The therapeutic potential of antibodies was discovered based on experiments evaluating serum from animals exposed to attenuated forms of pathogens. Since then, an enormous progress has been made in our understanding and designing of therapeutic antibodies or antibody-like pharmaceuticals (biologics such as antibody-like proteins).
Currently, monoclonal antibodies or antibody-like pharmaceuticals are used and developed for multiple indications ranging from cancer, autoimmune disorders, respiratory disorders, inflammatory and infectious disorders to neurodegenerative disorders such as Alzheimer’s disease (AD) and Parkinson’s disease (PD).
During the discovery and preclinical phases of drug development, the selection of lead candidate therapeutic antibodies to progress into efficacy studies can be based on multitude biophysical and functional assays. In this blog post, we discuss how histopathology can be used to evaluate the binding of multiple lead therapeutic antibody candidates to help select optimal leads going into the preclinical efficacy stage of drug development.
Application of therapeutic antibodies in neurodegenerative disease research
The histopathological hallmarks of AD are extracellular plaques composed of amyloid beta fibrils and intracellular inclusions of the protein Tau. The accumulation of amyloid beta plaques is hypothesized to play a central role in AD pathophysiology.
PD is characterized by specific histopathological hallmarks observed in post-mortem brain tissue, including the presence of intracellular inclusions called Lewy bodies, consisting of the protein alpha-synuclein, and cell death in the substantia nigra. Alpha-synuclein inclusions are the main histopathological hallmark correlating with clinical symptoms of not only PD, but also other synucleinopathies such as dementia with Lewy bodies, and multiple systems atrophy.
As such, the histopathological hallmarks of neurodegenerative disease represent a viable target for therapeutic antibodies. Reference of all developed therapeutic antibodies using in neurodegenerative research and their targets can be accessed here.
Evaluation of antibody-target binding ex vivo in neurodegenerative disease research
Therapeutic antibody-target binding can be evaluated using ex-vivo histopathology binding assays that make use of healthy and diseased human brain tissues, as well as mouse models. This offers a quick and effective method to evaluate the antibody candidates’ binding potential on tissues with the relevant human pathophysiology (e.g., human brain slices with amyloid beta plaques compared to healthy human brain slices), while also evaluating any off-target binding of the therapeutic antibody candidates. For example, off-target binding will show up as unspecific off-target signal, which will help inform further studies to optimise the antibody binding’s specificity. Evaluation of antibody-target binding ex vivo usually further informs the selection of lead candidates to advance to the efficacy stage of preclinical research using mouse models of neurodegenerative diseases.
Outsourcing antibody binding vivo assays to histopathology service providers
Outsourcing antibody binding ex vivo histopathology assays to contract research organisations (CROs) can be beneficial for multiple reasons, which we outline in this section.
- Access to relevant human tissues: histopathology CROs either possess or have readily access to human tissue biobanks via established strategic partnerships. This provides advantage, such as that brain tissues and/or frozen brain tissue slides can be readily and easily sourced and selected depending on the relevant target pathophysiology such as disease stage, severity, donors’ age etc,..
- Expertise and experience in custom assay development: Every therapeutic antibody has a unique structure; hence each project needs careful customisation and extensive IHC/ IF protocol development and optimisation stages to ensure reliable results. Optimisation of the detection antibody concentration, selection of proper positive and negative controls such as isotype controls are used. Experts at Connected-Pathology have experience and expertise in setting up customised assays for detection of various targets and applications.
- Expertise and evaluation of the results: The evaluation of the staining intensity, binding of the antibody to the pathology of interest and cellular localisation needs to be carefully evaluated to determine the antibody binding on the pathology of interest i.e., does the therapeutic antibody bind to amyloid beta plaques? Knowledge of the target antigen biology permits better interpretation of results.
- High-volume sample processing capabilities and technical processing: Histopathology service providers have access and necessary capabilities to run high-volume studies thanks to automated sample processing and staining capabilities using state-of-the-art machinery.
- Access to digital histopathology slides: digitalised slides offer superior quality which is especially important when evaluating the signal from fluorescent staining images (both simple and multiplex). High-quality digitalised whole-image slides can be used in publications and/or supporting company documentation of further study designs.
- Advice on future projects: collaboration with histopathology CROs such as Conencted-Pathology allows you to discuss your results with experts and obtain advice on future projects or can inform the next steps of the project. Such type of collaborations can inform the next steps of the projects such as initiating an efficacy study in a relevant mouse model with the target pathology (i.e., transgenic or seeding neurodegeneration mouse models). Connected-Pathology has an established partnership with its sister company InnoSer, who frequently carries out efficacy studies in mouse models of neurodegeneration.
Contact us to further inquire about outsourcing such type of study to Connected-Pathology. Experts at Connected-Pathology work together with you to develop and optimise relevant protocols to help you obtain the most relevant results for your research to accelerate the pace at which your project progresses at.