Recall Antigen Assay

Background: Lymphocytes that have previously been exposed to an antigen will show an enhanced response upon subsequent re-exposure. Primary lymphocytes from individuals vaccinated against tetanus are often used to initiate an in vitro recall antigenic response. In lieu of using tumor specific antigens (TSA) or tumor associated antigens (TAA), stimulation of lymphocytes with tetanus toxoid provides a useful alternative to assess the effects of candidate therapeutic articles, such as checkpoint inhibitors, and as a model for analogous responses to TAA and TSA.

Principle: Lymphocytes are antigenically stimulated following culture with loaded antigen presenting cells (APCs). Antigen stimulated lymphocytes are cultured in the presence of checkpoint inhibitors to modulate activation response. Endpoints that are assessed in this assay include lymphocyte proliferation, activation markers, and cytokine production.