Fig 2: (A) Enzymatic reaction by B4GalNT2. (B) Effect by B4GalNT2 overexpression to convert a2,3 sialic acid receptors into Sda like antigens (C)MDCK, MDCK-SiaT1 and MDCK-B4GalNT2 maintained for 20 passages were lysed for Immunoblot for B4GalNT2 and GAPDH.

Fig 3: Enzyme-linked lectin assay of cell lysates from MDCK, MDCK-SiaT1 (SiaT1), MDCK-YFP (YFP) and 3 MDCK-B4GalNT2 clones bound by (A)MAA1, (B) MAA2, (C) SNA_and (D) DBA. Signals are normalized to wild-type MDCK cells. Mean ± 1sd, n = 3. *p < 0.05, **p < 0.01, ***p < 0.001, one way-ANOVA.

Fig 4: (A,B) Number of PFU formed after incubated with same amount of (A) Cal04 or (B) OK323 in plaque assay using MDCK and MDCK-B4GalNT2, which overlaid agarose at the time specified. (C) Proportion of NP positive cells normalized to that of wild type MDCK. Mean ± sd, n = 2. (D) MDCK and MDCK-B4GalNT2 were infected with influenza virus at MOI 1 for 8 h. Mean ± sd, n = 3. *p < 0.05, **p < 0.01, ***p < 0.001 by 2 tailed T-test.

Fig 5: (A) MDCK and MDCK-B4GalNT2 were infected with PR8 and its PB2 mutants at MOI 1 for 8 h. Mean ± sd, n = 3. (B) MDCK and MDCK-B4GalNT2were infected with WSN, Dk/Bav, Cal04, HK09, 4167, OK323, Ar02 and OK309 at MOI 4 for 8 h. Mean ± 1sd, n = 3. (C) Proportion of NP positive cells normalized to that of wild type MDCK. Mean ± sd, n = 2. *p < 0.05, **p < 0.01, ***p < 0.001, 2 tailed T-test.