title: Three functionally distinct helper T-cell clones: the roles for antigen non-specific helper factors in B-cell activation through two different pathways.
abstract: We established three functionally distinct purified protein derivative (PPD)-reactive T-cell clones (B11.15, B12.F and D-2). Clone B11.15 could co-operate with DNP-primed B cells to induce anti-DNP IgG plaque-forming cell (PFC) responses only when high amounts of PPD were added to the culture, whereas stimulation of a low amount of DNP-PPD was ineffective (factor-mediated interaction). On the other hand, clone D-2 activated those B cells in a MHC-restricted manner only when DNP-PPD was added to the culture (cognate interaction). B12.F could stimulate B cells with either PPD or DNP-PPD. Antigen non-specific helper factors (lymphokines) responsible for B-cell activation produced by cloned T cells upon stimulation with PPD and antigen-presenting cells were then investigated. Lymphokine activities determined in the present study were IL-2, BCGF I, BCGF II and TRF. BCGF I activity was determined by proliferation-inducing activity on purified B cells in the presence of anti-IgM antibody. BCGF II activity was measured by proliferation-inducing activity on purified B cells in the presence of dextran sulphate. TRF activity was determined on DNP-primed B cells for inducing further differentiation into anti-DNP IgG PFC. BCGF I active molecules were eluted in the fraction at apparent MW of 50,000-70,000 and 8,000-10,000 in gel-permeation column chromatography.
mesh_terms: D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology*; D002850:Chromatography, Gel; D002999:Clone Cells; D006133:Growth Substances / Q000096:biosynthesis; D006462:Hemolytic Plaque Technique; D066298:In Vitro Techniques; D007376:Interleukin-2 / Q000096:biosynthesis; D015847:Interleukin-4; D015848:Interleukin-5; D008213:Lymphocyte Activation; D008222:Lymphokines / Q000096:biosynthesis*; D051379:Mice; D008810:Mice, Inbred C57BL; D006377:T-Lymphocytes, Helper-Inducer / Q000378:metabolism*; D014373:Tuberculin / Q000494:pharmacology
chemical_list: D006133:Growth Substances; D007376:Interleukin-2; D015848:Interleukin-5; D008222:Lymphokines; D014373:Tuberculin; D015847:Interleukin-4