EXCEED THE SPACE PROVIDED. Meningococcal disease primarily affects infants and very young children. The group B capsule is notimmuno- genie, and outer membrane protein vaccines provide only short-lived protection, in older children, that is restricted to serotypes in the vaccine. Protection is mediated by bactericidal antibodies that are induced by asymptomatic coloniza- tion by organisms that share lipooligosaccharides (LOS). By adolescence most children have LOS IgG that are bac- tericidal for most meningococcal strains. These antibodies prevent meningococcal disease, regardless of protein sero- type. LOS are immunogenic at birth, and LOS antibodies can be induced by vaccination. During disease, infants make bactericidal antibodies against their infecting strains. These antibodies bind to a conserved LOS structure that is expressed well by 126E (L1,8), other L1 strains, and by L3,7 and L4,6 strains. This structure has not been definitively identified. LOS antibodies induced during infancy can prevent the monoclonal anti- body (mAb), D6A, from binding to 126E LOS, and we have used this mAb, which binds to meningococci of all groups and types, as a surrogate for the LOS structure. MAb D6A binds the deeply truncated LOS of Ag,alE mutants that have only a conserved basal structure, but it is not clear that this truncated LOS is the optimal immunogen. We now propose to affinity purify human IgG that binds the conserved LOS structure by 1) passage of IVIG over AgalE LOS, and 2) by sequential passage of IVIG over L1, L1,8, L3,7 and L4,6 LOS, each coupled to Sepharose. We will assess how well each IgG kills 34 consecutive and unique endemic meningococcal case strains, and whether they can opsonize these meningococci for PMN killing. We will compare the binding of this pauciclonal IgG (pclgG) to that of mAb D6A and use Mass Spectrometry combined with chemical and enzymatic degradations to confirm the LOS structure recognized by mAb D6A and pclgG. We will immunize transgenic mice that have human immmunoglobulin loci (XenoMouse) with a AgalE mutant to insure that this LOS structure is immunogenic for the human immune system, and characterize the functional activity of the induced IgG, as for the IVIG IgG. We will use enrichment of a coliphage display library with mAb D6A to identify a peptide mimic of the mAb D6A LOS antigen, use this peptide to immunize XenoMouse mice and functionally charaterize the induced IgG. We also will try to identify a peptide mimic that binds the human pclgG. The resulting data should confirm the suitability of a conserved LOS structure as a vaccine for the prevention of endemic group B disease in infants and young children. PERFORMANCE SITE ========================================Section End===========================================
| John, Constance M; Liu, Mingfeng; Phillips, Nancy J et al. (2012) Lack of lipid A pyrophosphorylation and functional lptA reduces inflammation by Neisseria commensals. Infect Immun 80:4014-26 |
| Cheng, Hui; Yang, Zhijie; Estabrook, Michele M et al. (2011) Human lipooligosaccharide IGG that prevents endemic meningococcal disease recognizes an internal lacto-N-neotetraose structure. J Biol Chem 286:43622-33 |
| Brotman, R M; Melendez, J H; Ghanem, K G (2011) A case control study of anovaginal distance and bacterial vaginosis. Int J STD AIDS 22:231-3 |
| Estabrook, Michele M; Jarvis, Gary A; McLeod Griffiss, J (2007) Affinity-purified human immunoglobulin G that binds a lacto-N-neotetraose-dependent lipooligosaccharide structure is bactericidal for serogroup B Neisseria meningitidis. Infect Immun 75:1025-33 |
