TIA-1 is a 17kDa cytoplasmic granule-associated protein, expressed in cells possessing cytolytic potential and recently designated as GMP-17, for granule membrane protein of 17 kDa. The GMP-17/TIA-1 molecule could be involved in the molecular cascade of signaling Fas (CD95)-mediated apoptosis.
With hematopoietic cell lines, the “TIA-1” monoclonal antibody 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 A-activated thymocytes, but not with B lymphocytes or B-cell lines.