Human immunodeficiency virus type 1 infection of choriocarcinoma-derived trophoblasts.
An in vitro model of placental infection by human immunodeficiency virus type 1 (HIV-1) was established using human choriocarcinoma-derived trophoblast lines exposed to free HIV-1 or HIV-1-infected lymphocytic and monocytic cells. Virus infectivity was evaluated by measuring both the levels of p24 HIV-1 antigen and reverse transcriptase activity either from indicator MT-4 lymphocytes after co-cultivation with infected trophoblasts or directly from trophoblast cultures. None of the tested trophoblast lines were permissive, in a detectable manner, to infection by cell-free virus. Furthermore, there were no signs of infection when trophoblasts were exposed to HIV-1-carrying ACH-2 and U1 cells with impaired adhesion capacity. However, the exposure to MOLT-4/IIIB lymphocytes or U937/YH5 monocytes that adhere to substrate cells resulted invariably in productive infection. The ultrastructure of the trophoblasts suggests endocytosis of HIV-1. It appears that the infection of the host cell results from the escape of virions from degradation in lysosomes. Alternatively, HIV-1 may enter by budding directly from the lymphocyte surface into the cytoplasm of trophoblasts. These results confirm previous studies and suggest that CD4-negative placental trophoblasts--the only foetal cells in direct contact with maternal blood--can be susceptible to HIV-1 infection.
Bourinbaiar
A S
AS
Pediatrics Department, NYU Medical Center, NY 10016.
Nagorny
R
R
D002822:Choriocarcinoma / Q000382:microbiology*; D015658:HIV Infections / Q000635:transmission; D015497:HIV-1 / Q000254:growth & development* / Q000648:ultrastructure; D006801:Humans; D008214:Lymphocytes / Q000382:microbiology; D009000:Monocytes / Q000382:microbiology; D014327:Trophoblasts / Q000166:cytology / Q000382:microbiology*; D014407:Tumor Cells, Cultured