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05). PA-specific gamma interferon (IFN-␥) and interleukin-4 (IL-4) CD4؉ cell frequencies and T cell stimulation indices were sustained through 50.5 months (the last time point measured). PA-specific memory B cell frequencies were highly variable but, in general, were detectable in peripheral blood mononuclear cells (PBMC) by 2 months, were significantly above control levels by 7 months, and remained detectable in the HuAVA and 1:5 and 1:20 AVA groups through 42 months (the last time point measured). HuAVA and diluted AVA elicited a combined Th1/Th2 response and robust immunological priming, with sustained production of high-avidity PA-specific functional antibody, long-term immune cell competence, and immunological memory (30 months for 1:20 AVA and 52 months for 1:10 AVA). Vaccinated animals surviving inhalation anthrax developed high-magnitude anamnestic anti-PA IgG and TNA responses.

Botulinum neurotoxins (BoNT) are some of the most toxic proteins known, with a human LD50 of ~1 ng/kg. Equine antitoxin has a half-life in circulation of less than 1 day and is limited to a treatment rather than a prevention indication. The development of monoclonal antibodies (mAbs) may represent an alternative therapeutic option that can be produced at high quantities and of high quality and with half-lives of >10 days. Two different three mAb combinations are being developed that specifically neutralize BoNT serotypes A (BoNT/A) and B (BoNT/B). We investigated the pharmacokinetics of the anti-BoNT/A and anti-BoNT/B antibodies in guinea pigs (Cavia porcellus) and their ability to protect guinea pigs against an aerosol challenge of BoNT/A1 or BoNT/B1. Each antibody exhibited dose-dependent exposure and reached maximum circulating concentrations within 48 h post intraperitoneal or intramuscular injection. A single intramuscular dose of the three mAb combination protected guinea pigs against an aerosol challenge dose of 93 LD50 of BoNT/A1 and 116 LD50 of BoNT/B1 at 48 h post antibody administration. These mAbs are effective in preventing botulism after an aerosol challenge of BoNT/A1 and BoNT/B1 and may represent an alternative to vaccination to prevent type A or B botulism in those at risk of BoNT exposure.

Cutaneous exposure to sulfur mustard [bis(2-chloroethyl) sulfide (SM)] produces a delayed inflammatory skin response that is followed by severe dermal injury. Assessment of anti-inflammatory therapies against SM-induced skin injury has mainly relied on qualitative histopathological evaluation. The goal of this study was to identify proinflammatory biomarkers in the hairless mouse vesicant model that could be used as additional indicators of SM-induced skin injury for evaluating anti-inflammatory Cutaneous and Ocular Toxicology Downloaded from informahealthcare.com by University of Montreal on 12/01/14For personal use only.treatment. SM-induced inflammation was determined at 2, 6, and 24 hr postexposure by changes in edema. Ribonuclease protection assay (RPA) was used to determine changes in gene expression of inflammatory mediators. At 2, 6, and 24 hr postexposure, a time-dependent increase in edema was observed in SM-exposed skin, which was significant at 6 and 24 hr when compared to unexposed controls. Ribonuclease protection assay analysis revealed a two-fold or greater increase in monocyte chemoattractant protein-1 (MCP-1), macrophage inflammatory protein-2 (MIP-2), MIP-1a, tumor necrosis factor-a, and interleukin (IL)-1b following exposure to SM when compared to unexposed controls. A significant time-dependent increase was observed in MCP-1, MIP-1a, and IL-1b over the 24 hr time period. At 24 hr postexposure, skin treated with the anti-inflammatory drug olvanil showed a significant decrease in SM-induced edema. Additionally, mRNA levels of MCP-1, MIP-2, and IL1b were decreased when compared to skin exposed to SM alone. In this study, we identified molecular biomarkers at the mRNA level, up-regulated in skin exposed to SM, which can be partially suppressed by olvanil. Further characterization of the mRNA and protein expression patterns of proinflammatory biomarkers may enable the use of other classes of anti-inflammatory drugs or therapeutic treatments against SM dermal injury.

T o date, there has not been a systematic evaluation of the relationship between anthrax vaccine-stimulated humoral and cell-mediated immune responses, their relative contributions to protection, or their comparative importance when used singly or in combination to predict the probability of survival in animal models or in humans.Anthrax toxin protective antigen (PA) is the primary immunogen in licensed anthrax vaccines in the United States and the European Union, as well as in many of the second-generation anthrax vaccines in current development (1). Consequently, the quantitative analysis of anti-PA IgG antibody levels and lethal toxin neutralization activity (TNA) in serum are generally accepted as immunological correlates of protection (COP) for vaccine efficacy in animal models (2). Anti-PA IgG levels and TNA are also considered pivotal for cross-species predictions of anthrax vaccine efficacy in humans, for whom clinical efficacy studies are either impractical or ethically infeasible (3, 4) (http://www.fda .gov/AdvisoryCommittees/CommitteesMeetingMaterials/Blood VaccinesandOtherBiologics/VaccinesandRelatedBiologicalProducts AdvisoryCommittee/ucm239733.htm). Anti-PA IgG and TNA levels, however, are but one part of the spectrum of humoral and cell-mediated immune responses that may contribute to protection. The COP for anthrax may differ depending on vaccine formulations, schedules, and routes of administration (5-10).The U.S.-licensed anthrax vaccine adsorbed (AVA) (BioThrax) was approved in 1970 for the prevention of anthrax in humans (11)(12)(13)(14). The original regimen for AVA was a subcutaneous (s.c.) six-dose primary schedule at 0, 0.5, 1, 6, 12, and 18 months, with subsequent annual boosters. In May 2012, the U.S. Food and Drug Administration (FDA) approved the AVA regimen as an intramuscular (i.m.) three-dose priming schedule at 0, 1, and 6 months, with boosters at 12 and 18 months and annually thereafter (http://www .fda.gov/BiologicsBloodVaccines/Vaccines/ApprovedProducts /ucm304758.htm). These recent changes in the schedule and administration route were based on data from the Centers for Disease Control and Prevention Anthrax Vaccine Research Program (AVRP) (12, 13). The goals of the AVRP were to improve the AVA safety profile and ensure efficacy while minimizing the number of doses required. The study objectives included determining immunological correlates of protection, documenting vaccine efficacy, and optimizing the vaccination schedule and route of administration (14). Due to the low prevalence of inhalation anthrax and the ethical concerns of conducting an efficacy trial in humans, vaccine efficacy and duration of protection were evaluated in rhesus macaques (Macaca mulatta) (15).The AVRP nonhuman primate (NHP) study used the 0-, 1-, and 6-month intramuscular priming series (3-i.m.) with a full human dose or saline dilutions of AVA to modulate the immune response. The NHP were challenged with high-dose (median, 504ϫ the 50% lethal dose [LD 50 ]) aerosolized Bacillus anthracis spores at m...