Marek Ochman

Infection with human coronavirus NL63 enhances streptococcal adherence to epithelial cells.

Understanding the mechanisms of augmented bacterial pathogenicity in post-viral infections is the first step in the development of an effective therapy. This study assessed the effect of human coronavirus NL63 (HCoV-NL63) on the adherence of bacterial pathogens associated with respiratory tract illnesses. It was shown that HCoV-NL63 infection resulted in an increased adherence of Streptococcus pneumoniae to virus-infected cell lines and fully differentiated primary human airway epithelium cultures. The enhanced binding of bacteria correlated with an increased expression level of the platelet-activating factor receptor (PAF-R), but detailed evaluation of the bacterium-PAF-R interaction revealed a limited relevance of this process.

Staphylococcus aureus Proteases Degrade Lung Surfactant Protein A Potentially Impairing Innate Immunity of the Lung

The pulmonary surfactant is a complex mixture of lipids and proteins that is important for respiratory lung functions, which also provides the first line of innate immune defense. Pulmonary surfactant protein-A (SP-A) is a major surfactant component with immune functions with importance during Staphylococcus aureus infections that has been demonstrated in numerous studies. The current study showed that S. aureus can efficiently cleave the SP-A protein using its arsenal of proteolytic enzymes. This degradation appears to be mediated by cysteine proteases, in particular staphopain A (ScpA). The staphopain-mediated proteolysis of SP-A resulted in a decrease or complete abolishment of SP-A biological activity, including the promotion of S. aureus phagocytosis by neutrophils, aggregation of Gram-negative bacteria and bacterial cell adherence to epithelium. Significantly, ScpA has also efficiently degraded SP-A in complete bronchi-alveolar lavage fluid from human lungs. This indicates that staphopain activity in the lungs is resistant to protease inhibitors, thus suggesting that SP-A can be cleaved in vivo. Collectively, this study showed that the S. aureus protease ScpA is an important virulence factor that may impair innate immunity of the lungs.

Use of Sensitive, Broad-Spectrum Molecular Assays and Human Airway Epithelium Cultures for Detection of Respiratory Pathogens

Rapid and accurate detection and identification of viruses causing respiratory tract infections is important for patient care and disease control. Despite the fact that several assays are available, identification of an etiological agent is not possible in ∼30% of patients suffering from respiratory tract diseases. Therefore, the aim of the current study was to develop a diagnostic set for the detection of respiratory viruses with sensitivity as low as 1–10 copies per reaction. Evaluation of the assay using a training clinical sample set showed that viral nucleic acids were identified in ∼76% of cases. To improve assay performance and facilitate the identification of novel species or emerging strains, cultures of fully differentiated human airway epithelium were used to pre-amplify infectious viruses. This additional step resulted in the detection of pathogens in all samples tested. Based on these results it can be hypothesized that the lack of an etiological agent in some clinical samples, both reported previously and observed in the present study, may result not only from the presence of unknown viral species, but also from imperfections in the detection methods used.

APOBEC3-mediated restriction of RNA virus replication

APOBEC3 family members are cytidine deaminases with roles in intrinsic responses to infection by retroviruses and retrotransposons, and in the control of other DNA viruses, such as herpesviruses, parvoviruses and hepatitis B virus. Although effects of APOBEC3 members on viral DNA have been demonstrated, it is not known whether they edit RNA genomes through cytidine deamination. Here, we investigated APOBEC3-mediated restriction of Coronaviridae. In experiments in vitro, three human APOBEC3 proteins (A3C, A3F and A3H) inhibited HCoV-NL63 infection and limited production of progeny virus, but did not cause hypermutation of the coronaviral genome. APOBEC3-mediated restriction was partially dependent on enzyme activity, and was reduced by the use of enzymatically inactive APOBEC3. Moreover, APOBEC3 proteins bound to the coronaviral nucleoprotein, and this interaction also affected viral replication. Although the precise molecular mechanism of deaminase-dependent inhibition of coronavirus replication remains elusive, our results further our understanding of APOBEC-mediated restriction of RNA virus infections.

Pulmonary hypertension in advanced lung diseases: Echocardiography as an important part of patient evaluation for lung transplantation.

Pulmonary hypertension (PH) is common complication in advanced lung disease. Echocardiography provides additional information and may be useful to assess PH probability.

Superficial herpes simplex virus wound infection following lung transplantation

Surgical site infections (SSIs) are infections of tissues, organs, or spaces exposed by surgeons during performance of an invasive procedure. SSIs are classified into superficial, which are limited to skin and subcutaneous tissues, and deep. The incidence of deep SSIs in lung transplant (LTx) patients is estimated at 5%. No reports have been published as to the incidence of superficial SSIs specifically in LTx patients. Common sense would dictate that the majority of superficial SSIs would be bacterial. Uncommonly, fungal SSIs may occur, and we believe that no reports exist as to the incidence of viral wound infections in LTx patients, or in any solid organ transplant patients. We report a de novo superficial wound infection with herpes simplex virus following lung transplantation, its possible source, treatment, and resolution.

