COLOCALIZATION OF CLASS-II ANTIGEN AND EXOGENOUS ANTIGEN IN THE RAT ENTEROCYTE

The role of class II major histocompatibility antigens in classical an tigen-presenting cells has been described (Unanue (1984) Annu. Rev. Im munoL 2, 395-428; Watts and McConnell (1987) Rev. ImmunoL 5, 461-475). Whether enterocytes, which also express class II antigens, can act as antigen-presenting cells in vivo is not known. One pre-requisite for a role for enterocytes in antigen presentation is an interaction betwe en exogenous antigen and class H antigens. Our results demonstrate tha t class II antigen and exogenous antigen absorbed from the gastrointes tinal tract are co-localized within endocytic compartments and along t he basolateral membranes of enterocytes.