Murine immune responses to Neisseria meningitidis group C capsular polysaccharide and a thymus-dependent toxoid conjugate vaccine.
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 by a number of investigators of conjugate vaccines for other diseases. We describe here the response of several mouse strains to the capsular PS of Neisseria meningitidis group C (MCPS) conjugated to tetanus toxoid (MCPS-TT) and the same response in BALB/c mice as a model of the immune consequences of conjugate vaccine immunization. The use of a conjugate vaccine results in a shift in the isotype elicited in response to the MCPS, from immunoglobulin M (IgM) and IgG3 to primarily IgG1. A response to MCPS-TT is seen even among mouse strains which respond poorly to MCPS itself, emphasizing the importance of a strain survey when choosing a mouse model for a vaccine. The marked increase in IgG1 antibody titer was accompanied by a large increase in bactericidal activity of sera from these animals. Animals primed with the conjugate vaccine demonstrated a booster response after secondary immunization with either the MCPS or the conjugate. The ability to produce a boosted IgG1 anti-MCPS response to the MCPS can be transferred to adoptive recipients by B cells alone from mice primed with MCPS-TT but not mice primed with MCPS alone. These data indicate that in BALB/c mice a single immunization with MCPS-TT is sufficient to induce a shift to IgG1 and generate a memory B-cell population that does not require T cells for boosting.
Division of Monoclonal Antibodies, Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, Maryland 20892, USA.
L J
LJ
Rubinstein
P A
PA
García-Ojeda
F
F
Michon
H J
HJ
Jennings
K E
KE
Stein
D000818:Animals; D000907:Antibodies, Bacterial / Q000096:biosynthesis* / Q000235:genetics; D016667:Bacterial Capsules / Q000276:immunology*; D001428:Bacterial Vaccines / Q000276:immunology*; D001770:Blood Bactericidal Activity; D003433:Crosses, Genetic; D005260:Female; D007113:Immunity, Innate / Q000235:genetics; D007117:Immunization, Secondary; D007156:Immunologic Memory; D008297:Male; D051379:Mice; D008805:Mice, Inbred A; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D008808:Mice, Inbred CBA; D008811:Mice, Inbred DBA; D009345:Neisseria meningitidis / Q000276:immunology*; D011135:Polysaccharides, Bacterial / Q000276:immunology*; D013745:Tetanus Toxoid / Q000276:immunology*; D013950:Thymus Gland / Q000276:immunology*; D018074:Vaccines, Conjugate / Q000276:immunology*
D000907:Antibodies, Bacterial; D001428:Bacterial Vaccines; D011135:Polysaccharides, Bacterial; D013745:Tetanus Toxoid; D018074:Vaccines, Conjugate; C037676:meningococcal group C polysaccharide