Therefore, BALB/c mice were used to study adaptive immunity (Expt. 1); C57BL/6 mice were used figure 1 to study innate immunity (Expt. 2). Mice were bred and housed under barrier conditions in the Division of Veterinary Resources at the University of Miami Miller School of Medicine. Timed matings were set up for 24 h and the day of separation of the females from the males was considered d 0 of gestation. On d 16�C18 of gestation, pregnant mice were placed on control (Con)6 or lycopene-containing (Lyc) diets. Dams continued to receive these diets until the pups were weaned (3 wk of age). At weaning, the pups were placed on the Con diet. At the indicated times, mice were killed by CO2 asphyxiation followed by cervical dislocation.

All animal procedures used in this study were reviewed and approved by the Institutional Animal Care and Use Committee at the University of Miami Miller School of Medicine. Preparation of samples for lycopene concentration determination. Sera from BALB/c dams fed Lyc or Con diet were collected at the time of weaning of the pups. Seven�Cday-old BALB/c female pups suckling on dams fed the Lyc or Con diet were killed and stomachs and livers were removed and flash frozen in an isopropanol/dry ice slurry. Tissues and fluids were analyzed for lycopene content by Craft Technologies. Protein antigen immunization. Female neonatal (d7) BALB/c mice born to dams fed Con or Lyc diets were immunized with 25 ��g dinitrophenyl-keyhole limpet hemocyanin (DNP-KLH; Calbiochem) in PBS and then reimmunized 4�C5 wk later with 100 ��g DNP-KLH, as previously described (23).

Cytokine ELISA, serum ELISA, and enzyme-linked Immunospot assays. Detailed descriptions of these procedures can be found in previously published material (23�C25). Bacterial infection. Yersinia enterocolitica A127/90 yopP serotype 0:8/biotype IB was kindly provided by Guy R. Cornelis, Universitat Basel, Basel, Switzerland. D7 female C57BL/6 neonates born to dams fed a Lyc or Con diet were i.g. infected with 2 �� 107 CFU of Y. enterocolitica A127/90 yopP, as previously described in detail (26). Bacterial enumeration from organs of infected mice. Intestines, spleen, and livers from C57BL/6 pups born to dams fed a Lyc or Con diet were prepared and homogenized. Bacterial titers were measured by plating on Yersinia Selective Agar plates (DIFCO) as previously described in detail (26).

Control experiments with age-matched, uninfected mice demonstrated that intestinal commensal bacteria were undetectable using this selective medium (27) (data not shown). Cell staining, antibodies, and flow cytometry analyses. The staining of mesenteric lymph node (MLN) cells to detect Ly6G+CD11bhi neutrophil phenotype cells was performed as previously Anacetrapib described (26). Statistical analyses. All cytokine and antibody responses (Expt. 1) were tested for significance using unpaired Student��s t tests; Mann Whitney nonparametric analyses were used for Expt. 2.