title: Frequent intratype neutralization by plasma immunoglobulin a identified in HIV type 2 infection.
abstract: Human immunodeficiency virus type 2 (HIV-2) is less transmissible and less pathogenic compared to HIV-1 and, when matched for CD4(+) T cell count, the plasma viral load in HIV-2-infected individuals is approximately one log lower than in HIV-1-infected individuals. The explanation for these observations is elusive, but differences in virus controlling immunity generated in the two infections may be contributing factors. In the present study, we investigated neutralization by immunoglobulin A (IgA), in parallel with IgG, purified from plasma of HIV-1, HIV-2, and HIV-1/HIV-2 dually (HIV-D) infected individuals. Neutralization was analyzed against HIV-1 and HIV-2 isolates using a plaque reduction assay. In HIV-2 infection, intratype-specific neutralization by IgA was frequently detected, although at a lesser magnitude then the corresponding IgG neutralizing titers. In contrast, neutralization by IgA could rarely be demonstrated in HIV-1 infection despite similar plasma IgA levels in both infections. In addition, IgA and IgG of HIV-D plasma neutralized the HIV-2 isolate more potently than the HIV-1 isolate, suggesting that the difference between neutralizing activity of plasma IgA and IgG depends on the virus itself. Taken together, these findings suggest that both IgA and IgG add to the potent intratype neutralizing activity detected in HIV-2 plasma, which may contribute to virus control in HIV-2 infection.
authors.affiliation: Department of Laboratory Medicine Lund, Lund University, Lund, Sweden. gulsen.ozkaya_sahin@med.lu.se
authors.forename: Gülşen
authors.initials: G
authors.lastname: Özkaya Şahin
authors.forename: Fredrik
authors.initials: F
authors.lastname: Månsson
authors.forename: Angelica A
authors.initials: AA
authors.lastname: Palm
authors.forename: Elzbieta
authors.initials: E
authors.lastname: Vincic
authors.forename: Zacarias
authors.initials: Z
authors.lastname: da Silva
authors.forename: Patrik
authors.initials: P
authors.lastname: Medstrand
authors.forename: Hans
authors.initials: H
authors.lastname: Norrgren
authors.forename: Eva Maria
authors.initials: EM
authors.lastname: Fenyö
authors.forename: Marianne
authors.initials: M
authors.lastname: Jansson
mesh_terms: D000328:Adult; D057134:Antibodies, Neutralizing / Q000276:immunology* / Q000302:isolation & purification; D005260:Female; D015483:HIV Antibodies / Q000276:immunology* / Q000302:isolation & purification; D015658:HIV Infections / Q000276:immunology* / Q000821:virology*; D015497:HIV-1 / Q000276:immunology; D015498:HIV-2 / Q000276:immunology*; D006801:Humans; D007070:Immunoglobulin A / Q000276:immunology* / Q000302:isolation & purification; D009500:Neutralization Tests; D010949:Plasma / Q000276:immunology*; D010948:Viral Plaque Assay; D055815:Young Adult
chemical_list: D057134:Antibodies, Neutralizing; D015483:HIV Antibodies; D007070:Immunoglobulin A