Variations in Thymocyte Susceptibility to Clonal Deletion During Ontogeny: Implications for Neonatal Tolerance

Abstract

For mature T cells, the predominant outcomes of TCR occupancy include secretion of lymphokines and entry into the growth cycle. For many thymocytes, however, receptor occupancy leads to clonal inactivation. This process, known as negative selection, is fundamental to the establishment of immune self- tolerance. Two types of inactivation have been observed, clonal anergy and clonal deletion. Clonal anergy occurs when potentially autoreactive cells persist but fail to respond to self-Ag by secreting lymphokines and proliferating. Clonal deletion is the active elimination of the autoreactive cells and, in several experimental systems using thymocytes, has been shown to be the result of programmed cell death (apoptosis). Some of the hallmarks of activation-induced T cell programmed cell death are a requirement for extracellular Ca2+ and new mRNA and protein synthesis, the autofragmentation of nuclear DNA into 180-to 200-bp multimers, and prevention of the process by cyclosporine A.

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Document Details

Document Type
Technical Report
Publication Date
Jul 15, 1991
Accession Number
ADA240997

Entities

People

  • Allan M. Weissman
  • Carl H. June
  • Charles M. Zacharchuk
  • Jonathan D. Ashwell
  • Mladen Mercep

Organizations

  • Naval Medical Research Center

Tags

DTIC Thesaurus Topics

  • Anatomy
  • Anti-Bacterial Agents
  • Antibodies
  • Antigens
  • Apoptosis
  • Azo Compounds
  • Blood
  • Cell Physiological Processes
  • Cells
  • Gel Electrophoresis
  • Hydrolysis
  • Inoculation
  • Lymphocytes
  • Materials
  • Ontogeny
  • Programmed Cell Death
  • Thymocytes

Fields of Study

  • Biology

Readers

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