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 (II-I) and prostaglandin E 2 (PGE 2 ) 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-I release and a 6-fold increase of PGE 2 release in the growth medium. The growth reduction was partly counteracted by addition of Il-I and indomethacin. Addition of Il-I stimulated the PGE 2 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 PGE 2 showed no effect. These results suggest that TC have the capacity to interact with PBMC, and this potentially tissueprotective mechanism induced by TC may have clinical implications.