@article{BaptistaKeszeiOliveiraetal.2016, author = {Baptista, Marisa A.P. and Keszei, Marton and Oliveira, Mariana and Sunahara, Karen K.S. and Andersson, John and Dahlberg, Carin I.M. and Worth, Austen J. and Lied{\´e}n, Agne and Kuo, I-Chun and Wallin, Robert P.A. and Snapper, Scott B. and Eidsmo, Liv and Scheynius, Annika and Karlsson, Mikael C.I. and Bouma, Gerben and Burns, Siobhan O. and Forsell, Mattias N.E. and Thrasher, Adrian J. and Nyl{\´e}n, Susanne and Westerberg, Lisa S.}, title = {Deletion of Wiskott-Aldrich syndrome protein triggers Rac2 activity and increased cross-presentation by dendritic cells}, series = {Nature Communications}, volume = {7}, journal = {Nature Communications}, doi = {10.1038/ncomms12175}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-165966}, pages = {12175}, year = {2016}, abstract = {Wiskott-Aldrich syndrome (WAS) is caused by loss-of-function mutations in theWASp gene. Decreased cellular responses in WASp-deficient cells have been interpreted to mean that WASp directly regulates these responses in WASp-sufficient cells. Here, we identify an exception to this concept and show that WASp-deficient dendritic cells have increased activation of Rac2 that support cross-presentation to CD8þ T cells. Using two different skin pathology models, WASp-deficient mice show an accumulation of dendritic cells in the skin and increased expansion of IFNg-producing CD8þ T cells in the draining lymph node and spleen. Specific deletion of WASp in dendritic cells leads to marked expansion of CD8þ T cells at the expense of CD4þ T cells. WASp-deficient dendritic cells induce increased cross-presentation to CD8þ T cells by activating Rac2 that maintains a near neutral pH of phagosomes. Our data reveals an intricate balance between activation of WASp and Rac2 signalling pathways in dendritic cells.}, language = {en} } @article{LutzHeuerBehlichetal.2013, author = {Lutz, Manfred B. and Heuer, Marion and Behlich, Anna-Sophie and Lee, Ji-Sook and Ribechini, Eliana and Jo, Eun-Kyeong}, title = {The 30-kDa and 38-kDa antigens from Mycobacterium tuberculosis induce partial maturation of human dendritic cells shifting CD4+ T cell responses towards IL-4 production}, series = {BMC Immunology}, journal = {BMC Immunology}, doi = {10.1186/1471-2172-14-48}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-96871}, year = {2013}, abstract = {Background Mycobacterium tuberculosis (Mtb) infections are still a major cause of death among all infectious diseases. Although 99\% of individuals infected with Mtb develop a CD4+ Th1 and CD8+ T cell mediated immunity as measured by tuberculin skin test, this results only in partial protection and Mtb vaccines are not effective. Deviation of immune responses by pathogens towards a Th2 profile is a common mechanism of immune evasion, typically leading to the persistence of the microbes. Results Here we tested the stimulatory capacity of selective Mtb antigens on human monocyte-derived dendritic cell (DC) maturation and cytokine production. DC maturation markers CD80, CD86 and CD83 were readily upregulated by H37Ra- and H37Rv-associated antigens, the 30-kDa (from Ag85 B complex) and 38-KDa Mtb antigens only partially induced these markers. All Mtb antigens induced variable levels of IL-6 and low levels of IL-10, there was no release of IL-12p70 detectable. Substantial IL-12p40 production was restricted to LPS or H37Ra and H37Rv preparations. Although the proliferation levels of primary T cell responses were comparable using all the differentially stimulated DC, the 30-kDa and 38-kDa antigens showed a bias towards IL-4 secretion of polarized CD4+ T cells after secondary stimulation as compared to H37Ra and H37Rv preparations. Conclusion Together our data indicate that 30-kDa and 38-kDa Mtb antigens induced only partial DC maturation shifting immune responses towards a Th2 profile.}, language = {en} }