Fig 3. Passive transfer of SMB19 or vaccination with GBSIb improves survival in a mouse model of disseminated I.A.

(A) Survival of C57BL/6J mice passively transferred with 200 μg SMB19 (green, n=19), SIbD2 (red, n=18), A16 (blue, n=7), or PBS (black, n=8) i.p. immediately before i.v. infection with 2×LD₅₀ (2×10⁶) A.f. conidia. Results were pooled from 3 separate experiments. Asterisks denote significant differences in average survival compared to mice administered SIbD2, A16, or PBS. (B) Serum IgM^a levels were analyzed at various times before and after passive transfer of 200 μg SMB19 by ELISA. (C) Survival of mice vaccinated i.v. with GBSIb (green, n=12), GBSII (red, n=10), or PBS (black, n=17) 6 days before i.v. infection with A.f. Results are pooled from 2 separate experiments with similar results. Asterisks denote significant differences in average survival of GBSIb vaccinated animals compared with GBSII vaccinated and PBS control groups. (D-F) Serum GBSIb type-specific IgM (D), SMB19 idiotype-positive IgM(E), and GBSII type-specific IgM (F) quantified by ELISA immediately before (Day -6) or 6 days after (Day 0) vaccination with GBSIb (green) or GBSII (red). Asterisks denote significant differences between serum IgM levels at day -6 and day 0. Data were analyzed by a two-tailed unpaired t test, *=p<0.05; **= p<0.01; ***= p<0.001; ****= p<0.0001. In survival studies, statistical significance was determined by log rank test.