Complex associations between cancer progression and immune gene expression reveals early influence of transmissible cancer on Tasmanian devils

Front Immunol. 2024 Mar 7:15:1286352. doi: 10.3389/fimmu.2024.1286352. eCollection 2024.

Abstract

The world's largest extant carnivorous marsupial, the Tasmanian devil, is challenged by Devil Facial Tumor Disease (DFTD), a fatal, clonally transmitted cancer. In two decades, DFTD has spread across 95% of the species distributional range. A previous study has shown that factors such as season, geographic location, and infection with DFTD can impact the expression of immune genes in Tasmanian devils. To date, no study has investigated within-individual immune gene expression changes prior to and throughout the course of DFTD infection. To explore possible changes in immune response, we investigated four locations across Tasmania that differed in DFTD exposure history, ranging between 2 and >30 years. Our study demonstrated considerable complexity in the immune responses to DFTD. The same factors (sex, age, season, location and DFTD infection) affected immune gene expression both across and within devils, although seasonal and location specific variations were diminished in DFTD affected devils. We also found that expression of both adaptive and innate immune genes starts to alter early in DFTD infection and continues to change as DFTD progresses. A novel finding was that the lower expression of immune genes MHC-II, NKG2D and CD8 may predict susceptibility to earlier DFTD infection. A case study of a single devil with regressed tumor showed opposite/contrasting immune gene expression patterns compared to the general trends observed across devils with DFTD infection. Our study highlights the complexity of DFTD's interactions with the host immune system and the need for long-term studies to fully understand how DFTD alters the evolutionary trajectory of devil immunity.

Keywords: immune system; infectious disease; life-history traits; marsupial; regression; resistance; tolerance; tumor progression.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Daunorubicin / analogs & derivatives*
  • Facial Neoplasms* / genetics
  • Facial Neoplasms* / veterinary
  • Gene Expression
  • Immune System / pathology
  • Marsupialia* / genetics

Substances

  • 7-O-(2,6-dideoxy-2-fluorotalopyranosyl)daunomycinone
  • Daunorubicin

Supplementary concepts

  • Sarcophilus harrisii

Grants and funding

The author(s) declare financial support was received for the research, authorship, and/or publication of this article. This work was supported by an ARC Linkage (LP170101105), ARC Decra (DE170101116), Deakin SEBE_RGS_2019, Deakin CIE HDR Leading Research Award, an ANR TRANSCAN (ANR‐18‐CE35‐0009), the MAVA foundation and the Hoffmann family, The University of Tasmania Foundation (Save the Tasmanian Devil Appeal), a Holsworth Wildlife Research Endowment and a CNRS ‘International Associated Laboratory Grant’. The funders were not involved in the study design, collection, analysis, interpretation of data, the writing of this article or the decision to submit if for publication. Forico Pty Ltd. and Sustainable Timber Tasmania provided land access and logistic support during our study.