PHARMACOLOGICAL MODIFICATION OF IMMUNOREGULATORY LYMPHOCYTES-T .1. EFFECT OF ADENOSINE, H-1 AND H-2 HISTAMINE AGONISTS UPON LYMPHOCYTE-T REGULATION OF LYMPHOCYTE-B DIFFERENTIATION INVITRO

  • 1 January 1982
    • journal article
    • research article
    • Vol. 48  (1) , 218-230
Abstract
Human peripheral blood T lymphocytes were fractionated according to the lability of their sheep red blood cell (E) receptors to theophylline. Theophylline sensitive (TS) cells function as suppressors of pokeweed mitogen induced B cell differentiation into plasma cells while theophylline resistant (TR) cells function as helper/inducer cells in this reaction. The TS fraction is enriched for cells bearing receptors for the Fc portion of IgG (RFc.gamma.) while the TR fraction is depleted of RFc.gamma. bearing cells. Brief exposure of TR cells to adenosine or impromidine, an H2 histamine agonist, cause a rapid increase in the number of TR cells bearing RFc.gamma. and the development of radioresistant suppressor cell activity. The RFc.gamma. induced on TR cells by adenosine or impromidine are more stable in culture than the spontaneously occurring RFc.gamma. on TS cells. TS suppressor activity is radiosensitive and exposure of TS cells to 2(2-pyridyl)ethylamine, an H1 histamine agonist, results in a marked decrease in RFc.gamma. on TS cells and loss of TS suppressor activity. RFc.gamma. expression and the immunoregulatory function of T lymphocyte subsets apparently may be modified by drugs acting upon adenosine, H1 and H2 histamine recetpros.