Moriah Jovita Castleman
$318,085
Stephen Graham
Jordan Scott Orange
Richard Stanton
Eddie Chung Yern Wang
Michael Weekes
Wioleta Milena Zelek
Cardiff University
National Institute of Allergy and Infectious Diseases (NIAID)
The ability of an�bodies to bind infected cells and ac�vate cellular immunity through an�body-dependent cellular cytotoxicity (ADCC), an�body-dependent cellular phagocytosis (ADCP), and complement-dependent cytolysis (CDC) is cri�cal to control of intracellular virus and intra-host dissemina�on. The induc�on of these responses is therefore highly desirable in an�viral and immunotherapeu�c responses. However, our understanding of how to exploit ADCC/ADCP/CDC significantly lags that of neutralising ac�vity. Whereas neutralising an�bodies can be readily induced by vaccina�on with entry glycoproteins or receptor-binding subdomains, it remains unclear how to select an�gens, domains, or epitopes, for op�mal ADCC ac�vity. We have shown that there is litle correla�on between the ability of an�bodies to neutralise and to ac�vate cellular immunity, and that previously unsuspected an�gens can induce significantly enhanced Fc-dependent ac�vity compared to those that induce neutralising responses. It is now cri�cal to understand why some an�gens and epitopes offer superior ac�va�on of cellular immunity. Our previous work required laborious wet-lab screening with ex vivo cells, virus infected cells, and proteomics, to iden�fy op�mal targets for this ac�vity. Deciphering the underlying biology of this process offers the poten�al to predict ideal an�gens and to design epitope-specific vaccina�on strategies, that maximise ADCC/ADCP/CDC responses in addi�on to neutralisa�on. This has the poten�al to enhance the efficacy of future vaccines and immunotherapies, as well as de-risk and accelerate their development. Fc-dependent immunity requires effector cell, an�body, epitope, and an�gen, to each co-ordinate. We therefore seek to understand how each of these aspects contributes to effec�ve control of intracellular virus. The molecular determinants that govern how NK cells control virus dissemina�on through ADCC will be assessed func�onally and through high- resolu�on imaging of the ADCC immunological synapse (IS), with proteomics used to determine why NK cells from different donors exhibit markedly different ADCC capaci�es. Molecular engineering of an�bodies will inves�gate the specificity requirements for ADCC responses, and methods of op�mising ADCC-inducing immunotherapies. Structural and IS-imaging studies will reveal how an�gen structure and epitope conforma�on affect ADCC efficacy, and whether the same requirements apply to the induc�on of ADCP and CDC. Finally, we will determine how predic�ons of Fc-dependent immunity can be rapidly validated. Although the way that these parameters interact is likely independent of any specific virus, viruses drama�cally remodel the infected cell surface to counteract host immunity and this can significantly alter the func�onal outcome of interac�ons. We will therefore use two different viruses throughout these studies – one which manipulates the surface proteome extensively (HCMV), and one less so (SARS-CoV-2) – to reveal whether virus immune-evasion impacts outcome, and whether any underlying principles are therefore virus-dependent. For both viruses we have iden�fied novel an�gens and monoclonals that provide enhanced ADCC responses as compared to current vaccine/immunotherapeu�c approaches.