Characterization of a soluble suppressor of human B cell function produced by a continuous human suppressor T cell line. II. Evidence for suppression through a direct action of CTC-SISS-B on human B cells

J Immunol. 1982 Sep;129(3):1120-3.


CTC-SISS-B is an antigen-nonspecific suppressive lymphokine elaborated by an interleukin 2-dependent suppressor T cell line that produces noncytotoxic inhibition of human B cell but not T cell function. Like SISS-B, a soluble suppressive lymphokine present in the supernatants of Con A-activated peripheral blood T cell cultures, CTC-SISS-B is of 60,000 to 90,000 m.w., and its action is blocked by the simple sugar L-rhamnose. CTC-SISS-B inhibits human B cell Ig production and proliferation through a direct interaction with human B cells rather than through indirect effects on immunoregulatory T cells or monocytes. CTC-SISS-B suppression occurs through inhibition of an early event(s) in B cell activation since proliferation and Ig production by established human B cell lines are not inhibited by this lymphokine. Despite sharing many biochemical and biologic properties, CTC-SISS-B and gamma-interferon appear to be distinct mediators.

MeSH terms

  • B-Lymphocytes / immunology*
  • Cell Line
  • Cells, Cultured
  • Humans
  • Lymphocyte Activation
  • Lymphocyte Cooperation
  • Lymphokines / immunology*
  • Macrophages / immunology
  • Monocytes / immunology
  • Pokeweed Mitogens / antagonists & inhibitors
  • Suppressor Factors, Immunologic
  • T-Lymphocytes, Regulatory / immunology*


  • Lymphokines
  • Pokeweed Mitogens
  • Suppressor Factors, Immunologic