Phosphopeptides P140 cause oxidative burst responses of pulmonary macrophages in an imiquimod-induced lupus model.

Recent studies challenge the dogma that a 21-mer phosphopeptide P140 protects against direct cell damage in the phase-III clinical trial (NCT02504645) for lupus, involving reactive oxygen species (ROS)-dependent release of citrullinated histone H3 (H3cit)-linked neutrophil extracellular traps. An open question is the cellular location of ROS production and H3cit formation in lupus. In this study, we examined the effects of P140 peptides on ROS production and H3cit location in lupus with in vivo and situ fluorescence imaging with subcellular resolution. We developed a mouse model of the B6 strain harbouring a bioluminescent reporter under the control of the Lysozyme M promoter. Based on the imiquimod-induced disease model of B6 mice, we used bioluminescent imaging, flow cytometry analysis, and immunohistology staining to study the effects of P140 peptides in lupus. We found a profound accumulation of CX3CR1-positive macrophages in the lungs of lupus mice after the application of P140, accompanied by lung fibrosis formation. The defined P140-mediated macrophage responses were associated with an increase of H3cit in the cytosol, interleukin-1 receptor type 1 on the extracellular membrane, and intracellular production of ROS. Of interest, the disease of imiquimod-induced lupus was prevented with an antioxidant drug apocynin. This study shows that P140 peptides play a role in aggravated murine lupus in a manner dependent on ROS production and H3cit upregulation through pulmonary macrophages.

Noninvasive imaging of the lung NETosis by anti-Ly6G iron oxide nanoparticles.

It is challenging to visualize noninvasively the formation of neutrophil extracellular traps, known as NETosis, and therefore difficult to monitor disease progression. A desirable molecular imaging probe is the iron oxide nanoparticle (NP) that could induce reactive oxygen species. Here, we used C57BL/6 mice with pristane-induced lupus, which mimics systemic lupus erythematosus. Administration of anti-Ly6G antibody-conjugated NP allowed detection of NETosis with fluorescent molecular imaging, as evidenced by flow cytometric analysis of citrullinated histone H3 expression in lung neutrophils. This finding was consistent with NP-induced blood NETosis in a spontaneous lupus model of B6.MRL-lpr mice. A chronic assessment was performed in which the lupus mice were protected from enhanced oxidative burst by anti-Ly6G NP. This NP can migrate from the peritoneal cavity to the lungs, as visualized by magnetic particle imaging. Overall, our study provides evidence for a highly sensitive assessment of NETosis in lupus through magnetic particle imaging.

Developing a convenient large animal model for gene transfer to salivary glands in vivo.

BACKGROUND: Localized gene transfer to salivary glands has great potential for the treatment of salivary gland, systemic, and oral diseases. The minipig parotid gland, given its volume and morphological similarities to the human parotid gland, may be useful as a large animal model for pre-clinical gene transfer experiments. The purpose of this study was to perform an initial assessment of the efficacy and safety of adenoviral-vector-mediated gene transfer to parotid glands of miniature pigs. METHODS: AdCMVluc, a recombinant type 5 adenoviral (rAd5) vector containing a luciferase reporter gene, was administered to miniature pig parotid glands by intraductal cannulation. Five regions of gland tissue were obtained to measure the distribution of luciferase activity. The effects of time, viral dose, infusate buffer volume, and gland anatomical region on transgene expression were determined. Detailed serum chemistry and hematological analyses were performed. In addition, AdCMVlacZ, a similar rAd5 vector encoding beta-galactosidase, was also delivered to determine the parotid gland cell types transduced. RESULTS: Luciferase assays indicated that gene transfer to miniature pig salivary glands could be readily accomplished using rAd5 vectors. Highest transgene expression was found in the center of glands, which was > posterior > inferior > anterior > superior tissue regions. Expression was maximal on day 2 and declined to background by day 14, and observed in both acinar and ductal cells. Several serum chemistry and hematology parameters were transiently changed following rAd5 administration. CONCLUSIONS: Transgene expression by, and inflammatory response to, rAd5 vectors in minipig parotid glands are similar to results seen earlier in rodent studies. This suggests that results of salivary gland gene transfer from rodent studies can be extended to a larger animal model, and supports the value of using minipigs for pre-clinical applications of gene transfer to these tissues. Published in 2004 by John Wiley & Sons, Ltd.