FIG. 11.

Removal of surface-expressed MR activity by trypsin treatment at 4°C and recovery of activity by warm up of the cell at 37°C. MDMs were incubated in the presence of 0.01% trypsin for the indicated time at 4°C (0 to 40 min, left side of the figure) and then incubated with 6 × 10⁷ microspheres for 60 min at 4°C and fixed in formalin, and the number of microspheres was enumerated. For the recovery assay (right side of the figure), MDMs were incubated in the presence of 0.01% trypsin for 40 min at 4°C, warmed for the indicated time (0 to 10 min) at 37°C, and then incubated with 6 × 10⁷ microspheres for 60 min at 4°C and fixed in formalin, and the number of microspheres was enumerated. All points are means ± standard errors from two independent experiments.