Development of a chronically catheterized maternal-fetal macaque model to study in utero mother-to-fetus HIV transmission: A preliminary report

: The lack of a representative animal model that permits frequent in utero fetal blood sampling is a major limiting factor for the study of maternal-fetal HIV transmission. Therefore, we have developed a maternal-fetal virus infection model using chronically catheterized macaques to simultaneously study the time-course of viral infection in the mother and the response of the fetus to maternal HIV infection. Pregnant macaques were infected with 103 infectious units of HIV-2287; every 3 days blood samples from both the mother and the fetus as well as amniotic fluid samples were collected. We found a varying degree of peak and time-to-peak virus load, virus-infected PBMCs, and free virus (determined by QC-RNA-PCR method) in maternal blood. Two of the three mothers with more than 108 copies of viral RNA/ml of plasma at peak viremia transmitted the virus to their fetuses at about 14 days post-infection. As observed with HIV-2287 infected mothers, virus-infected fetuses also produced a rapid rate of CD4+ cell decline in utero.