title: Factors contributing to the lack of human immunodeficiency virus type 1 (HIV-1) transmission in HIV-1-discordant partners.
abstract: Correlates of resistance to infection by human immunodeficiency virus type 1 (HIV-1) are important for defining potential therapeutic interventions and for prophylactic vaccination. In this study, 11 couples discordant in their HIV-1 infection status were prospectively evaluated for the presence of protective factors. Behavioral characteristics of all subjects entailed a high risk of transmission. Cytotoxic T lymphocyte (CTL) responses against viruses isolated from the infected partner, and against laboratory virus isolates, were detected in 5 (45%) of 11 HIV-negative partners, including a CCR5Delta32-homozygous and a heterozygous subject. No CTL responses were observed in 6 control unexposed subjects. Marked variation in lymphocyte susceptibility to viral infection was noted. Resistance attributable to major histocompatibility complex discordance or anti-major histocompatibility complex antibodies was not identified. These results suggest that a combination of factors, including cellular immunity, viral characteristics, and coreceptor integrity, may be involved in the persistent nontransmission of HIV.
authors.affiliation: Department of Pathobiology, University of Guelph, Guelph, Ontario, Canada. dbienzle@ovc.uoguelph.ca
authors.forename: D
authors.initials: D
authors.lastname: Bienzle
authors.forename: K S
authors.initials: KS
authors.lastname: MacDonald
authors.forename: F M
authors.initials: FM
authors.lastname: Smaill
authors.forename: C
authors.initials: C
authors.lastname: Kovacs
authors.forename: M
authors.initials: M
authors.lastname: Baqi
authors.forename: B
authors.initials: B
authors.lastname: Courssaris
authors.forename: M A
authors.initials: MA
authors.lastname: Luscher
authors.forename: S L
authors.initials: SL
authors.lastname: Walmsley
authors.forename: K L
authors.initials: KL
authors.lastname: Rosenthal
mesh_terms: D000328:Adult; D000906:Antibodies; D001402:B-Lymphocytes / Q000276:immunology; D015704:CD4 Antigens / Q000235:genetics / Q000276:immunology; D005260:Female; D005838:Genotype; D015658:HIV Infections / Q000235:genetics / Q000378:metabolism / Q000635:transmission*; D015497:HIV-1 / Q000276:immunology* / Q000302:isolation & purification / Q000502:physiology; D006649:Histocompatibility Antigens / Q000032:analysis / Q000145:classification / Q000276:immunology; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D019713:Receptors, CCR5 / Q000235:genetics* / Q000276:immunology; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology* / Q000502:physiology; D014162:Transfection
chemical_list: D000906:Antibodies; D015704:CD4 Antigens; D006649:Histocompatibility Antigens; D019713:Receptors, CCR5