The early interferon catches the SARS-CoV-2

Interferons establish innate antiviral immunity. Two recent papers in JEM by Lopez et al. (2021. J. Exp. Med.https://doi.org/10.1084/jem.20211211) and Cheemarla et al. (2021. J. Exp. Med.https://doi.org/10.1084/jem.20210583) show that an appropriate supply of antiviral interferon enables epithelial cells of the nasopharyngeal mucosa to inhibit SARS-CoV-2 growth and that interferon-induced mucosal genes serve as biomarkers of infection.

Early nasal type I IFN immunity against SARS-CoV-2 is compromised in patients with autoantibodies against type I IFNs

IFN-I and IFN-III immunity in the nasal mucosa is poorly characterized during SARS-CoV-2 infection. We analyze the nasal IFN-I/III signature, namely the expression of ISGF-3–dependent IFN-stimulated genes, in mildly symptomatic COVID-19 patients and show its correlation with serum IFN-α2 levels, which peak at symptom onset and return to baseline from day 10 onward. Moreover, the nasal IFN-I/III signature correlates with the nasopharyngeal viral load and is associated with the presence of infectious viruses. By contrast, we observe low nasal IFN-I/III scores despite high nasal viral loads in a subset of critically ill COVID-19 patients, which correlates with the presence of autoantibodies (auto-Abs) against IFN-I in both blood and nasopharyngeal mucosa. In addition, functional assays in a reconstituted human airway epithelium model of SARS-CoV-2 infection confirm the role of such auto-Abs in abrogating the antiviral effects of IFN-I, but not those of IFN-III. Thus, IFN-I auto-Abs may compromise not only systemic but also local antiviral IFN-I immunity at the early stages of SARS-CoV-2 infection.

Treatment of acute nasopharyngitis in children

Acute nasopharyngitis in children is an inflammation of the nasopharyngeal mucosa. Recently, the use of saline solutions in the pathology of the nose and nasopharynx has become a leader in cleaning the mucous membrane. The main direction of modern pharmacotherapy of pathology of the nose and nasopharynx today is antiinflammatory therapy. There are a sufficient number of studies proving the effectiveness of mometasone furoate nasal spray in the treatment of inflammatory diseases of the nasopharynx in children. Our study examined the clinical efficacy of Etacid in the treatment of acute nasopharyngitis in children. Among the clinical symptoms were considered nasal breathing disorders, nasalness, snoring, cough during sleep. Endoscopy studied stagnant signs in the nasal cavity, nasopharyngeal discharge, enlargement of the pharyngeal tonsil. Proven sufficient clinical efficacy of the drug "Etacid" in the treatment of acute nasopharyngitis.

COVID-19 – doctor and patient. Clinical case

COVID-19 was initially described as a viral pneumonia because it produced an acute and possibly fatal respiratory distress. Later, however, other types of COVID-19 symptomatology were described, but also nonspecific: gastrointestinal, neurological, dermatological and even psychiatric. Therefore, to establish a definite diagnosis, a PCR test is needed to detect the virus on the nasopharyngeal mucosa. The treatment is not yet a specific one (there is no specific antiviral etiological treatment), being rather symptomatic (antipyretic, anti-inflammatory, antitussive etc.) and with the prophylaxis of complications (anticoagulant and antibiotic therapy, respiratory support, vitamin therapy).

Downregulation of RKIP promotes radioresistance of nasopharyngeal carcinoma by activating NRF2/NQO1 axis via downregulating miR-450b-5p

