Tsc1 Expression By Dendritic Cells Regulates The Antigen-Specific T-cell Responses

Objective: To investigate the direct role of Tsc1 in mature dendritic cells(DCs)function which can maintain the antigen –specific T-cell responses.Methods: We used Cre-Loxp system to constructe the CD11cCreTsc1f/f(KO)mice,Agarose gel electrophoresis and Western blot were used to qualitatively analyze the level of gene Tsc1 separately.Then Single cell suspensions of KO/wild-type(WT)were prepared from spleen and peripheral lymph nodes(LNs),Flow cytometry detected the proliferation and number of dendritic cells;CD11c+ DCs were purified with CD11 c Micro Beads(Miltenyi Biotec).Flow cytometry detected the proportion and cell numbers of CD11c+ cells;Apotosis instructed by Annexin V/PI apoptosis detection of dendritic cells;In vitro we used DC-T cells co-cultured system and in vivo asthma model to test the ability of Tsc1-deficient DCs to mount antigen –specific immune responses.Flow cytometry detected the level of cytokines secreted by T cellsResults: Tsc1 protein was ablated in splenic DCs from CD11cCreTsc1f/f mice;In spleen and lymph nodes,the proportion and quantity of DCs were significantly decreased.The proliferation of DCs were slightly increased and the apoptosis were significantly increased.In vitro,we co-cultured WT or Tsc1-deficient DCs with CD4+ T cells from OT-II mice or CD8+ T from OT-I mice.The result was that splenic Tsc1-deficient DCs showed a considerable defect in the ability to drive T cell proliferation in vitro.In vivo,Tsc1-deficient DCs also had an apparent impairment in inducing proliferation of OT-II and OT-I T cells adoptively transferred into CD11cCreTsc1f/f mice immunized with ovalbumin(OVA).CD11cCreTsc1f/f mice had a profound impairment in adaptive T-cell immunity and the Eosnophils of bronchoalveolar lavage fluid(BALF)decreased in asthma model,the expression of Ig G1 in the serum was significantly decreased,and the Th2/Th17 responses were significantly reduced.Conclusions : Tsc1 maintains the number of DCs and promotes DCs induced antigen-specific T-cell responses.