Variable Stimulation of Adenylate Cyclase Activity by Vasoactive Intestinal-Like Peptides and β-Adrenergic Agonists in Murine T Cell Lymphomas of Immature, Helper, and Cytotoxic Types

We examined several cultured murine T cell lymphomas, induced by a radiation leukemia virus MuRadLV, including cell lines derived from immature T cells (5 clones of the BL/VL3 cell line), antigen-specific T helper cells (5 lines of the TL2 series), and one T cytotoxic cell line (NS8).With one exception (the TL2-9 cell line), these cells showed common characteristics: 1) an efficient adenylate cyclase system; 2) increased cyclic AMP production in response to at least one type of neurotransmitter, i.e., to the catecholamine isoproterenol and/or the neuropeptide VIP; 3) on the basis of adenylate cyclase stimulation, beta- adrenoceptors were of the beta 2 subtype and VIP receptors were of a «helodermin-preferring» subtype previously encountered in a human T lymphoblast cell line. Although we analyzed only a limited number of cell lines, it appeared that the immature T BL/VL3 clones responded to peptides of the VIP family with higher potency and efficacy than T helper and T cytotoxic cells.The membranes from the specific TL2-9 helper cell line were without adenylate cyclase activity in the presence of Gpp[NH]p, NaF, and GTP alone or GTP in the presence of isoproterenol or VIP.They produced cyclic AMP in the presence of Mn²⁺ and forskolin only, suggesting a defect in Gs as in S49 cyc mouse lymphosarcoma cells.This was further demonstrated by the absence of cholera toxin-stimulated ADP-ribosylation in TL2-9 membranes.