[71] RECOMBINATION FOLLOWING SUPER-INFECTION BY HIV-1

2nd International AIDS Society Conference on HIV Pathogenesis and Treatment

Paris, France - July 13 - 16, 2003

[TITLE:] RECOMBINATION FOLLOWING SUPER-INFECTION BY HIV-1

[AUTHOR(S):] G Fang¹, B Weiser^1,2, C Kuiken³, S Philpott¹, S Rowland-Jones⁴, F Plummer⁵, J Kimani⁶, CH Chen¹, B Shi¹, R Kaul^5,6, J Bwayo⁶, O Anzala⁶ and H Burger^1,2
¹Wadsworth Center, NY State Dept. of Health, Albany, NY, USA; ²Dept. of Medicine, Albany Medical College, Albany, NY, USA; ³Los Alamos National Laboratory, Los Alamos, NM, USA; ⁴ Institute of Molecular Medicine, Univ. of Oxford, Oxford, UK; ⁵ Dept. of Medical Microbiology, Univ. of Manitoba, Winnipeg, Canada; and ⁶ Dept. of Medical Microbiology, Univ. of Nairobi, Nairobi, Kenya

IAS Conf HIV Pathog Treat 2003 Jul 13-16;2nd: Abstract No. 71
Antiviral Therapy 2003; 8(Suppl. 1):S202

[ABSTRACT:] The identification of new HIV-1 recombinants between genetically distinct subtypes strongly suggests that superinfection occurs, leading to subsequent recombination. These linked events, however, have not been observed in patients. We searched for evidence of superinfection in Africa, where multiple HIV-1 subtypes exist, by examining serial blood samples from highly exposed chronically infected women in Nairobi’s Pumwani Sex Workers Cohort. We performed serial, complete HIV-1 RNA sequence analyses from a Kenyan long-term survivor who was untreated. Complete HIV-1 RNA sequences were first derived from plasma obtained in 1986, when the woman had been HIV seropositive for at least 21 months; this sequence was entirely subtype A. The sequences obtained from plasma in 1995 and 1997, however, were subtype A/C recombinants. A similarity plot demonstrated that the subtype A fragment in 1995 and 1997 was derived from the original 1986 A sequence. To determine whether subtype C sequences were present as minor species in 1986, heteroduplex tracking assays were performed. The subtype C sequences were not detectable in 1986. We observed intersubtype recombination taking place between the original nonrecombinant subtype A strain and the superinfecting subtype C strain. This finding helps to explain the rising prevalence of recombinant HIV-1 in the world. Furthermore, it illustrates that chronic infection with one strain may not provide protection against challenge from another. Recombination resulting from superinfection with diverse strains may pose problems for eliciting broad immune responses necessary for an effective vaccine.

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