The effect of promoter strength in adenoviral vectors in hyperplastic synovium

OBJECTIVES: To compare the activity of the CytoMegaloVirus promoter (CMV) and the Major Late promoter (MLP) in synoviocytes in vitro and in vivo. To determine the phenotype of infected cells and the induction of inflammation. To investigate the effects of the cytomegalovirus (CMV) or major late (MLP) promoter on adenovirus-mediated reporter gene transduction of synoviocytes in vitro and in vivo. METHODS: After infection with adenoviral vectors harboring CMV- and MLP-driven luciferase and lacZ genes, gene expression was examined in cultured synoviocytes and in the synovium of rhesus monkeys with collagen-induced arthritis. Immunohistochemical staining for the macrophage-marker CD68 and lacZ expression was performed. Inflammation was scored in the synovial membrane of injected and non-injected joints. RESULTS: CMV-driven reporter gene expression was found to be 6 to 10 times higher than MLP-driven gene expression in both cultured synoviocytes and monkey synovium. Both CD68 positive and CD68 negative cells were lacZ positive. Inflammation in joints injected with CMV-driven adenoviral vectors was not higher than that in MLP-driven adenoviral vectors- or non-injected joints. CONCLUSION: These experiments show that the CMV promoter induces higher gene expression in synoviocytes than the MLP promoter. Both fibroblast-like and macrophage-like synoviocytes can be infected with adenoviral vectors. No deleterious effects of the CMV-promoter driven adenoviral vectors were observed.     

Increased Amoeboid Microglial Density in the Olfactory Bulb of Parkinson's and Alzheimer's Patients

The olfactory bulb (OB) is affected early in both Parkinson's (PD) and Alzheimer's disease (AD), evidenced by the presence of disease‐specific protein aggregates and an early loss of olfaction. Whereas previous studies showed amoeboid microglia in the classically affected brain regions of PD and AD patients, little was known about such changes in the OB. Using a morphometric approach, a significant increase in amoeboid microglia density within the anterior olfactory nucleus (AON) of AD and PD patients was observed. These amoeboid microglia cells were in close apposition to β‐amyloid, hyperphosphorylated tau or α‐synuclein deposits, but no uptake of pathological proteins by microglia could be visualized. Subsequent analysis showed (i) no correlation between microglia and α‐synuclein (PD), (ii) a positive correlation with β‐amyloid (AD), and (iii) a negative correlation with hyperphosphorylated tau (AD). Furthermore, despite the observed pathological alterations in neurite morphology, neuronal loss was not apparent in the AON of both patient groups. Thus, we hypothesize that, in contrast to the classically affected brain regions of AD and PD patients, within the AON rather than neuronal loss, the increased density in amoeboid microglial cells, possibly in combination with neurite pathology, may contribute to functional deficits.