Fig. 1.

Infection with H1N1pdm influenza stimulates the expression of GX-sPLA₂ in bronchial epithelial cells and inflammatory cells. Mice were infected with H1N1pdm (A/Mexico/4108/2009) and the lungs were assessed for the mRNA and protein expression and localization of PLAs during a 14 day time course. GX-sPLA₂ mRNA (Ai), cPLA₂ mRNA (Aii) and GV-sPLA₂ mRNA (Aiii) expression quantified by Real-Time RT-PCR was normalized to GAPDH, GX^+/+ (open bars) and GX^−/− (filled bars) mice (C3H/HeN background mice). GX^+/+ and GX^−/− mouse lungs were perfusion fixed in situ with 4% paraformaldehyde, sectioned and subject to immunohistochemical analysis with the IgG fraction of rabbit anti-mouse GX-sPLA₂ antiserum (1/100 dilution) (B). GIIA and GX-sPLA₂ protein expression determined by immunoblot analysis of lung tissue homogenates of wild type GX^+/+ (lane 1) and knockout GX^−/− (lane 2) mice (C). For each blot, the corresponding recombinant sPLA₂ enzyme (rec sPLA₂) was run alone (lane 3) as a control. Representative results for five separate experiments are shown. All the mice used in these experiments were genotyped littermates and grouped and analyzed by their genotype. a, p<0.05 GX^+/+ or GX^−/− vs. base; b, p<0.05 GX^+/+ vs. GX^−/− at any time point, ANOVA followed by paired t-test, two tailed, assuming unequal variance. n≥8 per group; 400×; scale bar: 50 μm for immunohistochemistry.