Figure 4. (A) Replication kinetics of HCoV-HKU1 in human alveolar type II cells.

Cultures were inoculated with a primary clinical isolate of HCoV-HKU1. Data represent RT-PCR of apical washes from HCoV-HKU1 infected cells harvested at the indicated time points postinoculation. Data lines represent two independent experiments performed in duplicate (mean±standard deviation). (B) Propagation of an HKU1 clinical isolate in human alveolar type II cells at the air liquid interface. Alveolar cells were inoculated with diluted nasal pharyngeal washes for the first passage and with apical washed 120 hr postinoculation for subsequent passages. The bars represent real-time RT-PCR analysis of apical washes at 120 hr. IFA performed at 120 hours confirmed the presence of infected cells at each passage.