Novel Polyanions Inhibiting Replication of Influenza Viruses

ABSTRACT Novel sulfonated derivatives of poly(allylamine hydrochloride) (NSPAHs) and N-sulfonated chitosan (NSCH) have been synthesized, and their activity against influenza A and B viruses has been studied and compared with that of a series of carrageenans, marine polysaccharides of well-documented anti-influenza activity. NSPAHs were found to be nontoxic and very soluble in water, in contrast to gel-forming and thus generally poorly soluble carrageenans. In vitro and ex vivo studies using susceptible cells (Madin-Darby canine kidney epithelial cells and fully differentiated human airway epithelial cultures) demonstrated the antiviral effectiveness of NSPAHs. The activity of NSPAHs was proportional to the molecular mass of the chain and the degree of substitution of amino groups with sulfonate groups. Mechanistic studies showed that the NSPAHs and carrageenans inhibit influenza A and B virus assembly in the cell.

Novel coronavirus-like particles targeting cells lining the respiratory tract

Virus like particles (VLPs) produced by the expression of viral structural proteins can serve as versatile nanovectors or potential vaccine candidates. In this study we describe for the first time the generation of HCoV-NL63 VLPs using baculovirus system. Major structural proteins of HCoV-NL63 have been expressed in tagged or native form, and their assembly to form VLPs was evaluated. Additionally, a novel procedure for chromatography purification of HCoV-NL63 VLPs was developed. Interestingly, we show that these nanoparticles may deliver cargo and selectively transduce cells expressing the ACE2 protein such as ciliated cells of the respiratory tract. Production of a specific delivery vector is a major challenge for research concerning targeting molecules. The obtained results show that HCoV-NL63 VLPs may be efficiently produced, purified, modified and serve as a delivery platform. This study constitutes an important basis for further development of a promising viral vector displaying narrow tissue tropism.

A functional assessment of patients two years after lung transplantation in Poland.

The aim of the study The aim of the study was to assess the long-term results of lung transplantation (LT) in Poland two years after the procedure. Material and methods The study included patients who underwent LT between December 2004 and December 2009 in the Silesian Center for Heart Diseases in Zabrze. Various lung functions (forced vital capacity – FVC; forced expiratory volume in 1 second – FEV1), the quality of life (SF-36 questionnaire), the level of perceived dyspnea (Medical Research Council – MRC; basic dyspnea index – BDI), and the patients mobility (the 6-minute walking test – 6MWT) were assessed before and approximately 24 months after LT. Among 35 patients who underwent LT, 20 patients were referred to our study (mean age: 46.6 ± 9.03 years). Results After LT, a statistically significant increase was observed in the distance achieved in the 6MWT (323.8 vs. 505.8 m), FVC (1.64 vs. 2.88 L), and FEV1 (1.37 vs. 2.09 L). An improvement in perceived dyspnea in MRC and BDI questionnaires was observed in patients with chronic obstructive pulmonary disease (COPD) after LT. The assessment of the quality of life, excluding perceived pain, showed the most significant improvement in the physical cumulative score (PCS; 25 vs. 45 points), especially in patients with idiopathic pulmonary fibrosis. Conclusions Lung transplantation in Poland, in patients who live longer than 2 years after the procedure, significantly improves the mobility, lung function, perceived dyspnea, and the quality of life.

Urinary iodine as an iodine deficiency test in lung transplant recipients in order to prevent iodine deficiency disorders.

BACKGROUND In Poland, lung transplantation (LTx) as a routine method began in 2004, and since then, the Silesian Center for Heart Disease in Zabrze 85 LTx has performed (54 single-lung transplantations, 30 double-lung transplantations, and 1 heart-lung) transplantation. The recommendation to take vitamin supplements (without specific indication of the iodine content) does not apply to another iodine prophylaxis in patients after lung transplantation, excluding patients with known thyroid disease. The aim of this study was to assess thyroid gland function based on hormones and urinary iodine (UI) concentration in patients after LTx. MATERIAL AND METHODS UI analysis was performed in 19 lung recipients (12 men and 7 women; mean age: 46.2 ± 12.47 years, BMI: 21 ± 2.25) and compared to TSH, free T3, and free T4. RESULTS Sufficient UI was observed only in 2 (9%) samples. In 12 samples (54.5%), mild iodine deficiency was recorded, in 4 samples (18.2%) moderate iodine deficiency was noted, and in 3 (13.6%) severe iodine deficiency was found. No correlation between BMI and UI, as well as hormones concentration, was observed. No correlation was revealed when analyzed samples were divided by patient sex. CONCLUSIONS Although thyroid gland hormones were in the normal range, we found moderate, mild, and severe iodine deficiency in the majority of analyzed samples. Measurements of urinary iodine in lung transplant recipients should accompany thyroid hormone measurements as an iodine deficiency test and in order to prevent iodine deficiency disorders.