Dysregulation of RKIP and NRF2 has been widely involved in the therapy resistance of multiple malignances, however, their relation and the corresponding mechanisms, especially in radiation response, have not been elucidated. In this study, we revealed that RKIP could negatively regulate the expression of NRF2 in nasopharyngeal carcinoma (NPC) cells. Depletion or ectopic expression of NRF2 countered the pro- or anti- radioresistant effects of RKIP knockdown or overexpression on NPC cells, respectively, both in vitro and in vivo. Furthermore, our results indicated that NQO1 was positively regulated by NRF2 and served as the downstream effector of RKIP/NRF2 axis in regulation of NPC radioresistance. Mechanistically, miR-450b-5p, being positively regulated by RKIP in NPC cells, could sensitize NPC cells to irradiation by directly targeting and suppressing the level of NRF2. Besides, we analyzed the level of aforementioned molecules in NPC tissues. The results indicated that RKIP was significantly downregulated, NRF2 and NQO1 were notably upregulated in NPC tissues compared with in normal nasopharyngeal mucosa (NNM) tissues. Furthermore, RKIP and miR-450b-5p were remarkably lower, yet NRF2 and NQO1 were notably higher, in radioresistant NPC tissues relative to in radiosensitive NPC tissues. Consistent with the pattern in NPC cells, the RKIP/miR-450b-5p/NRF2/NQO1 axis was significantly correlated in NPC tissues. Downregulation of RKIP and miR-450b-5p, and upregulation of NRF2 and NQO1, positively correlated to malignant pathological parameters such as primary T stage, Lymph node (N) metastasis, and TNM stage. Finally, RKIP and miR-450b-5p served as favorable prognostic indicators, and NRF2 and NQO1 acted as unfavorable prognostic biomarkers in patients with NPC. Collectively, our outcomes reveal that RKIP downregulation promotes radioresistance of NPC by downregulating miR-450b-5p and subsequently upregulating and activating NRF2 and NQO1, highlighting RKIP/miR-450b-5p/NRF2/NQO1 axis as a potential therapeutic target for improving the radiosensitivity of NPC.

Mass Spectrometric detection of SARS-CoV-2 virus in scrapings of the epithelium of the nasopharynx of infected patients via Nucleocapsid N protein

ABSTRACTDetection of viral RNA by PCR is currently the main diagnostic tool for COVID-19 [1]. The PCR-based test, however, shows limited sensitivity, especially at early and late stages of the disease development [2,3], and is relatively time consuming. Fast and reliable complementary methods for detecting the viral infection would be of help in the current pandemia conditions. Mass-spectrometry is one of such possibilities. We have developed a mass-spectrometry based method for the detection of the SARS CoV-2 virus in nasopharynx epithelial swabs, based on the detection of the viral nucleocapsid N protein. The N protein of the SARS-COV-2 virus, the most abundant protein in the virion, is the best candidate for mass-spectrometric detection of the infection, and MS-based detection of several peptides from the SARS-COoV-2 nucleoprotein has been reported earlier by the Sinz group [4]. Our approach shows confident identification of the N protein in patient samples even with the lowest viral loads and a much simpler preparation procedure. Our main protocol consists of virus inactivation by heating and adding of isopropanol, and tryptic digestion of the proteins sedimented from the swabs followed by MS analysis. A set of unique peptides, produced as a result of proteolysis of the nucleocapsid phosphoprotein of SARS-CoV-2, is detected. The obtained results can further be used to create fast parallel mass-spectrometric approaches for the detection of the virus in the nasopharyngeal mucosa, saliva, sputum and other physiological fluids.

Rhinitis following intraoperative gastro-oesophageal reflux in a dog

A four-month-old, male dog underwent surgical repair of femoral and pelvic fracture. The dog was premedicated with acepromazine combined with morphine; anaesthesia was induced with propofol to effect and maintained with isoflurane in 100 per cent oxygen. One hour after induction the dog regurgitated and gastric contents emerged through the nares. At the end of the surgery rhinoscopy and oesophagoscopy were performed. The oesophageal mucosa was apparently normal, while posterior and retrograde rhinoscopy revealed diffused hyperaemia and oedema of the nasal cavity and nasopharyngeal mucosa; food particles and moderate amount of mucous exudates were also seen. Copious lavage was performed, and administration of antibiotics, metoclopramide, cimetidine and sucralfate was initiated. Nasal mucosa was re-evaluated four days later. No abnormalities were detected in both nasal cavities and nasopharynx. The development of rhinitis following regurgitation during anaesthesia should be considered as a possible complication.

