Use of a monoclonal antibody to determine the mode of transmembrane pore formation by streptolysin O

Abstract

Murine monoclonal antibodies were generated against streptolysin 0. One out of 10 tested immunoglobulin clones exhibited strong neutralizing activity; in solution, the presence of approximately two to four antibody molecules per toxin monomer effected 50% neutralization of hemolytic toxin activity. An enzyme-linked immunosorbent assay performed with target cell membranes that were treated with streptolysin 0 in the presence and absence of neutralizing antibodies showed that the antibodies did not block primary binding of the toxin to the cells. When membranes were solubilized in deoxycholate detergent and centrifuged in sucrose density gradients, those lysed with streptolysin 0 contained detergent-resistant, high-molecular-weight oligomers identical to the pore lesions, whereas those given toxin and neutralizing antibody contained the toxin exclusively in low-molecular-weight, nonoligomerized form. The process of pore formation by streptolysin 0 must thus involve two distinct steps, i.e., the primary binding of toxin molecules to the membrane followed by oligomerization of bound toxin monomers by lateral aggregation in the lipid bilayer to form the transmembrane pores.

Clostridium perfringens invasiveness is enhanced by effects of theta toxin upon PMNL structure and function: The role of leukocytotoxicity and expression of CD11/CD18 adherence glycoprotein

“…These latter formations could represent cellular attempts to recycle membrane fragments translocated to the cell surface during degranulation [36]. Alternatively, similar TAC-toxin-induced changes in erythrocyte membranes have been described [37,38] and have been suggested to consist of toxin-cholesterol aggregates [39][40][41][42] that contribute to cell lysis via a colloid-osmotic mechanism [43]. It is of interest that early toxin-induced ultrastructural changes included the coalescence of the multi-lobed nucleus with homogenous redistribution of the nuclear contents, and that disruption of the nuclear membrane occurred in the absence of plasma membrane lysis (Fig.…”

Kinetics of Streptolysin O Self-Assembly

“…Three different models (No. [2][3][4] were developed and tested. All of these yield equivalent numerical approximations to the kinetics data collected ; thus, choice between them cannot be based on kinetics data alone.…”

“…While an influence on binding has not been detected [6], oligomerization (and hence hemolysis [7]) is very inefficient at low temperatures [l]. Moreover, even after binding, oligomerization can be suppressed with a monoclonal antibody [3].The most quantitative data available on the binding and oligomerization for any toxin from this cytolysin family stem from the work of Ohno-Iwashita et al. [8].…”

Effects of group‐A streptolysin O on neonatal and adult red blood cell deformability and haemolysis

“…As SLO interacts with cholesterol, cells without cholesterol do not bind SLO. After binding to cholesterol, SLO forms polymers that generate large transmembrane channels through the lipid bilayer in the RBC membrane [11]. Bhakdi et al [6] have shown that adult human RBCs require 70-125 SLO molecules for the formation of one lesion per cell.…”