Helper activity for immunoglobulin synthesis of T helper type 1 (Th1) and Th2 human T cell clones: the help of Th1 clones is limited by their cytolytic capacity

J Exp Med. 1991 Oct 1;174(4):809-13. doi: 10.1084/jem.174.4.809.


A large number of CD4+ human T helper type 1 (Th1) clones specific for purified protein derivative and of Th2 clones specific for the excretory/secretory antigen of Toxocara canis, derived from the same individuals, were analyzed for both cytotoxic capacity and helper function for immunoglobulin (Ig) synthesis. The great majority of Th1, but only a minority of Th2 clones exhibited cytolytic activity. All Th2 (noncytolytic) clones induced IgM, IgG, IgA, and IgE synthesis by autologous B cells in the presence of the specific antigen, and the degree of response was proportional to the number of Th2 cells added to B cells. Under the same experimental conditions, Th1 (cytolytic) clones provided helper function for IgM, IgG, and IgA, but not IgE, synthesis with a peak response at 1:1 T/B cell ratio. At higher T/B cell ratios, a strong decrease of Ig synthesis was observed. All Th1 clones lysed Epstein-Barr virus transformed autologous B cells pulsed with the specific antigen. The decrease of Ig production at high T/B cell ratios correlated with the lytic activity of Th1 clones against autologous antigen-presenting B cell targets. These data suggest that Th1 differ from Th2 human T cell clones not only for their profile of cytokine secretion, but also for cytolytic potential and mode of help for B cell Ig synthesis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antibody Formation*
  • B-Lymphocytes / immunology
  • CD4 Antigens / analysis
  • Cell Communication
  • Clone Cells
  • Cytotoxicity, Immunologic*
  • Humans
  • Immunoglobulin A / biosynthesis
  • Immunoglobulin E / biosynthesis
  • Immunoglobulin G / biosynthesis
  • Immunoglobulin M / biosynthesis
  • Kinetics
  • T-Lymphocyte Subsets / immunology*
  • T-Lymphocytes, Helper-Inducer / immunology*


  • CD4 Antigens
  • Immunoglobulin A
  • Immunoglobulin G
  • Immunoglobulin M
  • Immunoglobulin E