RESUMO
L-selectin initiates lymphocyte interactions with high endothelial venules (HEVs) of lymphoid organs through binding to ligands with specific glycosylation modifications. 6-Sulfo sLe(x), a sulfated carbohydrate determinant for L-selectin, is carried on core 2 and extended core 1 O-glycans of HEV-expressed glycoproteins. The MECA-79 monoclonal antibody recognizes sulfated extended core 1 O-glycans and partially blocks lymphocyte-HEV interactions in lymphoid organs. Recent evidence has identified the contribution of 6-sulfo sLe(x) carried on N-glycans to lymphocyte homing in mice. Here, we characterize CL40, a novel IgG monoclonal antibody. CL40 equaled or surpassed MECA-79 as a histochemical staining reagent for HEVs and HEV-like vessels in mouse and human. Using synthetic carbohydrates, we found that CL40 bound to 6-sulfo sLe(x) structures, on both core 2 and extended core 1 structures, with an absolute dependency on 6-O-sulfation. Using transfected CHO cells and gene-targeted mice, we observed that CL40 bound its epitope on both N-glycans and O-glycans. Consistent with its broader glycan-binding, CL40 was superior to MECA-79 in blocking lymphocyte-HEV interactions in both wild-type mice and mice deficient in forming O-glycans. This superiority was more marked in human, as CL40 completely blocked lymphocyte binding to tonsillar HEVs, whereas MECA-79 inhibited only 60%. These findings extend the evidence for the importance of N-glycans in lymphocyte homing in mouse and indicate that this dependency also applies to human lymphoid organs.
Assuntos
Antígenos de Superfície/imunologia , Selectina L/imunologia , Linfonodos/imunologia , Proteínas de Membrana/imunologia , Tonsila Palatina/imunologia , Polissacarídeos/imunologia , Animais , Anticorpos Monoclonais Murinos/imunologia , Células CHO , Cricetinae , Cricetulus , Epitopos/imunologia , Epitopos/metabolismo , Humanos , Selectina L/metabolismo , Ligantes , Camundongos , Polissacarídeos/metabolismo , Processamento de Proteína Pós-Traducional , RatosRESUMO
In present work we described, for the first time, the phylogenic structure of the microbial community in a shallow freshwater lake (Hawk Island Lake, located in the Lower Peninsula of the State of Michigan, U.S.A.) after one season (four times during May to August 2007) of CuSO4 treatment for algae growth control. The microbial community structure was characterized by terminal restriction fragment length polymorphism (TRFLP), clone library and 454 pyrosequencing. The similar structure of water chemistry measured across three sampling sites suggested that the lake was well mixed. The concentration of chlorophyll a (chl-a) and turbidity was low, 3.35 ± 1.62 µg/L and 2.5 ± 1.9 NTU, respectively, implying that photosynthesis was suppressed. TRFLP profiles showed that the lake was dominated by 16 terminal fragments (TFs), accounting for 85.5-92.6% abundance. Analysis of similarity (ANOSIM) showed that the difference in microbial community structure between upper and lower depths of the water column was not significant (P=0.101). These results suggested that the microbial community structure within the lake was similar. Clone library and 454 pyrosequencing indicated that the lake was dominated by freshwater phyla, Proteobacteria, Bacteroides, and Actinobacteria. Moreover, the large number of unclassified bacteria (27.4% of total 2090,454 sequences) suggested a complex microbial community structure in the lake.
Assuntos
Anti-Infecciosos/administração & dosagem , Biodiversidade , Sulfato de Cobre/administração & dosagem , Lagos/microbiologia , Microbiota , Estações do Ano , Microbiologia da Água , Análise por Conglomerados , Geografia , Lagos/química , Metagenoma , Michigan , Dados de Sequência Molecular , Filogenia , Polimorfismo de Fragmento de Restrição , RNA Ribossômico 16S/genéticaRESUMO
BACKGROUND: SULF2 is an extracellular sulfatase that acts on heparan sulfate proteoglycans and modulates multiple signaling pathways. It is normally bound to the cell surface but can be released into the medium of cultured cells. SULF2 is known to be increased in cirrhotic liver compared to healthy liver. We asked whether SULF2 protein was present in the blood of healthy controls and increased in patients with liver cirrhosis. METHODS: We devised a sandwich ELISA for SULF2 using 2 novel monoclonal antibodies (mAbs) and measured its levels in sera of normal individuals and cirrhosis patients. RESULTS: SULF2 was higher in cirrhosis patients (1460 ± 1160 pg/ml, N=34) than in healthy individuals (728 ± 400 pg/ml, N=37). SULF2 levels increased with age in both healthy and patient groups. CONCLUSIONS: SULF2 may be a useful serologic biomarker for liver cirrhosis.
Assuntos
Biomarcadores/sangue , Ensaio de Imunoadsorção Enzimática/métodos , Fibrose/sangue , Sulfotransferases/sangue , Adulto , Fatores Etários , Idoso , Animais , Estudos de Casos e Controles , Feminino , Humanos , Masculino , Camundongos , Pessoa de Meia-Idade , Valores de Referência , Sulfatases , Sulfotransferases/imunologiaRESUMO
Cr(VI) has been causing serious environmental pollution due to its carcinogenicity, teratogenicity and strong migration. Reduction of Cr( VI) to Cr(III), a precipitation that is much less toxic, is an efficient strategy to control Cr pollution. Within the strategy, bacterial reduction of Cr(VI) to Cr(III) has been considered as one of the best bioremediation methods because of its efficiency, environment friendly, and low cost; however, the molecular mechanism remains large unknown. This review summarizes Cr(VI) reduction bacterial species and its application in pollution control, elaborates the pathways of Cr( VI) reduction and functional proteins involved, concludes the molecular mechanism of baterial reduction Cr(VI), and discusses the orientation of the future research.