Immune Response of Infants and Children to Disseminated Infections with Neisseria meningitidis

Abstract

Acute- and convalescent-phase sera from 34 children and 10 young adults were studied to determine if, at what age, and to which antigens of Neisseria meningitidis they respond during disseminated disease. Seven children older than two years of age who were infected with group C or Y strains developed significant increases in both binding and bactericidal antibody. Children infected with group B strains infrequently (eight [31%] of 26) had measurable increases in serum antibody to this capsular polysaccharide; response was meager when it did occur, was unrelated to age, and was considerably poorer than that of young adults, of whom 80% responded. Convalescent-phase sera from all children contained bactericidal antibody. Binding capacity for group B polysaccharide accounted for only 35% of the bactericidal activity in convalescent-phase sera of children infected with group B strains. Bactericidal antibody in the sera of children who did not respond to capsular polysaccharides was often to a lipooligosaccharide antigen.

Human Lipooligosaccharide IGG That Prevents Endemic Meningococcal Disease Recognizes an Internal Lacto-N-neotetraose Structure

“…Each LOS glycoform was thought to present a single antigen centered on the non-reducing terminal glycose, the "immunodominant glycose," as modified by the various substitutions of Hep2. This paradigm informs the LOS serotyping system (16 -20) and many previous studies, including some of our own (12)(13)(14). The diversity of LOS antibodies, according to this notion, was provided by the diversity of LOS glycoforms.…”

“…Structures assigned to the serotypes of the strains (16 -18, 20) are in Table 2. All organisms were cultured as described previously (12)(13)(14).…”

“…This suggests that the earliest bactericidal antibodies induced in infants may be LOS-specific. However, because each LOS glycoform molecule conforms multiple different epitopes (10,11), and each meningococcal strain makes several different LOS glycoforms (12), it has been difficult to sort out just which LOS antigens induce protective antibodies (10,11,13).…”

Importance of Antibodies to Lipopolysaccharide in Natural and Vaccine-Induced Serum Bactericidal Activity against Neisseria meningitidis Group B

“…The presence of bactericidal antibodies to meningococcal LPS in human sera has been demonstrated by several investigators (13,19,23,54). These antibodies are typically specific for the wild-type LPS that contains the LNnT.…”

Inter-strain Homology of Pilin Gene Sequences in Neisseria meningitidis Isolates That Express Markedly Different Antigenic Pilus Types

“…Capsular polysaccharide (Masson et al, 1982), lipooligosaccharide (Griffiths et al, 1984) and at least one outer-membrane protein (Brodeur et al, 1985) have been implicated in the pathogenicity of N. meningitidis but little is known of the involvement of pili in meningococcal disease. Pili have however been demonstrated by electron microscopy on 80-100% of meningococci from the nasopharynx, blood and cerebro-spinal fluid (CSF) of patients with meningococcal infection (Stephens & McGee, 1981).…”