In cynomolgus and rhesus monkeys high levels of antibodies could be achieved in a dose dependent fashion, with a robust memory CD4 recall response to TpD in all animals that received sufficient doses of

vaccine. For mouse experiments female 6–8-week-old Balb/C mice (Jackson Laboratories) were housed and handled at Vivisource (Cambridge, MA) in accordance to Institutional Animal Care and Use Committee (IACUC) requirements. For vaccine injections, mice were injected subcutaneously with a single click here bolus of nanoparticle preparations in PBS (50 μl/limb). Mice were injected 3 times (1 prime and 2 boosts immunizations) with 2-week intervals between immunizations. For serum collection, blood was collected by lateral tail vain bleeding 12 days after each immunization and after that as indicated. At the termination of the experiment, mice were euthanized by CO2 asphyxiation and blood collected by cardiac puncture. For long term memory recall assays Balb/C mice were inoculated on days 0, 14 and 28 with nicotine nanoparticles containing R848 and either TpD or ovalbumin 323–339 (Ova) peptide. Spleens were harvested between 122 and 152

days after final inoculation and both CD4+ and CD11c+ cells were isolated see more directly ex vivo by MACS cell separation system (Miltenyi, Cambridge, MA). Cells were incubated at 37 °C at a 10:1 ratio (500,000 CD4 T cells to 50,000 dendritic cells) with 10uM peptide. Supernatants were harvested 18 h later and assayed for IFN-γ by ELISA. For Rhesus macaques (Macaca mulatta) experimental procedures as outlined in Harvard Medical Associates standing committee on animal’s protocol # 04758 were followed throughout the study. The study followed The Public Health Service (PHS) Policy Florfenicol on Humane Care and Use of Laboratory Animals, and was administered in accordance with IACUC requirements. Four, three year old Rhesus macaques received a total of three vaccinations at 4-week intervals. At each procedure time point, the animals were sedated with 10 mg/kg ketamine-HCl administered intramuscularly. 1 mL of the test substance was administered via the subcutaneous route. Briefly,

the skin on the quadriceps was shaved, wiped with alcohol and allowed to dry. The immunizing material was then administered via a 23 gauge, 1-inch needle. The animals were monitored and returned to their home cage when awake. The animals were weighed when sedated for each procedure. Blood samples (in 10 mL round bottom tubes with EDTA; used for ELISPOT) and 5 mL of serum (used for antibody analysis) were collected at approximately bi-weekly intervals. For the cynomolgus monkey study, animal welfare was in compliance with the U.S. Department of Agriculture’s (USDA) Animal Welfare Act (9 CFR Parts 1–3). The Guide for the Care and Use of Laboratory Animals, Institute of Laboratory Animal Resources, National Academy Press, Washington, D.C., 1996, was followed. The non-clinical laboratory (MPI Research, Inc.