Delayed immunological reaction of Human Microvascular Lung Endothelium in response to Human Coronavirus 229E infection

ABSTRACT

Introduction: In the natural conditions first and major target for respiratory viruses (RVs) are epithelial cells. Nonetheless, recently we have demonstrated that RVs are able to infect not only epithelium, but also Human Microvascular Lung Endothelial Cells (HMVEC-L) which increased network is observed during severe asthma due to increased angiogenesis. Furthermore, on the surface of HMVEC-L we observed intense expression of aminopeptidase N (AP-N)- an entry receptor for Human Coronavirus 229E (HCoV-229E). Due to the facts, that possibility of being infected by HCoV-229E should be considered and there is no research based on this model the aim of this study was to assess the vulnerability of HMVEC-L to HCoV-229E infection. Method(s) HMVEC-L was incubated with HCoV-229E (MOI 0,1;1,0;3,0) for 3 hours, 3x PBS washed and cultured for 120 hours. In relevant time points (5;24;48;72;96 and 120h) viral copy number and mRNA expression of inflammatory, anti-viral and receptor factors were evaluated in Real-Time PCR. Confocal microscopy (CM) and flow cytometry (FACS) were used to measure AP-N surface expression. Result(s) FACS and CM confirmed intense surface expression of AP-N on HMVEC-L. HCoV-229E efficiently infected HMVEC-L (604 945,5 +/-194 930,2 viral copies/mul) in 48h cultures (MOI 0,1) and induced relatively late (between 72- 96h) mRNA expression of RANTES (1181,12);IL-6 (89,6);IFN-beta (53,7);OAS-1 (64,3);PKR (11,4) and TLR-3 (42,4). Increased mRNA expression was also accompanied by protein release to the supernatants. Conclusion(s) HCoV-229E may efficiently infect HMVEC-L and induce delayed inflammatory and anti-viral response.