Strong HIV-1-specific T cell responses in HIV-1-exposed uninfected infants and neonates revealed after regulatory T cell removal.
PLoS One
; 1: e102, 2006 Dec 20.
Article
en En
| MEDLINE
| ID: mdl-17183635
ABSTRACT
BACKGROUND:
In utero transmission of HIV-1 occurs on average in only 3%-15% of HIV-1-exposed neonates born to mothers not on antiretroviral drug therapy. Thus, despite potential exposure, the majority of infants remain uninfected. Weak HIV-1-specific T-cell responses have been detected in children exposed to HIV-1, and potentially contribute to protection against infection. We, and others, have recently shown that the removal of CD4(+) CD25(+) T-regulatory (Treg) cells can reveal strong HIV-1 specific T-cell responses in some HIV-1 infected adults. Here, we hypothesized that Treg cells could suppress HIV-1-specific immune responses in young children. METHODOLOGY/PRINCIPALFINDINGS:
We studied two cohorts of children. The first group included HIV-1-exposed-uninfected (EU) as well as unexposed (UNEX) neonates. The second group comprised HIV-1-infected and HIV-1-EU children. We quantified the frequency of Treg cells, T-cell activation, and cell-mediated immune responses. We detected high levels of CD4(+) CD25(+) CD127(-) Treg cells and low levels of CD4(+) and CD8(+) T cell activation in the cord blood of the EU neonates. We observed HIV-1-specific T cell immune responses in all of the children exposed to the virus. These T-cell responses were not seen in the cord blood of control HIV-1 unexposed neonates. Moreover, the depletion of CD4(+) CD25(+) Treg cells from the cord blood of EU newborns strikingly augmented both CD4(+) and CD8(+) HIV-1-specific immune responses. CONCLUSIONS/SIGNIFICANCE:
This study provides new evidence that EU infants can mount strong HIV-1-specific T cell responses, and that in utero CD4(+) CD25(+) T-regulatory cells may be contributing to the lack of vertical transmission by reducing T cell activation.
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Complicaciones Infecciosas del Embarazo
/
Infecciones por VIH
/
VIH-1
/
Linfocitos T Reguladores
Tipo de estudio:
Etiology_studies
/
Incidence_studies
/
Observational_studies
Límite:
Adult
/
Female
/
Humans
/
Infant
/
Newborn
/
Pregnancy
Idioma:
En
Revista:
PLoS One
Asunto de la revista:
CIENCIA
/
MEDICINA
Año:
2006
Tipo del documento:
Article
País de afiliación:
Estados Unidos