A Reappraisal of the Forces Involved in Hemagglutination

Abstract

The underlying principles governing the second stage of hemagglutination, as described in 1965, have been reevaluated. This reappraisal reaffirms that red cell aggregation is dependent on the potential energy barrier (λ) between erythrocytes. This in turn is dependent on the ionic strength and dielectric constant of the bulk medium. Hemagglutination by IgG and IgM antibody is a function of the effective length of these immunoglobulins and the λ of the cells in the reaction mixture. Agglutination of cells occurs when the λ-potential is below a critical level. The enhancing action of natural and synthetic polymers (e. g., bovine albumin) is to lower zeta by raising the dielectric constant of the bulk medium. Several other recent concepts are discussed and the major differences discussed in light of data available.

Optimization and application of electrophoretic mobility analysis of human red blood cells to study their in vitro stability, interaction with polycations and proteolytic enzymes

“…This dependence of the ζ potential of RBCs with ionic strength has also been reported by Pollack and Reckel 12…”

Novel Nanosomes for Gene Delivery to Plasmodium falciparum-infected Red Blood Cells

“…Natural cationic peptides such as protamine sulfate (PS) have been shown to increase gene transfection efficiency of both liposomal and polymeric nanoparticles1618. In addition, it is also known that sialylated glycoproteins of the RBC membrane contribute to its negatively charged surface, creating a repulsive electric zeta potential1920. There is hence a likelihood that positively charged nanosomes entrapping pDNA increase the chances of pDNA uptake through the RBC membrane.…”

Zeta Potentials, van der Waals Forces and Hemagglutination

“…This surface potential (\j/0) cannot be measured directly, but it is simply related to the Ç-potential (which itself can be derived from electrophoretic mobilities) [18]: bination of these opposing forces, on which the 'DLVO theory' (named after the initials of its initiators, Derjaguin and Landau, and Verwey and Overbeek) [21] of the stability of suspensions of particles is based, tends to where z is the distance from the surface of the cell to the plane of shear ( « 5 x 10~8 cm), a is the Stokes radius of the cells («3.0X10-4 cm) and x the inverse Debye length (at the ionic strength p = 0.15 of saline water, l/x = 8xl0~8 cm). The electrophoretic mo bility of human erythrocytes at ionic strength (x = 0.15 may be taken as 1.27x10^ cm/s/V/cm [19], which can be con verted [9] to Ç=-17.945mV.…”

“…Unsensitized erythrocytes can approach each other, to within ==79Â of their sialoglycoprotein surfaces, leaving a distance between their actual cell membranes of ~ 180Â, which is considerably more than the maximum distance between the two valencies of an IgG molecule ( = 120 Â). diametrically opposed valencies (out of the ten available valencies) of IgM class antibod ies can easily bridge a distance of = 300 Â [13,14], It also is usually accepted that this in turn is due to the fact that two erythrocytes, suspended in isotonic saline water, cannot approach each other more closely than within 50-100 Â [13,14,18], on account of the interplay between the mutual repulsion caused by the cells' negative surface (or Q potential [18] and the intercellular attraction induced by van der Waals forces. The com-…”