title: Activation/suppression of the immune response in vitro by antigen and dextran sulfate. 2. The role of T-cell subsets determined by cell separation and partition analysis.
abstract: Culture of spleen cells with dextran sulfate (DxS) and antigen at various different cell densities revealed a T-cell-dependent regulatory pathway not observed in conventional culture. This finding can be explained by the frequent presence in the cultures of a helper cell and the less frequent presence of a suppressor cell, both activated by antigen and DxS. The classic, radioresistant, antigen-specific, helper T cell was not regulated by this newly revealed pathway. The highly frequent, DxS-dependent helper T cell is Lyt-1+2-. The suppressive effect is mediated by a Lyt-1+2+ population consisting of helpers and latent suppressors that can be made active by DxS or Lyt-1+ cells. The specificity of the Lyt-1+ helper cells was not established, but the high frequency observed implies a nonspecific mechanism. The specificity of the suppressor effect was not determined by these experiments. This regulatory mechanism is similar to the phenomena exhibited by polyclonally activated T-cell populations.
mesh_terms: D000818:Animals; D000917:Antibody Formation; D000950:Antigens, Ly / Q000032:analysis; D001402:B-Lymphocytes / Q000276:immunology; D002469:Cell Separation; D016264:Dextran Sulfate; D003911:Dextrans / Q000276:immunology*; D051379:Mice; D013601:T-Lymphocytes / Q000276:immunology*; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology; D050378:T-Lymphocytes, Regulatory / Q000276:immunology
chemical_list: D000950:Antigens, Ly; D003911:Dextrans; D016264:Dextran Sulfate