title: Polyclonal antibody-forming cell activation and immunomodulation of the in vitro immune response induced by streptococcal extracellular products.
abstract: The capacity of three different extracellular streptococcal products to induce polyclonal activation of precursors of plaque-forming cells (PFC) was investigated. The gamma fraction (pI = 4.2), previously shown to be only weakly mitogenic, was the most potent activator of rabbit and mouse immunoglobulin-secreting cells. The polyclonal stimulation induced by the two other fractions (kappa: pI = 4.8 and epsilon: pI = 10.3), shown to be mitogenic in both systems, was only observed in the rabbit system. Using these fractions, the in vitro immunomodulation of the anti-sheep red blood cell immune response was also investigated. Both gamma and epsilon fractions were shown to possess adjuvant properties, whereas the kappa fraction was a suppressor of the specific immune response. It appears, therefore, that the diversified immunological activities observed with extracellular streptococcal products can be dissociated and belong to different entities.
mesh_terms: D000818:Animals; D000921:Antibody-Producing Cells / Q000276:immunology*; D001426:Bacterial Proteins; D006462:Hemolytic Plaque Technique; D008070:Lipopolysaccharides / Q000494:pharmacology; D051379:Mice; D008808:Mice, Inbred CBA; D008811:Mice, Inbred DBA; D008934:Mitogens / Q000494:pharmacology*; D011817:Rabbits; D013205:Staphylococcal Protein A / Q000494:pharmacology; D000511:alpha-Macroglobulins / Q000502:physiology*
chemical_list: D001426:Bacterial Proteins; D008070:Lipopolysaccharides; D008934:Mitogens; D013205:Staphylococcal Protein A; D000511:alpha-Macroglobulins; C032306:polyclonal B cell activator; C034866:streptococcal group A mitogen