The HIV-1 transmission bottleneck.
It is well established that most new systemic infections of HIV-1 can be traced back to one or a limited number of founder viruses. Usually, these founders are more closely related to minor HIV-1 populations in the blood of the presumed donor than to more abundant lineages. This has led to the widely accepted idea that transmission selects for viral characteristics that facilitate crossing the mucosal barrier of the recipient's genital tract, although the specific selective forces or advantages are not completely defined. However, there are other steps along the way to becoming a founder virus at which selection may occur. These steps include the transition from the donor's general circulation to the genital tract compartment, survival within the transmission fluid, and establishment of a nascent stable local infection in the recipient's genital tract. Finally, there is the possibility that important narrowing events may also occur during establishment of systemic infection. This is suggested by the surprising observation that the number of founder viruses detected after transmission in intravenous drug users is also limited. Although some of these steps may be heavily selective, others may result mostly in a stochastic narrowing of the available founder pool. Collectively, they shape the initial infection in each recipient.
Division of Immunology, Department of Pathology, Falmouth 3.25, University of Cape Town, Anzio Rd, Observatory, Cape Town, 7925, South Africa.|International Centre for Genetic Engineering and Biotechnology, Cape Town, South Africa.|Department of Biological Sciences, University of Eldoret, Eldoret, Kenya.
Samuel Mundia
SM
Kariuki
Division of Medical Virology, Department of Pathology, University of Cape Town, Cape Town, South Africa.
Philippe
P
Selhorst
Virology Unit, Department of Biomedical Sciences, Institute of Tropical Medicine, Antwerp, Belgium.|Department of Biomedical Sciences, University of Antwerp, Antwerp, Belgium.
Kevin K
KK
Ariën
Division of Immunology, Department of Pathology, Falmouth 3.25, University of Cape Town, Anzio Rd, Observatory, Cape Town, 7925, South Africa. jeffrey.dorfman@uct.ac.za.
Jeffrey R
0000-0001-9938-8911
JR
Dorfman
D018562:Disease Transmission, Infectious; D005260:Female; D006678:HIV / Q000502:physiology*; D015658:HIV Infections / Q000635:transmission* / Q000821:virology*; D054884:Host-Pathogen Interactions; D006801:Humans; D008297:Male; D012641:Selection, Genetic
Bottleneck; Genital mucosa; HIV-1; Intravenous drug user; Transmission