RT Journal Article SR Electronic(1) A1 Bieback, Karen A1 Breer, Claudia A1 Nanan, Ralph A1 Meulen, Volker ter A1 Schneider-Schaulies, SibylleYR 2003 T1 Expansion of human γ/δ T cells in vitro is differentially regulated by the measles virus glycoproteins JF Journal of General Virology, VO 84 IS 5 SP 1179 OP 1188 DO https://doi.org/10.1099/vir.0.19027-0 PB Microbiology Society, SN 1465-2099, AB Impaired proliferative response of lymphocytes after mitogenic stimulation ex vivo is a key feature of the generalized immunosuppression induced by measles virus (MV). Compelling evidence suggests that negative signalling by the MV glycoprotein (gp) complex and the surface of uninfected lymphocytes is essential for this effect. So far, the inhibitory activity of this complex applied to all lymphocyte subpopulations irrespective of the mode of stimulation and could not be overcome by external stimulation. This study shows that the isopentenyl pyrophosphate (IPP)/IL-2-stimulated expansion of human γ/δ T cell receptor (TCR) T cells from peripheral blood mononuclear cells (PBMCs) is inhibited efficiently when the MV gp complex is expressed on the surface of persistently MV-infected T or monocytic cells. In contrast, persistently infected B cells or infected human dendritic cells (DCs) do not interfere with expansion of γ/δ TCR T cells from PBMCs. These particular two cell populations, however, efficiently inhibit IPP/IL-2-stimulated expansion of γ/δ TCR T cells from purified T cells and this is reverted by resubstitution with monocytes. As revealed by filter experiments, cocultivation with B cells and DCs empower monocytes, at least partially by soluble mediators, to provide membrane contact-dependent costimulatory signals that neutralize the inhibitory effect of the MV gp complex. Thus, γ/δ TCR T cells are sensitive to MV gp-mediated inhibition; however, this is overcome efficiently by signals delivered from monocytes conditioned by B cells and DCs., UL https://www.microbiologyresearch.org/content/journal/jgv/10.1099/vir.0.19027-0