Epitope specificities of the group Y and W-135 polysaccharides of Neisseria meningitidis.
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 and GWMP, respectively) by mild acid hydrolysis. The relative affinities of anticapsular antibodies binding to derivative OSs of different chain lengths were measured in inhibition enzyme-linked immunosorbent assays. As OS size increased from two to three RU, there was a notable increase in binding inhibition of rabbit anti-group Y antiserum. This pattern of antibody binding inhibition was also observed for rabbit antiserum to group W-135, though the inhibition increase was much more pronounced. In the cases of both OS species, the concentration of inhibiting antigen required to achieve 50% inhibition of rabbit immunoglobulin binding increased progressively as the inhibiting disaccharide chain length increased from 1 RU through greater than 50 RU. These data suggest that antibodies directed against both of these meningococcal PSs recognize conformational epitopes only fully expressed in higher-molecular-weight forms of these antigens.
Moore
Samuel L
SL
Department of Vaccine Research, Wellstat Vaccines, 9 West Watkins Mill Road, Gaithersburg, MD 20878, USA. smoore@wellstatdiagnostics.com
Uitz
Catherine
C
Ling
Chang-Chun
CC
Bundle
David R
DR
Fusco
Peter C
PC
Michon
Francis
F
D000818:Animals; D000907:Antibodies, Bacterial / Q000378:metabolism; D000942:Antigens, Bacterial / Q000737:chemistry / Q000276:immunology* / Q000378:metabolism; D001666:Binding Sites, Antibody; D002236:Carbohydrate Conformation; D000939:Epitopes / Q000737:chemistry / Q000276:immunology* / Q000378:metabolism; D007106:Immune Sera / Q000378:metabolism; D009345:Neisseria meningitidis / Q000737:chemistry / Q000276:immunology*; D011135:Polysaccharides, Bacterial / Q000737:chemistry / Q000276:immunology* / Q000378:metabolism; D011817:Rabbits