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"Gough, Michael"
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Optimizing Timing of Immunotherapy Improves Control of Tumors by Hypofractionated Radiation Therapy
2016
The anecdotal reports of promising results seen with immunotherapy and radiation in advanced malignancies have prompted several trials combining immunotherapy and radiation. However, the ideal timing of immunotherapy with radiation has not been clarified. Tumor bearing mice were treated with 20Gy radiation delivered only to the tumor combined with either anti-CTLA4 antibody or anti-OX40 agonist antibody. Immunotherapy was delivered at a single timepoint around radiation. Surprisingly, the optimal timing of these therapies varied. Anti-CTLA4 was most effective when given prior to radiation therapy, in part due to regulatory T cell depletion. Administration of anti-OX40 agonist antibody was optimal when delivered one day following radiation during the post-radiation window of increased antigen presentation. Combination treatment of anti-CTLA4, radiation, and anti-OX40 using the ideal timing in a transplanted spontaneous mammary tumor model demonstrated tumor cures. These data demonstrate that the combination of immunotherapy and radiation results in improved therapeutic efficacy, and that the ideal timing of administration with radiation is dependent on the mechanism of action of the immunotherapy utilized.
Journal Article
TGFβ suppresses CD8+ T cell expression of CXCR3 and tumor trafficking
2020
Transforming growth factor beta (TGFβ) is a multipotent immunosuppressive cytokine. TGFβ excludes immune cells from tumors, and TGFβ inhibition improves the efficacy of cytotoxic and immune therapies. Using preclinical colorectal cancer models in cell type-conditional TGFβ receptor I (ALK5) knockout mice, we interrogate this mechanism. Tumor growth delay and radiation response are unchanged in animals with Treg or macrophage-specific ALK5 deletion. However, CD8αCre-ALK5
flox/flox
(ALK5
ΔCD8
) mice reject tumors in high proportions, dependent on CD8
+
T cells. ALK5
ΔCD8
mice have more tumor-infiltrating effector CD8
+
T cells, with more cytotoxic capacity. ALK5-deficient CD8
+
T cells exhibit increased CXCR3 expression and enhanced migration towards CXCL10. TGFβ reduces CXCR3 expression, and increases binding of Smad2 to the CXCR3 promoter. In vivo CXCR3 blockade partially abrogates the survival advantage of an ALK5
ΔCD8
host. These data demonstrate a mechanism of TGFβ immunosuppression through inhibition of CXCR3 in CD8
+
T cells, thereby limiting their trafficking into tumors.
TGFβ has a role in cancer immunosuppression but the exact mechanisms haven’t been fully elucidated. Here, using mouse models deficient in TGFβ-signaling, the authors show that loss of ALK5 in CD8 + T cells enhances their tumour trafficking and cytotoxicity suggesting that ALK5 inhibitors may have clinical utility.
Journal Article
Blockade of fibroblast activation protein in combination with radiation treatment in murine models of pancreatic adenocarcinoma
by
Alice, Alejandro
,
Newell, Pippa
,
Crittenden, Marka R.
in
Adenocarcinoma
,
Adoptive Transfer
,
Animal models
2019
Pancreatic ductal adenocarcinoma (PDAC) is characterized by a fibrotic stroma with a poor lymphocyte infiltrate, in part driven by cancer-associated fibroblasts (CAFs). CAFs, which express fibroblast activation protein (FAP), contribute to immune escape via exclusion of anti-tumor CD8+ T cells from cancer cells, upregulation of immune checkpoint ligand expression, immunosuppressive cytokine production, and polarization of tumor infiltrating inflammatory cells. FAP is a post-proline peptidase selectively expressed during tissue remodeling and repair, such as with wound healing, and in the tumor microenvironment by cancer-associated fibroblasts. We targeted FAP function using a novel small molecule inhibitor, UAMC-1110, and mice with germline knockout of FAP and concomitant knock-in of E. coli beta-galactosidase. We depleted CAFs by adoptive transfer of anti-βgal T cells into the FAP knockout animals. Established syngeneic pancreatic tumors in immune competent mice were targeted with these 3 strategies, followed by focal radiotherapy to the tumor. FAP loss was associated with improved antigen-specific tumor T cell infiltrate and enhanced collagen deposition. However, FAP targeting alone or with tumor-directed radiation did not improve survival even when combined with anti-PD1 therapy. Targeting of CAFs alone or in combination with radiation did not improve survival. We conclude that targeting FAP and CAFs in combination with radiation is capable of enhancing anti-tumor T cell infiltrate and function, but does not result in sufficient tumor clearance to extend survival.
