title: Theophylline modulation of E-rosette formation: an indicator of T-cell maturation.
abstract: The binding of unsensitized sheep erythrocytes is a characteristic of human thymus dependent T-lymphocytes. We have investigated the effect of theophylline on E-rosette formation using cells from normal individuals, and patients with immunodeficiency or acute lymphoblastic leukaemia, and have attempted to correlate the influence of the drug on distinct T-lymphocyte subpopulations. Three subpopulations of E-rosetting T-lymphocytes can be delineated: theophylline-sensitive T-cells which lose the capacity to form E-rosettes following treatment; theophylline-resistant T-cells which are unaffected by the drug; and theophylline-dependent cells which acquire the ability to form E-rosettes following incubation with theophylline. The action of theophylline was shown to be dose-dependent, temperature-dependent and reversible. Reversibility or re-expression of the receptor for sheep red cells could be blocked by the addition of puromycin. In peripheral blood, E-rosetting T-lymphocytes were roughly divided into two equal populations, one sensitive, the other resistant. Thymocytes were shown to be entirely theophylline-resistant, whereas a small population of cells in peripheral blood and bone marrow were induced to become E-rosetting in the presence of theophylline. Induction by theophylline may be effective at a distinct stage of precursor T-cell differentiation.
mesh_terms: D002648:Child; D004305:Dose-Response Relationship, Drug; D006128:Growth; D006801:Humans; D007153:Immunologic Deficiency Syndromes / Q000276:immunology; D007945:Leukemia, Lymphoid / Q000276:immunology; D011691:Puromycin / Q000494:pharmacology; D012397:Rosette Formation; D013601:T-Lymphocytes / Q000187:drug effects / Q000276:immunology*; D013696:Temperature; D013806:Theophylline / Q000494:pharmacology*
chemical_list: D011691:Puromycin; D013806:Theophylline