Polyclonal activation of human lymphocytes and induction of cytotoxic lymphocytes by streptococcal preparations

Toshihiro Sato, Masahiko Fujii, Hideki Satoh, Tetsuro Itoh, Hidemi Rikiishi, Katsuo Kumagai

Research output: Contribution to journalArticlepeer-review

4 Citations (Scopus)


Polyclonal activation of human peripheral blood lymphocytes (PBLs)in vitro by preparations of Streptococcus pyogenes Su strain (OK-432) and other heat-killed strains was investigated. The streptococcal preparations tested induce a proliferative response of PBLs via interleukin-2 (IL-2)-independent pathways. The proliferative response is accompanied by the generation of lymphoblastic cells (LBCs), which consist of heterologous lymphocyte populations: CD4+ helper type of T cells, and CD4-CD8- double-negative (DN) lymphocytes, including both CD3+ TcR γδ+ T cells and CD2+CD3- immature type of T or non-T cell type of lymphocytes. Almost all the LBCs express Leu19, TfR (transferrin receptor), LFA-1 and CD38 (OKT10) antigens, which are expressed on activated T cells, NK cells and some other lymphocytes. The proliferative response of human PBLs is also accompanied by the generation of potent cytotoxic activity against NK-sensitive and -resistant targets. C-dependent cytolysis and cell sorting experiments of OK-432-activated LBCs revealed that both CD3+ and CD3- types of CD4-CD8- DN lymphocytes, but not CD4+ helper T cells, may be major populations responsible for the cytotoxicity induced. On the other hand, CD4-CD8 T cells may be required for the proliferation of PBLs and generation of cytotoxic effector cells. These results suggest that the OK-432 and other streptococcal preparations stimulate the human PBLs in vitro to induce the proliferation/activation of CD4+ T cells, mediating the following generation of DN cytotoxic effector lymphocytes.

Original languageEnglish
Pages (from-to)53-63
Number of pages11
Issue number1
Publication statusPublished - 1992 Jan
Externally publishedYes


  • Streptococcus
  • helper T cells
  • lymphocyte activation
  • γδ T cells

ASJC Scopus subject areas

  • Pharmacology


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