Localization of preformed, circulating immune complexes in murine skin.

The cutaneous localization of intravenously injected preformed immune complexes was examined in C57B1/6J mice and the importance of complex size and antibody charge was assessed for deposition and persistence in cutaneous structures. After a single intravenous bolus, large-latticed complexes deposited transiently in an interstitial extravasated pattern, and persisted longer in a vascular pattern. Small-latticed complexes, prepared at 50 times antigen excess, did not deposit. When large-latticed complexes were prepared with reduced and alkylated antibodies, their vascular deposition was similar, but they did not localize in the interstitium due to decreased extravasation. Large-latticed complexes prepared with cationized antibodies deposited in a vascular and interstitial pattern as well as at the dermal-epidermal junction. Complexes prepared with anionized antibodies deposited comparable to unaltered complexes. Cutaneous deposition of circulating immune complexes in mice requires a large lattice. Circulating immune complexes formed with cationic antibodies deposit at the dermal-epidermal junction.