SIAT^® In Vivo Immunogenicity Assessment Services

Background SIAT® In Vivo Immunogenicity Assessment Published Data FAQ Resources

Background

In vitro and ex vivo assays are straightforward and able to provide a preview of the immunogenicity of biotherapeutic drug candidates. However, these assays also have some limitations. For instance, the frequency of antigen-specific T cells in naïve cell population derived from peripheral blood mononuclear cells (PBMCs) is quite low. Therefore, some positive response may be neglected. Moreover, various cell types, such as NK cells, NKT cells, CD4⁺ and CD8⁺ T cells, can secret many different cytokines, which interferes the measurement of cytokine production of a specific cell type, e.g. CD4⁺ T cells. On the other hand, NK cells, CD8⁺ T cells and other cell types play supportive roles in CD4⁺ T cell activation. Thus, tuning the balance between removal of irrelevant responses and reservation of supportiveness for the ex vivo culture becomes a major obstacle to more accurate assessments.

Diadigom of immuno reactions after therapeutic administration. (Lollini et al. 2006)

SIAT® In Vivo Immunogenicity Assessment

Creative Biolabs offers one-stop in vivo immunogenicity assessment service taking advantages of our exclusive Sensitive Immunogenicity Assessment Technology® (SIAT®) platform. SIAT® in vivo immunogenicity assessment employs various animal models including HLA transgenic mice and humanized mice to deliver the most straightforward evaluation of both innate and adaptive human immune responses without putting patients at risk.

The use of normal mouse models to study the immunogenicity of biotherapeutic drugs is flawed. Biotherapeutic drugs that are non-immunogenic in human may be foreign to mice and therefore elicit immune responses in mice. In collaboration with partners, Creative Biolabs has developed several enhanced mouse models to conduct in vivo immunogenicity assessment. The featured mouse models are described below.

HLA transgenic mice

Specific human HLA genes are incorporated into HLA class II-deficient mice to construct a mouse model that expresses human HLA II molecules other than mouse ones. These mice are able to process and present epitopes in complex with human HLA II and subsequently activate the epitope-specific T cells. This kind of mouse model is of great help in evaluating, predicting, and comparing the immunogenicity of structural similar biotherapeutic drugs.

Immunologic Analysis in Humanized Mouse Model

In the HLA transgenic mice, antigens are presented with human HLA molecules to mouse TCR, which confines the usage of HLA transgenic mice for testing the immunogenicity of a human biotherapeutic drug candidate. Therefore, humanized mouse models have been developed to improve this situation. Immunodeficient SCID-SID-NSG mice are engrafted with functional human hematopoietic stem cells (CD34⁺), liver and/or thymus so that a functional human immune system is reconstructed. This kind of humanized mouse models can be used to study the immunogenicity of biotherapeutic drugs in a full human immune system.

SIAT® in vivo immunogenicity assessment service provides versatile assays for the investigation of immunogenicity of novel candidate drugs, such as local lymph node assay, hypersensitivity response measurement, and cutaneous anaphylaxis assays. Our service will help to accelerate the development of your novel drug candidates by systematically addressing the evaluation of immunogenicity, which promises a clear vision and guideline before entering clinical trials.

More SIAT® Immunogenicity Related Services at Creative Biolabs

Published Data

In Vivo Immunogenicity Assessment of A Chimeric Tandem Repeat of Epitopic Region of OMP31 Antigen Fused to IL-2

Fig. 2 Conferred protection of immunized mice with vaccine or recombinant proteins against B. melitensis M16. (Narges Nazifi, 2019)

The research article focuses on the immunogenicity assessment of a chimeric tandem repeat of the epitopic region of the OMP31 antigen fused to interleukin 2 (IL-2) for vaccine efficacy against Brucella melitensis in mice. The study's results indicated that all recombinant proteins stimulated the immune system to produce Th1 cytokines and antibodies more effectively than negative controls. Particularly, the 3E-IL2 and OMP31-IL2 proteins induced higher levels of IFN-γ and IL-2. Additionally, the inclusion of a chemical adjuvant (IFA) alongside the molecular adjuvant (IL-2) significantly enhanced immune stimulation. The application of in vivo immunogenicity assessment in this study involved challenging immunized mice with the B. melitensis M16 strain after vaccination and then evaluating the microbial load in splenocytes. This approach demonstrated that the chimeric proteins significantly reduced the microbial load, indicating effective stimulation of the immune system and potential for use as a vaccine candidate. This method provides a practical model for assessing the protective efficacy of vaccine candidates against infectious diseases in a controlled, reproducible manner.

References

Lollini, Pier-Luigi, et al. "Vaccines for tumour prevention." Nature Reviews Cancer 6.3 (2006): 204-216.
Nazifi, Narges, et al. "In vivo immunogenicity assessment and vaccine efficacy evaluation of a chimeric tandem repeat of epitopic region of OMP31 antigen fused to interleukin 2 (IL-2) against Brucella melitensis in BALB/c mice." BMC veterinary research 15 (2019): 1-11.

FAQ

What is in vivo immunogenicity assessment in biotherapeutic drug development?
In vivo immunogenicity assessment is a crucial process in biotherapeutic drug development, where a drug's potential to induce immune responses in a living organism is evaluated. This assessment helps to predict the drug's safety and efficacy by observing immune reactions directly in the target species.
Why is in vivo testing important for assessing immunogenicity of biotherapeutics?
In vivo testing provides comprehensive data on how a biotherapeutic interacts with the immune system in a complex biological environment. This method assesses antibody formation, cytokine release, and other immune-modulating effects that in vitro experiments cannot fully replicate.
How are animal models used in in vivo immunogenicity studies?
Animal models are selected based on their genetic, physiological, and immunological similarities to humans. Common models include mice, rats, and non-human primates. These models help in understanding the immunogenic potential of biotherapeutics under conditions that closely mimic human biology.
What are the key factors to consider when designing an in vivo immunogenicity study?
Key factors include the choice of animal model, dosing regimen, duration of the study, route of administration, and the immunological assays used to detect immune responses. Each factor must align with the drug's intended clinical use and pharmacological properties.
What type of immune responses are monitored in in vivo immunogenicity assessments?
Typical immune responses monitored include the production of anti-drug antibodies (ADAs), T-cell activation, cytokine profiles, and any allergic or hypersensitivity reactions. These responses provide a broad understanding of the drug's immunogenic potential.
How does the route of administration affect immunogenicity in in vivo studies?
The route of administration can significantly influence the immunogenic response. Intravenous, subcutaneous, intramuscular, and other routes can lead to different levels and types of immune responses, reflecting how the drug will interact with the immune system in clinical settings.
How do in vivo studies complement in vitro immunogenicity assessments?
In vivo studies provide contextual insights that in vitro studies cannot, such as drug metabolism, whole-body immune system interactions, and the influence of physiological factors on drug behavior. Combining both approaches offers a more robust assessment of a biotherapeutic's immunogenicity.
What advancements are improving in vivo immunogenicity assessments?
Technological advancements such as genetically engineered models, humanized mice, and sophisticated biomarkers are enhancing the relevance and predictive value of in vivo studies. These innovations help in mimicking human immune responses more accurately and improving safety profiles before clinical trials.