Langerhans Cells Stimulated by Mechanical Stress Are Susceptible to Measles Virus Infection

Objective: Measles virus (MV) first infects the human respiratory tract, but the initial target cells are unknown. We examined whether MV infects Langerhans cell-like dendritic cells (LCs) generated from CD14 + monocytes in the presence of GM-CSF, IL-4, and TGF-β1. Methods: Cultured LCs were established as described recently [Biochem Biophys Res Commun 2003;306:674–679]. The expression of immunological markers was detected by FACScan. Infection with MV was assessed by syncytia formation, viral-specific fluorescence, and Western blotting. Results: MV did not infect and replicate the freshly established, unstimulated LCs expressing CD1a, E-cadherin and Langerin but not CD83. Also, CD150, a receptor for MV was not expressed on the surface of the LCs. However, LCs stimulated by mechanical stress such as washing and centrifugation became susceptible to MV infection. Conclusion: A subset of mechanically stimulated LCs but not unstimulated immature ones became susceptible to MV. The actual role of Langerhans cells in local immunity seems to be to suppress unfavorable reactions initiated by virus intrusion.