Biomedical subjects
Publications and source records attributed to D Pende.
Murine monoclonal antibodies (MoAb) to distinct determinants of human Ia antigens and low doses of prednisone induce different effects on the autologous mixed lymphocyte reaction (MLR), stimulated by PHA-T cells or by non-T cells, and on allogeneic MLRs. These results suggest that distinct domains of Ia antigens and/or mechanisms are involved in these types of MLRs.
Human peripheral blood T cells were cloned under conditions allowing the clonal expansion of virtually all T cells. Clones derived from T4+ or T4- (T8+) subsets were screened for their ability to induce B cell proliferation either in the Staphylococcus aureus Cowan-I (SAC)-driven assay or in the costimulation assay based on the use of anti-mu antibodies. BCGF activity in the SAC- and in the anti-mu-driven system was displayed by 13% and 15% T8+ clones, respectively, while 74% and 79% T4+ clones had BCGF activity in the same assay. SN of clones with BCGF activity were further screened for their susceptibility to the inhibition by CM 269 (anti-IL-2 receptor) monoclonal antibody. All clones were inhibited in the SAC assay, whereas several clones were partially or totally resistant to inhibition in the anti-mu assay. Nine of such non-inhibited clones were further analyzed for their ability to produce gamma-IFN (known to act as a BCGF) and IL-2: six of them were found to produce gamma-IFN, while none produced any detectable IL-2 activity.
The present experiments were designed to perform a further investigation of the cell lineage of lymphokine-activated killer (LAK) cells. In the presence of adherent cells both T and not-T cells, separated on the basis of rosette formation with sheep erythrocytes (E rosettes), generated LAK activity after short-term culture in recombinant interleukin-2 in 5 different individuals tested. Since at the termination of the culture more than 98% of cells were T11-positive, it is evident that both LAK precursor and effector cells may belong to the T cell lineage. By applying a culture technique which allows the clonal expansion of virtually all T cells, we further selected and analyzed T cell clones with LAK activity. Under the culture conditions used, LAK clones represented approximately 4% of all proliferating clones. All had cytolytic activity against K562 target cells as well and also released large amounts of gamma-interferon following phytohemagglutinin stimulation.
Four clones were isolated from CD3+ 4- 8- normal peripheral blood T lymphocytes. They lacked expression of the typical alpha/beta T cell receptor, as assessed by reactivity with the WT31 monoclonal antibody (mAb) recognizing a non-polymorphic structure of the alpha/beta heterodimer. All the four clones lysed the natural killer-sensitive K562 target cells and released interleukin-2 following stimulation with phytohemagglutinin. After cell treatment with the cross-linking agent dithiobis-succinimidyl-propionate, molecules immunoprecipitated with an anti-CD3 mAb were represented by a major 45-kD and a minor 43-kD band. These molecules were different from typical alpha/beta molecules and are likely to represent the molecular product of the human gamma gene.