Genetic capsid labeling provides a promising approach for the dynamic assessment of oncolytic adenovirus function in vivo.

The study of adenovirus could greatly benefit from diverse methods of virus detection. Recently, it has been demonstrated that carboxy-terminal EGFP fusions of adenovirus core proteins Mu, V, and VII properly localize to the nucleus and display novel function in the cell. Based on these observations, we hypothesized that the core proteins may serve as targets for labeling the adenovirus core with fluorescent proteins. To this end, we constructed various chimeric expression vectors with fusion core genes (Mu-EGFP, V-EGFP, preVII-EGFP, and matVII-EGFP) while maintaining expression of the native proteins. Expression of the fusion core proteins was suboptimal using E1 expression vectors with both conventional CMV and modified (with adenovirus tripartite leader sequence) CMV5 promoters, resulting in non-labeled viral particles. However, robust expression equivalent to the native protein was observed when the fusion genes were placed in the deleted E3 region. The efficient Ad-wt-E3-V-EGFP and Ad-wt-E3-preVII-EGFP expression vectors were labeled allowing visualization of purified virus and tracking of the viral core during early infection. The vectors maintained their viral function, including viral DNA replication, viral DNA encapsidation, cytopathic effect, and thermostability. Core labeling offers a means to track the adenovirus core in vector targeting studies as well as basic adenovirus virology.

INTRODUCTION: Vedolizumab is a selective monoclonal antibody directed against a4b7 integrin on lymphocytes and is safe and effective for the induction and maintenance of remission in Crohn’s disease. Serum biomarkers are needed to help guide therapy and predict patient outcomes. This study evaluated biomarker concentrations and patient outcomes during vedolizumab treatment. METHODS: Serum was collected from patients with Crohn’s disease receiving vedolizumab infusions at weeks 0, 2, 6, 14 and ≥26. Biomarkers including soluble(s)-a4b7, s-vascular cell adhesion molecule (VCAM)-1, s-intracellular adhesion molecule (ICAM)-1, and s-mucosal addressin cell adhesion molecule (MAdCAM)-1 were measured and evaluated as surrogate markers associated with clinical and endoscopic outcomes. Statistical analysis was performed using the Mann-Whitney U test for continuous data. RESULTS: Twenty-two patients with Crohn’s disease were included (Table 1). In all patients, s-MAdCAM significantly decreased over time as compared to baseline, and s-a4b7 increased compared to baseline (Figure 1). Overall, s-ICAM1 and s-VCAM1 did not change significantly over time in the entire cohort, however, differentially changed in patients with remission. At week 2, median concentrations of s-ICAM1 were higher in patients with compared to those without clinical remission: 675.1 ng/mL vs. 270.1 ng/mL, respectively (P = 0.046). At week 6, median s-ICAM1 concentrations were higher in patients with compared to without endoscopic remission: 545.7 ng/mL vs. 286.2 ng/mL, respectively (P = 0.027) and clinical remission: 669.1 ng/mL vs. 291 ng/mL, respectively (P = 0.034). At week 6, median s-VCAM1 concentrations were higher in patients with compared to without endoscopic remission: 859.6 vs. 460.31, respectively (P = 0.027) and numerically higher in patients with clinical remission: 859.6 ng/mL vs. 460.6 ng/mL, respectively (P = 0.1). At week 26, there was no difference in median s-VCAM1 or s-ICAM1 concentrations between remitters vs. non-remitters (Table 2). CONCLUSION: Higher concentrations of s-ICAM-1 and s-VCAM-1 early in treatment with vedolizumab may be predictive of subsequent remission in patients with Crohn’s disease. During maintenance, there was no association between serum biomarkers and endoscopic or clinical outcomes. These findings may help predict early patient response to treatment with vedolizumab in Crohn’s disease but will require further validation.