Yoko Obata | PubMed Health

PubMed2005

Role of cyclophilin B in activation of interferon regulatory factor-3.

IRF-3 is a member of the interferon regulatory factors (IRFs) and plays a principal role in the induction of interferon-beta (IFN-beta) by virus infection. Virus infection results in the phosphorylation of IRF-3 by IkappaB kinase epsilon and TANK-binding kinase 1, leading to its dimerization and association with the coactivators CREB-binding protein/p300. The IRF-3 holocomplex translocates to the nucleus, where it induces IFN-beta. In the present study, we examined the molecular mechanism of IRF-3 activation. Using bacterial two-hybrid screening, we isolated molecules that interact with IRF-3. One of these was cyclophilin B, a member of the immunophilins with a cis-trans peptidyl-prolyl isomerase activity. A GST pull-down assay suggested that one of the autoinhibition domains of IRF-3 and the peptidyl-prolyl isomerase domain of cyclophilin B are required for the binding. A knockdown of cyclophilin B expression by RNA interference resulted in the suppression of virus-induced IRF-3 phosphorylation, leading to the inhibition of the subsequent dimerization, association with CREB-binding protein, binding to the target DNA element, and induction of IFN-beta. These findings indicate that cyclophilin B plays a critical role in IRF-3 activation.

Amino Acid Sequence↗

PubMedDate not supplied

Gene transfer using nonviral delivery systems.

In peritoneal dialysis, loss of peritoneal function is a major factor in treatment failure. The alterations in peritoneal function are related to structural changes in the peritoneal membrane, including peritoneal sclerosis with increased extracellular matrix. Although peritoneal sclerosis is considered reversible to some extent through peritoneal rest, which improves peritoneal function and facilitates morphological changes, there has been no therapeutic intervention and no drug against the development and progression of peritoneal sclerosis. Using recent biotechnological advances in genetic engineering, a strategy based on genetic modification of the peritoneal membrane could be a potential therapeutic maneuver against peritoneal sclerosis and peritoneal membrane failure. Before this gene therapy may be applied clinically, a safe and effective gene delivery system as well as the selection of a gene therapy method must be established. There are presently two kinds of gene transfer vectors: viral and nonviral. Viral vectors are used mainly as a gene delivery system in the field of continuous ambulatory peritoneal dialysis research; however, they have several problems such as immunogenicity and toxicity. On the other hand, nonviral vectors have several advantages over viral vectors. We review here gene transfer using nonviral vector systems in the peritoneum: electroporation, liposomes, and cationized gelatin microspheres. In the field of peritoneal dialysis, gene therapy research using nonviral vectors is presently limited. Improvement in delivery methods together with an intelligent design of targeted genes has brought about large degrees of enhancement in the efficiency, specificity, and temporal control of nonviral vectors.

Gene Transfer Techniques↗