Analysis of Anti-Influenza Virus Neuraminidase Antibodies in Children, Adults, and the Elderly by ELISA and Enzyme Inhibition: Evidence for Original Antigenic Sin.
Antibody responses to influenza virus hemagglutinin provide protection against infection and are well studied. Less is known about the human antibody responses to the second surface glycoprotein, neuraminidase. Here, we assessed human antibody reactivity to a panel of N1, N2, and influenza B virus neuraminidases in different age groups, including children, adults, and the elderly. Using enzyme-linked immunosorbent assays (ELISA), we determined the breadth, magnitude, and isotype distribution of neuraminidase antibody responses to historic, current, and avian strains, as well as to recent isolates to which these individuals have not been exposed. It appears that antibody levels against N1 neuraminidases were lower than those against N2 or B neuraminidases. The anti-neuraminidase antibody levels increased with age and were, in general, highest against strains that circulated during the childhood of the tested individuals, providing evidence for "original antigenic sin." Titers measured by ELISA correlated well with titers measured by the neuraminidase inhibition assays. However, in the case of the 2009 pandemic H1N1 virus, we found evidence of interference from antibodies binding to the conserved stalk domain of the hemagglutinin. In conclusion, we found that antibodies against the neuraminidase differ in magnitude and breadth between subtypes and age groups in the human population. (This study has been registered at ClinicalTrials.gov under registration no. NCT00336453, NCT00539981, and NCT00395174.)IMPORTANCEAnti-neuraminidase antibodies can afford broad protection from influenza virus infection in animal models and humans. However, little is known about the breadth and magnitude of the anti-neuraminidase response in the human population. Here we assessed antibody levels of children, adults, and the elderly against a panel of N1, N2, and type B influenza virus neuraminidases. We demonstrated that antibody levels measured by ELISA correlate well with functional neuraminidase inhibition titers. This is an important finding since ELISA is a simpler method than functional assays and can be implemented in high-throughput settings to analyze large numbers of samples. Furthermore, we showed that low titers of broadly cross-reactive antibodies against neuraminidase are prevalent in humans. By the use of an appropriate vaccination strategy, these titers could potentially be boosted to levels that might provide broad protection from influenza virus infection.
Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, New York, USA.
Madhusudan
M
Rajendran
Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, New York, USA Raffael.Nachbagauer@mssm.edu Florian.Krammer@mssm.edu.
Raffael
0000-0001-5568-5420
R
Nachbagauer
Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, New York, USA.
Megan E
ME
Ermler
Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, New York, USA.
Paul
P
Bunduc
Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, New York, USA.
Fatima
F
Amanat
Protein Sciences Corp., Meriden, Connecticut, USA.
Ruvim
R
Izikson
Protein Sciences Corp., Meriden, Connecticut, USA.
Manon
M
Cox
Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, New York, USA.|Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, USA.
Peter
P
Palese
Division of Viral Products, Center for Biologics Evaluation and Research, Food and Drug Administration, Silver Spring, Maryland, USA.
Maryna
M
Eichelberger
Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, New York, USA Raffael.Nachbagauer@mssm.edu Florian.Krammer@mssm.edu.
Florian
0000-0003-4121-776X
F
Krammer
D000293:Adolescent; D000328:Adult; D032721:Adult Children; D000367:Age Factors; D000368:Aged; D000914:Antibodies, Viral / Q000097:blood*; D002675:Child, Preschool; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D007223:Infant; D008875:Middle Aged; D009439:Neuraminidase / Q000032:analysis / Q000276:immunology*; D016032:Randomized Controlled Trials as Topic; D014764:Viral Proteins / Q000276:immunology*; D055815:Young Adult
D000914:Antibodies, Viral; D014764:Viral Proteins; C487630:NA protein, influenza A virus; C541223:NA protein, influenza B virus; D009439:Neuraminidase
influenza; influenza virus; neuraminidase; neuraminidase inhibition