Journal Article
The Stanford Hall consensus statement for post-COVID-19 rehabilitation
by
Bahadur, Sardar
,
Roscoe, David
,
Nicol, Alastair M
in
Betacoronavirus
,
Cognitive ability
,
consensus
2020
The highly infectious and pathogenic novel coronavirus (CoV), severe acute respiratory syndrome (SARS)-CoV-2, has emerged causing a global pandemic. Although COVID-19 predominantly affects the respiratory system, evidence indicates a multisystem disease which is frequently severe and often results in death. Long-term sequelae of COVID-19 are unknown, but evidence from previous CoV outbreaks demonstrates impaired pulmonary and physical function, reduced quality of life and emotional distress. Many COVID-19 survivors who require critical care may develop psychological, physical and cognitive impairments. There is a clear need for guidance on the rehabilitation of COVID-19 survivors. This consensus statement was developed by an expert panel in the fields of rehabilitation, sport and exercise medicine (SEM), rheumatology, psychiatry, general practice, psychology and specialist pain, working at the Defence Medical Rehabilitation Centre, Stanford Hall, UK. Seven teams appraised evidence for the following domains relating to COVID-19 rehabilitation requirements: pulmonary, cardiac, SEM, psychological, musculoskeletal, neurorehabilitation and general medical. A chair combined recommendations generated within teams. A writing committee prepared the consensus statement in accordance with the appraisal of guidelines research and evaluation criteria, grading all recommendations with levels of evidence. Authors scored their level of agreement with each recommendation on a scale of 0–10. Substantial agreement (range 7.5–10) was reached for 36 recommendations following a chaired agreement meeting that was attended by all authors. This consensus statement provides an overarching framework assimilating evidence and likely requirements of multidisciplinary rehabilitation post COVID-19 illness, for a target population of active individuals, including military personnel and athletes.
Journal Article
Expression of NF-κB p50 in Tumor Stroma Limits the Control of Tumors by Radiation Therapy
by
Newell, Pippa
,
Savage, Talicia
,
Crittenden, Marka R.
in
Adaptive immunity
,
Adjuvants
,
Animal models
2012
Radiation therapy aims to kill cancer cells with a minimum of normal tissue toxicity. Dying cancer cells have been proposed to be a source of tumor antigens and may release endogenous immune adjuvants into the tumor environment. For these reasons, radiation therapy may be an effective modality to initiate new anti-tumor adaptive immune responses that can target residual disease and distant metastases. However, tumors engender an environment dominated by M2 differentiated tumor macrophages that support tumor invasion, metastases and escape from immune control. In this study, we demonstrate that following radiation therapy of tumors in mice, there is an influx of tumor macrophages that ultimately polarize towards immune suppression. We demonstrate using in vitro models that this polarization is mediated by transcriptional regulation by NFκB p50, and that in mice lacking NFκB p50, radiation therapy is more effective. We propose that despite the opportunity for increased antigen-specific adaptive immune responses, the intrinsic processes of repair following radiation therapy may limit the ability to control residual disease.
Journal Article
Tumor cure by radiation therapy and checkpoint inhibitors depends on pre-existing immunity
2018
Radiation therapy is a source of tumor antigen release that has the potential to serve as an endogenous tumor vaccination event. In preclinical models radiation therapy synergizes with checkpoint inhibitors to cure tumors via CD8 T cell responses. To evaluate the immune response initiated by radiation therapy, we used a range of approaches to block the pre-existing immune response artifact initiated by tumor implantation. We demonstrate that blocking immune responses at tumor implantation blocks development of a tumor-resident antigen specific T cell population and prevents tumor cure by radiation therapy combined with checkpoint immunotherapy. These data demonstrate that this treatment combination relies on a pre-existing immune response to cure tumors, and may not be a solution for patients without pre-existing immunity.
Journal Article
Transcriptional Upregulation of NLRC5 by Radiation Drives STING- and Interferon-Independent MHC-I Expression on Cancer Cells and T Cell Cytotoxicity
by
Zebertavage, Lauren K.
