Carbon monoxide decreases endosome-lysosome fusion and inhibits soluble antigen presentation by dendritic cells to T cells.
Eur J Immunol
; 43(11): 2832-44, 2013 Nov.
Article
em En
| MEDLINE
| ID: mdl-23852701
ABSTRACT
Heme oxygenase-1 (HO-1) inhibits immune responses and inflammatory reactions via the catabolism of heme into carbon monoxide (CO), Fe(2+) , and biliverdin. We have previously shown that either induction of HO-1 or treatment with exogenous CO inhibits LPS-induced maturation of dendritic cells (DCs) and protects in vivo and in vitro antigen-specific inflammation. Here, we evaluated the capacity of HO-1 and CO to regulate antigen presentation on MHC class I and MHC class II molecules by LPS-treated DCs. We observed that HO-1 and CO treatment significantly inhibited the capacity of DCs to present soluble antigens to T cells. Inhibition was restricted to soluble OVA protein, as no inhibition was observed for antigenic OVA-derived peptides, bead-bound OVA protein, or OVA as an endogenous antigen. Inhibition of soluble antigen presentation was not due to reduced antigen uptake by DCs, as endocytosis remained functional after HO-1 induction and CO treatment. On the contrary, CO significantly reduced the efficiency of fusion between late endosomes and lysosomes and not by phagosomes and lysosomes. These data suggest that HO-1 and CO can inhibit the ability of LPS-treated DCs to present exogenous soluble antigens to naïve T cells by blocking antigen trafficking at the level of late endosome-lysosome fusion.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Endossomos
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Monóxido de Carbono
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Apresentação de Antígeno
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Lisossomos
Limite:
Animals
Idioma:
En
Ano de publicação:
2013
Tipo de documento:
Article