Human lung vascular endothelium may limit infection with HRV16 via IFN-ß-dependent mechanisms.

Human rhinovirus 16 (HRV16) may induce inflammatory and antiviral responses in the human lung vascular endothelium (ECs) and impair its barrier functions after infection. However, ECs may regain barrier and metabolic functions. Mechanisms of limitation of HRV16 infection in the lung vascular endothelium are unknown. Human lung vascular endothelium (HMVEC-L) was infected with HRV16. IFN-ß, OAS-1, and PKR expression was assessed by real-time PCR, flow cytometry, and confocal microscope. To prove the significance of IFN-ß in the limitation of HRV16 replication, HMVEC-Ls were preincubated with anti-IFN-ß Abs. To prove the involvement of OAS-1 and PKR in the IFN-dependent limitation of HRV16 replication, HMVEC-Ls were transfected with respective siRNA. HRV16 stimulated IFN-ß production and activated intracellular mechanisms of antiviral immunity based on OAS-1 and PKR activation. Blocking of IFN-ß contributed to the inhibition of intracellular mechanisms of antiviral immunity (OAS-1, PKR) and boosted replication of HRV16. Effective OAS-1 silencing by siRNA caused the increase of HRV16 copy numbers after HRV16 infection. siRNA upregulated the other genes related to the antiviral response. The infected lung vascular endothelium may limit the HRV16 infection. This limitation may be associated with the induction of IFN-ß-dependent intracellular mechanisms based on OAS-1 and PKR activity.

Human lung vascular endothelium may limit viral replication and recover in time upon the infection with rhinovirus HRV16.

Vascular endothelium is a semi-permeable barrier that regulates the flow of nutrients, ions, cytokines and immune cells between blood and tissues. Barrier properties of endothelium, its ability to regenerate and the potential for secretion of inflammatory mediators play a crucial role in maintaining local tissue homeostasis. The lung vascular endothelial cells were shown to be infected by human rhinovirus (HRV) and generate antiviral, inflammatory and cytopathic responses. The current study reveals that in the long-time manner, the lung vascular endothelium may efficiently limit the HRV replication via the IFN-dependent 2'-5'-oligoadenylate synthetase 1 activation. This leads to the restoration of integrity accompanied by the up-regulation of adherens and tight junctions, increase of metabolic activity and proliferation rate. Secondly, HRV16-infected cells show delayed and transient up-regulation of the expression of vascular endothelial growth factor (VEGF), fibroblast growth factor, angiopoietin 1 and 2, and neuropilin-1, as well as VEGF receptors. The lung vascular endothelium infected with HRV may limit the infection, recover in time, and regain barrier properties and metabolic functions, thus leading to the restoration of integrated barrier tissue.