A Potential Tolerogenic Immune Mechanism in a Trophoblast Cell Line Through the Activation of Chemokine-Induced T Cell Death and Regulatory T Cell Modulation

Hum Reprod. 2009 Jan;24(1):166-75. doi: 10.1093/humrep/den344. Epub 2008 Sep 29.

Abstract

Background: Successful implantation is followed by a local pro-inflammatory and Th1 response, subsequently controlled by Th2. Regulated upon activation, normal T cell expressed and secreted (RANTES) promotes a Th1 response and is implicated as a physiologic tolerogenic factor; therefore, we studied its potential role in the trophoblast-maternal leukocyte dialog.

Methods: We performed co-cultures of immortalized trophoblast cell line (Swan 71) and peripheral blood mononuclear cells (PBMCs) from fertile women (n = 23) or with recurrent spontaneous abortions (n = 18, RSA). After 24 and 48 h, supernatant and cells were analyzed by enzyme-linked immunosorbent assay, fluorescence-activated cell sorting, Western blot and apoptosis assay. To investigate the physiological effects at peripheral level, we co-cultured maternal and paternal PBMCs with conditioned media from Swan cells and progesterone.

Results: Following interaction of maternal PBMCs and trophoblast cells, RANTES production increased (P < 0.05) and was accompanied by low levels of interferon gamma, interleukin-12 p70 and high levels of tumor necrosis factor-alpha, nitrites and leukemia-inhibitory factor. RANTES production resulted in elevated apoptosis of potentially deleterious maternal CD3+ lymphocytes, accompanied by a decrease in the proliferative maternal response. During fetal-maternal dialog, the anti-RANTES antibody significantly reduced the frequency of CD4+CD25+Foxp3+ cells (P < 0.05) and was associated with trophoblast cell survival. However, co-cultures of Swan cells and RSA-PBMCs displayed a differential RANTES kinetics, lower levels of regulatory T cells (Tregs) and CD3+annexin-V+cells, accompanied by higher levels of apoptotic trophoblast cells.

Conclusions: RANTES promotes an adequate pro-implantatory microenvironment that influences trophoblast cell survival and modulates the balance of maternal Treg/T effector lymphocytes in favor of maternal tolerance.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Abortion, Habitual / immunology
  • Apoptosis / immunology*
  • Blotting, Western
  • Cell Line
  • Cell Proliferation
  • Chemokine CCL5 / metabolism
  • Chemokine CCL5 / physiology*
  • Culture Media, Conditioned
  • Embryo Implantation / immunology
  • Female
  • Flow Cytometry
  • Forkhead Transcription Factors / metabolism
  • Humans
  • Leukocytes, Mononuclear / immunology*
  • Leukocytes, Mononuclear / physiology
  • Maternal-Fetal Exchange / immunology
  • Pregnancy
  • Receptors, CCR1 / metabolism
  • Receptors, CCR5 / metabolism
  • T-Lymphocytes / cytology
  • T-Lymphocytes / immunology*
  • T-Lymphocytes / physiology
  • Trophoblasts / immunology*
  • Trophoblasts / metabolism
  • Trophoblasts / physiology

Substances

  • CCR1 protein, human
  • Chemokine CCL5
  • Culture Media, Conditioned
  • FOXP3 protein, human
  • Forkhead Transcription Factors
  • Receptors, CCR1
  • Receptors, CCR5