,
Alice, Alejandro
,
Crittenden, Marka R.
in
631/250/1619/554
,
631/250/1619/554/1834
,
631/250/2152
2020
Radiation therapy has been shown to enhance the efficacy of various T cell-targeted immunotherapies that improve antigen-specific T cell expansion, T regulatory cell depletion, or effector T cell function. Additionally, radiation therapy has been proposed as a means to recruit T cells to the treatment site and modulate cancer cells as effector T cell targets. The significance of these features remains unclear. We set out to determine, in checkpoint inhibitor resistant models, which components of radiation are primarily responsible for overcoming this resistance. In order to model the vaccination effect of radiation, we used a
Listeria monocytogenes
based vaccine to generate a large population of tumor antigen specific T cells but found that the presence of cells with cytotoxic capacity was unable to replicate the efficacy of radiation with combination checkpoint blockade. Instead, we demonstrated that a major role of radiation was to increase the susceptibility of surviving cancer cells to CD8+ T cell-mediated control through enhanced MHC-I expression. We observed a novel mechanism of genetic induction of MHC-I in cancer cells through upregulation of the MHC-I transactivator NLRC5. These data support the critical role of local modulation of tumors by radiation to improve tumor control with combination immunotherapy.
Journal Article
Tumor resident memory CD8 T cells and concomitant tumor immunity develop independently of CD4 help
2023
Tissue resident memory (Trm) CD8 T cells infiltrating tumors represent an enriched population of tumor antigen-specific T cells, and their presence is associated with improved outcomes in patients. Using genetically engineered mouse pancreatic tumor models we demonstrate that tumor implantation generates a Trm niche that is dependent on direct antigen presentation by cancer cells. However, we observe that initial CCR7-mediated localization of CD8 T cells to tumor draining lymph nodes is required to subsequently generate CD103
+
CD8 T cells in tumors. We observe that the formation of CD103
+
CD8 T cells in tumors is dependent on CD40L but independent of CD4 T cells, and using mixed chimeras we show that CD8 T cells can provide their own CD40L to permit CD103
+
CD8 T cell differentiation. Finally, we show that CD40L is required to provide systemic protection against secondary tumors. These data suggest that CD103
+
CD8 T cell formation in tumors can occur independent of the two-factor authentication provided by CD4 T cells and highlight CD103
+
CD8 T cells as a distinct differentiation decision from CD4-dependent central memory.
Journal Article
Evidence for Dark Energy Driven by Star Formation: Information Dark Energy?
2025
Evidence is presented for dark energy resulting directly from star formation. A survey of stellar mass density measurements, SMD(a), as a function of universe scale size a, was found to be described by a simple CPL w0 − wa parameterisation that was in good agreement with the dark energy results of Planck 2018, Pantheon+ 2022, the Dark Energy Survey 2024, and the Dark Energy Spectroscopic Instrument 2024. The best-fit CPL values found were w0 = −0.90 and wa = −1.49 for SMD(a), and w0 = −0.94 and wa = −0.76 for SMD(a)0.5, corresponding with, respectively, good and very good agreement with all dark energy results. The preference for SMD(a)0.5 suggests that it is the temperature of astrophysical objects that determines the dark energy density. The equivalent energy of the information/entropy of gas and plasma heated by star and structure formations is proportional to temperature, and is then a possible candidate for such a dark energy source. Information dark energy is also capable of resolving many of the problems and tensions of ΛCDM, including the cosmological constant problem, the cosmological coincidence problem, and the H0 and σ8 tensions, and may account for some effects previously attributed to dark matter.
Journal Article
A microbial-based cancer vaccine for induction of EGFRvIII-specific CD8+ T cells and anti-tumor immunity
2019
Dysregulated signaling via the epidermal growth factor receptor (EGFR)-family is believed to contribute to the progression of a diverse array of cancers. The most common variant of EGFR is EGFRvIII, which results from a consistent and tumor-specific in-frame deletion of exons 2-7 of the EGFR gene. This deletion generates a novel glycine at the junction and leads to constitutive ligand-independent activity. This junction forms a novel shared tumor neo-antigen with demonstrated immunogenicity in both mice and humans. A 21-amino acid peptide spanning the junctional region was selected, and then one or five copies of this 21-AA neo-peptide were incorporated into live-attenuated Listeria monocytogenes-based vaccine vector. These vaccine candidates demonstrated efficient secretion of the recombinant protein and potent induction of EGFRvIII-specific CD8+ T cells, which prevented growth of an EGFRvIII-expressing squamous cell carcinoma. These data demonstrate the potency of a novel cancer-specific vaccine candidate that can elicit EGFRvIII-specific cellular immunity, for the purpose of targeting EGFRvIII positive cancers that are resistant to conventional therapies.
Journal Article