An Agent-Based Model of the Spread of Devil Facial Tumor Disease in an Isolated Population of Tasmanian Devils

2012 ◽  
Vol 4 (4) ◽  
pp. 1-16
Author(s):  
Charles E. Knadler
Keyword(s):  
Life History ◽  
Cancer Cells ◽  
Tasmanian Devil ◽  
Isolated Population ◽  
Agent Based Model ◽  
Disease Mechanism ◽  
Agent Based ◽  
In The Wild ◽  
Devil Facial Tumor Disease

The Tasmanian devil population is being reduced in the wild at an alarming rate due to an epidemic, which is the result of an unusual disease mechanism. Infected animals “inject” cancer cells into other devils, which then clone the cells, developing tumors. These tumors are invariably fatal. Field observers have developed hypotheses that include a life- history change for the species. It is hypothesized that this change has the potential to improve the population’s survivability. An agent-based model of Tasmanian devils is used to evaluate these hypotheses. The model results suggest that the devils’ intra-gender aggression as well as their aggressive mating practices render the life-history change hypotheses’ correctness improbable.

scholarly journals Agent based models to investigate cooperation between cancer cells

2015 ◽  
Author(s):  
Joao Xavier ◽  
William Chang
Keyword(s):  
Growth Factor ◽  
Cancer Cells ◽  
Solid Tumor ◽  
Kin Selection ◽  
Evolution Of Cooperation ◽  
Emergent Properties ◽  
Agent Based Model ◽  
Agent Based ◽  
Chemical Gradients ◽  
Close Proximity

We present a type of agent-based model that uses off-lattice spheres to represent individual cells in a solid tumor. The model calculates chemical gradients and determines the dynamics of the tumor as emergent properties of the interactions between the cells. As an example, we present an investigation of cooperation among cancer cells where cooperators secrete a growth factor that is costly to synthesize. Simulations reveal that cooperation is favored when cancer cells from the same lineage stay in close proximity. The result supports the hypothesis that kin selection, a theory that explains the evolution of cooperation in animals, also applies to cancers.

scholarly journals An Agent-Based Model of monocyte differentiation into Tumour-Associated Macrophages in Chronic Lymphocytic Leukemia

2021 ◽  
Author(s):  
Nina Verstraete ◽  
Malvina Marku ◽  
Marcin Domagala ◽  
Julie Bordenave ◽  
H&eacutelène Arduin ◽  
...  
Keyword(s):  
Chronic Lymphocytic Leukemia ◽  
Cancer Cells ◽  
Mononuclear Cells ◽  
Lymphocytic Leukemia ◽  
Leukemic Cells ◽  
Patient Specific ◽  
Model Parameters ◽  
Agent Based Model ◽  
Agent Based ◽  
Monocyte Differentiation

Monocyte-derived macrophages are immune cells which help maintain tissue homeostasis and defend the organism against pathogens. In solid tumours, recent studies have uncovered complex macrophage populations, among which tumour-associated macrophages, supporting tumorigenesis through multiple cancer hallmarks such as immunosuppression, angiogenesis or matrix remodelling. In the case of chronic lymphocytic leukemia, these macrophages are known as nurse-like cells and have been shown to protect leukemic cells from spontaneous apoptosis and contribute to their chemoresistance. We propose an agent-based model of monocytes differentiation into nurse-like cells upon contact with leukemic B cells in-vitro. We studied monocyte differentiation and cancer cells survival dynamics depending on diverse hypotheses on monocytes and cancer cells relative proportions, sensitivity to their surrounding environment and cell-cell interactions. Peripheral blood mononuclear cells from patients were cultured and monitored during 13 days to calibrate the model parameters, such as phagocytosis efficiency, death rates or protective effect from the nurse-like cells. Our model is able to reproduce experimental results and predict cancer cells survival dynamics in a patient-specific manner. Our results shed light on important factors at play in cancer cells survival, highlighting a potentially important role of phagocytosis.

scholarly journals Macronutrient intakes and the lifespan-fecundity trade-off: a geometric framework agent-based model

2019 ◽  
Vol 16 (151) ◽  
pp. 20180733 ◽  
Author(s):  
Cameron J. Hosking ◽  
David Raubenheimer ◽  
Michael A. Charleston ◽  
Stephen J. Simpson ◽  
Alistair M. Senior
Keyword(s):  
Life History ◽  
Ecological Factors ◽  
Primary Component ◽  
Agent Based Model ◽  
Geometric Framework ◽  
Trade Off ◽  
Agent Based ◽  
Extrinsic Mortality ◽  
Trade Offs ◽  
Evolutionary Fitness

Lifespan and fecundity, the main components in evolutionary fitness, are both strongly affected by nutritional state. Geometric framework of nutrition (GFN) experiments has shown that lifespan and fecundity are separated in nutrient space leading to a functional trade-off between the two traits. Here we develop a spatially explicit agent-based model (ABM) using the GFN to explore how ecological factors may cause selection on macronutrient appetites to optimally balance these life-history traits. We show that increasing the risk of extrinsic mortality favours intake of a mixture of nutrients that is associated with maximal fecundity at the expense of reduced longevity and that this result is robust across spatial and nutritional environments. These model behaviours are consistent with what has been observed in studies that quantify changes in life history in response to environmental manipulations. Previous GFN-derived ABMs have treated fitness as a single value. This is the first such model to instead decompose fitness into its primary component traits, longevity and fecundity, allowing evolutionary fitness to be an emergent property of the two. Our model demonstrates that selection on macronutrient appetites may affect life-history trade-offs and makes predictions that can be directly tested in artificial selection experiments.

