Biophysical assessment of HLA-alloantibody interactions and profiling of alloantibody function
Development of alloantibodies against donor HLA in the context of pregnancy, transplantation of donor cells/tissues/organs and/or blood transfusion is a major immunological barrier in transplantation. Detection and characterisation of alloantibodies underpins risk assessment in transplantation but many HLA specificities detected by current immunoassays are of low affinity and clinically insignificant. We are interested in understanding how alloantibodies mediate their action through their Fab and Fc regions and in developing novel assays to profile their functional properties. In collaboration with the Department of Chemistry in Cambridge, we have developed a fundamentally new way to characterise protein-protein interactions in solution, under native conditions, using microfluidic systems (Microfluidic Antibody Affinity Profiling). This technology has now been licenced to Fluidic Analytics Ltd. We have applied this technology to quantify the fundamental parameters (affinity and antibody concentration) of antibody-antigen interactions in transplantation and in the context of COVID-19. We combine this approach with in vitro molecular biology assays (e.g. flow cytometry, Luminex, cytotoxicity, antibody Fc interaction analyses) to profile alloantibodies in patient sera.
Our aim is to accurately determine the clinical significance of alloantibodies in transplant patients, reduce the burden of sensitisation in waitlisted patients thus facilitating access to transplantation, and to enable personalised immunological risk assessment in transplantation.
Key References
Schneider MM, Scheidt T, Priddey A, Xu CK, Hu M, Devenish SRA, Meisl G, Dobson CM, Kosmoliaptsis V*, Knowles TPJ*. Microfluidic Antibody Affinity Profiling for In-Solution Characterisation of Alloantibody - HLA Interactions in Human Serum. Biosensors and Bioelectronics 2023; 228:115196
Fiedler S, Devenish SRA, Morgunov AS, Ilsley A, Ricci F, Emmenegger M, Kosmoliaptsis V, Theel ES, Mills JR, Sholukh AM, Aguzzi A, Iwasaki A, Lynn AK, Knowles TPJ. Serological fingerprints link antiviral activity of therapeutic antibodies to affinity and concentration. Sci Rep. 2022; 12: 19791
Denninger V, Xu CK, Meisl G, Morgunov AS, Fiedler S, Ilsley A, Emmenegger M, Malik AY, Piziorska MA, Schneider MM, Devenish SRA, Kosmoliaptsis V, Aguzzi A, Fiegler H, Knowles TPJ. Microfluidic Antibody Affinity Profiling Reveals the Role of Memory Reactivation and Cross-Reactivity in the Defense Against SARS-CoV-2. ACS Infect Dis. 2022; 8: 790
Schneider MM, Emmenegger M, Xu CK, Condado Morales I, Meisl G, Turelli P, Zografou C, Zimmermann MR, Frey BM, Fiedler S, Denninger V, Jacquat RP, Madrigal L, Ilsley A, Kosmoliaptsis V, Fiegler H, Trono D, Knowles TP, Aguzzi A. Microfluidic characterisation reveals broad range of SARS-CoV-2 antibody affinity in human plasma. Life Sci Alliance. 2021; 5: e202101270