AEGiS-12IAC: Genetic characteristics of SIV after intravenous, intrarectal or intravaginal exposure of macaques.

12th International AIDS Conference

Geneva, Switzerland - June 28-July 3, 1998

Genetic characteristics of SIV after intravenous, intrarectal or intravaginal exposure of macaques.

Int Conf AIDS 1998 Jun 28-Jul 3; 12:26 (abstract no. 11221)

Neildez O, Le Grand R, Caufour P, Cheret A, Matheux F, Vaslin B, Dormont D
CEA Service de Neurovirologie DSV/DRM, Fontenay AUX Roses, France.

OBJECTIVES: Viral populations recovered from sexually infected individuals are genotypically and phenotypically homogeneous during primary infection. They often represent minor variants from the related transmitters. However, it is uncleared whether this selection of transmitted viruses is due to a quasispecie compartmentalization in the transmitter, to a selection by the exposed mucosa, or to the selective expansion of particular variants in the host. To clarify this point, we compared the env genotype of transmitted viruses after intravenous (i.v.), intrarectal (IR) or intravaginal (IVAG) exposure of macaques to a pathogenic isolate of SIVmac251.

METHODS: The env gene of day 14 p.i. proviruses recovered from macaques PBMCs was directly sequenced. Further analysis of transmitted populations was performed by the PCR-SSCP method (single strand conformation polymorphism analysis).

RESULTS: Virological and immunological outcomes significantly differed between IVAG (transient viremia, late seroconversion) and i.v. or IR inoculated animals. Sequence analysis of the env gene revealed that the most variable region was V1. Three V1 distinct quasispecies were associated with vaginal transmission. The predominant variants from i.v. or IR infected animals widely differed from those of the IVAG inoculated monkeys and clustered into two other quasispecies. PCR-SSCP analysis of V1 quasispecies from blood, lymph nodes or genital secretions showed that major variants recovered from i.v. or IR inoculated macaques were not transmitted via the vaginal mucosa.

CONCLUSION: These results are in favour of a selection of specific viral variants by the vaginal mucosa. They highlight that specific mechanisms, peculiar to vaginal transmission, as particular cell tropism, implicate viral envelope structure.

Keywords: AEGIS, SIV, Macaca, Genes, env, Viremia, Vagina, Variation (Genetics), Polymorphism, Single-Stranded Conformational, Polymerase Chain Reaction, Selection (Genetics), Animal, Female, genetics, ICA12
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