No description available.

The diversity of virus-specific antibodies and of B cells among different individuals is unknown. Using single-cell cloning of antibody genes, we generated recombinant human monoclonal antibodies from influenza nucleoprotein-specific memory B cells in four adult humans with and without preceding influenza vaccination. We examined the diversity of the antibody repertoires and found that NP-specific B cells used numerous immunoglobulin genes. The heavy chains (HCs) originated from 26 and the kappa light chains (LCs) from 19 different germ line genes. Matching HC and LC chains gave rise to 43 genetically distinct antibodies that bound influenza NP. The median lengths of the CDR3 of the HC, kappa and lambda LC were 14, 9 and 11 amino acids, respectively. We identified changes at 13.6% of the amino acid positions in the V gene of the antibody heavy chain, at 8.4 % in the kappa and at 10.6 % in the lambda V gene. We identified somatic insertions or deletions in 8.1% of the variable genes. We also found several small groups of clonal relatives that were highly diversified. Our findings demonstrate broadly diverse memory B cell repertoires for the influenza nucleoprotein. We found extensive variation within individuals with a high number of point mutations, insertions, and deletions, and extensive clonal diversification. Thus, structurally conserved proteins can elicit broadly diverse and highly mutated B-cell responses.

No description available.

No description available.

The seasonal influenza (flu) vaccine has been shown to prevent flu outbreaks that can cause debilitating effects on the body and even death. Underserved members of Black communities are more likely to refuse the flu vaccine than are persons of other ethnicities. The purpose of the project was to determine from a needs assessment the reasons for flu vaccine refusal in the Black population of an inner city clinic in order to develop tailored communication and nursing actions that promote awareness of the flu vaccine's importance and safety. The health belief model constructs (perceived susceptibility, perceived severity, perceived benefits, and perceived barriers) were used to guide the project. A survey based on the constructs of the health belief model was administered to a convenience sample of 40 adult patients in an inner city clinic who completed the anonymous survey while they waited for the physician. Descriptive statistics showed that adults ages 18 to 36, who were the largest group of respondents (n = 33), agreed to be vaccinated and believed the flu to be a serious disease for their age group. Reported barriers to vaccination included finding time to get vaccinated and the belief that the vaccine causes the flu. The findings supported development of an annual seasonal flu vaccine campaign that included verbal and written education, informational posters, social media messages, and a standing order to offer and administer the injection to all adults served by the practice. Social change implications are expected to include decreased morbidity and mortality from flu among the Black inner city patients and closer alignment of the clinic with the Healthy People 2020 vaccination goals.

No description available.

Influenza A virus (IAV) is a zoonotic pathogen which consists of a large genetically and antigenically diverse viral population. Swine IAVs not only cause disease outbreaks among swine, but can also be transmitted to humans, causing sporadic infections and even pandemic outbreaks apart from human seasonal IAV. Antigenic variant identification is fundamental for an effective vaccination program. Red blood cell based immunological tests have been used to identify antigenic variants among circulating IAV strains. Because these assays require viral isolation, they are time consuming and labor intensive. Thus only limited numbers of virus isolates are subjected to antigenic characterization in influenza surveillance studies and much of this important information is lost. In this project, a novel polyclonal antibody based proximity ligation assays (polyPLA) was developed and validated to characterize IAV antigenic variants directly using clinical samples. The application of this method with clinical samples from influenza surveillance had aided in the understanding of the antigenic evolution of IAV in human and swine populations.

No description available.

Wild birds are the natural reservoirs of Influenza A viruses (IAVs) which cause occasional pandemics and seasonal epidemics. Avian IAVs can be transmitted from wild birds to domestic poultry, low mammals, and humans. It is well accepted that avian IAVs prefer to sialic acids (Sia) α2,3-linked galactose (SAα2,3-Gal), whereas human IAVs to α2,6-linked galactose (SAα2,6-Gal). However, SAα2,3-Gal in wild bird tissues is widely distributed with little variation while some subtypes of avian IAVs have species preference. The different isolation rates among wild bird species cannot be explained by avian IAVs binding to SAα2,3-Gal alone. Specifically, this dissertation had the following aims: Firstly, to determine distribution of glycan receptors across respiratory and gastrointestinal tissues of wild birds and domestic poultry; Secondly, to determine the viral-receptor binding specificity of avian IAVs; Thirdly, to understand the role of glycan motifs in shaping virus evolution during the natural history of IAVs, especially from wild bird to poultry transmission. We found that avian H7 and H10 viruses acquired the binding ability to SAα2,6-Gal without adaptation, furthermore, we evaluated one of these H10 virus that possess the ability of binding to SAα2,6-Gal in ferret model and found it could cause aerosol and contact transmissions. On the other hand, H7 viruses have strong binding avidity to SLex which are present widely in epithelial cells of chicken trachea, which could facilitate the transmission of avian H7 viruses from waterfowl to poultry. Lastly, we found that H7 viruses from waterfowl bound both Neu5Ac and Neu5Gc while chicken isolates from China only prefer to Neu5Ac. Of interest, we found Neu5Gc was found in mallards but not in chickens, which indicated that viruses reduce or lost binding ability to Neu5Gc by adapting in chicken. In summary, this dissertation focused on certain subtypes of avian IAVs, which have caused threats to domestic poultry and public health, and primary avian species for influenza risk. The glycan substructures may play an important role in avian IAVs transmission and adaptation. The knowledge derived from this dissertation will help identify species for influenza surveillance in wild birds and facilitate risk assessment of avian IAVs.

No description available.