Marek's disease virus prolongs survival of primary chicken B-cells by inducing a senescence-like phenotype

PLoS Pathog. 2021 Oct 21;17(10):e1010006. doi: 10.1371/journal.ppat.1010006. eCollection 2021 Oct.

Abstract

Marek's disease virus (MDV) is an alphaherpesvirus that causes immunosuppression and deadly lymphoma in chickens. Lymphoid organs play a central role in MDV infection in animals. B-cells in the bursa of Fabricius facilitate high levels of MDV replication and contribute to dissemination at early stages of infection. Several studies investigated host responses in bursal tissue of MDV-infected chickens; however, the cellular responses specifically in bursal B-cells has never been investigated. We took advantage of our recently established in vitro infection system to decipher the cellular responses of bursal B-cells to infection with a very virulent MDV strain. Here, we demonstrate that MDV infection extends the survival of bursal B-cells in culture. Microarray analyses revealed that most cytokine/cytokine-receptor-, cell cycle- and apoptosis-associated genes are significantly down-regulated in these cells. Further functional assays validated these strong effects of MDV infections on cell cycle progression and thus, B-cell proliferation. In addition, we confirmed that MDV infections protect B-cells from apoptosis and trigger an accumulation of the autophagy marker Lc3-II. Taken together, our data indicate that MDV-infected bursal B-cells show hallmarks of a senescence-like phenotype, leading to a prolonged B-cell survival. This study provides an in-depth analysis of bursal B-cell responses to MDV infection and important insights into how the virus extends the survival of these cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • B-Lymphocytes / virology*
  • Cellular Senescence / physiology
  • Chickens
  • Mardivirus
  • Marek Disease*
  • Phenotype

Grants and funding

This research was funded by the Agence Nationale de la Recherche as part of the Animal Health and Welfare ERA-Net MADISUP project awarded to CD (ANR-13-ANWA-0002-01; https://www.anihwa.eu) and the Volkswagen Foundation Lichtenberg grant A112662 awarded to BBK (https://www.volkswagenstiftung.de/en/funding/our-funding-portfolio-at-a-glance/lichtenberg-endowed-professorships). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.