AEGiS-11IAC: Infectivity of different HIV-1 strains in the human placenta in vitro.

11th International AIDS Conference

Vancouver, British Columbia — July 7-12, 1996

Infectivity of different HIV-1 strains in the human placenta in vitro.

Int Conf AIDS 1996 Jul 7-12; 11:218 (abstract no. Tu.A.145)
Polliotti BM, Demeter L, Subbarao S, Keesling S, Lee GR, Caba J, Panigel M, Nahmias AJ, Reichman R, Miller RK; Dept. of Obst/Gynec, Univ of Rochester Medical Center, School of Medicine & Dentistry, NY, USA. Fax: (716) 244-1234. E-mail: BPOLLIOTTI@OBGYN.ROCHESTER.EDU.

OBJECTIVE: The aim of this study is to investigate the infectivity of HIV-1 strains in the human placenta in vitro.

METHODS: Three viral strains are utilized: two laboratory strains: Bal and IIIb and VI-5, isolated from an HIV-infected baby at birth (viral culture and PCR positive). Bal and VI-5 are non-syncytium-inducing (non-SI) as assessed in MT-2 cells and both are macrophage-tropic. IIIb is syncytium-inducing (SI) as assessed in MT-2 cells and is lymphocytetropic. Human placentae from first and third trimesters are incubated for 24 hours with free virus from each strain before an intensive rinse to remove the inoculum. Placental villi are cultured for 5 days post inoculation. Infection is documented by p24 release into the culture medium and by viral DNA detection via PCR - gag gene using two primer pairs (JM850/JM851 and JM852/JM853) after extraction from the incubated tissue.

RESULTS: Only the two non-SI strains (Bal and VI-5) are able to infect placental tissue both from first trimester and full term: p24 production increases during the third day post inoculation and remains sustained for the next three days; PCR detection of gag gene is consistently positive at the end of the incubation. P24 release increase can be completely abolished by the use of HIV-Ig (1/100 for one hour exposure before inoculation). The SI strain (IIIb) cannot infect placental tissue: p24 remains at background levels and PCR detection, like non-infected control, is negative.

CONCLUSION: We can infect first and third trimester human placental tissue with different HIV-1 strains. In addition, non-SI viral strains may be more efficient in infecting in vitro the human placenta, which has been observed for strains that infect the baby in utero.

Keywords: AEGIS, HIV-1, Genes, gag, Placenta, DNA, Viral, Giant Cells, Macrophages, HIV-1 Reverse Transcriptase, Polymerase Chain Reaction, Chorionic Villi, Infant, Human, In Vitro, genetics, ICA11

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TuA145