Interaction between proximal tubular cells and allogenic leukocytes mediated by interleukin-1 and prostaglandin

The present study investigates the interaction between proximal tubular cells (TC) and peripheral blood mononuclear cells (PBMC) with respect to interleukin-1 (Il-1) and prostaglandin E2 (PGE2) in co-culture experiments. Stimulator cells were proliferating human TC propagated in culture and characterized by expression of ICAM-1 and MHC-class II in response to cytokines. The presence of TC reduced spontaneous growth of PBMC by 42%, with a concomittant 50% reduction of Il-1 release and a 6-fold increase of PGE2 release in the growth medium. The growth reduction was partly counteracted by addition of II-1 and indomethacin. Addition of II-1 stimulated the PGE2 release from PBMC and TC by about 75% and 500%, respectively. Growth of TC cultured alone was inhibited by II-1 in a dose-dependent manner, with maximum effect at 10 U/ml, whereas PGE2 showed no effect. These results suggest that TC have the capacity to interact with PBMC, and this potentially tissue-protective mechanism induced by TC may have clinical implications.