title: Stimulation of human lymphocytes by phytohemagglutinin (PHA) in a new ultra-microtest plate.
abstract: The requirements for monocytes in lymphocyte proliferation were studied in ultra-microcultures. For this purpose, an ultra-microtest plate was developed which comprises 121 wells, each having 0.23 microliter volume and 0.28 mm2 culture area. Human peripheral lymphocytes were seeded in the wells in numbers ranging from 1-57 cells/well and subsequently stimulated with phytohemagglutinin (PHA). Proliferation, assessed by microscopy in situ, was established in 46% of the wells where adherent non-specific, esterase-positive cells were present and in 6% where such cells were absent. The results indicate that PHA-stimulated human lymphocytes can proliferate in the absence of monocytes. The new microplate should be a valuable tool for dissecting the early events in T cell activation, especially if combined with various analytical methods such as time-lapse video, autoradiography and surface-marker techniques.
mesh_terms: D002478:Cells, Cultured; D004950:Esterases / Q000032:analysis; D006801:Humans; D007158:Immunologic Techniques / Q000295:instrumentation; D008213:Lymphocyte Activation; D008214:Lymphocytes / Q000276:immunology*; D009000:Monocytes / Q000276:immunology; D010835:Phytohemagglutinins / Q000494:pharmacology
chemical_list: D010835:Phytohemagglutinins; D004950:Esterases