THE REPERTOIRE OF HUMAN-ANTIBODIES TO THE CARBOHYDRATE CAPSULE OF STREPTOCOCCUS-PNEUMONIAE 6B

Antibodies to Streptococcus pneumoniae 6B capsular polysaccharide (PS) induced with a 23-valent PS vaccine among 25 adults were examined. Th e magnitude of antibody responses among different subjects was highly correlated with the amount of anti-6B antibodies expressing IgG (r = 0 .98) and lambda (r = 0.93) isotypes. Most individuals produced one or two dominant IgG antibody clones as identified by their isoelectric po ints. Two antibody clones with unique amino acid sequences could be re adily purified, and the sequences of their light chains match those of A1/A17 V kappa and hslv2046 V lambda genes. Anti-6B antibodies isolat ed from different subjects used various VL genes and differed in their cross-reactivity with 6A PS. An isoelectric focusing study suggests t hat some IgG antibodies induced with 6B PS bind 6A PS with lower avidi ty.