Human dendritic cells very efficiently present a heterologous antigen expressed on the surface of recombinant gram-positive bacteria to CD4+ T lymphocytes.
J Immunol
; 163(6): 3029-36, 1999 Sep 15.
Article
em En
| MEDLINE
| ID: mdl-10477566
ABSTRACT
Recombinant Streptococcus gordonii expressing on the surface the C-fragment of tetanus toxin was tested as an Ag delivery system for human monocyte-derived dendritic cells (DCs). DCs incubated with recombinant S. gordonii were much more efficient than DCs pulsed with soluble C-fragment of tetanus toxin at stimulating specific CD4+ T cells as determined by cell proliferation and IFN-gamma release. Compared with DCs treated with soluble Ag, DCs fed with recombinant bacteria required 102- to 103-fold less Ag and were at least 102 times more effective on a per-cell basis for activating specific T cells. S. gordonii was internalized in DCs by conventional phagocytosis, and cytochalasin D inhibited presentation of bacteria-associated Ag, but not of soluble Ag, suggesting that phagocytosis was required for proper delivery of recombinant Ag. Bacteria were also very potent inducers of DC maturation, although they enhanced the capacity of DCs to activate specific CD4+ T cells at concentrations that did not stimulate DC maturation. In particular, S. gordonii dose-dependently up-regulated expression of membrane molecules (MHC I and II, CD80, CD86, CD54, CD40, CD83) and reduced both phagocytic and endocytic activities. Furthermore, bacteria promoted in a dose-dependent manner DC release of cytokines (IL-6, TNF-alpha, IL-1beta, IL-12, TGF-beta, and IL-10) and of the chemokines IL-8, RANTES, IFN-gamma-inducible protein-10, and monokine induced by IFN-gamma. Thus, recombinant Gram-positive bacteria appear a powerful tool for vaccine design due to their extremely high capacity to deliver Ags into DCs, as well as induce DC maturation and secretion of T cell chemoattractans.
Buscar no Google
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Streptococcus
/
Células Dendríticas
/
Proteínas Recombinantes de Fusão
/
Linfócitos T CD4-Positivos
/
Apresentação de Antígeno
/
Antígenos de Bactérias
Limite:
Humans
Idioma:
En
Revista:
J Immunol
Ano de publicação:
1999
Tipo de documento:
Article