CD4+CD25+ cells regulate CD8 cell anergy in neonatal tolerant mice

Transplantation. 1999 Dec 27;68(12):1891-7. doi: 10.1097/00007890-199912270-00013.

Abstract

Background: Injection of neonatal BALB/c mice with semi-allogeneic splenocytes leads to antigen-specific tolerance lasting into adulthood. Tolerant mice accept A/J skin grafts and fail to generate CD8 cytotoxic T lymphocyte (CTL) activity against A/J targets. Anergic CD8 T cells are present in tolerant mice, and CD4 regulatory cells function to maintain CD8 cell anergy.

Methods: Neonatal BALB/c mice were injected with 108 live CAF, splenocytes, and mice were deemed tolerant by accepting A/J grafts over 40 days. CD8 cell proliferation was measured by in vitro incorporation of bromodeoxyuridine coupled with fluorescence-activated cell sorter analysis. Alloantigen-specific cytotoxicity was tested using 51Cr release assays of A/J or third-party targets.

Results: We demonstrate that A/J-specific anergic CD8 cells are present in neonatal primed mice that develop tolerance but not in neonatal primed mice that reject A/J skin grafts. Anergic CD8 cells show decreased proliferation and no CTL activity against A/J targets. Addition of interleukin-2 (IL-2) to unfractionated cultures fails to restore CTL activity against A/J targets. However, addition of IL-2 to CD4-depleted cultures restores A/J-specific CD8 CTL activity. Removal of CD4+/CD25+ cells, but not CD4+/CD25- cells, also restores CD8 CTL activity against A/J in the presence, but not the absence, of IL-2. Moreover, when added back into cultures, purified CD4+/CD25+ cells from tolerant mice inhibit the generation of CD8 CTL against A/J targets.

Conclusion: These data indicate that CD8 anergy is associated with the state of tolerance, and that CD4+CD25+ cells from tolerant mice function to maintain A/J-specific CD8 cell anergy in vitro.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Animals, Newborn / physiology*
  • Antigens, CD / analysis
  • Antigens, Differentiation, T-Lymphocyte / analysis
  • CD4-Positive T-Lymphocytes / immunology*
  • CD4-Positive T-Lymphocytes / physiology*
  • CD8-Positive T-Lymphocytes / physiology*
  • Immune Tolerance / physiology*
  • Lectins, C-Type
  • Mice
  • Mice, Inbred BALB C
  • Mice, Inbred C57BL
  • Receptors, Interleukin-2 / analysis*
  • T-Lymphocytes, Cytotoxic / physiology

Substances

  • Antigens, CD
  • Antigens, Differentiation, T-Lymphocyte
  • CD69 antigen
  • Lectins, C-Type
  • Receptors, Interleukin-2