Glioblastoma multiforme is the most prevalent and malignant tumor of the central nervous system. In the last few years, accumulating evidence has suggested an association between human cytomegalovirus (HCMV) infection and glioblastoma multiforme. In this study, tumor tissues and peripheral blood of patients with glioblastoma multiforme were examined for the presence of HCMV DNA. Twenty-two fresh surgical brain specimens and 20 peripheral blood samples were analyzed by real-time PCR (qPCR) and hemi-nested PCR (nPCR) for the presence of pp65 and (glycoprotein B) gB viral genomic regions, respectively. HCMV DNA was detected in the majority of the tumor samples analyzed (95% by qPCR and 91% by nPCR). About half of the patients with tumors positive for HCMV also had detectable viral DNA in their peripheral blood (47% by qPCR and 61% by nPCR). Genome copy numbers were determined and in the majority of the tumor samples cellular DNA outnumbers viral DNA (average of 1 infected cell in 33 cells). The gB genotypes were determined in HCMV-positive samples and gB2 was the most prevalent genotype in the tumor and blood samples. The results show a high prevalence of HCMV in glioblastoma multiforme samples reinforcing a possible association between HCMV infection and tumor development.

Gliomas are the most common type of primary brain tumors. The most aggressive type, Glioblastoma multiforme (GBM), is one of the deadliest human diseases, with an average survival at diagnosis of about 1 year. Previous evidence suggests a link between human cytomegalovirus (HCMV) and gliomas. HCMV has been shown to be present in these tumors and several viral proteins can have oncogenic properties in glioma cells. Here we have investigated the presence of HCMV DNA, RNA and proteins in fifty-two gliomas of different grades of malignancy. The UL83 viral region, the early beta 2.7 RNA and viral protein were detected in 73%, 36% and 57% by qPCR, ISH and IHC, respectively. Positivity of the viral targets and viral load was independent of tumor type or grade suggesting no correlation between viral presence and tumor progression. Our results demonstrate high prevalence of the virus in gliomas from Brazilian patients, contributing to a better understanding of the association between HCMV infection and gliomas worldwide and supporting further investigations of the virus oncomodulatory properties.

Human cytomegalovirus is a ubiquitous infectious agent that affects mainly immunosuppressed, fetuses, and newborns. The virus has several polymorphic regions, in particular in the envelope glycoproteins. The UL55 gene encodes the glycoprotein B that has a variable region, containing a furin cleavage site and according to the variability different genotypes are characterized. Here we investigated variability and existence of selective pressure on the UL55 variable region containing the furin cleavage site in 213 clinical sequences from patients worldwide. We showed the occurrence of positive selective pressure on gB codons 461 and 462, near the furin cleavage site. Cleavage analysis of synthesized peptides demonstrated that most mutations confer better cleavage by furin, suggesting that evolution is acting in order to increase the efficiency cleavage and supporting the hypothesis that gB processing is important in the host. We also demonstrated that peptides containing sequences, that characterize genotypes gB2 and 3, are differentially cleaved by furin. Our data demonstrate for the first time that variability in the cleavage site is related to degree of gB processing by furin.

The success of targeted drug delivery systems still requires a detailed understanding about the biological consequences of self-developed biomolecular coronas around them, since this is the surface that interacts with living cells. Herein, we report the behavior of carbohydrate-decorated amphiphilic nanoparticles in a plasma environment with regard to the formation and biological consequences of the protein corona. Naked amphiphilic nanoparticles were produced through the self-assembly of azido-PEO 900 -docosanoate molecules, and the coupling of N-acetylglucosamine via click chemistry enabled the fabrication of the corresponding bioactive glyco-nanostructures. Light scattering measurements, sodium dodecyl sulfate−polyacrylamide gel electrophoresis, liquid chromatography−mass spectrometry, and the Pierce BCA protein assay all confirmed the presence of protein coronas around the self-assembled nanoparticles, regardless of the presence of the sugar residues, although it reduces the amount of adsorbed proteins. The protein coronas were formed mainly by human serum albumin, complement proteins, apolipoproteins, immunoglobulins, and proteins involved in the coagulation cascade (fibrinogen and prothrombin). While the presence of these protein coronas significantly reduced cellular uptake of the amphiphilic assemblies, they also notably reduced the cytotoxic and hemolytic effects that result from the contact of the nanoparticles with living cells. Accordingly, we highlight that protein coronas should not always be treated as artifacts that have to be avoided because they can also provide beneficial effects.

The formation of biomolecular coronas around nanoparticles as soon as they come in contact with biological media is nowadays well accepted. The self-developed biological outer surfaces can affect the targeting...