Case report: Regression of Glioblastoma after flavivirus infection

Glioblastoma is the most frequent and aggressive primary brain cancer. In preclinical studies, Zika virus, a flavivirus that triggers the death of glioblastoma stem-like cells. However, the flavivirus oncolytic activity has not been demonstrated in human patients. Here we report a glioblastoma patient who received the standard of care therapy, including surgical resection, radiotherapy and temozolomide. However, shortly after the tumor mass resection, the patient was clinically diagnosed with a typical arbovirus-like infection, during a Zika virus outbreak in Brazil. Following the infection resolution, the glioblastoma regressed, and no recurrence was observed. This clinical response continues 6 years after the glioblastoma initial diagnosis.

Safety and immunogenicity of 17DD attenuated yellow fever vaccine in howler monkeys (Alouatta spp.)

BACKGROUND

Alouatta spp. are highly susceptible to yellow fever (YF) infection and develop an often fatal disease. The threat posed by an outbreak started in 2016 leads us to investigate vaccination as a potential tool in preventing YF in non-human primates (NHP).

METHODS

Susceptible howler monkeys were immunized with three different concentrations of the human Brazilian commercial YF17DD vaccine. Post-vaccination viremia/RNAemia, immunogenicity, and safety were characterized.

RESULTS

The vaccine did not produce YF clinical manifestations in any of the NHPs. After immunization, all animals seroconverted demonstrating the ability of the YF vaccine to induce humoral response in Alouatta species.

CONCLUSIONS

The present work has demonstrated the safe and immunogenic profile of the existing YF 17DD vaccine in howler monkeys. This knowledge may support further studies with other susceptible monkey species and provide a possible solution for controlling epizootics and preventing the devastation of endangered species.

Comparison between site-specific DNA binding proteins of male and female Schistosoma mansoni

Several amplicons with approximately 120 bp each, obtained from the upstream domain of Schistosoma mansoni female-specific gene F-10, were coupled to Dynabeads M-280 streptavidin. The beads were used as a matrix for affinity purification of nuclear proteins obtained from mixed populations of adult worms. A protein of approximately 12 kDa, bound to the DNA in a sequence-independent manner. In contrast, when the DNA matrix was narrowed down to smaller synthetic oligonucleotides, bearing sequences corresponding to the TATA box and the CAAT box, band-shift assays revealed that different nuclear proteins from either adult male or female worms formed complexes with the DNA adduct. In order to characterise the bound proteins, the same oligonucleotides were UV cross-linked to the male and female protein extracts. Whilst the band shift experiments showed that the proteins from each sex produced a distinct mobility pattern when the TATA box sequences were tested and a similar one when the CAAT box sequences were added to the proteins, UV cross-linking experiments revealed clear qualitative differences between both, male and female proteins and also between the proteins binding to the two motifs. These results are compatible with a model in which the differential expression of the F-10 gene might depend on individual sub-sets of proteins.

Molecular aspects of Schistosoma mansoni female maturation

Incubation of total protein extracts of Schistosoma mansoni with 3H 17-beta-estradiol and 20-hydroxyecdysone, revealed steroid binding proteins in both, male and female worms. The interaction of nuclear proteins with restriction fragments of the gender and stage-specific gene F-10 was investigated using the "Band-Shift" technique. Distinct male and female nuclear proteins bound to the fragments of this gene. Among the nuclear proteins, only those rich in cysteine residues bound to DNA. In vitro incubation of live worms with the estrogen antagonist Tamoxifen, altered the pattern of the DNA binding proteins, producing in females, a band profile similar to that obtained with male worm protein extracts. When Tamoxifen was injected into schistosome infected mice, the eggs produced by females presented an abnormal morphology, compatible with non-viable eggs. These results suggest that the regulation of transcription of the F-10 gene might involve steroid receptors.

F-10 nuclear binding proteins of Schistosoma mansoni: structural and functional features

By incubating total protein extracts of Schistosoma mansoni with 3H-17-beta-estradiol and 20-hydroxyecdysone, steroid binding proteins were detected in both male and female worms. The interaction of nuclear proteins with a restriction fragment of the gender and stage-specific gene F-10 was investigated using the 'band-shift' technique. Male and female nuclear proteins bound in a distinct way to the fragment of this gene containing putative regulatory consensus motifs. Among the nuclear proteins, only those rich in cysteine residues bound to DNA. In vitro incubation of live worms with the oestrogen antagonist Tamoxifen, altered the pattern of the DNA binding proteins, producing in females a profile similar to that obtained with male worm protein extracts. This effect of Tamoxifen could not be correlated to inhibition of protein biosynthesis. These results suggest that the regulation of transcription of the F-10 gene might involve steroid receptors.