Francis Michon

Learn More
A T cell-dependent immune response to group C meningococcal capsular polysaccharide (CPS) can be elicited when CPS is conjugated to the class 3 neisserial porin (CPS-porin). Treatment of CPS-porin-immunized mice with B7-2 blocking monoclonal antibody (MAb) caused a dramatic reduction in the CPS-specific IgG response, treatment with anti-B7-1 MAb had no(More)
A genetically detoxified pneumolysin, pneumolysoid (PLD), was investigated as a carrier protein for pneumococcal capsular polysaccharide (CPS). Such a CPS-PLD conjugate might provide additional protection against pneumococcal infections and resultant tissue damage. A single point mutant of pneumolysin was selected, which lacked measurable haemolytic(More)
The native capsular polysaccharide of type III group B Streptococcus elicits a specific antibody response in only 60% of nonimmune human subjects. To enhance the immunogenicity of this polysaccharide, we coupled the type III polysaccharide to tetanus toxoid. Prior to coupling, aldehyde groups were introduced on the polysaccharide by controlled periodate(More)
Previous studies have identified the length dependency of several polysaccharide (PS) protective epitopes. We have investigated whether meningococcal polysaccharides Y and W-135 possess such epitopes. Oligosaccharides (OSs) consisting of one or more disaccharide repeating units (RU) were derived from the capsular PSs of group Y and W-135 meningococci (GYMP(More)
Two methods are described for direct molar-mass measurement of low-molar-mass fragments obtained by oxidative cleavage of the capsular polysaccharide of Haemophilus influenzae type b. Absolute molar masses were determined by size-exclusion chromatography (SEC) with detection by multiangle laser-light-scattering photometry (MALLS) and differential(More)
The N-propionylated group B meningococcal polysaccharide mimics a unique bactericidal epitope on the surface of group B meningococci and Escherichia coli K1. This was confirmed when both the above organisms were able to absorb the bactericidal antibodies from a mouse-anti-N-propionylated group B meningococcal polysaccharide-tetanus toxoid conjugate serum.(More)
The L3 immunotype lipopolysaccharide (LPS) of Neisseria meningitidis was subjected to degradation procedures, which produced a number of different oligosaccharide fragments. The high resolution 1H and 13C NMR spectroscopic analyses of these oligosaccharides yielded structural information on a number of different regions of the LPS. For example, from one(More)
The polysaccharide (PS) capsules of many pathogenic bacteria are poor immunogens in infants and young children as a result of the delayed response to PS antigens during ontogeny. The development of polysaccharide-protein conjugate vaccines for Haemophilus influenzae type b, which have proven to be efficacious in this age group, has led to active development(More)
Three different oligosaccharides were isolated by mild acid hydrolysis of the lipopolysaccharides, obtained from Neisseria meningitidis serotype 5, and their structures were elucidated by combined chemical and physical techniques. The use of 500-MHz 1H NMR in both one-dimensional and two-dimensional modes as well as nuclear Overhauser effect experiments(More)
The group-specific antigen was isolated from a type Ia group B streptococcal strain and is a complex polysaccharide composed of alpha-L-rhamnopyranosyl, alpha-D-galactopyranosyl, 2-acetamido-2-deoxy-beta-D-glucopyranosyl, D-glucitol, and phosphate residues. The complexity of the group B polysaccharide antigen is evident from the fact that when depolymerized(More)