Related Experiment Video

Updated: Aug 8, 2026

Directed Differentiation of Induced Pluripotent Stem Cells towards T Lymphocytes
12:47

Directed Differentiation of Induced Pluripotent Stem Cells towards T Lymphocytes

Published on: May 14, 2012

IL-7 induces proliferation of CD3-/low CD4- CD8- human thymocyte precursors by an IL-2 independent pathway

M Fabbi1, V Groh, J L Strominger

  • 1Department of Biochemistry and Molecular Biology, Harvard University, Cambridge, MA 02138.

International Immunology
|January 1, 1992
PubMed

Insights

Interleukin-7 (IL-7) promotes the in vitro proliferation of human thymocyte precursors, including triple negative and CD3low cells. This growth is independent of the IL-2 pathway, suggesting a significant role for IL-7 in human T cell development.

Area of Science:

  • Immunology
  • Developmental Biology
  • Cell Biology

Background:

  • Human thymocyte precursors, specifically CD3-CD4-CD8- (triple negative) and CD3low(lo)CD4-CD8-, are critical for T cell development.
  • Understanding the cytokine-driven proliferation of these precursors is essential for elucidating T cell ontogeny.

Purpose of the Study:

  • To investigate the proliferation potential of human thymocyte precursors in response to various cytokines.
  • To determine the role of Interleukin-7 (IL-7) and Interleukin-2 (IL-2) in the growth of these precursor cells.

Main Methods:

  • In vitro culture of highly purified human CD3-CD4-CD8- and CD3low(lo)CD4-CD8- thymocyte precursors.
  • Treatment with recombinant human cytokines including IL-2, IL-7, IL-4, and IL-6, with and without phorbol 12-myristate 13-acetate (PMA).
  • Analysis of cell proliferation, IL-2 receptor (IL-2R) p55 expression, and surface phenotype (CD3, CD4, CD8) using flow cytometry.

Main Results:

  • Recombinant human IL-2 (rIL-2) and IL-7 (rIL-7) significantly enhanced in vitro proliferation of thymocyte precursors, both with and without PMA.
  • Proliferation in response to rIL-7 was independent of the autocrine IL-2 pathway, as antibodies to IL-2 and IL-2R p55 did not inhibit rIL-7-mediated growth.
  • rIL-7 synergized with rIL-2, but not with rIL-4 or rIL-6.
  • rIL-7 induced proliferation of both CD3- and CD3low thymocyte precursors, accompanied by upregulation of CD3 antigen expression.

Conclusions:

  • IL-7 is identified as a potent growth factor for human thymocyte precursors, similar to its known roles in pre-B and mature T cells.
  • The proliferative effect of IL-7 on these precursors is independent of the IL-2 pathway, highlighting a distinct mechanism of action.
  • These findings suggest that IL-7 plays a crucial role in human T cell ontogeny, analogous to its function in mouse T cell development.

More Related Videos

Mouse Naïve CD4+ T Cell Isolation and In vitro Differentiation into T Cell Subsets07:12

Mouse Naïve CD4+ T Cell Isolation and In vitro Differentiation into T Cell Subsets

Published on: April 16, 2015

A Three-dimensional Thymic Culture System to Generate Murine Induced Pluripotent Stem Cell-derived Tumor Antigen-specific Thymic Emigrants10:44

A Three-dimensional Thymic Culture System to Generate Murine Induced Pluripotent Stem Cell-derived Tumor Antigen-specific Thymic Emigrants

Published on: August 9, 2019

Related Concept Videos

T Cell Activation and Clonal Selection01:22

T Cell Activation and Clonal Selection

T cells are integral to our adaptive immune system, recognizing and effectively responding to foreign antigens. T cell activation and clonal selection are pivotal in orchestrating this immune response. This article elucidates these mechanisms, detailing the roles of cluster of differentiation (CD) markers, major histocompatibility complex (MHC) molecules, costimulatory signals, and the process of clonal selection.
Naive T cells that have not yet encountered an antigen express two primary CD...
T Cell Types and Functions01:24

T Cell Types and Functions

When T cells with CD4 markers are activated, they give rise to two types of effector cells: helper T cells and regulatory T cells. Meanwhile, T cells with CD8 markers differentiate into effector cytotoxic T cells. The differentiation of CD4 T cells into helper T cell subsets, such as Th1, Th2, and Th17 cells, is dependent on the antigen type, antigen-presenting cell, and regulatory cytokines.
Th1 cells stimulate dendritic cells to express necessary co-stimulatory molecules on their surfaces for...