ROLE OF NONSPECIFIC CROSS-REACTING ANTIGEN, A CD66 CLUSTER ANTIGEN, IN ACTIVATION OF HUMAN GRANULOCYTES

Nonspecific cross-reacting antigen (NCA) is the name of a family of hi ghly glycosylated bacterial-binding receptors found on human granulocy tes and other tissues. These glycoproteins are members of the immunogl obulin supergene family and are related structurally to carcinoembryon ic antigen. In this study, we demonstrate that ligation of granulocyte NCA results in the activation of the cells, as measured by degranulat ion and the flux of intracellular calcium. These studies further the p roposition that NCA has a function in the immune response of granulocy tes against bacterial infections.