Removal and refixation of surface Ig from isolated rat mast cells

This study showed that under well-defined conditions all immunoglobulins could be removed from the rat mast cell surface. Surface immunoglobulins were examined by immunofluorescence technique, and cell function by the allergic reaction to antigen as judged by histamine release. Refixation of eluted surface Ig to the mast cell was easily accomplished. Furthermore, fixation of specific surface Ig to already sensitized cells resulted in increased cell sensitivity to antigen, whereas fixation of nonspecific surface Ig resulted in decreased sensitivity. The results indicate that removed immunoglobulins are intact, have affinity for mast cells, and are able to compete with cell-bound Ig.