SIAT® Antigen Presentation Assay

Creative Biolabs provides SIAT® antigen presentation assay service to identify potential epitopes from biotherapeutic drugs in complex with HLA molecules by mass spectrometry. The SIAT® antigen presentation assay can be used to measure antigen processing and presentation, which can directly identify the epitopes of a protein antigen that are bound to HLA molecules and displayed to T cells by antigen-presenting cells (APCs). This service offers valuable and accurate information for epitopes from biotherapeutic drug candidates and other proteins of interest to help understand and manage their potential immunogenicity. It can be employed to explore the population bias of responses to the same epitopes by using HLA-typed blood cells from different donors. Also, it can facilitate the profiling and comparison of the immune responses between novel agents or biosimilars and existing safe drugs or proteins. In addition, the efficacy of agents that interfere with antigen presentation process can also be evaluated by SIAT® antigen presentation assay.

Professional antigen-presenting cells process intracellular and extracellular pathogens. (Roy, 2003) Professional antigen-presenting cells process intracellular and extracellular pathogens.
(Roy, 2003)

Antigen recognition by immune effector cells requires APCs, such as dendritic cells (DCs), to present the epitopes with human leukocyte antigen (HLA, also known as major histocompatibility complex, MHC) class II molecules on the cell surface. DCs process antigens into small peptides consisting of 13-18 amino acids and HLA class II molecules are loaded with these peptides within endosomes and subsequently transported to the plasma membrane of DCs. Peptides in the form of HLA-II:peptide complexes can then lead to T cell activation by interaction with specific T cell receptors (TCRs). The peptides within the complexes are hence termed TCR epitopes. TCR epitopes can be utilized not only for the optimization of biotherapeutic drug candidates in their efficiency and safety but also for the development of novel drugs and basic research.

Despite the fact that there are diverse ways of predicting and identifying this valuable information, it is the most direct approach by analyzing the presented molecules with HLA molecules. SIAT® antigen presentation assay service from Creative Biolabs is able to deliver this information about TCR epitopes through interpretation of what DCs naturally says. Below is a brief description of our workflow of SIAT® antigen presentation assay service.

As a leading life science service provider, Creative Biolabs has extensive experience in the development of biotherapeutic drugs at exploratory, preclinical and clinical stages. The functional relevance of the TCR epitopes identified by SIAT® antigen presentation assay can be confirmed by various other services of the SIAT® platform including in silico, in vitro, ex vivo, in vivo immunogenicity assessments. We are dedicated to providing the best services to help our clients accelerate their new biotherapeutic drug discovery and development.


  1. Roy, Craig R. "Immunology: professional secrets." Nature 425.6956 (2003): 351-352.

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

All listed customized services & products are for research use only, not intended for pharmaceutical, diagnostic, therapeutic or any in vivo human use.

Online Inquiry


Call us at:
Our customer service representatives are available 24 hours a day, 7 days a week. Contact Us