Wc. Lee et al., ELECTRON-MICROSCOPE STUDIES OF THE REPLICATION OF A BRITISH ISOLATE OF MAEDI-VISNA VIRUS IN MACROPHAGES AND SKIN CELL-LINES, Veterinary microbiology, 49(1-2), 1996, pp. 93-104
The replication of EV1, a British isolate of maedi visna virus (MVV),
in macrophages has not previously been studied, We therefore used tran
smission and scanning electron microscopy (TEM and SEM respectively) t
o compare the replication of EV in macrophages versus skin cell lines.
Monocyte-derived macrophages (MDM), alveolar macrophages (AM) and ski
n cell lines were all permissive for replication by EV1. Virus grew ra
pidly and to high titers in skin cell lines and mature MDM. However re
plication was slower in less mature MDM or AM. Virion budding occurred
through (i) cytoplasmic membranes only (skin cells), (ii) cytoplasmic
and vesicular membranes (MDM) or (iii) Yesicular membranes only (AM).
This meant that virions accumulated in vacuoles within macrophages. R
etroviral intracytoplasmic type A particles were seen in the cytoplasm
of AM and MDM infected with strain EV1, but not MDM infected with str
ain 1514 (an Icelandic MVV strain) and were shown to contain MVV gag a
ntigen by immunogold staining.