T-Cell Intracellular Antigen-1 Antibody / TIA-1

The T cell intracellular antigen 1 (TIA 1) is a 17 kDa cytoplasmic granule associated protein also designated as GMP 17, for granule membrane protein of 17 kDa. The GMP 17/TIA 1 molecule is expressed in cells possessing cytolytic potential and could be involved in the signaling cascade of Fas (CD95) mediated apoptosis. Within hematopoietic cell lines, the rTIA1/1353 monoclonal antibody (mAb) reacts with about 90% of CD16+, 50 60% of CD8+, and less than 10% of CD4+ normal peripheral blood lymphocytes. It reacts with almost all monocytes and granulocytes. This antibody also reacts with CD4+ activated T cell clones, activated NK cell clones, and Con activated thymocytes, but not with B lymphocytes or B cell lines. 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.