Catalogue Search | MBRL
Search Results Heading
Explore the vast range of titles available.
MBRLSearchResults
-
LanguageLanguage
-
SubjectSubject
-
Item TypeItem Type
-
DisciplineDiscipline
-
YearFrom:-To:
-
More FiltersMore FiltersIs Peer Reviewed
Done
Filters
Reset
29
result(s) for
"Smothers, James"
Sort by:
Tumor-immune profiling of murine syngeneic tumor models as a framework to guide mechanistic studies and predict therapy response in distinct tumor microenvironments
by
Brett, Sara
,
Bhattacharya, Sabyasachi
,
Smothers, James F.
in
Animal models
,
Anticancer properties
,
Antigen presentation
2018
Mouse syngeneic tumor models are widely used tools to demonstrate activity of novel anti-cancer immunotherapies. Despite their widespread use, a comprehensive view of their tumor-immune compositions and their relevance to human tumors has only begun to emerge. We propose each model possesses a unique tumor-immune infiltrate profile that can be probed with immunotherapies to inform on anti-tumor mechanisms and treatment strategies in human tumors with similar profiles. In support of this endeavor, we characterized the tumor microenvironment of four commonly used models and demonstrate they encompass a range of immunogenicities, from highly immune infiltrated RENCA tumors to poorly infiltrated B16F10 tumors. Tumor cell lines for each model exhibit different intrinsic factors in vitro that likely influence immune infiltration upon subcutaneous implantation. Similarly, solid tumors in vivo for each model are unique, each enriched in distinct features ranging from pathogen response elements to antigen presentation machinery. As RENCA tumors progress in size, all major T cell populations diminish while myeloid-derived suppressor cells become more enriched, possibly driving immune suppression and tumor progression. In CT26 tumors, CD8 T cells paradoxically increase in density yet are restrained as tumor volume increases. Finally, immunotherapy treatment across these different tumor-immune landscapes segregate into responders and non-responders based on features partially dependent on pre-existing immune infiltrates. Overall, these studies provide an important resource to enhance our translation of syngeneic models to human tumors. Future mechanistic studies paired with this resource will help identify responsive patient populations and improve strategies where immunotherapies are predicted to be ineffective.
Journal Article
Emergence of the CD226 Axis in Cancer Immunotherapy
2022
In recent years, a set of immune receptors that interact with members of the nectin/nectin-like (necl) family has garnered significant attention as possible points of manipulation in cancer. Central to this axis, CD226, TIGIT, and CD96 represent ligand (CD155)-competitive co-stimulatory/inhibitory receptors, analogous to the CTLA-4/B7/CD28 tripartite. The identification of PVRIG (CD112R) and CD112 has introduced complexity and enabled additional nodes of therapeutic intervention. By virtue of the clinical progression of TIGIT antagonists and emergence of novel CD96- and PVRIG-based approaches, our overall understanding of the ‘CD226 axis’ in cancer immunotherapy is starting to take shape. However, several questions remain regarding the unique characteristics of, and mechanistic interplay between, each receptor-ligand pair. This review provides an overview of the CD226 axis in the context of cancer, with a focus on the status of immunotherapeutic strategies (TIGIT, CD96, and PVRIG) and their underlying biology (i.e., cis / trans interactions). We also integrate our emerging knowledge of the immune populations involved, key considerations for Fc gamma (γ) receptor biology in therapeutic activity, and a snapshot of the rapidly evolving clinical landscape.
Journal Article
Impact of isotype on the mechanism of action of agonist anti-OX40 antibodies in cancer: implications for therapeutic combinations
by
Shepherd, Andrew J
,
Bhattacharya, Sabyasachi
,
Bover, Laura
in
Agonists
,
Animals
,
Antibodies, Monoclonal - pharmacology
2024
BackgroundOX40 has been widely studied as a target for immunotherapy with agonist antibodies taken forward into clinical trials for cancer where they are yet to show substantial efficacy. Here, we investigated potential mechanisms of action of anti-mouse (m) OX40 and anti-human (h) OX40 antibodies, including a clinically relevant monoclonal antibody (mAb) (GSK3174998) and evaluated how isotype can alter those mechanisms with the aim to develop improved antibodies for use in rational combination treatments for cancer.MethodsAnti-mOX40 and anti-hOX40 mAbs were evaluated in a number of in vivo models, including an OT-I adoptive transfer immunization model in hOX40 knock-in (KI) mice and syngeneic tumor models. The impact of FcγR engagement was evaluated in hOX40 KI mice deficient for Fc gamma receptors (FcγR). Additionally, combination studies using anti-mouse programmed cell death protein-1 (mPD-1) were assessed. In vitro experiments using peripheral blood mononuclear cells (PBMCs) examining possible anti-hOX40 mAb mechanisms of action were also performed.ResultsIsotype variants of the clinically relevant mAb GSK3174998 showed immunomodulatory effects that differed in mechanism; mIgG1 mediated direct T-cell agonism while mIgG2a acted indirectly, likely through depletion of regulatory T cells (Tregs) via activating FcγRs. In both the OT-I and EG.7-OVA models, hIgG1 was the most effective human isotype, capable of acting both directly and through Treg depletion. The anti-hOX40 hIgG1 synergized with anti-mPD-1 to improve therapeutic outcomes in the EG.7-OVA model. Finally, in vitro assays with human peripheral blood mononuclear cells (hPBMCs), anti-hOX40 hIgG1 also showed the potential for T-cell stimulation and Treg depletion.ConclusionsThese findings underline the importance of understanding the role of isotype in the mechanism of action of therapeutic mAbs. As an hIgG1, the anti-hOX40 mAb can elicit multiple mechanisms of action that could aid or hinder therapeutic outcomes, dependent on the microenvironment. This should be considered when designing potential combinatorial partners and their FcγR requirements to achieve maximal benefit and improvement of patient outcomes.
