Passive infusion of immune serum into simian immunodeficiency virus-infected rhesus macaques undergoing a rapid disease course has minimal effect on plasma viremia

Citation
Jm. Binley et al., Passive infusion of immune serum into simian immunodeficiency virus-infected rhesus macaques undergoing a rapid disease course has minimal effect on plasma viremia, VIROLOGY, 270(1), 2000, pp. 237-249
Citations number
70
Categorie Soggetti
Microbiology
Journal title
VIROLOGY
ISSN journal
00426822 → ACNP
Volume
270
Issue
1
Year of publication
2000
Pages
237 - 249
Database
ISI
SICI code
0042-6822(20000425)270:1<237:PIOISI>2.0.ZU;2-9
Abstract
Antibody responses are often considered to play only a limited role in cont rolling viremia during chronic infections with human or simian immunodefici ency virus (SIV). We investigated this by determining the effect of passive ly infused antibody on plasma viremia in infected rhesus macaques. The emph asis of the study was to understand the mechanism(s) underlying any observe d effects. We infused serum immunoglobulins (SIVIG) purified from SIV(mac)2 51-infected macaques into other SIV(mac)251-infected macaques. The rapid pr ogressor recipients had high Viral loads but negligible titers of antibodie s to SIV. Thus, we could significantly increase antibody liters with exogen ous SIVIG. Despite restoring anti-SIV titers to levels typical of macaques with a normal disease course, SIVIG had only a modest effect on plasma SIV RNA and cell-associated viral load; the maximum, transient, reduction was t hreefold. The decrease in plasma RNA commenced within 1-2 h of SIVIG infusi on, the nadir was at 12 h, and then a rebound occurred. A two- to threefold drop in cell-associated viral RNA was simultaneous with the decrease in pl asma RNA. The kinetics of the viremia changes are inconsistent with neutral ization of new cycles of infection. More likely, perhaps unexpectedly is th at infused antibodies killed SIV-infected cells, via an effector mechanism such as antibody-dependent cellular cytotoxicity. (C) 2000 Academic Press.