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 ute ro fetal blood sampling is a major limiting factor for the study of ma ternal-fetal HIV transmission. Therefore, we have developed a maternal -fetal virus infection model using chronically catheterized macaques t o simultaneously study the time-course of viral infection in the mothe r and the response of the fetus to maternal HIV infection. Pregnant ma caques were infected with 10(3) infectious units of HIV-2(287); every 3 days blood samples from both the mother and the fetus as well as amn iotic fluid samples were collected. We found a varying degree of peak and time-to-peak virus load, virus-infected PBMCs, and free virus (det ermined by QC-RNA-PCR method) in maternal blood. Two of the three moth ers with more than 10(8) copies of viral RNA/ml of plasma at peak vire mia transmitted the virus to their fetuses at about 14 days post-infec tion. As observed with HIV-2(287) infected mothers, virus-infected fet uses also produced a rapid rate of CD4(+) cell decline in utero.