M. Lalinn et al., ANTIBODY-DEPENDENT ENHANCEMENT AND PERSISTENCE IN MACROPHAGES OF AN ARBOVIRUS ASSOCIATED WITH ARTHRITIS, Journal of General Virology, 77, 1996, pp. 407-411
Ross River virus (RRV) is the aetiological agent of epidemic polyarthr
itis (EPA) a predominantly rheumatic disease afflicting up to 5000 Aus
tralians annually. We show here for the first time that macrophages ca
n be productively infected by RRV. Subneutralizing titres of anti-RRV
IgG (but not IgM) also showed classical antibody-dependent enhancement
(ADE) of RRV infection in macrophage and monocyte cell lines. No corr
elation between development of EPA and the preexistence of AIDE titres
was apparent, nor could sera raised against a related arbovirus, Barm
ah Forest, enhance RRV infection. Tumour necrosis factor-alpha, implic
ated in the immunopathogenesis of rheumatoid arthritis, was not secret
ed by RRV-infected monocytes or macrophages. Macrophage cell lines inf
ected with RRV were, however, capable of producing virus for over 50 d
ays. RRV-induced arthritis may therefore be due to the persistent prod
uctive infection of macrophages, perhaps established by a brief period
of ADE early in infection.