Non-Specific Binding by Macrophages : Evaluation of the Influence of Medium-Range Electrostatic Repulsion and Short-Range Hydrophobic Interaction

Rat peritoneal macrophages oan bind glutaraldehyde-treated human red cells (GHRC), but not normal human red cells (HRC). When the surface oharge of HRC was reduced by treating them with noura-minidase (to remove some negative aialio acid residnes) or ooating them with polylymine (a positively oharged polymer), no substantial binding to macrophages was obtained. However, a similar reduction of the surface oharge of GHRC resulted in sevenfold onhanoemont of their binding to maorophages. All erythrocyte batches were tested with a phase partition technique 1 only glutaraldehyde-treated cells were found hydrophobic.

It is concluded that:

1. Short range hydrophobic interactions are responsible for maorophage-GSRC adhesion.

(ii)Medium range eleotrostatic repulsion may substantially hamper any close approach of the macrophage and partiole surfaoes in physiological conditions.