Accessory cell functions in mononuclear cell cultures uremic patients.

Abstract

Mononuclear cells (PBMC) were isolated from dialyzed patients and healthy control subjects. Lymphocyte responses to stimulation with optimal and suboptimal concentrations of lectin (PHA), or stimulation with T cell receptor antibody (Leu 4) were found decreased in the patient cultures. The separate and the combined effects of exogenous interleukin-1 (IL-1) and interleukin-2 (IL-2) were examined in PHA and Leu 4 stimulated cell cultures. Addition of IL-1 did not normalize the decreased proliferation response of the patient cultures. In contrast, addition of IL-2 alone clearly enhanced and almost normalized the response of patient cultures stimulated with suboptimal concentrations of PHA. The combined addition of IL-1 and IL-2 gave no evidence of an additive effect of IL-1 and IL-2. Cell cultures from uremic and normal HLA-identical relative were examined. Substitution of uremic adherent monocytes with normal adherent monocytes as accessory cells did not improve the uremic T cell responses to stimulation with PHA. Furthermore, uremic adherent cells did not suppress the normal T cell responses. These results suggest that uremic accessory cells support T cell activation and, in particular, do not suppress T cell responses. The effect of IL-2 in the present study as well as previous findings of decreased IL-2 production in patients cultures may indicate that uremia primarily influences the proliferation of T cells.