Albumin magnetic microspheres: a novel carrier for myelin basic protein.

Myelin basic protein (MBP) of guinea pig origin was incorporated into magnetically responsive albumin microspheres. Protein-protein bonding and stabilization of the GPMBP microspheres by heating at 120 degrees C did not adversely influence their capacity to bind anti-MBP antibodies or demonstrably alter the encephalitogenic activity of the incorporated GPMBP. The magnetic properties of the particles and the fact that immunodeterminants of some of the incorporated MBP fortuitously were distributed on the exterior surfaces of the microspheres allowed a number of experiments to be carried out in Lewis rats for the first time: (a) selective capture and deletion of that particular subpopulation of lymphoid cells responsible for transfer of experimental allergic encephalomyelitis (EAE) represented within the lymph node cells (LNC) of donor animals sensitized to neutral antigen, (b) enhancement of in vivo uptake of MBP by macrophages (M phi s) contained in oil-induced peritoneal cell exudates and exposed briefly to MBP microspheres, and (c) preparation of cell suspensions specifically enriched with respect to MBP-containing M phi s.