Background

In silico immunogenicity assessment typically has some limitations because the prediction algorithms for most T cell receptor (TCR) epitopes are based on the analysis of the binding affinity and stability of human leukocyte antigen (HLA, also known as major histocompatibility complex, MHC) molecules to peptides. However, there are many other factors including protease cleavage sites within the antigen-presenting cells and T cell precursor frequency that all have certain impacts in defining the TCR epitopes. The binding affinity of HLA:peptide complex to TCR influences the immune response of an epitope as well. Therefore, further ex vivo immunogenicity assessment is needed to validate the results from in silico prediction.

SIAT® Ex Vivo Immunogenicity Assessment

Creative Biolabs offers the SIAT^® ex vivo immunogenicity assessment service that utilizes human peripheral blood mononuclear cells (PBMCs) to provide a preview of immune response that closely resembles the immune response in vivo. The responses of human immune effector cells to candidate biotherapeutics are tested without the risks associated with first human dose. This ex vivo assessment provides a fast and cost-effective way to gain a full and first-hand understanding of the immunogenicity of your biotherapeutic drug candidates under the condition close to that in vivo. At the same time, it evaluates the overall developability for further advancement into animal models and clinical trials, as well as supports the regulatory filings for IND application.

Activation of CD4 T cells and the T-cell dependent antibody response. （De Groot AS et al. 2007）

Our platform sets the foundation of a comprehensive human blood bank from healthy donors, which represents different populations across the entire world. Multiple techniques such as ELISPOT, ELISA, and Flow Cytometry can be used. Our SIAT^® ex vivo immunogenicity assessment service contains two major assays.

DC-T Cell Proliferation Assay

The SIAT^® DC-T cell assay uses whole proteins to assess the factors that contribute to the immunogenicity. This ex vivo immunogenicity assessment can predict immunogenicity on a human population basis without the need of animal models. The released cytokines by T cells can be detected by Flow Cytometry or ELISPOT, the results of which are good indicators of T cell activation and proliferation status. Information provided by this assay instructs early development of biotherapeutic drug candidates in lead selection, humanization, and/or de-immunization. read more…

Antigen Presentation Assay

SIAT^® antigen presentation assay is designed to evaluate antigen processing and presentation in vitro, which provides direct information for epitopes of an antigen that bind to HLA molecules and displayed to T cells by antigen-presenting cells. Our human blood cell bank covers all main human races. These HLA-typed cells can be used for customer's interests in specific research topic. The sequence information of T cell epitopes is analyzed by LC-MS/MS and other advanced techniques. read more…

More SIAT^® Immunogenicity Related Services at Creative Biolabs

• In Silico Immunogenicity Assessment
• In Vitro Class II HLA Binding Assay
• Ex Vivo Immunogenicity Assessment
  • DC-T Cell Proliferation Assay
  • Antigen Presentation Assay
• In Vivo Immunogenicity Assessment
• Anti-drug Antibodies (ADA) Assays
• De-immunization Service

Published Data

• Pre-Clinical Evaluation of Therapeutic Cancer Vaccines

Fig. 2 Histogram representation and quantification of IFNγ intracellular expression by ex vivo unstimulated T cells or stimulated CD4+ and CD8+ T cells extracted from the spleen at 21 days post-PBMC transference. (Bijun Zeng, 2023)

The article details the development and use of skin-grafting and dendritic cell "boosted" humanized mouse models for pre-clinical evaluation of therapeutic cancer vaccines, particularly targeting HPV16 antigens. The significance of this research lies in addressing the limitations of traditional preclinical mouse models in mimicking the human immune response, which is crucial for evaluating the effectiveness of therapeutic cancer vaccines. The study successfully demonstrated that these humanized models could robustly mimic human immune responses and effectively measure the immunogenicity and therapeutic potential of vaccines. This method was crucial for confirming that the immune system of the humanized mice could respond to the vaccine by activating T cells against the specific antigens presented, providing a valuable tool for predicting how a vaccine might perform in human clinical settings.

FAQ

1. What is ex vivo immunogenicity assessment in biotherapeutics?

   Ex vivo immunogenicity assessment involves testing candidate biotherapeutics on human or animal cells outside their natural biological context to predict the immune response they might elicit in vivo. This helps in identifying potential immunogenic risks before proceeding to clinical trials.

2. Why is immunogenicity assessment critical for biotherapeutics?

   Immunogenicity assessment is crucial because it helps predict whether a biotherapeutic could trigger undesirable immune responses such as neutralizing antibodies or allergic reactions, which can impact efficacy and safety.

3. What types of biotherapeutics typically require immunogenicity testing?

   All types of biotherapeutics, including monoclonal antibodies, fusion proteins, enzyme replacements, and other recombinant proteins, typically require immunogenicity testing to ensure they are safe and effective.

4. How are ex vivo models used for immunogenicity testing?

   Ex vivo models involve cultured human or animal immune cells, such as lymphocytes or dendritic cells, which are exposed to the biotherapeutic to observe potential activation, proliferation, and cytokine production as indicators of immunogenicity.

5. What are the advantages of using ex vivo assays in immunogenicity assessment?

   Ex vivo assays allow for controlled, detailed studies of immune responses to biotherapeutics without the ethical and logistical complexities of in vivo studies. They can also be more cost-effective and quicker to execute.

6. Can ex vivo assays fully predict the immunogenic potential of biotherapeutics?

   While ex vivo assays provide valuable insights, they do not fully replicate the complexity of an entire living organism. Therefore, they are usually part of a broader array of preclinical tests to predict immunogenicity.

7. What are the common biomarkers used in ex vivo immunogenicity assessments?

   Common biomarkers include levels of cytokines, T-cell proliferation rates, and the presence of specific antibodies. These biomarkers help in understanding the type and extent of immune responses elicited by the biotherapeutic.

8. How is ex vivo data integrated with other immunogenicity assessments?

   Ex vivo data is typically integrated with in silico predictions, in vitro assays, and animal model studies to provide a comprehensive evaluation of a biotherapeutic's immunogenic potential. This multi-tiered approach helps in making informed decisions about progressing with clinical development.

Resources

Use the resources in our library to help you understand your options and make critical decisions for your study.

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