J. gen. Virol. (1982), 58, 195-198. Printed in Great Britain
Key words: CAEV/arthritis/monocytes/in vitro
195
Caprine Arthritis-Encephalitis Virus Infection of Caprine Monocytes
(Accepted 14 September 1981)
SUMMARY
Monocyte-enriched cultures of goat peripheral blood leukocytes were exposed to
caprine arthritis-encephalitis virus (CAEV) at an m.o.i, of 8 TCIDs0 per cell as
measured in goat synovial membrane cell cultures. At the time of infection, 90 % of
the adherent cells displayed characteristic macrophage markers of phagocytic
activity and cytoplasmic non-specific esterase. A productive infection was
established, with extracellular infectious virus titres reaching a maximum of 105.2
TCIDs0 per ml at day 4 post-infection. Synthesis of CAEV antigens was detected by
direct immunofluorescence and it was shown that 85% of the adherent cells
contained virus antigen by day 6 post-infection. A cytopathic effect, characterized
by giant cell formation and cell death, developed concomitantly with increased virus
replication.
Caprine arthritis-encephalitis (CAE) syndrome is a naturally occurring persistent virus
infection of goats (Crawford et al., 1980a). This disease syndrome is most often manifested
as (i)acute leuko-encephalomyelitis occurring with low incidence primarily in young goats
(Cork et aL, 1974) and (ii) chronic proliferative synovitis and periarthritis in a high percentage
of adult animals (Crawford et al., 1980b). The aetiological agent of this disease complex,
designated eaprine arthritis-encephalitis virus (CAEV), has been classified as a retrovirus
based on characteristic physical and biochemical features (Crawford et al., 1980a; Cheevers
et aL, 1981). In vivo, CAEV demonstrates a tropism for synovial membrane cells, but can
also be recovered from many other tissues including brain, lung, kidney and spleen (Adams
et al., 1980; P. Klevjer-Anderson, unpublished results). The CAE syndrome represents an
interesting chronic disease in that the joint lesion which develops as a resul