title: Rat memory T lymphocytes: in vitro proliferation induced by antigens of Actinomyces viscosus.
abstract: Peripheral T lymphocytes from RIC-Sprague-Dawley rats primed in vivo several months earlier with Actinomyces viscosus Ny 1 reacted with a strong proliferative response upon antigenic challenge in vitro. Two different antigen preparations from A. viscosus Ny 1, a broken cell supernatant (BCS) and an extracellular fraction (EXC) gave maximum responses as measured by the uptake of [3H]thymidine at a concentration of 10 microgram at day 4 of culture. Phytohaemagglutinin (PHA) used as a control provoked a maximum proliferation in the same order of magnitude. T lymphocytes from unprimed, germfree and conventional animals showed a similar stimulation to PHA, but only a marginal reaction to BCS, and were not at all activated by EXC. Evidence is thus presented for efficient removal of cells responding non-specifically to B-cell mitogens.
mesh_terms: D000190:Actinomyces / Q000276:immunology*; D000818:Animals; D000942:Antigens, Bacterial; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D007156:Immunologic Memory; D037102:Lectins / Q000494:pharmacology; D008213:Lymphocyte Activation / Q000187:drug effects; D051379:Mice; D008815:Mice, Inbred Strains; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D000942:Antigens, Bacterial; D037102:Lectins