EARLY APPEARANCE OF ANTIBODIES TO SIMIAN IMMUNODEFICIENCY VIRUS IN SALIVA AND SERUM OF INFECTED MACAQUES

Simian immunodeficiency virus (SIV) infection in macaques is an import ant animal model for human immunodeficiency virus infection in humans. This study evaluated the temporal development of antibodies to SIV in the parotid saliva of macaques inoculated with the virus and compared these findings with the development of antibodies to SIV in the anima ls' sera. Three animals (ages, 14, 18, and 18 years) were inoculated w ith the macrophagetropic strain SIV(mac)239. Prior to inoculation and at consecutive weekly intervals during a four-week period following th e initial virus inoculations, parotid saliva and serum were collected from each animal. A fourth animal (age, 9 years) served as a negative control, and the fifth and sixth animals (ages, 2 and 22 years) served as positive controls (6 and 18 months postinoculation, respectively) with SIV(mac)239. Saliva and serum samples were reacted against SIV an tigen in Western blots (immunoblots) prepared in the standard fashion to determine the presence of antibodies. The reactions of these antige n-antibody complexes with biotinylated anti-human immunoglobulin A (Ig A), IgM, and IgG and biotinylated anti-human secretory component (SC) determined the class of antibody present or the presence of SC in the original parotid saliva or serum samples. In infected animals, the IgM to SIV was detectable in serum and saliva at 13 days, and antiviral I gA and IgG in serum and saliva were detectable at 20 to 27 days postin oculation. The antibody to SC reacted to saliva from only two animals at 20 and 27 days, and long-term positive controls were positive for S C in saliva, indicating that either secretory IgA or secretory IgM was present in these samples, Antibodies to SIV(mac)239 antigens have the refore been detected in saliva as early as 13 days postinfection. Sali va may be as useful as serum as a diagnostic specimen and/or disease-m onitoring method in this important animal model.