SIYNFEKL TFA is a variant of major MHC class I-restricted epitope SIINFEKL. SIYNFEKL TFA is an antigenic peptide, that can stimulate specific T cells in experimental settings to study the competitive interaction between T cell. SIYNFEKL TFA exhibits low affinity for the OT-I T cell receptor (TCR), and can be used for detection of CD8+ T cells.
References:
[1]. Burchill MA, et al., T cells compete by cleaving cell surface CD27 and blocking access to CD70-bearing APCs. Eur J Immunol. 2015 Nov;45(11):3140-9.