Ubiquitin Ligases CBL and CBL-B Maintain the Homeostasis and Immune Quiescence of Dendritic Cells.

Dendritic cells (DCs) are composed of multiple lineages of hematopoietic cells and orchestrate immune responses upon detecting the danger and inflammatory signals associated with pathogen and damaged tissues. Under steady-state, DCs are maintained at limited numbers and the functionally quiescent status. While it is known that a fine balance in the DC homeostasis and activation status is also important to prevent autoimmune diseases and hyperinflammation, mechanisms that control DC development and activation under stead-state remain not fully understood.

Cbl Ubiquitin Ligases Control B Cell Exit from the Germinal-Center Reaction.

Selective expansion of high-affinity antigen-specific B cells in germinal centers (GCs) is a key event in antibody affinity maturation. GC B cells with improved affinity can either continue affinity-driven selection or exit the GC to differentiate into plasma cells (PCs) or memory B cells. Here we found that deleting E3 ubiquitin ligases Cbl and Cbl-b (Cbls) in GC B cells resulted in the early exit of high-affinity antigen-specific B cells from the GC reaction and thus impaired clonal expansion.

Polyethylenimine600-β-cyclodextrin: a promising nanopolymer for nonviral gene delivery of primary mesenchymal stem cells.

Genetically modified mesenchymal stem cells (MSCs) have great potential in the application of regenerative medicine and molecular therapy. In the present manuscript, we introduce a nanopolymer, polyethylenimine600-β-cyclodextrin (PEI600-β-CyD), as an efficient polyplex-forming plasmid delivery agent with low toxicity and ideal transfection efficiency on primary MSCs. PEI600-β-CyD causes significantly less cytotoxicity and apoptosis on MSCs than 25 kDa high-molecular-weight PEI (PEI25kDa).

Biscarbamate cross-linked low molecular weight PEI for delivering IL-1 receptor antagonist gene to synoviocytes for arthritis therapy.

Cytoxicity is an essential concern for polyethyleneimine 25 kDa (PEI 25 kDa), a widely reported, highly effective transfection agent used in gene delivery. In our recent experiments, Small molecular weight cross-linked poly(ethylene imine) by biscarbamate linkage (PEI-Bu) (Mn: 3278, Mw: 4289) can reduce target cell apoptosis induced by polycationic transfection, and has almost the same DNA condensation capability as PEI 25 kDa. PEI-Bu showed significantly higher activity and lower cytotoxicity than PEI 25 kDa in transfecting the anti-inflammatory cytokine interleukin-1 receptor antagonist (IL-1Ra) gene to rat synoviocytes, an optimal target for arthritis treatment.

[Altered expression of endogenous transforming growth factor β1 and early calcification related genes in rat endplate].

Objective: To explore the relationship between endogenous transforming growth factor (TGF)-β1 and calcification-related genes through an in vitro degeneration model by propagating rat endplate chondrocytes during a natural degeneration process.

Methods: Endplate chondrocytes were extracted from rat lumbar vertebrae, isolated by enzyme digestion and P2 and P4 generations selected for a 6-day in vitro culture. The specimens were photographed microscopically to observe the cellular differences by alizarin red staining.

Uptake mechanisms of non-viral gene delivery.

Non-viral gene delivery is currently a hot subject for its relative safety and simplicity of use; however, it is still far from being ideal enough to be clinically used for its comparatively lower efficiency than viral gene delivery. To improve the efficiency of non-viral gene delivery needs a comprehensive understanding of the uptake mechanisms. Macromolecules are internalized into cells by a variety of mechanisms, and their intracellular fates are usually relevant with the uptake pathways.

Progress and prospects of chitosan and its derivatives as non-viral gene vectors in gene therapy.

Although cell transfection by viral vectors is highly efficient, undesirable side effects including immunogenicity, toxicity and carcinogenesis have to be taken into consideration before their clinical applications. In contrast, most non-viral vectors, such as chitosan, are advantageous due to their biocompatibility, biodegradability, low toxicity and immunogenicity. However, the tranfection efficiency of chitosan as gene vector is rather low because of its low stability and low buffering capacity.