title: Elderly immune response to a TI-2 antigen: heavy and light chain use and bactericidal activity to Neisseria meningitidis serogroup C polysaccharide.
abstract: Previous studies of the elderly immune response to TI-2 antigens failed to correlate specific antibody levels with function and to compare responses with those of young adults. Neisseria meningitidis serogroup C capsular polysaccharide (MCPS) was used as a model TI-2 antigen. Anti-MCPS antibody levels were determined in elderly individuals and correlated with bactericidal activity. The anti-MCPS response in most persons was characterized by predominant IgG usage, with IgG2>IgG1. No light chain or IgA subclass predominated, but some responses showed a particular chain type. Bactericidal activity correlated best with IgG2 levels. Elderly subjects had lower anti-MCPS responses than the young adults did in all chain-specific anti-MCPS levels, and levels declined more rapidly. Bactericidal activity following immunization was significantly lower in the elderly persons. These results suggest the anti-MCPS antibody repertoire in the elderly is likely maintained, and the lower level of function is related to the lower antibody levels.
authors.affiliation: Department of Microbiology and Infectious Diseases, Unviersity of Calgary, Calgary, Alberta, Canada. hutchins@ucalgary.ca.
authors.forename: W A
authors.initials: WA
authors.lastname: Hutchins
authors.forename: G M
authors.initials: GM
authors.lastname: Carlone
authors.forename: M A
authors.initials: MA
authors.lastname: Westerink
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000276:immunology*; D000907:Antibodies, Bacterial / Q000097:blood*; D000955:Antigens, T-Independent / Q000276:immunology*; D005260:Female; D006801:Humans; D007070:Immunoglobulin A / Q000097:blood; D007074:Immunoglobulin G / Q000097:blood; D007143:Immunoglobulin Heavy Chains / Q000097:blood; D007132:Immunoglobulin Isotypes / Q000097:blood*; D007147:Immunoglobulin Light Chains / Q000097:blood; D007075:Immunoglobulin M / Q000097:blood; D008297:Male; D008875:Middle Aged; D009345:Neisseria meningitidis / Q000276:immunology*; D011135:Polysaccharides, Bacterial / Q000276:immunology*; D014611:Vaccination
chemical_list: D000907:Antibodies, Bacterial; D000955:Antigens, T-Independent; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D007143:Immunoglobulin Heavy Chains; D007132:Immunoglobulin Isotypes; D007147:Immunoglobulin Light Chains; D007075:Immunoglobulin M; D011135:Polysaccharides, Bacterial; C037676:meningococcal group C polysaccharide