Small amounts of sub-visible aggregates enhance the immunogenic potential of monoclonal antibody therapeutics
PURPOSE: Determine the effect of minute quantities of sub-visible aggregates on the in vitro immunogenicity of clinically relevant protein therapeutics.
- Ahmadi, M.; Bryson, C.J.; Cloake, E.A.; Welch, K.; Filipe, V.; Romeijn, S.; Hawe, A.; Jiskoot, W.; Baker, M.P.; Fogg, M.H.
- 01 April 2015
- Online publication (DOI)
METHODS: Monoclonal chimeric (rituximab) and humanized (trastuzumab) antibodies were subjected to fine-tuned stress conditions to achieve low levels (<3% of total protein) of sub-visible aggregates. The effect of stimulating human dendritic cells (DC) and CD4(+) T cells with the aggregates was measured in vitro using cytokine secretion, proliferation and confocal microscopy.
RESULTS: Due to its intrinsic high clinical immunogenicity, aggregation of rituximab had minimal effects on DC activation and T cell responses compared to monomeric rituximab. However, in the case of trastuzumab (low clinical immunogenicity) small quantities of aggregates led to potent CD4(+) T cell proliferation as a result of strong cytokine and co-stimulatory signals derived from DC. Consistent with this, confocal studies showed that stir-stressed rituximab was rapidly internalised and associated with late endosomes of DC.
CONCLUSIONS: These data link minute amounts of aggregates with activation of the innate immune response, involving DC, resulting in T cell activation. Thus, when protein therapeutics with little or no clinical immunogenicity, such as trastuzumab, contain minute amounts of sub-visible aggregates, they are associated with significantly increased potential risk of clinical immunogenicity.