Expression of LEF1 and TCF1 (TCF7) proteins associates with clinical progression of nasopharyngeal carcinoma

AimsOur previous study has demonstrated that β-catenin pathway was abnormally activated in nasopharyngeal carcinoma (NPC). The purposes of the present study are to investigate whether the alterations of LEF1 and TCF1 (TCF7) proteins, the important components of the canonical Wnt/β-catenin pathway, are associated with clinicopathological features and prognostic implications.MethodsWe collected 391 cases of NPC, 53 non-cancerous control nasopharyngeal mucosa and 28 pairs of NPC and their matched metastases, detected expression of LEF1 and TCF1 (TCF7) proteins in these tissues by immunohistochemistry. ResultsResults showed that there were significantly increased expression of both LEF1 and TCF1 (TCF7) proteins and coexpression of LEF1 and TCF1 (TCF7) in NPC than these in non-cancerous nasopharyngeal mucosa (all p<0.001), as well as LEF1 and coexpression of LEF1 and TCF1 (TCF7) in matched metastasis NPCs than these in the primary NPCs (p=0.003 and p=0.014, respectively). In addition, expression of LEF1 and the coexpression of LEF1 and TCF1 (TCF7) proteins were positively correlated with lymph node metastasis (p=0.001 and p=0.020, respectively), advanced clinical stage (p<0.003 and p=0.027, respectively) and poor survival status of patients with NPC (p<0.001 and p=0.004, respectively). Moreover, multivariate Cox regression analysis identified that the positive expression of LEF1 was the independent poor prognostic factor for overall survival of patients with NPC (p<0.001).ConclusionsThe expression of LEF1 associated positively with TCF1 (TCF7) and clinical progression of NPC, and positive expression of LEF1 protein may act as valuable independent biomarker to predict poor prognosis for patients with NPC.

Contact Challenge of Cattle with Foot-and-Mouth Disease Virus Validates the Role of the Nasopharyngeal Epithelium as the Site of Primary and Persistent Infection

ABSTRACTThe pathogenesis of foot-and-mouth disease virus (FMDV) in cattle was investigated through early and late stages of infection by use of an optimized experimental model for controlled contact exposure. Time-limited exposure of cattle to FMDV-infected pigs led to primary FMDV infection of the nasopharyngeal mucosa in both vaccinated and nonvaccinated cattle. In nonvaccinated cattle, the infection generalized rapidly to cause clinical disease, without apparent virus amplification in the lungs prior to establishment of viremia. Vaccinated cattle were protected against clinical disease and viremia; however, all vaccinated cattle were subclinically infected, and persistent infection occurred at similarly high prevalences in both animal cohorts. Infection dynamics in cattle were consistent and synchronous and comparable to those of simulated natural and needle inoculation systems. However, the current experimental model utilizes a natural route of virus exposure and is therefore superior for investigations of disease pathogenesis and host response. Deep sequencing of viruses obtained during early infection of pigs and cattle indicated that virus populations sampled from sites of primary infection were markedly more diverse than viruses from vesicular lesions of cattle, suggesting the occurrence of substantial bottlenecks associated with vesicle formation. These data expand previous knowledge of FMDV pathogenesis in cattle and provide novel insights for validation of inoculation models of bovine FMD studies.IMPORTANCEFoot-and-mouth disease virus (FMDV) is an important livestock pathogen that is often described as the greatest constraint to global trade in animal products. The present study utilized a standardized pig-to-cow contact exposure model to demonstrate that FMDV infection of cattle initiates in the nasopharyngeal mucosa following natural virus exposure. Furthermore, this work confirmed the role of the bovine nasopharyngeal mucosa as the site of persistent FMDV infection in vaccinated and nonvaccinated cattle. The critical output of this study validates previous studies that have used simulated natural inoculation models to characterize FMDV pathogenesis in cattle and emphasizes the importance of continued research of the unique virus-host interactions that occur within the bovine nasopharynx. Specifically, vaccines and biotherapeutic countermeasures designed to prevent nasopharyngeal infection of vaccinated animals could contribute to substantially improved control of FMDV.