تأثيرمركبات لتيولين، ميدستيورين (PKC-412) و PD173074 على مراحل حياة فيروس Cytomegalovirus (HCMV) المختلفة.
عامر عزت محمد دوفش
Amer Izzat Mohammad Doufish
The cytoplasmic assembly compartment (AC) in HCMV-infected human foreskin fibroblasts (HFF) is a unique juxtanuclear ―bulb‖-like structure. Morphology of the AC is dependent on the activity of the viral-encoded serine/threonine kinase, pUL97. The ―bulb‖-like structure morphology is also altered when wt-HCMV infected cells are treated with kinase inhibitors NGIC-I, a kinase C inhibitor, or Staurosporine, a wide range serine/threonine kinase inhibitor. Infection with a UL97 deletion mutant simulated the inhibition with NGIC-I or Staurosporine of wt-HCMV infection, resulting in a less compact and a vacuole-rich AC. In all three cases viral titers were reduced 2-3 logs. Cellular kinases play central roles in regulation of cell replication and differentiation, making cellular kinase inhibitors attractive antiviral targets. Different protein kinases were identified to affect different stages of HCMV life cycle and infectivity, which prompted us to explore yet not recognized kinase inhibitors for their activity against HCMV infection. In this study, we employed protein kinase inhibitors Luteolin, Midostaurin (PKC-412) and PD173074, and investigated their influence on the assembly compartment, early stages of HCMV infection and viral load. Luteolin at 20 μM did indeed reduce viral load without any detectable effects on the assembly complex. Midostaurin, PKC-412, did not affect viral load or the assembly compartment. The most striking result was observed with the tyrosine kinase inhibitor, PD173074, at 5 μM concentration. Although PD173074 did not affect early stages of HCMV infection, it reduced viral load and induced a specific structure of the assembly compartment we referred to as ―vesicles’-rich AC pattern. Hereby, the AC remained its ―bulb‖-like structure, but was remarkably accompanied withvesicles spread throughout the cytoplasm, which arose at 48 h p.i. and were remarkable by 72 h p.i. and 96 h p.i.. These vesicles stained for markers of the assembly complex; viral tegument proteins pp28 and pp65 as well as WGA Golgi marker and accumulated densely along the cytoplasmic membrane of the infected cells. Taken together, our data provide the first evidence for a role of tyrosine kinase in HCMV assembly.
العلوم الصيدلانية , Pharmaceutical Sciences