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Yeast As a Chassis for Developing Functional Assays to Study Human P53
14:57

Yeast As a Chassis for Developing Functional Assays to Study Human P53

Published on: August 4, 2019

Survivin loss in thymocytes triggers p53-mediated growth arrest and p53-independent cell death

Hitoshi Okada1, Chris Bakal, Arda Shahinian

  • 1Advanced Medical Discovery Institute, University of Toronto, 620 University Avenue, Suite 706, Ontario M5G 2C1, Canada. hokada@uhnres.utoronto.ca

The Journal of Experimental Medicine
|February 6, 2004
PubMed

Insights

Survivin is essential for early thymocyte development, blocking the transition from double-negative to double-positive cells. Its loss causes cell cycle arrest and death, independent of p53 or Bcl-2.

Area of Science:

  • Immunology
  • Cell Biology
  • Developmental Biology

Background:

  • Survivin is crucial for embryonic development, but its specific role in T-cell maturation is unknown.
  • Survivin-null embryos exhibit early lethality, precluding analysis of its function in later developmental stages.

Purpose of the Study:

  • To elucidate the role of survivin in T-cell development within the thymus.
  • To investigate the impact of survivin deficiency on thymocyte differentiation and survival.

Main Methods:

  • Conditional deletion of the survivin gene specifically in the T-cell lineage.
  • Analysis of thymocyte populations using flow cytometry.
  • Assessment of cell cycle progression, spindle formation, and apoptosis in survivin-deficient thymocytes.

Main Results:

  • Loss of survivin arrests thymocyte development at the CD4- CD8- double-negative (DN) to CD4+ CD8+ double-positive transition.
  • Survivin-deficient DN thymocytes show cell cycle arrest, defective spindle formation, and increased cell death upon stimulation.
  • The pre-T cell receptor signaling pathway remains functional, but cells fail to respond to its signals.
  • Survivin deficiency activates the tumor suppressor p53.
  • Inactivation of p53 or addition of Bcl-2 does not rescue the developmental defects.

Conclusions:

  • Survivin is critical for early thymocyte development, ensuring proper progression through the DN to DP stage.
  • The cytoprotective function of survivin is essential for thymocyte proliferation and survival.
  • Survivin's role in thymocyte development is independent of p53 and Bcl-2 pathways.

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