Cd 7 Immunohistochemistry Biopsy Tissue

CD7 is expressed normally on all T cells (one of the pan T-cell antigens) and natural killer cells. Expression of CD7 can be aberrantly lost in T-cell lymphomas, providing support for a diagnosis of T-cell lymphoma. In normal tonsil, the T cells predominate in interfollicular regions. The adaptive immune response of human CD8 T cells to invading pathogens involves the differentiation of naive cells into memory and effector cells. Lineage relationship between memory and effector cells and the differentiation of CD8 T cells into distinct subsets of effector cell subpopulations are subjects of considerable debate. CD7 identifies three populations of CD8 T cells: CD7 high (CD7(high)), low (CD7(low)), and negative (CD7(neg)) that translate into subsets with distinct functional properties. The CD7(high) subset contains naive and memory cells and the CD7(low) and CD7(neg) subsets contain effector cells. The effector cells can functionally be divided into cytokine-secreting effector CD8 T cells and lytic effector CD8 T cells.