Resumen
Heme oxygenase-1 (HO-1) inhibits immune responses and inflammatory reactions via the catabolism of heme into carbon monoxide (CO), Fe2+, 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.
Idioma original | Inglés |
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Páginas (desde-hasta) | 2832-2844 |
Número de páginas | 13 |
Publicación | European Journal of Immunology |
Volumen | 43 |
N.º | 11 |
DOI | |
Estado | Publicada - nov. 2013 |
Áreas temáticas de ASJC Scopus
- Inmulogía y alergología
- Inmunología