T cell surface antigen expression on lymphocytes of patients with AIDS during in vitro mitogen stimulation

Surface marker expression on peripheral blood mononuclear cells (PBMC) was evaluated daily in PHA- and PWM-stimulated cultures of eight AIDS patients and eight normals. Before culture, the patients' cells showed the characteristic decrease in OKT 4+ cells (normals 40.4%, patients 22.3%; P<0.001), increase in OKT 8+ cells (normals 27.6%, AIDS 38.4%; P=0.002), increase in OKT 10+ cells (normals 15.5%, AIDS 42.8%; P=0.002), and increase in HLA-DR+ cells (normals 11.4%, AIDS 28.7%; P=0.01). The percentage of OKT 11+ cells remained unchanged, while the percentage of OKT 3+ cells dropped over the first 2 days in PHA but not in PWM cultures of both groups (PHA: normals 69.8% to 35.1%; P=0.001, AIDS 56.5 to 38.5%; P=0.001, PWM: normals 62.8%-65.9%, AIDS 66.8% to 63.9%), and recovered in both groups by day 5. In PWM cultures OKT 3+ cells increased significantly in normals but not in AIDS (normals 62.6%-77.7%; P=0.04, AIDS 61.8 to 48.7%). OKT 4 expression decreased in normal PHA cultures after 1 day (38.9% to 29.6%; P=0.05) and then recovered by day 5. Its expression increased in AIDS PHA cultures by day 5 (18.0%-41.1%; P<0.001). The final percentage of OKT 4+ cells in AIDS cultures was within the normal range (35.0%-49.0%). OKT 8 expression increased in both study groups after PHA stimulation (normals 29.5%-50.4%; P=0.002, AIDS 37.4%-50.7%; P=0.02) and in normals but not AIDS after PWM stimulation (normals 28.9%-35.5%; P=0.004, AIDS 38.5%-35.6%). Because of the relative changes in expression of OKT 4 and OKT 8, the 4/8 ratio declined in the normal PHA cultures (1.89 to 1.03; P=0.1) and increased in the AIDS cultures (0.68-1.18; P=0.09). Also, the sum of OKT 4+ and OKT 8+ cells in PHA cultures increased from 68% to 94% whist expression of OKT 11 remained unchanged, indicating co-expression of these antigens on individual cells. Both PHA- and PWM-stimulated normal cells showed an increase in OKT 10 (PHA 16.0%-53.4%; P=0.01, PWM 16.1%-33.9%; P=0.03) and HLA-DR (PHA 8.6%-27.3%; P=0.03, PWM 12.5%-26.6%; P=0.07). In AIDS PHA cultures this did not change, and in their PWM cultures OKT 10 expression declined (44.8 to 23.0%; P=0.05). The PHA- and PWM-stimulated cultures of AIDS patients showed a marked deficit in generation of Tac (PHA increased from 5.4% to 77.1% in normals and from 3.2% to 48.0% in AIDS; P=0.001; PWM increased from 6.1% to 35.3% in normals, and from 5.0% to 15.5% in AIDS; P=0.04). Analysis showed that this deficit was limited to a reduced expression on small lymphocytes and that those cells that did become lymphoblasts expressed Tac normally. These results indicate that the poor blastogenic responses in AIDS are related to failure of OKT 10, HLA-DR, and Tac to increase after stimulation.