Abstract
Antibodies have enormous diversity and form a crucial component of the humoral immune response. The relationship between antibody variable region sequences and specificity is still poorly understood, however recent advances in high-throughput sequencing technology has made the study of B cell repertoires possible. In this thesis we use, among other methods, high-throughput sequencing of B cell repertoires to examine variable region properties and specificity in a number of contexts.First, we attempted to identify common characteristics of autoreactive/polyreactive antibody variable regions by analysing a high-throughput sequencing dataset constructed from B cell variable region sequences isolated from pre- and post-tolerance B cell repertoires. We tested our predictions using immunocytochemistry and ELISA. We found that some antibodies which show a polyreactive phenotype in ELISA do not show polyreactivity in other settings, leading us to question the definition of these antibodies and their role in the immune response.
Next, we investigated the physicochemical and structural properties of kappa and lambda light chains and the heavy chains with which they are paired. We found that the properties of the two light chain classes differ considerably, suggesting different roles in the immune response. However, we found no distinction between heavy chains paired with kappa and lambda light chains, providing no evidence of bias in heavy-light chain pairing.
Finally, we used high-throughput sequencing and ribosome display to investigate the B cell repertoires of recent Ebola survivors to determine how this disease affects the repertoire and to attempt to identify new, cross-reactive, anti-Ebola glycoprotein antibodies. The most significant repertoire feature of the Ebola survivors was the high prevalence of clonal expansions incorporating multiple heavy chain classes. Several new anti-Ebola glycoprotein single chains were isolated using ribosome display and some of these showed evidence of binding N-linked glycans on various viral glycoproteins.
| Date of Award | 2019 |
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| Original language | English |
| Awarding Institution |
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| Supervisor | Deborah Dunn-Walters (Supervisor) & Franca Fraternali (Supervisor) |