Immunohistochemical Distribution of Human Basigin by Using a Novel Monoclonal Antibody

Basigin is a member of the immunoglobulin (Ig) superfamily which has strong homology with both Ig Vkappa domain and the beta-chain of the major histocompatibility complex (MHC) class II antigen. Human basigin is also known as M6 antigen, neurothelin and EMMPRIN (extracellular matrix metalloproteinase inducer). In this study, we developed a novel anti-human basigin monoclonal antibody, J-BIT-1 and used it to map out the distribution of basigin in human tissues. The specificity of J-BIT-1 was confirmed by western blot analysis and immunocytochemical techniques utilizing basigin cDNA transfected L cells. J-BIT-1 appropriated to immunohistochemical staining for formalin-fixed, paraffinembedded tissues and methanol-fixed cells. Excellent immunostaining results were obtained with formalin-fixed tissues after the antigen retrieval procedure. Our immunohistochemical observations revealed that basigin is widely expressed in various organs, but on specific cell types, such as blood capillaries of the brain, proximal convoluted tubules of the kidney, cardiac muscle of the heart, trophoblasts of the placenta and basal cells of the stratified squamous epithelium. The location of basigin is the cell surface, especially the site of cell adhesion. These observations suggest that basigin might be involved in basic cell functions which are promoted with cell-cell and cell-extracellular matrix interaction.