Dendritic cells(DCs) are professinal antigen-presenting cells with the ability to initiate primary Tcell responses. While it iswell known that inflammatory stimuli induce the functional maturation of immature DCs, whe...Dendritic cells(DCs) are professinal antigen-presenting cells with the ability to initiate primary Tcell responses. While it iswell known that inflammatory stimuli induce the functional maturation of immature DCs, whether adhesion molecule selectins regulate DCmaturation is poorly understood. Using anti-P-selectin lectin-EGF domain monoclonal antibody (PsL-EGFmAb) that blocks the adhesionof P-, E-, and L-selectin, we demonstrate herein that selectins play important role in stimulating functional maturation of immature DCs.Immature DCs are generated from human cord blood CD34+hematopoietic stem/progenitor cells that were cultured in the presence of stemcell factor, Fms-like tyrosine-kinase-3 ligand, granulocyte-macrophage colony stimulating factor, and transform growth factor-β1. Whenstimulated with tumor necrosis factor-alpha(TNF-α), immature DCs differentiated into mature DCs, producing increased levels of costim-ulatory molecules and interleukin (IL)-12 and obtaining the ability to potently activate naive Tcells. Interestingly, in contrast to matureDCs derived from TNF-α-induced immature DC cultures without PsL-EGFmAb, immature DCs treated with PsL-EGFmAb for7 days werecompletely blocked their maturation, as evidenced by decreased expression of costimulatory molecules CD80, CD86, and CD83, inhibi-ted production of IL-12, and inability to activate naive Tcellsin vitro. Thus, blockade of selectins using PsL-EGFmAb will prove to bea valuable tool for the study of the molecuar mechanisms of DC maturation, as well as for the prevention and treatment of DC-mediated au-toimmunity.展开更多
C-type lectins are among the most significant pattern recognition receptors（PRRs） found in invertebrate. They are a class of carbohydrate-binding proteins that can recognize specific sugar moieties on the surface of...C-type lectins are among the most significant pattern recognition receptors（PRRs） found in invertebrate. They are a class of carbohydrate-binding proteins that can recognize specific sugar moieties on the surface of pathogens. In the present study, a novel C-type lecitn（termed Mj Lectin） from kuruma shrimp Marsupenaeus japonicus was identified. The full-length c DNA of Mj Lectin was 1 245 bp with a 1 011 bp open reading frame（ORF） that encoded a polypeptide of 336 amino acid residues. Mj Lectin consisted of two tandemly arrayed carbohydrate-recognition domains（CRDs）, unlike other reported M. japonicus C-type lectins with only one CRD. It showed a high similarity to other shrimp dual-CRD lectins. Among the Ca2＋-binding Site 2, the tripeptide motif dictating the carbohydrate binding specificity was exhibited as a rare mutant LPN（Leu134-Pro135-Asn136） in CRD1 and a traditional EPN（Glu299-Pro300-Asn301） in CRD2, respectively. Mj Lectin showed a specific expression pattern in both tissue and cellular levels, for its m RNA transcript was mainly expressed in the F-cells of the hepatopancreas. After white spot syndrome virus（WSSV） challenge（3.6×108 virions/μL）, the expression of Mj Lectin in the hepatopancreas was up-regulated significantly at 48 h（P〈0.01） compared with the control group. These results suggested that Mj Lectin might be involved in the innate immune defense against WSSV infection.展开更多
文摘Dendritic cells(DCs) are professinal antigen-presenting cells with the ability to initiate primary Tcell responses. While it iswell known that inflammatory stimuli induce the functional maturation of immature DCs, whether adhesion molecule selectins regulate DCmaturation is poorly understood. Using anti-P-selectin lectin-EGF domain monoclonal antibody (PsL-EGFmAb) that blocks the adhesionof P-, E-, and L-selectin, we demonstrate herein that selectins play important role in stimulating functional maturation of immature DCs.Immature DCs are generated from human cord blood CD34+hematopoietic stem/progenitor cells that were cultured in the presence of stemcell factor, Fms-like tyrosine-kinase-3 ligand, granulocyte-macrophage colony stimulating factor, and transform growth factor-β1. Whenstimulated with tumor necrosis factor-alpha(TNF-α), immature DCs differentiated into mature DCs, producing increased levels of costim-ulatory molecules and interleukin (IL)-12 and obtaining the ability to potently activate naive Tcells. Interestingly, in contrast to matureDCs derived from TNF-α-induced immature DC cultures without PsL-EGFmAb, immature DCs treated with PsL-EGFmAb for7 days werecompletely blocked their maturation, as evidenced by decreased expression of costimulatory molecules CD80, CD86, and CD83, inhibi-ted production of IL-12, and inability to activate naive Tcellsin vitro. Thus, blockade of selectins using PsL-EGFmAb will prove to bea valuable tool for the study of the molecuar mechanisms of DC maturation, as well as for the prevention and treatment of DC-mediated au-toimmunity.
基金The National High-Technology R&D Program(863 Program) of China under contract No.2012AA10A409China Agriculture Research System under contract No.CARS-47
文摘C-type lectins are among the most significant pattern recognition receptors（PRRs） found in invertebrate. They are a class of carbohydrate-binding proteins that can recognize specific sugar moieties on the surface of pathogens. In the present study, a novel C-type lecitn（termed Mj Lectin） from kuruma shrimp Marsupenaeus japonicus was identified. The full-length c DNA of Mj Lectin was 1 245 bp with a 1 011 bp open reading frame（ORF） that encoded a polypeptide of 336 amino acid residues. Mj Lectin consisted of two tandemly arrayed carbohydrate-recognition domains（CRDs）, unlike other reported M. japonicus C-type lectins with only one CRD. It showed a high similarity to other shrimp dual-CRD lectins. Among the Ca2＋-binding Site 2, the tripeptide motif dictating the carbohydrate binding specificity was exhibited as a rare mutant LPN（Leu134-Pro135-Asn136） in CRD1 and a traditional EPN（Glu299-Pro300-Asn301） in CRD2, respectively. Mj Lectin showed a specific expression pattern in both tissue and cellular levels, for its m RNA transcript was mainly expressed in the F-cells of the hepatopancreas. After white spot syndrome virus（WSSV） challenge（3.6×108 virions/μL）, the expression of Mj Lectin in the hepatopancreas was up-regulated significantly at 48 h（P〈0.01） compared with the control group. These results suggested that Mj Lectin might be involved in the innate immune defense against WSSV infection.
