Construction of AAV-rat-IL4 and Evaluation of its Modulating Effect on Aß (1-42)-Induced Proinflammatory Cytokines in Primary Microglia and the B92 Cell Line by Quantitative PCR Assay.

BACKGROUND: Interleukin-4 (IL-4), as the most prominent anti-inflammatory cytokine, plays an important role in modulating microglial activation and inflammatory responses in Alzheimer's disease (AD), a chronic inflammatory disorder. OBJECTIVES: The current study aimed to develop a new recombinant Adeno-associated viral (rAAV) vector that delivers IL-4 and then assess the counterbalancing effect of the new construct along with recombinant IL-4 (rIL-4) protein in in-vitro models of AD. MATERIALS AND METHODS: The rAAV-IL4 was originally prepared and then employed along with rIL-4 protein to counter Amyloid ß (1-42)-induced proinflammatory cytokines in a primary microglia cell culture and the B92 rat microglia continuous cell line, using relative Real-Time PCR assay. RESULTS: Aß (1-42) stimulated the production of the proinflammatory cytokines IL6, IL1ß, TNFα, and IL18 in both the primary microglia cell culture and the B92 cell line. Both the rAAV-IL4 construct and the rIL-4 protein were found to inhibit production of the most important Aß (1-42)-induced proinflammatory cytokine mRNAs in the two types of cells with different patterns. CONCLUSIONS: It seems that the new construct can serve as an appropriate option in the modulation of Aß-induced proinflammatory cytokine gene expression and microglia activation in patients affected by AD.