Fig. 4.

The H2-HA is not processed in Tmprss2^−/− mice. Female 8–12-week-old C57BL/6 J wild type (WT) and Tmprss2^−/− knock-out (KO) mice were infected intranasally with 2 × 10⁴ focus forming units (ffu) PR8_HA(H2). On day 2 post infection (dpi) broncho-alveolar lavages (BAL) were prepared. a H2 cleavage and nuclear protein (NP) in BAL (day 2 p.i.) were analysed by Western blots. b Enhanced image of (a) using ImageJ software (B/C: brightness/contrast). HA₀: uncleaved HA, HA₁: N-terminal part of cleaved HA, HA₂: C-terminal part of cleaved HA; NP: nuclear protein