RESUMO
Capsular polysaccharides are important virulence factors of Streptococcus pneumoniae. The polysaccharide has been used as a component of vaccines against pneumococcal diseases either as plain polysaccharide or better conjugated to a protein. The last one is the vaccine of choice to target child protection. The immune responses depend on several polysaccharide physicochemical properties that can be affected during either purification or modification in the case of conjugate vaccines. In serotype 18C, the repeating unit has a complex structure having a branched pentasaccharide with two apparently labile subtituents: glycerol-phosphate and O-acetyl group. The loss of these groups may potentially reduce the ability of the 18C polysaccharide to induce the desired immune response. Therefore, the relationship of both groups with the antigenicity and immunogenicity of 18C capsular polysaccharide is explored. It is shown that glycerol-phosphate must be preserved for conserving adequate antigenicity of the 18C capsular polysaccharide. At the same time, it was proved that O-acetyl groups do not play any role for the antigenicity and immunogenicity.
Assuntos
Antígenos de Bactérias/química , Antígenos de Bactérias/imunologia , Polissacarídeos Bacterianos/química , Polissacarídeos Bacterianos/imunologia , Streptococcus pneumoniae/química , Streptococcus pneumoniae/imunologia , Animais , Humanos , Éteres Fosfolipídicos/química , Éteres Fosfolipídicos/imunologia , CoelhosRESUMO
The relationship between autoantibodies (autoAbs) to oxidized LDL (oxLDL) and coronary artery disease (CAD) remains controversial. IgM and IgG autoAbs to oxLDL and 1-palmitoyl-2 (5'-oxo-valeroyl)-sn-glycero-3-phosphorylcholine (POVPC), as well as the levels of non modified or modified ApoB-100 immune complexes (ICs), were measured in twenty patients undergoing clinically indicated coronary angiography, and in ten young healthy volunteer sera. The levels of IgM autoAbs to oxLDL did not differ between no CAD patients and healthy subjects, but the levels of these autoAbs were significantly higher in no CAD patients and healthy subjects in comparison with CAD patients. There was not difference in the levels of IgM anti-ApoB-100 ICs between both groups of patients. In contrast, the levels of ICs formed by IgM autoAbs and oxidative modified ApoB-100 were lower in patients with CAD than in patients without CAD. No differences were observed in the levels of autoAbs to POVPC among the groups. In conclusion, our results showed that the level of circulating oxLDL IgM autoAbs was lower in CAD patients than in no CAD patients, supporting the hypothesis that this kind of autoAbs might be inversely associated with the presence of atherosclerosis.