Amino acids 279-380 from the human protein were used as the immunogen for the TIA1 antibody.
TIA-1 (T-cell intracytoplasmic antigen) is a cytoplasmic granule-associated protein, expressed in lymphocytes processing cytolytic potential. TIA-1 is a member of an RNA-binding protein family and possesses nucleolytic activity against cytotoxic lymphocyte (CTL) target cells. It has been suggested that this protein may be involved in the induction of apoptosis as it preferentially recognizes poly(A) homopolymers and induces DNA fragmentation in CTL targets. The major granule-associated species is a 15kDa protein thought to be derived from the carboxyl terminus of the 40kDa product by proteolytic processing. TIA1 antibody labels cytotoxic T cells and natural killer cells (NK cells). It is also expressed in T-cell lymphoma, large granular lymphocyte (LGL) leukemia and hairy cell leukemia. TIA1 expression in T-cell malignancies may help in differentiating LGL leukemia (high expression) from T-cell lymphocytosis and other T-cell diseases (low expression). TIA1 may also be used to label tumor-infiltrating lymphocytes in the study of immune response to malignancies.
