Intravenous DNA immunization during pregnancy primes the fetal immune system.

<p>Pregnant mice were IV immunized approximately 15–16 days into gestation with 100 µg of <i>Lamp/gag</i> (LG) or <i>gag</i> (G) vaccine DNA. Offspring were either immunized (IM) or not (NI) at 7-d-o with 5 µg of the DNA vaccine. (A) Mother: IFN-γ SFCs from spleen cells of immunized mothers 35 days after delivery and (B) Offspring: IFN-γ SFCs from spleen cells of 35-d-o offspring after stimulation with class I and class II Gag peptides and recombinant p24 of HIV-1. The figure represents 2–3 assays per group (2–3 animals per group). (C) Offspring: Serum samples from 35-d-o NI or IM offspring were evaluated by ELISA using HIV-1 lysates for anti-Gag IgG concentrations. Bars represent the mean ± SEM. Schematic diagram of the immunization protocol is shown. *p≤0.05, **p<0.01, and *** p<0.001 when compared with G-offspring from a G-mother; +++p<0.001 when compared with NI offspring from a G-immunized mother.