Journal Article
662 Dissecting the CD226 immune axis in the tumor microenvironment using CyTOF-based high-dimensional immunophenotyping
by
Bojczuk, Paul
,
Vowell, Katie
,
Smothers, James
in
Immunotherapy
,
Regular and Young Investigator Award Abstracts
,
Tumors
2021
BackgroundIn recent years, a regulatory network involving nectin/nectin-like immune receptors has emerged as a potential point of manipulation for cancer immunotherapy. Central to this axis, CD226 (DNAM-1) is a T and NK cell co-stimulatory receptor that competes for ligand (CD155 and CD112) binding with multiple inhibitory receptors (TIGIT, CD96, and PVRIG [CD112R]). Despite a large body of literature for TIGIT, detailed cellular characterization of the entire axis is still lacking. Therefore, we used mass cytometry (CyTOF) to systematically evaluate expression of the CD226 axis in tumors from a range of indications.MethodsTo thoroughly characterize the CD226 axis in the tumor microenvironment, we immunophenotyped approximately 100 tumor samples derived from a variety of cancer types using a bespoke 46-parameter CyTOF panel. Human biological samples were sourced ethically and their research use was in accord with the terms of the informed consents under an IRB/EC approved protocol. Using a suite of high-dimensional analytical tools, including FlowSOM, UMAP, and tSNE, we revealed distinct expression profiles for each receptor; a finding that was previously obscured due to a lack of sufficient resolution.ResultsWe observed a notable divergence in expression profiles between the CD226 axis members across tumor indications. For example, TIGIT expression was found to be highest on activated CD4+ regulatory T (Treg) cells, where its expression correlated strongly with ICOS, FoxP3, CD25, and CCR8. By contrast, CD96 and PVRIG exhibited broad expression across intratumoral T and NK cell populations. Other receptors (e.g., CD226) demonstrated variegated expression profiles across T and NK cell subsets. Finally, despite relatively consistent expression profiles of certain CD226 axis (i.e., TIGIT on Treg cells) across tumors, we also found several cell subsets/clusters unique to specific indications.ConclusionsUsing high-parameter CyTOF analysis, we were able to thoroughly characterize the CD226 axis (CD226, TIGIT, CD96, PVRIG) and related immune receptors across a range of tumor indications. These analyses revealed divergent expression profiles for each CD226 axis member, suggesting distinct/contextual biological role(s) for each receptor. However, future studies will need to dissect the importance of the distinct cellular representation for each CD226 axis member.Ethics ApprovalAll samples were purchased from Discovery Life Sciences (DLS). DLS represents and warrants that it has ownership of all Products available for sale and has properly obtained, where required under HHS/OHRP 45 CFR 46.102 (d) (f), IRB approval (or appropriate research approval for institutions outside the U.S.) for study protocols and informed consent documents for all human subject derived biological materials.
Journal Article
Design of amidobenzimidazole STING receptor agonists with systemic activity
2018
Stimulator of interferon genes (STING) is a receptor in the endoplasmic reticulum that propagates innate immune sensing of cytosolic pathogen-derived and self DNA
1
. The development of compounds that modulate STING has recently been the focus of intense research for the treatment of cancer and infectious diseases and as vaccine adjuvants
2
. To our knowledge, current efforts are focused on the development of modified cyclic dinucleotides that mimic the endogenous STING ligand cGAMP; these have progressed into clinical trials in patients with solid accessible tumours amenable to intratumoral delivery
3
. Here we report the discovery of a small molecule STING agonist that is not a cyclic dinucleotide and is systemically efficacious for treating tumours in mice. We developed a linking strategy to synergize the effect of two symmetry-related amidobenzimidazole (ABZI)-based compounds to create linked ABZIs (diABZIs) with enhanced binding to STING and cellular function. Intravenous administration of a diABZI STING agonist to immunocompetent mice with established syngeneic colon tumours elicited strong anti-tumour activity, with complete and lasting regression of tumours. Our findings represent a milestone in the rapidly growing field of immune-modifying cancer therapies.
A small-molecule agonist for the cGAS–STING pathway has systemic activity in a mouse model of colon cancer.
