Robert G. Ulrich

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The biological effects of staphylococcal enterotoxins (SE), potentiated by bacterial lipopolysaccharide (LPS), were studied with mice. Control animals survived the maximum dose of either SE or LPS, while mice receiving both agents died. SEA was 43-fold more potent than SEB and 20-fold more potent than SEC1. The mechanism of toxicity was further examined(More)
Staphylococcal and streptococcal superantigens are exotoxins that may be linked to many human pathologies involving impaired immune functions. Despite considerable sequence divergence, bacterial superantigens share extensive secondary and tertiary structure and use similar structural strategies to bind major histocompatibility complex class II receptors. We(More)
Binary complexes formed by components of the Yersinia pestis type III secretion system were investigated by surface plasmon resonance (SPR) and matrix-assisted laser desorption time-of-flight mass spectrometry. Pairwise interactions between 15 recombinant Yersinia outer proteins (Yops), regulators, and chaperones were first identified by SPR. Mass(More)
The recombinant protective antigen (rPA) of Bacillus anthracis is a promising anthrax vaccine. We compared serum immunoglobulin G levels and toxin-neutralizing antibody titers in rabbits following delivery of various doses of vaccine by microneedle-based intradermal (i.d.) delivery or intramuscular (i.m.) injection using conventional needles. Intradermal(More)
IL-15 is produced by a wide variety of tissues in response to inflammatory stimuli. We examined the effect of IL-15 in supporting the maturation of monocytes to dendritic cells in ex vivo culture. IL-15 transformed CD14(+) monocytes to mature dendritic cells. These dendritic cells were similar to those obtained from monocyte cultures treated with a(More)
Anthrax remains a serious threat worldwide as a bioterror agent. A second-generation anthrax vaccine currently under clinical evaluation consists of a recombinant Protective Antigen (rPA) of Bacillus anthracis. We have previously demonstrated that complete protection against inhalational anthrax can be achieved in a rabbit model, by intranasal delivery of a(More)
The development of new protein subunit vaccines has stimulated the search for improved adjuvants to replace traditional aluminum-containing products. We investigated the adjuvant effects of a synthetic Toll-like receptor 4 (TLR4) agonist on vaccine efficacy in an experimental model of toxic shock syndrome. The TLR4 agonist E6020 has a simplified structure(More)
A comparative site-directed mutagenesis study of staphylococcal enterotoxins A and B was undertaken to identify key amino-acid residues which govern interactions with major histocompatibility class II molecules. This involved generating a three-dimensional homology model for enterotoxin A in complex with the HLA-DR1 molecule, based on the reported X-ray(More)
A candidate vaccine against staphylococcal enterotoxin B (SEB) was developed using a Venezuelan equine encephalitis (VEE) virus vector. This vaccine is composed of a self-replicating RNA, termed "replicon," containing the VEE nonstructural genes and cis-acting elements and a gene encoding mutagenized SEB (mSEB). Cotransfection of baby hamster kidney cells(More)
This study examined the biologic responses of transgenic mice expressing human leukocyte antigen (HLA)-DR3 and human CD4 molecules, in the absence of murine major histocompatibility complex (MHC) class II molecules (Ab(0)), to staphylococcal enterotoxins (SEs) and evaluated protective immunity of a nonsuperantigen form of SEB against wild-type holotoxin.(More)