PubMed Health⌕ Search

Biomedical subjects

G Gromo

Publications and source records attributed to G Gromo.

47 records · Page 3Linked to original sources
PubMed1983

Spontaneous "in vitro" variations of theophylline sensitivity in human peripheral blood lymphocytes.

Theophylline reversibly inhibits E rosette formation by a portion of human circulating T lymphocytes. We investigated the effect of theophylline on E rosette formation and intracellular content of cyclic nucleotides (cAMP, cGMP). When the amine is added to 15 human healthy donors' lymphocytes either before or after 24 hours of culture at 37 degrees C, in absence of mitogens, a portion of theophylline-sensitive T cells spontaneously becomes theophylline-resistant after 24 hours of culture. While the intracellular content of cAMP does not significantly vary, the ability of theophylline to induce an increase of cAMP appears to be impaired after 24 hours of culture. The possible correlation between theophylline resistance and impaired turnover of cAMP in the cultured lymphocytes is discussed.

Cyclic AMP↗
PubMedDate not supplied

Signal requirements in the step-wise functional maturation of cytotoxic T lymphocytes.

The generation of effector cytotoxic T lymphocytes from resting precursors proceeds through a series of steps in a pathway that, in aggregate, involves both proliferation and development of cytotoxicity. To understand the relationship of the various signals (mitogens and/or lymphokines) that bring about progress along this pathway, it is desirable to define a series of 'minimal signals', each of which stimulates the cell to proceed to a further stage in this process of differentiation. Stimulation of lymphocytes with two different monoclonal antibodies directed against the CD2 surface molecule induces a proliferative response; we report here that both CD4+ and CD8+ cells proliferate in response to such a stimulus but do not develop cytotoxicity. Addition of recombinant gamma-interferon (rIFN-gamma) or recombinant IL-2 (rIL-2) to the activated cells leads to acquisition of cytotoxic status by the CD8+ cells but not the CD4+ cells. The availability, in addition to precursors and effectors, of an apparently intermediate stage in the form of proliferating CD8+ cells that are non-cytotoxic should facilitate both cellular and molecular studies of this maturation pathway; the differences between CD4+ and CD8+ cells in development of cytotoxicity under these experimental conditions is a valuable model for understanding differentiation of T lymphocytes.

Cells, Cultured↗