Purpose: The underlying mechanism for radiation as a potentiator of immune checkpoint inhibition (ICI) is unclear. We developed a novel murine model to investigate the effects of post-irradiation intratumoral heterogeneity (ITH) on response to ICI.
Experimental Design: Parental mouse melanoma B16F10 cells were irradiated in vitro (5Gy x 3 fractions), then an a priori determined number of resulting colonies were implanted in C57BL/6J immunocompetent mice creating syngeneic models of unirradiated (parental) and irradiated tumors with low (irradiated-L) and high (irradiated-H) ITH. Mice were treated with placebo, α-PD-L1, α-CTLA-4 or dual ICI. Murine tumors underwent whole exome sequencing (WES). Clinically correlated paired pre- and post-irradiation patient rectal adenocarcinoma samples underwent WES.
Results: Irradiated-L tumors showed increased tumor mutational burden (TMB) and a sustained decrease in ITH. Irradiated-L tumors were predicted to express five neoantigens with high variant allele frequency/clonal distribution. Mice with irradiated-L and irradiated-H versus parental B16F10 tumors demonstrated longer overall survival with dual ICI. Only mice with irradiated-L tumors experienced an overall survival benefit with single agent ICI. Clinically correlated rectal adenocarcinoma samples showed similarly increased TMB and decreased ITH following irradiation.
Conclusions: Post-irradiation ITH modulates ICI response in a murine melanoma model. Irradiation may offer a mechanism to widen the therapeutic window of ICI.
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http://dx.doi.org/10.1016/j.neo.2022.100864 | DOI Listing |
Neoplasia
February 2023
Department of Radiation Oncology University of North Carolina-Chapel Hill, Chapel Hill, NC; Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX. Electronic address:
Purpose: The underlying mechanism for radiation as a potentiator of immune checkpoint inhibition (ICI) is unclear. We developed a novel murine model to investigate the effects of post-irradiation intratumoral heterogeneity (ITH) on response to ICI.
Experimental Design: Parental mouse melanoma B16F10 cells were irradiated in vitro (5Gy x 3 fractions), then an a priori determined number of resulting colonies were implanted in C57BL/6J immunocompetent mice creating syngeneic models of unirradiated (parental) and irradiated tumors with low (irradiated-L) and high (irradiated-H) ITH.
Cytokine
December 2020
College of Veterinary Medicine, Northeast Agricultural University, Harbin, PR China; Northeastern Science Inspection Station, China Ministry of Agriculture Key Laboratory of Animal Pathogen Biology, PR China. Electronic address:
Lactobacillus species are typical members of gut microflora that immunomodulatory effects and can regulate a variety of immune cells, such as dendritic cells (DCs). Notably, DCs possess the unique ability to initiate primary immune responses. Notably, DCs possess the unique ability to initiate primary immune responses.
View Article and Find Full Text PDFOxid Med Cell Longev
March 2017
College of Biological Science and Engineering, Fuzhou University, No. 2 Xue Yuan Road, University Town, Fuzhou, Fujian 350108, China; Food Nutrition Sciences Centre, Zhejiang Gongshang University, Room 407, No. 1 Laboratory Building, No. 149 Jiaogong Road, Xihu District, Hangzhou 310012, China.
Superoxide dismutase (SOD) fusion of TAT was proved to be radioprotective in our previous work. On that basis, a bifunctional recombinant protein which was the fusion of glutathione S-transferase (GST), SOD, and TAT was constructed and named GST-TAT-SOD. Herein we report the investigation of the cytotoxicity, cell-penetrating activity, and in vitro radioprotective effect of GST-TAT-SOD compared with wild SOD, single-function recombinant protein SOD-TAT, and amifostine.
View Article and Find Full Text PDFBMC Cancer
March 2006
Equipe Cytokines et Cancer, Unité INSERM U590, Centre Léon Bérard, 28 rue Laënnec, 69373 Lyon cedex 08, France.
Background: CD40L was found to reduce doxorubicin-induced apoptosis in non Hodgkin's lymphoma cell lines through caspase-3 dependent mechanism. Whether this represents a general mechanism for other tumor types is unknown.
Methods: The resistance induced by CD40L against apoptosis induced by a panel of cytotoxic chemotherapeutic drugs in non Hodgkin's lymphoma and breast carcinoma cell lines was investigated.
Infect Immun
September 2004
Department of Pathology and Molecular Medicine, McMaster University, The Brain-Body Institute, St. Joseph's Healthcare Hamilton, Ontario, Canada.
The mechanism of the apparent anti-inflammatory action of probiotic organisms is unclear. Lactobacillus reuteri is effective in inhibiting colitis in interleukin-10 (IL-10)-deficient mice. Nerve growth factor (NGF), in addition to its activity on neuronal cell growth, has significant anti-inflammatory effects in several experimental systems in vitro and in vivo, including a model of colitis.
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