PUBLICAÇÕES científicas

Regulatory role of tryptophan degradation pathway in HLA-G expression by human monocyte-derived dendritic cells

López AS, Alegre E [ES], LeMaoult J, Carosella E, González A. [ES]
Department of Clinical Biochemistry, Clínica Universitaria de Navarra, Av. Pío XII 36, 31008 Pamplona, Spain.

Revisão:Molecular immunology

Data: 1/Jul/2006

Bioquímica Clínica [ES]

Dendritic cells (DC) are strong inducers of immunity but they can also be tolerogenic.

During monocyte differentiation to DC the immunosuppressive indoleamine-2,3-dioxygenase (IDO) is induced. IDO degrades Trp to kynurenine, which is further metabolized to 3-hydroxyanthranilic acid. DC can also express mRNA and protein of the tolerogenic molecule HLA-G, but there is no surface expression. We studied the effect of the Trp degrading pathway on HLA-G expression by DC. When monocytes were differentiated to immature DC in presence of either Trp or its metabolites kynurenine or 3-hydroxyanthranilic acid they expressed cell surface HLA-G, and Trp also increased shedding of HLA-G1. Trp induced HLA-G cell surface expression when present during maturation with IFN-gamma+LPS, but not with TNF-alpha. Kynurenine increased HLA-G expression in both TNF-alpha and IFN-gamma+LPS matured DC, and 3-hydroxyanthranilic acid had a very weak effect on HLA-G cell surface expression when present during maturation. Shedding of HLA-G1 was more pronounced in IFN-gamma+LPS-matured DC than in immatured DC. Maturation with IFN-gamma+LPS in presence of kynurenine also increased HLA-G5 secretion.

The mechanism involved seems to be post-translational as mRNA and cellular HLA-G protein content was not increased with Trp, kynurenine or 3-hydroxyanthranilic acid treatments. Finally, immature DC preincubated with Trp, kynurenine and 3-hydroxyanthranilic acid have after a decreased capacity to stimulate T cells in mixed lymphocyte reaction. In IFN-gamma+LPS-matured DC this decreased capacity was obtained with kynurenine and 3-hydroxyanthranilic acid. These results suggest that IDO can induce HLA-G cell surface expression in DC, and that these two molecules can cooperate in the immune suppression.

CITAÇÃO DO ARTIGO  Mol Immunol. 2006 Jul;43(14):2151-60. Epub 2006 Feb 21

talvezlhe interesse

QUE TECNOLOGIA UTILIZAMOS? 

A Clínica é o hospital privado com maiores recursos tecnológicos de Espanha, tudo num único centro.

Imagen de un PET, tecnología de vanguardia en la Clínica Universidad de Navarra

OS NOSSOS
PROFISSIONAIS

Os profissionais da Clínica realizam um trabalho contínuo de investigação e formação, sempre em benefício do paciente.

Imagen profesionales de la Clínica Universidad de Navarra

RAZÕES PARA VIR
À CLÍNICA

Conheça porque é que somos diferentes em relação a outros centros sanitários. Qualidade, rapidez, comodidade e resultados.

Imagen del edificio de la Clínica Universidad de Navarra