Fig. 6.

Receptor specificity and cell tropism of influenza viruses. (a) Association constants (K_ass) of virus complexes with monospecific HRP-labeled fetuin, which carried either 2-3-linked or 2-6-linked sialic acids (filled and hatched bars, respectively). Higher K_ass values indicate stronger binding. (b) HTBE cultures were infected, fixed 7 h after infection, and double-immunostained for light microscopy. Percentages of infected ciliated cells (filled bars) and infected nonciliated cells (hatched bars) with respect to the total amount of infected cells were determined as described in Materials and Methods. For Mem96-M and DkH1, the experiments were repeated three times with different lots of HTBE cultures. Mem96-E1 was tested in parallel with two other viruses in the first two experiments.