RT Journal Article SR Electronic(1) A1 Flanagan, James A1 Middeldorp, Jaap A1 Sculley, TomYR 2003 T1 Localization of the Epstein–Barr virus protein LMP 1 to exosomes JF Journal of General Virology, VO 84 IS 7 SP 1871 OP 1879 DO https://doi.org/10.1099/vir.0.18944-0 PB Microbiology Society, SN 1465-2099, AB The Epstein–Barr virus latent membrane protein (LMP 1) functions as a constitutively active signalling molecule and associates in lipid rafts clustered with other signalling molecules. Using immunofluorescent confocal microscopy, LMP 1 was shown to have an heterogeneous distribution among individual cells which was not related to the cell cycle stage. LMP 1 was shown to localize to intracellular compartments in cells other than the plasma membrane. Co-labelling of cells with both an LMP 1 antibody and an antibody to the Golgi protein GS15 revealed that the intracellular LMP 1 partly co-localized with the Golgi apparatus. Further confirmation of intracellular LMP 1 localization was obtained by immunoelectron microscopy with rabbit polyclonal LMP 1 antibodies and cryosectioning. As well as being present in intracellular foci, LMP 1 co-localized in part with MHC-II and was present on exosomes derived from a lymphoblastoid cell line. Preparations of LMP 1 containing exosomes were shown to inhibit the proliferation of peripheral blood mononuclear cells, suggesting that LMP 1 could be involved in immune regulation. This may be of particular relevance in EBV-associated tumours such as nasopharyngeal carcinoma and Hodgkin's disease, as LMP 1-containing exosomes may be taken up by infiltrating T-lymphocytes, where LMP 1 could exert an anti-proliferative effect, allowing the tumour cells to evade the immune system., UL https://www.microbiologyresearch.org/content/journal/jgv/10.1099/vir.0.18944-0