Characterization of CD6 Ligand: 3A11
Motyl, Christopher D.
MetadataShow full item record
CD6 is a glycoprotein found on T cells, and may function as a costimulatory molecule in the immune response. A CD6 ligand known as CD 166 or activated leukocyte cell adhesion molecule (ALCAM) is expressed on brain, lung, liver, kidney, thymic epithelial, activated T cells and antigen-presenting cells. Studies have found evidence for a second CD6 ligand termed, 3A11, on cultured synovial fibroblasts. Both ALCAM and 3A11 were analyzed by flow cytometry on CaCo-2, HBL-I00, Saos-2, and hFOB 1.19 cell lines. ALCAM and 3A11 were found on hFOB 1.19 and HBL-I00 while Saos-2 only expressed ALCAM and CaCo-2 only expressed 3A11. Biochemical characterization of 3A11 was conducted by immunoprecipitation of synovial fibroblast cell lysate with visualization of a 130 kd band. Isolation and purification of this protein is necessary for sequencing. Regulation of 3A11 was examined by flow cytometry of mature and immature dendritic cells (DC) and was present intercellularly in mature DCs. Also there is evidence CD6 may be in complex with the Fc receptors on the DC surface. These results indicate that 3A11 possibly plays an important role in the activation of T cells by CD6.