Fig. 2.
Anti-simian immunodeficiency virus (SIV) antibody levels in cervicovaginal secretions (CVS) of targeted iliac lymphnode-immunized rhesus macaques before and after intravaginal challenge with SIVmac251. (I and II) Group A, whole SIV-immunized animals (22575, 24331, 25428) had (I) immunoglobulin (Ig) G antibodies to SIV, and (II) detectable anti-SIV IgA in vaginal secretions at some point prior to challenge. One animal (22575) had IgA antibodies to SIV in CVS at the time of challenge (indicated by asterisk and dashed vertical line). After challenge, all the animals had anti-SIV IgG and IgA antibodies in CVS. (III and IV) Group B, p27 and gp120 immunized animals, (III) two animals (21747 and 24428) had IgG antibodies to SIV and (IV) one animal (21747) had IgA antibodies to SIV at time of the challenge. All these animals were anti-SIV IgG and IgA antibody-positive at 4 weeks post-challenge. (V and VI) Group D, Pr55 and gp130 immunized animals (20634, 22212, 22590), (V) all animals had anti-SIV IgG in vaginal secretions before challenge, and (VI) two animals (22590 and 22212) had anti-SIV IgA antibodies to SIV in CVS before challenge. After challenge, anti-SIV IgG and IgA were detected in the CVS of all animals. Anti-SIV IgA had a transient pattern but was detectable at least one timepoint after challenge. The displayed numerical value is the ratio of the difference in optical density (ΔOD) of the sample to the cut-off value (see Materials and methods for explanation). A ΔOD/CO ratio of < 2 was considered negative (indicated by horizontal dashed line). It was estimated that the sample collection technique resulted in at least a 100-fold dilution of the secretions.