title: Serum Concentrations of Antibodies against Outer Membrane Protein P6, Protein D, and T- and B-Cell Combined Antigenic Epitopes of Nontypeable Haemophilus influenzae in Children and Adults of Different Ages.
abstract: Nontypeable Haemophilus influenzae (NTHi) is one of the most common etiologies of acute otitis media, rhinosinusitis, and pneumonia. Outer membrane proteins (OMPs) are the main focus in new vaccine development against NTHi, as the H. influenzae type b (Hib) vaccine does not cover noncapsulated NTHi. The OMPs P6 and protein D are the most promising candidate antigens for an NTHi vaccine, and low antibody levels against them in serum may be correlated with infection caused by NTHi. In the current study, we measured the antibody titers against P6, protein D, and their T- and B-cell combined peptide epitopes in healthy individuals of different ages. We found that children <1 month old had the lowest antibody levels against NTHi P6, protein D, and their T- and B-cell combined antigenic epitopes. Antibody titers increased at ages 1 to 6 months, peaked at 7 months to 3 years, and remained high at 4 to 6 years. The antibody titers started to decrease after 6 years and were the lowest in the 21- to 30-year group. The geometric mean titers (GMTs) of T- and B-cell combined antigenic epitopes in P6 and protein D were positively correlated with those of the protein antigens. Among 12 peptides tested, P6-61, P6-123, and protein D-167 epitopes were better recognized than others in human serum. These findings might contribute to the development of an effective serotype-independent vaccine for H. influenzae.
authors.affiliation: Division of Infectious Diseases, Children's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, People's Republic of China.
authors.forename: Chun-Zhen
authors.initials: CZ
authors.lastname: Hua
authors.affiliation: Department of Medical Microbiology and Parasitology, Zhejiang University School of Medicine, Hangzhou, Zhejiang, People's Republic of China Division of Basic Medical Microbiology, State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, People's Republic of China.
authors.forename: Wei-Lin
authors.initials: WL
authors.lastname: Hu
authors.affiliation: Department of Clinical Laboratory, Children's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, People's Republic of China shangsq33@sina.com med_bp@zju.edu.cn.
authors.forename: Shi-Qiang
authors.initials: SQ
authors.lastname: Shang
authors.affiliation: Department of Clinical Laboratory, Children's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, People's Republic of China.
authors.forename: Jian-Ping
authors.initials: JP
authors.lastname: Li
authors.affiliation: Department of Clinical Laboratory, The Affiliated Hospital of Hangzhou Normal University, Hangzhou, Zhejiang, People's Republic of China.
authors.forename: Li-Quan
authors.initials: LQ
authors.lastname: Hong
authors.affiliation: Department of Medical Microbiology and Parasitology, Zhejiang University School of Medicine, Hangzhou, Zhejiang, People's Republic of China Division of Basic Medical Microbiology, State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, People's Republic of China shangsq33@sina.com med_bp@zju.edu.cn.
authors.forename: Jie
authors.initials: J
authors.lastname: Yan
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000907:Antibodies, Bacterial / Q000097:blood*; D001425:Bacterial Outer Membrane Proteins / Q000276:immunology*; D001426:Bacterial Proteins / Q000737:chemistry / Q000276:immunology*; D002648:Child; D002675:Child, Preschool; D000939:Epitopes; D005260:Female; D006192:Haemophilus Infections / Q000276:immunology / Q000382:microbiology / Q000517:prevention & control*; D018073:Haemophilus Vaccines / Q000276:immunology*; D006193:Haemophilus influenzae / Q000145:classification / Q000276:immunology*; D064368:Healthy Volunteers; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood*; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D055815:Young Adult
chemical_list: D000907:Antibodies, Bacterial; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D000939:Epitopes; D018073:Haemophilus Vaccines; D007074:Immunoglobulin G; C069990:P6 outer membrane protein, Haemophilus