L. Wakrim et al., SUPERINFECTION OF HIV-2-PREINFECTED MACAQUES AFTER RECTAL EXPOSURE TOA PRIMARY ISOLATE OF SIVMAC251, Virology, 221(2), 1996, pp. 260-270
To test the protection afforded by a weakly pathogenic HIV-2 isolate a
gainst the superinfection or development of SIV-induced disease, we in
trarectally challenged six HIV-P-preinfected rhesus monkeys with a pat
hogenic Isolate of SIVmac251. At the time of SIV challenge, none of th
ese HIV-2-infected animals was positive for virus isolation, p27-Gag a
ntigenemla, or HIV-2 provirus detection in PBMCs or peripheral lymph n
odes. However, all monkeys exhibited anti-HIV-2 antibody titers rangin
g from 10(2) to 10(3). Neutralizing antibodies against the challenge S
IV strain were also detected in two animals. After rectal exposure to
SIVmac251, five of the six HIV-2-preinfected macaques were superinfect
ed. SIVmac251 DNA sequences were detected repeatedly in the PBMCs of t
he five superinfected animals and the two controls, whereas no HIV-2 p
rovirus was detected for 14 months postchallenge. The one monkey that
resisted superinfection was negative for all SIV infection criteria. T
his monkey exhibited the highest anti-SIV ELISA and cross-neutralizing
antibody titers on the day of SIV challenge. Preinfection with a weak
ly pathogenic HIV-2 ROD isolate protected one of six macaques from inf
ection with the closely related pathogenic SIVmac251 isolate, but no p
rotection from the progression of disease was evidenced in the other f
ive. (C) 1996 Academic Press, Inc.