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Barabas, J.

Publications and source records attributed to Barabas, J..

3 recordsLinked to original sources

Myoferlin is an essential component of late-stage vRNP trafficking vesicles for enveloped RNA viruses.

The Rab11a endosomal recycling pathway is exploited by important respiratory RNA viruses such as IAV and RSV, aiding viral egress from the apical surface of polarized epithelial cells. Late in infection, Rab11a-containing vesicles specifically transport viral ribonucleoprotein (vRNP) complexes towards the cell surface before packaging and budding. Rather than employing traditional Rab11a-positive recycling endosomes, virus-infected cells generate remodelled Rab11a-containing vesicles, as observed during IAV infection. Besides Rab11a, no other conserved host co-factors have been identified among these various vRNP trafficking vesicles. Here we discovered and confirmed myoferlins association with IAV vRNPs in the cytoplasm and colocalisation with Rab11a during late stages of infection. We also found that this role was conserved in late-stage vRNP trafficking of other viruses, including RSV and SeV. Myoferlin likely recruits the EHD family of proteins, which are involved in endosomal biogenesis, to these unique vRNP trafficking endosomes, highlighting myoferlins pivotal role in viral replication.

microbiology↗

Inhibition of the TLR4 signalling pathway with TAK-242 reduces RSV infection and cytokine release in primary airway epithelial cells

Respiratory syncytial virus (RSV) infection is the leading cause of hospitalisation in children worldwide, but there is still no vaccine or anti-viral treatment available. RSV has been implicated in the development of respiratory diseases such as asthma. Toll like receptor 4 (TLR4) has been well characterised in the immune responses to RSV. However, the role of TLR4 in RSV infection remains unclear. To study RSV in the lung epithelium, where RSV preferentially infects ciliated cells, we used a well-differentiated primary airway epithelial cell (WD-PAEC) model: a pseudostratified epithelium that produces mucus and beating cilia. We demonstrate in this physiologically relevant model that TLR4 is a pro-viral factor. Inhibition of TLR4 using TAK-242 significantly reduces RSV titres in WD-PAECs in a dose-dependent manner but has no effect on RSV growth kinetics in a range of immortalised respiratory-derived cell lines. Specific inhibition of a range of downstream effectors of TLR4 signalling in the WD-PAEC model identified p38 MAPK as a pro-viral factor, whereas inhibition of MEK1/2 significantly increased RSV titres. Our data demonstrate a role for TLR4 in RSV infection and highlight the importance of biologically relevant models to study virus-host interactions. Author summaryRespiratory Syncytial Virus (RSV) can cause severe respiratory infection in young children and is responsible for approximately 200,000 deaths worldwide every year. Despite decades of research since the identification of this virus in the 1950s there is still no vaccine or treatment available. Advances in research have led to the development of cell cultures that are very similar to the cells that line human airways. These cultures provide an opportunity to study how viruses interacts with airway cells in a representative model and may provide insights that traditional research models have not yet been able to answer. Using this experimental model we show that a drug, TAK-242 which targets a pathogen recognition receptor on the surface of cells, reduces growth of RSV and dampens the immune response to infection in these airway cells. Our data demonstrate potential targets for RSV treatments and also highlight the importance of using relevant experimental models.

microbiology↗

Comparative primary paediatric nasal epithelial cell culture differentiation and RSV-induced cytopathogenesis following culture in two commercial media.

The culture of differentiated human airway epithelial cells allows the study of pathogen-host interactions and innate immune responses in a physiologically relevant in vitro model. As the use of primary cell culture has gained popularity the availability of the reagents needed to generate these cultures has increased. In this study we assessed two different media, Promocell and PneumaCult, during the differentiation and maintenance of well-differentiated primary nasal epithelial cell cultures (WD-PNECs). We compared and contrasted the consequences of these media on WD-PNEC morphological and physiological characteristics and their responses to respiratory syncytial virus (RSV) infection. We found that cultures generated using PneumaCult resulted in greater total numbers of smaller, tightly packed, pseudostratified cells. However, cultures from both media resulted in similar proportions of ciliated and goblet cells. There were no differences in RSV growth kinetics, although more ciliated cells were infected in the PneumaCult cultures. There was also significantly more IL-29/IFN{lambda}1 secreted from PneumaCult compared to Promocell cultures. In conclusion, the type of medium used for the differentiation of primary human airway epithelial cells impacts experimental results.

cell biology↗