Formalin-fixed and paraffin-embedded human tonsil tissue (4 um) stained with CD8A monoclonal antibody, clone P17-V (Cat # MAB8436) shows strong membranous immunostaining of T-lymphocytes. Kindly performed and provided by Katarina Poliakova, MD and Lubomir Straka, MD, Ph. D. from Clinical Pathology Presov, Ltd., Presov, Slovak republic.
The CD8 antigen is a cell surface glycoprotein found on most cytotoxic T lymphocytes that mediates efficient cell-cell interactions within the immune system. The CD8 antigen acts as a corepressor with the T-cell receptor on the T lymphocyte to recognize antigens displayed by an antigen presenting cell (APC) in the context of class I MHC molecules. The coreceptor functions as either a homodimer composed of two alpha chains, or as a heterodimer composed of one alpha and one beta chain. Both alpha and beta chains share significant homology to immunoglobulin variable light chains. This gene encodes the CD8 alpha chain isoforms. Multiple transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq