Showing papers by "Richard W. Titball published in 1994"
TL;DR: It is suggested that the use of S. typhimurium to deliver PA is an effective approach for inducing protection against B. anthracis and that the degree of protection demonstrated in the mouse may not fully indicate the potential of the recombinant Salmonella as an effective vaccine in other species.
87 citations
TL;DR: The stability of plasmids pBR322, pUC19 and pBluescript and their effect on bacterial colonization of mice was determined and the significance of these data for vaccine design is discussed.
43 citations
TL;DR: The techniques described should improve the detection by PCR of B. anthracis and other sporulating bacteria.
Abstract: Polymerase chain reactions (PCRs) for the capsule and oedema factor genes of Bacillus anthracis were used to assess methods for detecting B. anthracis spores. Untreated spore preparations were found to contain significant amounts of extracellular template DNA which probably accounted for observed amplification from these preparations without spore lysis. Germination of spores with suitable media allowed the detection of less than 10 spores in a PCR test. Mechanical disruption of spores with glass or zirconia beads yielded similar results to germination but in a much shorter time. The techniques described should improve the detection by PCR of B. anthracis and other sporulating bacteria.
40 citations
TL;DR: Alpha-toxin of Clostridium perfringens, cloned in Escherichia coli, has been purified and crystallized from ammonium sulphate using the hanging drop vapour diffusion method at 20 degrees C.
21 citations
TL;DR: The technique of antibody reshaping is used to produce a humanized antibody specific for the alpha toxin of Clostridium perfringens, and amino acids adjacent to CDRs can either contribute to, or distort, CDR loop conformation and must be adjusted to achieve high binding affinity.
Abstract: We have used the technique of antibody reshaping to produce a humanized antibody specific for the alpha toxin of Clostridium perfringens. The starting antibody was from a mouse hybridoma from which variable (V) region nucleotide sequences were determined. The complementarity-determining regions (CDRs) from these V regions were then inserted into human heavy and light chain V region genes with human constant region gene fragments subsequently added. The insertion of CDRs alone into human frameworks did not produce a functional reshaped antibody and modifications to the V region framework were required. With minor framework modifications, the affinity of the original murine mAb was restored and even exceeded. Where affinity was increased, an altered binding profile to overlapping peptides was observed. Computer modelling of the reshaped heavy chain V regions suggested that amino acids adjacent to CDRs can either contribute to, or distort, CDR loop conformation and must be adjusted to achieve high binding affinity.
10 citations