Protection efficacy of recombinant LAB against infections with divergent influenza virus subtypes.

<p>Five-week-old female BALB/c mice (5 per group) were vaccinated with PBS, pgsA/<i>L. casei</i>, pgsA-sM2/<i>L. casei</i> or pgsA-CTA1-sM2/<i>L. casei</i> at 0 to 3, 7 to 9 and 21 days i.n. or 0 to 3, 7 to 9 and 21 to 23 days orally. Vaccinated mice were infected i.n. with 10 LD₅₀ of mouse-adapted divergent influenza subtypes. (A-J left panel) The percent change of initial body weight and, (A-J right panel) survival post challenge are shown. (A-J left panel) Error bars depict the standard error of the mean. *, Groups differ for weight loss, P<0.05 (Student's <i>t</i> test). In survival, mice vaccinated (particularly i.n. group) with pgsA-CTA1-sM2/<i>L. casei</i> was significantly better protected than PBS, pgsA/<i>L. casei</i>, pgsA-sM2/<i>L. casei</i> mice after lethal challenge with (A and B, right panel) A/Aquatic bird/Korea/W81/2005(H5N2) (log-rank test, <i>P</i> = 0.00063 and <i>P</i> = 0.045 respectively), (C and D, right panel) A/Puerto Rico/8/34(H1N1) (log-rank test, <i>P</i> = 0.01 and <i>P</i> = 0.02 respectively), (E and F, right panel) A/Chicken/Korea/116/2004(H9N2) (log-rank test, <i>P</i> = 0.0004 and <i>P</i> = 0.004 respectively), (G and H, right panel) A/EM/Korea/W149/06(H5N1) (log-rank test, <i>P</i> = 0.001 and <i>P</i> = 0.06 respectively) and (I and J, right panel) A/Aquatic bird/Korea/W44/2005(H7N3) (log-rank test, <i>P</i> = 0.02 and <i>P</i> = 0.56 respectively).