Isolation and growth characterization of novel full length and deletion mutant human MERS-CoV strains from clinical specimens collected during 2015

Middle East respiratory syndrome (MERS) is a viral respiratory illness first reported in Saudi Arabia in September 2012 caused by the human coronavirus (CoV), MERS-CoV. Using full-genome sequencing and phylogenetic analysis, scientists have identified three clades and multiple lineages of MERS-CoV in humans and the zoonotic host, dromedary camels. In this study, we have characterized eight MERS-CoV isolates collected from patients in Saudi Arabia in 2015. We have performed full-genome sequencing on the viral isolates, and compared them to the corresponding clinical specimens. All isolates were clade B, lineages 4 and 5. Three of the isolates carry deletions located on three independent regions of the genome in the 5'UTR, ORF1a and ORF3. All novel MERS-CoV strains replicated efficiently in Vero and Huh7 cells. Viruses with deletions in the 5'UTR and ORF1a exhibited impaired viral release in Vero cells. These data emphasize the plasticity of the MERS-CoV genome during human infection.

MON-267 The Girl Who Never Cries: Allgrove Syndrome with Uncommon Cardiac Complication

Background: Allgrove syndrome (triple A syndrome) is a rare autosomal recessive disorder. Cardinal features include: alacrima, adrenal insufficiency and achalasia. Presentation is variable and diagnosis often delayed. cardiac complications are not previously reported. Case-report: A 15-year-old Yemeni girl born to consanguineous parents. She Had normal developmental milestones but often had a poor appetite and lacked energy. At age of 4, Addison’s disease was diagnosed after a hypoglycemic seizure. Commenced on hydrocortisone and fludrocortisone (stopped 6 months prior to presentation) but she lost follow-up. At age of 7, she was diagnosed with mild cognitive impairment, requiring special education. At age of 15, she presented to our ED with abdominal pain, recurrent vomiting and weakness for 4 days. she was hypotensive. Examination revealed abnormal mentation, nasal speech, gingival and buccal hyperpigmentation, muscle wasting and systolic murmur at the apex area. Initial blood works suggest adrenal crisis and subclinical hypothyroidism. Intravenous fluids and hydrocortisone were initiated. ICU course was complicated with pulmonary edema and bilateral pleural effusion requiring intubation and ionotropic support. Thoracentesis revealed transudate fluid. Echo showed a severe tricuspid and mitral regurgitation with right-sided ventricular dysfunction and mild pericardial effusion. Diuretics were administrated and cardiologist recommend for mitral and tricuspid valve replacement. After extubation, her symptoms resolved but vomiting persisted. CT-chest showed dilated esophagus and achalasia was confirmed with barium swallow. She underwent balloon dilatation and vomiting resolved. Further history, confirmed absence of tears since birth but dismissed as normal. Genetic testing confirmed a homozygous loss of function variant of AAAS. She was discharged on hydrocortisone 15 mg/day and artificial tears (didn't require fludrocortisone). Follow-up: she dramatically improved and has been gaining weight since. Interestingly, follow-up Echo was normal.Conclusion: triple A syndrome is often an under diagnosed disease. It can be fatal if not promptly recognized and treated. isolated right sided heart failure with severe valvular regurgitation are secondary to acute adrenal crisis and can be managed medically with steroids replacement.

DDX17 (P72), a Sox2 binding partner, promotes stem-like features conferred by Sox2 in a small cell population in estrogen receptor-positive breast cancer

We have previously demonstrated the existence of two phenotypically distinct cell subsets in estrogen receptor (ER)-positive breast cancer (BC) based on their differential response to a Sox2 reporter (SRR2), with reporter responsive (RR) cells being more tumorigenic and stem-like than reporter unresponsive (RU) cells. To delineate the molecular mechanisms underlying this phenotypic dichotomy, we tested our hypothesis that Sox2, which is a key regulator of the RR phenotype, is under the control of its binding partners. In this study, we focused on DDX17, known to be a transcription co-activator and found to be a Sox2 binding partner by liquid chromatography-mass spectrometry. Using immunoprecipitation, we confirmed the binding between DDX17 and Sox2, although this interaction was largely restricted to RR cells. While DDX17 was found in both the cytoplasm and nuclei in RU cells, it is confined to the nuclei in RR cells. siRNA knockdown of DDX17 in RR cells substantially decreased the Sox2-SRR2 binding and significantly decreased the SRR2 reporter activity without affecting the protein level of Sox2. Using ChIP-PCR, DDX17 knockdown also significantly decreased the binding of Sox2 to genomic SRR2, as well as 3 of its specific gene targets including MUC15, CCND1 and CD133. Correlating with these findings, siRNA knockdown of DDX17 significantly reduced soft agar colony formation and mammosphere formation in RR cells but not RU cells. To conclude, DDX17 is a Sox2-binding protein in ER-positive BC. In RR but not RU cells, DDX17 enhances the tumorigenic and stem-like features of Sox2 by promoting its binding to its target genes.