FAM 19A4 is an abbreviation for family with sequence similarity 19 （chemokine （C-C motif）-Iike） member A4, which is a secretory protein expressed in low levels in normal tissues. The biological functions of FAM19A...FAM 19A4 is an abbreviation for family with sequence similarity 19 （chemokine （C-C motif）-Iike） member A4, which is a secretory protein expressed in low levels in normal tissues. The biological functions of FAM19A4 remain to be determined, and its potential receptor（s） is unclarified. In this study, we demonstrated that FAM 19A4 was a classical secretory protein and we verified for the first time that its mature protein is composed of 95 amino acids. We found that the expression of this novel cytokine was upregulated in lipopolysaccharide （LPS）-stimulated monocytes and macrophages and was typically in polarized M 1. FAM 19A4 shows chemotactic activities on macrophages and enhances the macrophage phagocytosis of zymosan both in vitro and in vivo with noticeable increases of the phosphorylation of protein kinase B （Akt）. FAM 19A4 can also increase the release of reactive oxygen species （ROS） upon zymosan stimulation. Furthermore, based on receptor internalization, radio ligand binding assays and receptor blockage, we demonstrated for the first time that FAM19A4 is a novel ligand of formyl peptide receptor 1 （FPR1）. The above data indicate that upon inflammatory stimulation, monocyte/macrophage-derived FAM 19A4 may play a crucial role in the migration and activation of macrophages during pathogenic infections.展开更多
In order to make entire HBV preSAg secrete from mammalian cells, we constructed an eukaryotic expression vector by using leader sequence of human interleukin-2 (IL-2) as secretory signal peptide, and using high hydrop...In order to make entire HBV preSAg secrete from mammalian cells, we constructed an eukaryotic expression vector by using leader sequence of human interleukin-2 (IL-2) as secretory signal peptide, and using high hydrophilic amino acids as the linker between IL-2 C end and preSAg N end. As a result, the IL-2preS fusing protein could be secreted from mammalian cells transfected with the reconstructed vector and the expression efficiency was identical to that of natural IL-2. It was considered that the retentive effect of preS1Ag could be successfully bypassed. The results not only laid a theoretical and practical foundation for constructing specific gene vaccine against HBV persistent infection, but also supplied experimental evidence for studying modulation of protein secretory expression.展开更多
文摘FAM 19A4 is an abbreviation for family with sequence similarity 19 （chemokine （C-C motif）-Iike） member A4, which is a secretory protein expressed in low levels in normal tissues. The biological functions of FAM19A4 remain to be determined, and its potential receptor（s） is unclarified. In this study, we demonstrated that FAM 19A4 was a classical secretory protein and we verified for the first time that its mature protein is composed of 95 amino acids. We found that the expression of this novel cytokine was upregulated in lipopolysaccharide （LPS）-stimulated monocytes and macrophages and was typically in polarized M 1. FAM 19A4 shows chemotactic activities on macrophages and enhances the macrophage phagocytosis of zymosan both in vitro and in vivo with noticeable increases of the phosphorylation of protein kinase B （Akt）. FAM 19A4 can also increase the release of reactive oxygen species （ROS） upon zymosan stimulation. Furthermore, based on receptor internalization, radio ligand binding assays and receptor blockage, we demonstrated for the first time that FAM19A4 is a novel ligand of formyl peptide receptor 1 （FPR1）. The above data indicate that upon inflammatory stimulation, monocyte/macrophage-derived FAM 19A4 may play a crucial role in the migration and activation of macrophages during pathogenic infections.
文摘In order to make entire HBV preSAg secrete from mammalian cells, we constructed an eukaryotic expression vector by using leader sequence of human interleukin-2 (IL-2) as secretory signal peptide, and using high hydrophilic amino acids as the linker between IL-2 C end and preSAg N end. As a result, the IL-2preS fusing protein could be secreted from mammalian cells transfected with the reconstructed vector and the expression efficiency was identical to that of natural IL-2. It was considered that the retentive effect of preS1Ag could be successfully bypassed. The results not only laid a theoretical and practical foundation for constructing specific gene vaccine against HBV persistent infection, but also supplied experimental evidence for studying modulation of protein secretory expression.
