Abstract Text: Background Alternatives to animal, cell lines or isolated cell models are wanted to provide higher relevance and less ethical concerns for pre-clinical research. Despite extended capabilities, we believe that whole blood is not frequently enough considered. Easy to collect and applicable to functional studies, it contains many components (cells, proteins, metabolites, etc.) and enables to capture donor heterogeneity.
Rheumatoid arthritis (RA) is a chronic inflammatory disease for which many treatments, such as anti-TNFs, exist. Still, they are not fully satisfactory since 30% of patients are non-responders, yielding a need for better pre-clinical models and approaches to patient characterization and stratification.
Objective We propose a whole blood-based functional assay applicable to characterize therapeutic molecules and RA samples.
Methods Whole blood from control or RA individuals fulfilling ACR/EULAR 2010 criteria was incubated with LPS alone or combined with anti-TNFs. Activation marker expression was measured using a 10-color flow cytometry panel following a streamlined workflow.
Results Anti-TNF mechanisms of action were assessed following CD69, CD16, tmTNF and CD54 expressions in control samples. When considering untreated RA patients, higher basal activations through dysregulated CD69, CD11b or CD62L levels in a variety of cell subsets were observed together with impaired capabilities to up/downregulate these markers upon LPS activation. Finally, untreated and treated RA patients exhibited differences in activation marker expressions, providing a certain degree of segregation according to different clinical questions.
Conclusion In conclusion, we believe whole blood based functional assays could be relevant and valuable tools to open new perspectives for RA pre-clinical research.
