Opsonisation

Opsonisation describes the immune process by which pathogens, particles, or cells are coated with opsonins such as antibodies or complement proteins, enhancing recognition and uptake by phagocytic cells including macrophages and neutrophils. This mechanism improves immune clearance by increasing binding affinity between targets and phagocyte receptors, linking antibody specificity and complement activation to efficient pathogen elimination.

The biopharmaceutical industry considers opsonisation across immunology research, infectious disease therapeutics, and biologic drug development. Therapeutic antibodies may rely on opsonisation to promote clearance of tumour cells or infected cells through Fc receptor engagement and immune effector recruitment. Vaccine development aims to induce antibodies that opsonise pathogens effectively, supporting functional immunity beyond neutralisation alone. In drug delivery, nanoparticle opsonisation can lead to rapid clearance by the mononuclear phagocyte system, making surface engineering such as PEGylation important for avoiding premature immune uptake. Safety assessments evaluate unintended opsonisation that could trigger inflammatory responses. As immune engineering advances and understanding deepens regarding antibody Fc function and complement pathways, opsonisation remains central to therapeutic design and immune efficacy evaluation.