scholarly journals A computational multiscale agent-based model for simulating spatio-temporal tumour immune response to PD1 and PDL1 inhibition

2017 ◽  
Vol 14 (134) ◽  
pp. 20170320 ◽  
Author(s):  
Chang Gong ◽  
Oleg Milberg ◽  
Bing Wang ◽  
Paolo Vicini ◽  
Rajesh Narwal ◽  
...  
Keyword(s):  
Cancer Cells ◽  
Immune Checkpoint ◽  
Temporal Dynamics ◽  
Checkpoint Inhibitors ◽  
Tumour Progression ◽  
Cytotoxic T Cells ◽  
Three Dimensional ◽  
Agent Based Model ◽  
Agent Based ◽  
Tumour Development

When the immune system responds to tumour development, patterns of immune infiltrates emerge, highlighted by the expression of immune checkpoint-related molecules such as PDL1 on the surface of cancer cells. Such spatial heterogeneity carries information on intrinsic characteristics of the tumour lesion for individual patients, and thus is a potential source for biomarkers for anti-tumour therapeutics. We developed a systems biology multiscale agent-based model to capture the interactions between immune cells and cancer cells, and analysed the emergent global behaviour during tumour development and immunotherapy. Using this model, we are able to reproduce temporal dynamics of cytotoxic T cells and cancer cells during tumour progression, as well as three-dimensional spatial distributions of these cells. By varying the characteristics of the neoantigen profile of individual patients, such as mutational burden and antigen strength, a spectrum of pretreatment spatial patterns of PDL1 expression is generated in our simulations, resembling immuno-architectures obtained via immunohistochemistry from patient biopsies. By correlating these spatial characteristics with in silico treatment results using immune checkpoint inhibitors, the model provides a framework for use to predict treatment/biomarker combinations in different cancer types based on cancer-specific experimental data.

scholarly journals Lessons from the Looming Extinction of the Tasmanian Devil

2008 ◽  
Vol 14 (3) ◽  
pp. 151 ◽  
Author(s):  
D. Lunney ◽  
M. Jones ◽  
H. McCullum
Keyword(s):  
Cancer Cells ◽  
Captive Breeding ◽  
Active Management ◽  
Tasmanian Devil ◽  
Population Bottlenecks ◽  
Low Genetic Diversity ◽  
Devil Facial Tumour Disease ◽  
In The Wild ◽  
Breeding Programmes ◽  
Infectious Cancer

Extinction in the wild is now regarded as likely for the Tasmanian Devil Sarcophilus harrissi. In 1996, a disease, Devil Facial Tumour Disease (DFTD), was seen in a Devil in the wild. By mid-2008, the population had declined by about 70%, and the disease was spreading rapidly from east to west across Tasmania. DFTD is an infectious cancer, passed from one Devil to another principally, or entirely, by biting. The bite implants the cancer cells; the low genetic diversity in the Tasmanian Devil population from previous population bottlenecks or selective sweeps means that those cancer cells are not recognized by the immune system and the cancer grows in the infected Devil. Estimates of the time to extinction in the wild range from about 20 to 35 years. If, however, there are resistant genotypes within the Devil population then extinction in the wild may be averted, with numbers augmented through captive breeding programmes and active management to spread these genotypes in the wild.

scholarly journals The Value of Reference Genomes in the Conservation of Threatened Species

Genes ◽  
2019 ◽  
Vol 10 (11) ◽  
pp. 846 ◽  
Author(s):  
Brandies ◽  
Peel ◽  
Hogg ◽  
Belov
Keyword(s):  
Threatened Species ◽  
Reference Genome ◽  
Management Practice ◽  
Full Range ◽  
Tasmanian Devil ◽  
Genetic Management ◽  
Management Actions ◽  
Genomic Technologies ◽  
In The Wild ◽  
Devil Facial Tumor Disease

Conservation initiatives are now more crucial than ever—over a million plant and animal species are at risk of extinction over the coming decades. The genetic management of threatened species held in insurance programs is recommended; however, few are taking advantage of the full range of genomic technologies available today. Less than 1% of the 13505 species currently listed as threated by the International Union for Conservation of Nature (IUCN) have a published genome. While there has been much discussion in the literature about the importance of genomics for conservation, there are limited examples of how having a reference genome has changed conservation management practice. The Tasmanian devil (Sarcophilus harrisii), is an endangered Australian marsupial, threatened by an infectious clonal cancer devil facial tumor disease (DFTD). Populations have declined by 80% since the disease was first recorded in 1996. A reference genome for this species was published in 2012 and has been crucial for understanding DFTD and the management of the species in the wild. Here we use the Tasmanian devil as an example of how a reference genome has influenced management actions in the conservation of a species.

Simulations of an Agent-Based Model that Consists of a Large Number of Agents Moving Stochastically in a Wide Bounded Domain

2001 ◽  
Author(s):  
Minoru Tabata ◽  
Akira Ide ◽  
Nobuoki Eshima ◽  
Kyushu Takagi ◽  
Yasuhiro Takei ◽  
...  
Keyword(s):  
Bounded Domain ◽  
Agent Based Model ◽  
Agent Based
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