Journal Article
Affinity Selection from Biological Libraries
by
Henikoff, Steven
,
Smothers, James F.
,
Carter, Paul
in
Bacteriophage typing
,
Biology
,
Biotechnology
2002
Phage display is a simple yet powerful technology that is used to rapidly characterize protein-protein interactions from amongst billions of candidates. This widely practiced technique is used to map antibody epitopes, create vaccines and to engineer peptides, antibodies and other proteins as both diagnostic tools and as human therapeutics. We overview the history of phage display and several recent applications.
Journal Article
Big opportunities for small molecules in immuno-oncology
2015
Key Points
The concept of immuno-oncology, using the immune system to fight cancer, dates back 150 years.
However, broad clinical success for immunotherapies in cancer has only recently been achieved and comprises a class of biologics that includes vaccines, engineered immune cells and mAbs.
Some areas of immune biology cannot be modulated with biologic therapies either due to intracellular access restriction or enzymatic properties that require smaller moieties for intervention.
Most small-molecule drugs are tumour-targeted agents, some of which induce immunogenic cell death that could assist an immune response or create synergy in combination with an immunotherapy.
Multiple small-molecule drugs aiming to block the function of immune suppressor cells (for example, myeloid-derived suppressor cells, regulatory T cells, dendritic cells and tumour-associated macrophages) have been identified.
The hypoxic environment of solid tumours creates a hypoxia–adenosinergic axis of gene regulation, which enforces tumour immune tolerance and can be targeted by small-molecule drugs.
Small-molecule immunotherapy for cancer is a growing area ripe with opportunity for exploitation of critical immune biology and potential new drugs to offer patient benefit.
Small-molecule drugs have several advantages that are complementary to, and possibly synergistic with, biologic approaches for anticancer immunotherapy. This Review provides an overview of immunological pathways that can best be targeted with small molecules and discusses how these approaches fit into the armamentarium of immunotherapeutic strategies for cancer.
The regulatory approval of ipilimumab (Yervoy) in 2011 ushered in a new era of cancer immunotherapies with durable clinical effects. Most of these breakthrough medicines are monoclonal antibodies that block protein–protein interactions between T cell checkpoint receptors and their cognate ligands. In addition, genetically engineered autologous T cell therapies have also recently demonstrated significant clinical responses in haematological cancers. Conspicuously missing from this class of therapies are traditional small-molecule drugs, which have previously served as the backbone of targeted cancer therapies. Modulating the immune system through a small-molecule approach offers several unique advantages that are complementary to, and potentially synergistic with, biologic modalities. This Review highlights immuno-oncology pathways and mechanisms that can be best or solely targeted by small-molecule medicines. Agents aimed at these mechanisms — modulation of the immune response, trafficking to the tumour microenvironment and cellular infiltration — are poised to significantly extend the scope of immuno-oncology applications and enhance the opportunities for combination with tumour-targeted agents and biologic immunotherapies.
Journal Article
Molecular Evidence That the Myxozoan Protists Are Metazoans
by
von Dohlen, Carol D.
,
Smith, Laurens H.
,
Smothers, James F.
in
Animals
,
Base Sequence
,
Biological and medical sciences
1994
The evolutionary origins of the protistan phylum, Myxozoa, have long been questioned. Although these obligate parasites are like protozoans in many features, several aspects of their ontogeny and morphology have implied a closer relationship to metazoan lineages. Phylogenetic analyses of 18 S ribosomal RNA sequences from myxozoans and other eukaryotes, with the use of parsimony, distance, and maximum-likelihood methods, support the hypothesis that myxozoans are closely related to the bilateral animals. These results suggest that the Myxozoa, long considered an assemblage of protozoans, should be considered a metazoan phylum.
Journal Article
Author Correction: Design of amidobenzimidazole STING receptor agonists with systemic activity
by
Marquis, Robert W.
,
Mehlmann, John
,
Gough, Peter J.
in
631/154/309/2420
,
631/250/580/1884
,
631/80/304
2019
Change history:
In this Letter, author Ana Puhl was inadvertently omitted; this error has been corrected online.
An amendment to this paper has been published and can be accessed via a link at the top of the paper
Journal Article
In Your Mouth and in Your Heart: A Study of Deuteronomy 30:12-14 in Paul's Letter to the Romans in Canonical Context
2018
By quoting Deuteronomy 30:12–14 as the content of the message of the righteousness of faith over against Leviticus 18:5 and the righteousness of the law in Romans 10:5–8, Paul proclaims a promise fulfilled in accord with the original meaning of the text written by Moses in Deuteronomy. More precisely, Paul reads Deuteronomy 30:11–14 as an extension of the reality foretold in Deuteronomy 30:1–10, which points forward to the new covenant experience of faith-empowered obedience, or heart circumcision, which includes the internalization of the word of God—the eschatological torah —by the Spirit of God. What Paul has found in Deuteronomy 30:11–14 is a prophetic promise of righteousness which he declares fulfilled in the gospel of the Lord Jesus, the message of the righteousness of faith.
Dissertation