Important note: Information in this article was accurate in 1994. The state of the art may have changed since the publication date.
Replication of SIVmac251 and SIVB670 in vitro in placental syncytiotrophoblasts.
Symp Nonhum Primate Models AIDS. 1993 Sep 19-22;11:abstract no. 6. Unique Identifier : AIDSLINE PRIM11/94191655 Krugner-Higby LA; Schultz KT; Johnson KJ; Golos TG; Wisconsin Regional Primate Research Center, Madison.
Abstract:
We have infected rhesus placental cells with SIV as an in vitro model for studying mechanisms of maternal/fetal HIV transmission. Placental chorionic villi were obtained from rhesus macaques at Cesarean section and cytotrophoblast cells were isolated by differential centrifugation on a Percoll gradient. Cells were cultured for at least 7 days prior to inoculation during which cytotrophoblast cells differentiate to form multinuclear syncytiotrophoblasts (STBs). Cells were inoculated with either SIVmac251 or SIVB670. Previous experiments indicated that p27 core antigen could be found in culture supernatants 1-2 weeks post inoculation (pi), but was not detectable by 4 weeks pi. However, placental cells were still able to infect CEMX174 cells upon coculture. Therefore, experiments were done to determine a) if the trophoblast cultures support active virus replication, b) the immunophenotype of infected cells, and c) if the ability of the cells to support virus replication was dependent on the length of time the cells had been in culture. To demonstrate active viral replication, cells were washed twice after exposure to inoculum and supernatants collected at 0, 4, 8, 24, 48, 72, and 96 hrs and 1 and 2 wks pi were assayed for p27 core antigen. A period of viral eclipse (< 72 hrs) was followed by an increase in p27 core antigen in the supernatant within 96 hrs pi. Viral antigen was detectable in culture supernatants at 1-2 weeks pi as found previously. At one week pi, some infected cultures were fixed and prepared for electron microscopy or immunocytochemistry. Identify of infected cells was demonstrated by double immunostaining for p27 and CD68 (macrophages), or pregnancy-specific beta 1 glycoprotein (STBs). The predominant infected cell type was the STB: up to 50% of the cells were infected. Cultures also contained a small number of macrophages (< 1.0%), few of which were infected. Virus also was identified in the peripheral cytoplasm in infected STBs by electron microscopy. To investigate the temporal dynamics of virus replication, we inoculated cultures at 1-4 weeks after plating and assayed supernatants weekly for 4 weeks pi. Cell viability determinations were made throughout the experiment on replicate plates. The ability of freshly inoculated STB cultures to support active SIV replication declined progressively with time in culture, however, the decrease in replication was not due to cell death. Thus we have evidence that STB cells support transient, active replication of SIV in vitro and that transient viral replication is not solely due to decreased viability.
Keywords: Animal Cell Differentiation Cell Line Cell Separation/METHODS Cells, Cultured Centrifugation, Density Gradient Cesarean Section/VETERINARY Female Human Immunohistochemistry Macaca mulatta Macrophages/CYTOLOGY/MICROBIOLOGY Placenta/*CYTOLOGY/MICROBIOLOGY Pregnancy Pregnancy-Specific beta 1-Glycoprotein/ANALYSIS SIV/GENETICS/*PHYSIOLOGY/ULTRASTRUCTURE Time Factors Trophoblast/CYTOLOGY/*MICROBIOLOGY *Virus Replication ABSTRACT 940730
M9470863
AEGiS presents published material, reprinted with permission and neither endorses nor opposes any material. All information contained on this website, including information relating to health conditions, products, and treatments, is for informational purposes only. It is often presented in summary or aggregate form. It is not meant to be a substitute for the advice provided by your own physician or other medical professionals. Always discuss treatment options with a doctor who specializes in treating HIV.
Important note: Information in this article was accurate in 1994. The state of the art may have changed since the publication date.
