Immune defence against HIV-1 infection in HIV-1-exposed seronegative persons

Citation
Sc. Schmechel et al., Immune defence against HIV-1 infection in HIV-1-exposed seronegative persons, IMMUNOL LET, 79(1-2), 2001, pp. 21-27
Citations number
9
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Immunology
Journal title
IMMUNOLOGY LETTERS
ISSN journal
0165-2478 → ACNP
Volume
79
Issue
1-2
Year of publication
2001
Pages
21 - 27
Database
ISI
SICI code
0165-2478(20011101)79:1-2<21:IDAHII>2.0.ZU;2-2
Abstract
Rare individuals who are repeatedly exposed to HIV-1 through unprotected se xual contact fail to acquire HIV-1 infection. These persons represent a uni que study population to evaluate mechanisms by which HIV-1 replication is e ither prevented or controlled. We followed longitudinally a group of health y HIV-1 seronegative persons each reporting repeated high-risk sexual activ ities with their HIV-1-infected partner at enrollment. The volunteers were primarily (90%) male homosexuals, maintaining high risk activities with the ir known infected partner (45%) or multiple other partners (61%). We evalua ted the quantity and specificity of HIV-1-specific T cells in 31 exposed se ronegatives (ES) using a IFN-gamma ELISPOT assay to enumerate T cells recog nizing epitopes within HIV-1 Env, Gag, Pol and Nef. PBMC from only three of the 31 volunteers demonstrated ex vivo HIV-1-specific IFN-gamma secretion, in contrast to nearly 30% exhibiting cytolytic responses in previous studi es. These findings suggest that if T cell responses in ES are induced by HI V-1 exposure, the frequency is at low levels in most of them, and below the level of detection using the ELISPOT assay. Alternative approaches to impr ove the sensitivity of detection may include use of dendritic cells as anti gen-presenting cells in the ex vivo assay and more careful definition of th e risk behavior and extent of HIV-1 exposure in conjunction with the evalua tion of T cell responses. (C) 2001 Elsevier Science B.V. All rights reserve d.