The lethal toxin produced by Bacillus anthracis is a bipartite toxin in which the first protein, protective antigen (PA), transports the second protein, lethal factor, across the host cell membrane. We have previously shown that CD8(+) T-cell epitopes fused to a nontoxic derivative of lethal factor (LFn) are delivered into the host cell cytosol in a PA-dependent manner. Delivery of these antige...

Antibody (Ab) responses to Bacillus anthracis toxins are protective, but relatively few protective monoclonal antibodies (MAbs) have been reported. Protective antigen (PA) is essential for the action of B. anthracis lethal toxin (LeTx) and edema toxin. In this study, we generated two MAbs to PA, MAbs 7.5G and 10F4. These MAbs did not compete for binding to PA, consistent with specificities for ...

The generation of protective humoral immune responses against the receptor-binding domain (domain IV) of protective antigen [PA(dIV)] of Bacillus anthracis represents a plausible approach against anthrax toxin. In the current study, we have developed a naked DNA vaccine encoding calreticulin (CRT) linked to PA(dIV) of Bacillus anthracis [CRT/PA(dIV)]. We transfected a human embryonic kidney cel...

Detection of antigen-specific CD4+ T cells is facilitated by the use of fluorescently labeled soluble peptide-major histocompatibility complex (MHC) multimers which mirror the antigen specificity of T-cell receptor recognition. We have used soluble peptide-MHC class II tetramers containing peptides from the protective antigen (PA) of Bacillus anthracis to detect circulating T cells in periphera...

The protective antigen (PA) of Bacillus anthracis and the V antigen of Yersinia pestis are potent immunogens and candidate vaccine sub-units. When plasmid DNA encoding either PA or V antigen was used to immunise the Balb/c mouse, a low serum IgG titre was detected (log (10)1.0 or less) which was slightly increased by boosting with plasmid DNA. However, when mice immunised with plasmid DNA were ...

Viral-like particles (VLPs) of parvovirus B19 were employed as an antigen carrier to present antigenic determinants of Bacillus anthracis. The small-loop peptide and the full-length domain 4 of protective antigen (PA) were chosen as immunogens for presentation on the VLP-capsid surface and subsequent immunization of BALB/c mice. The recombinant VLPs induced anti-PA IgG titers of up to 2.5 x 10(...

Protective immunity against infection with Bacillus anthracis is almost entirely based on a response to the protective antigen (PA), the binding moiety for the two other toxin components. We cloned the PA gene into an auxotrophic mutant of Salmonella enterica serovar Typhimurium as a fusion with the signal sequence of the hemolysin (Hly) A gene of Escherichia coli to allow the export of PA via ...

Foot-and-mouth disease (FMD) is a highly infectious affecting cloven-hoofed animals and causes significant economic losses to the livestock industry. The Type O PanAsia-2 (O PA-2) vaccine strain protective against wide range of serotype FMD virus (FMDV) strains in East Asia, A22 Iraq/24/64 (A22 IRQ) most widely used antigen banks. aim this study was produce antigens from PA-2 IRQ viruses using ...

Monoclonal antibodies (MoAbs) were generated following immunization of BALB/c mice with protective antigen (PA) of B. anthracis. Five clones reactive to this protein were stabilized and preserved. These MoAbs could detect nanogram levels of PA when tested in ELISA. In Western blotting, they reacted with all PA preparations tested and no cross-reactivity was observed with lethal factor, edema fa...