Identification and biochemical characterization of human plasma soluble IL-7R: lower concentrations in HIV-1-infected patients.
J Immunol
; 182(12): 7389-97, 2009 Jun 15.
Article
em En
| MEDLINE
| ID: mdl-19494261
ABSTRACT
The IL-7R alpha-chain and the common gamma-chain (gamma(c)) are both components of IL-7R. Human plasma harbors soluble forms of IL-7R (sIL-7Ralpha and sgamma(c)) that are detected and assayed by Western blotting, showing that the levels of sIL-7Ralpha are higher than the levels of sgamma(c) (47.5 ng/ml and 1.5 ng/ml, respectively). Gel electrophoresis and tandem mass spectrometry used to analyze deglycosylated, affinity-purified protein showed that sIL-7Ralpha is generated through differentially spliced mRNA, not by membrane receptor shedding. Plasma sIL-7Ralpha and sgamma(c) are present as heterocomplexes and sgamma(c) was found to be mainly associated with sIL-7Ralpha. The affinities of two IL-7 binding sites (K(d) = 35 +/- 8 pM and K(d) = 3 +/- 1 nM) were similar to that of the membrane receptor, suggesting that the sIL-7Ralpha/sgamma(c) complex retains high affinity for IL-7. sIL-7Ralpha mRNA is constitutively present among peripheral T lymphocytes and is down-modulated in vitro by IL-7. Chronically HIV-1-infected patients (n = 20) showed no significant (p > 0.714) variation in sgamma(c) levels and a significant (p < 0.0014) 2-fold decrease in plasma sIL-7Ralpha levels compared with those in control healthy individuals. Plasma IL-7 and sIL-7Ralpha levels did not show any obvious relationship.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Infecções por HIV
/
HIV-1
/
Subunidade gama Comum de Receptores de Interleucina
/
Subunidade alfa de Receptor de Interleucina-7
Tipo de estudo:
Diagnostic_studies
Limite:
Adult
/
Humans
/
Middle aged
Idioma:
En
Ano de publicação:
2009
Tipo de documento:
Article