Proliferative signals for suppressor T cells. Helper cells stimulated with pokeweed mitogen in vitro produce a suppressor cell growth factor

J Clin Invest. 1986 Jul;78(1):214-20. doi: 10.1172/JCI112554.


To define molecular signals elaborated by inducer populations supporting growth or differentiation of T8+ cells, we collected supernatants of pokeweed mitogen (PWM)-stimulated cultures depleted of T8+ cells. When added to purified T8+ cells, these supernatants caused significant proliferation. PWM plus interleukin 2 (IL-2) in amounts equivalent to those in the supernatant could not reconstitute the response caused by the supernatant. T8+ cells activated by supernatants obtained from PWM-pulsed T4+ cells suppressed fresh PWM cultures. Although exhibiting little proliferation, T8+ cells cultured for 6 d in PWM plus IL-2 still suppressed a fresh PWM response. The supernatants therefore contain an additional T suppressor cell growth factor (TsGF). Elaboration of TsGF required radiosensitive T4+Leu8+ cells. Molecular weight determination by high performance liquid chromatography gave a single peak of TsGF activity at approximately 8,000. Finally, whereas TsGF in the absence of IL-2 could not support the proliferation of T suppressor cells, it did cause T8+ cells to become strongly IL-2 receptor-positive.

Publication types

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

MeSH terms

  • Antibodies, Monoclonal / metabolism
  • Antigens, Differentiation, T-Lymphocyte
  • Antigens, Surface / analysis
  • Cell Division / drug effects
  • Growth Substances / biosynthesis*
  • HLA-DR Antigens
  • Histocompatibility Antigens Class II / analysis
  • Humans
  • In Vitro Techniques
  • Interferon-gamma / isolation & purification
  • Interleukin-1 / isolation & purification
  • Interleukin-2 / isolation & purification
  • Molecular Weight
  • Pokeweed Mitogens / pharmacology*
  • T-Lymphocytes, Helper-Inducer / cytology*
  • T-Lymphocytes, Regulatory / cytology*


  • Antibodies, Monoclonal
  • Antigens, Differentiation, T-Lymphocyte
  • Antigens, Surface
  • Growth Substances
  • HLA-DR Antigens
  • Histocompatibility Antigens Class II
  • Interleukin-1
  • Interleukin-2
  • Pokeweed Mitogens
  • Interferon-gamma