Tracing HIV-1 transmission: envelope traits of HIV-1 transmitter and recipient pairs. Retrovirology
Oberle et al. investigated phenotypic virus characteristics of nine HIV-1 subtype B transmission pairs to define if transmitted/founder (T/F) viruses harbor distinct features that are crucial during the earliest stages of HIV-1 infection endowing viruses with a transmission advantage.
Their analyses revealed that recipient and transmitter viruses showed no signs of selection for specific Env modifications. Recipient viruses were resistant to circulating plasma antibodies of the transmitter but there was no difference between transmitted and founder virus in neutralization sensitivity to a large panel of entry inhibitors and neutralizing antibodies, in cell-cell transmission, and in replicative capacity. However, there was a higher sensitivity of several recipient virus isolates to interferon-α.
In sum, the study-findings suggest that contrary to previous studies resistance to IFNα cannot be a general driving force in T/F establishment. The finding that none of the other phenotypic properties consistently distinguished recipient from transmitter HIV-1 subtype B viruses suggests that transmission is to a considerable extent a stochastic event.