore, mass cytometry can enumerate AuNPs with a lower detection limit of ∼10 AuNPs (3 nm core size) in a single cell with tandem multiparameter cellular phenotyping. Using the cellular distribution insights, we selected an amphiphilic surface ligand-coated AuNP that targeted myeloid dendritic cells in lymph nodes as a peptide antigen carrier, substantially increasing the efficacy of a model vaccine in a B16-OVA melanoma mouse model. This technology provides a powerful new level of insight into nanoparticle fate in vivo.United States. Army Research Office. Institute for Soldier Nanotechnologies (contract number W911NF-13-D-0001)National Institutes of Health (U.S.) (award CA174795)National Institutes of Health (U.S.) (award CA172164)Horizon 2020 FutureNanoNeeds Project (European Commission