Persistence of antigen on the surface of macrophages

MOUSE peritoneal macrophages can take up and catabolize two different haemocyanins^1,2. Although in tissue culture experiments most of these materials were broken down in a few hours after uptake, haemocyanin nevertheless elicited the formation of specific antibodies when the macrophages were transferred to syngeneic hosts, and the haemocyanin bound to macrophages retained its immunogenic activity relatively unchanged for several days. In view of the observation that a small percentage of the haemocyanin bound to macrophages remained intact during in vitro culture for 72 h, we undertook the experiments described here to determine the localization of the persisting antigen (which would presumably comprise the immunogenic moiety).