Cells transformedby Kirsten murine sarcoma virus (Ki-MSV) have basal adenylate cyclase activity (AC) higher than control cells and comparable level of forskohn-stimulated AC activity. Moreover, a htgher protem kinase C (PKC) activtty was found to be present in the transformed cells. The molecular mechanism underlying the Increase of AC activtty was mvesttgated. Our findmgs strongly suggest that this biochemtcal event is due to a marked decrease of the LX, negative control of the enzyme. even though the a, of transformed cells appears to possess fully functional domains Interacting wtth both the effector enzyme and the agonist-acttvated receptor.

The treatment of human peripheral blood mononuclear cells (PBMC) with micromolar concentrations of SV-IV, a major protein secreted from the rat seminal vesicle epithelium, promotes in this cell population a marked cytotoxic activity against the Raji lymphoblastoid cell line. This activity is apparently due to cell-to-cell contact interactions. The expression of HLA DR on Raji cells has a modulatory effect on the SV-IV-induced cytotoxic activity. The experimental evidence strongly suggests that the cytotoxic effector cells are functionally activated NK cells.

The treatment of human peripheral blood mononuclear cells (PBMC) with micromolar concentrations of SV-IV, a major protein secreted from the rat seminal vesicle epithelium, promotes in this cell population a marked cytotoxic activity against the Raji lymphoblastoid cell line. This activity is apparently due to cell-to-cell contact interactions. The expression of HLA DR on Raji cells has a modulatory effect on the SV-IV-induced cytotoxic activity. The experimental evidence strongly suggests that the cytotoxic effector cells are functionally activated NK cells. Int.