Measles virus modulates human T-cell somatostatin receptors and their coupling to adenylyl cyclase.

摘要: The possible role of immunomodulatory peptide somatostatin (SRIF) in measles virus (MV)-induced immunopathology was addressed by analysis SRIF receptors and their coupling to adenylyl cyclase mitogen-stimulated Jurkat T cells human peripheral blood mononuclear (PBMC). SRIF-specific were assayed semipurified membrane preparations using SRIF14 containing iodinated tyrosine at the first position amino acid chain ([125I]Tyr1) as a radioligand. A determination receptor number saturation radioligand binding equilibrium showed that cells, MV infection led dramatic decrease total number. virus-associated disappearance one (Ki2 = 12 +/- 4 nM [mean standard error mean [SEM]]; n 4) two sites identified control (Ki1 78 3 pM Ki2 SEM]; also observed. Almost identical results obtained for phytohemagglutinin-activated PBMC. In absence infection, present 111 31 17 2 2), whereas MV-infected only high-affinity 48 15 2) site remained. addition, reinforced inhibitory effects on activity, since maximal inhibition 1 microM 11% 4% versus 25% 3% (P < 0.05) infected cells. Moreover, severely impaired capacity be activated directly (by forskolin) or indirectly (via Gs protein-coupled vasoactive intestinal receptor). An assessment [methyl-3H]thymidine incorporation increased proliferative responses mitogens not Altogether, our data emphasize MV-associated alteration transduction appears related loss SRIF-dependent increase mitogen-induced proliferation.