Differentiation and interaction of secretory immunoglobulin A and a calcium-dependent parotid agglutinin for several bacterial strains

Abstract

Previous studies have suggested that both secretory immunoglobulin A (sIgA) and various nonimmunoglobulin salivary glycoproteins are capable of agglutinating a variety of bacteria. The present study was designed to compare the nature of the agglutinins for Streptococcus mutans and Salmonella typhimurium in parotid saliva and colostrum. S. mutans was aggregated by saliva and colostrum, whereas S. typhimurium was aggregated only by saliva as detected by a spectrophotometric method. The principal salivary agglutinin for both S. mutans and S. typhimurium was calcium dependent and could be desorbed in phosphate-buffered saline (pH 6.8). In contrast, the colostral agglutinin was calcium independent and not readily desorbed. The agglutinin activities of saliva and colostrum for S. mutans were additive, suggesting independent target sites on the bacterial surface. The agglutinin activity of colostrum was totally associated with sIgA as was suggested by blocking of the agglutinating activity with anti-a-chain serum and the absence of blocking with an antibody specific for salivary agglutinin. Interestingly, anti-a-chain serum removed all agglutinating activity from saliva, but not from the phosphate-buffered saline-desorbed agglutinin. Dialysis of parotid saliva against 0.1 M disodium EDTA eliminated the agglutinin blocking activity of anti-a,-chain serum but not that of the antiagglutinin antibody. The ability of anti-a-chain serum to block agglutination of the EDTA-dialyzed saliva could be restored by the addition of calcium chloride, suggesting that sIgA and salivary agglutinin are associated through a calcium-mediated interaction. These results indicate that bacterial agglutinating activity of colostrum, as detected spectrophotometrically, is mediated by sIgA, and that of saliva is mainly dependent upon a calcium-dependent nonimmunoglobulin agglutinin. The agglutinating activities of sIgA and parotid agglutinin seem to be additive, and their calcium-dependent association may favor the enhancement of their respective activities.

On the rôle of human salivary micelle‐like globules in bacterial agglutination

“…However, the indication in Lhe present study that the interaction between the SMGs and the streptococci has a largely calciumdependent, electrostatic basis, does not support this concept. Results of experiments by RUNDEGREN & ARNOLD (20) also showed that the bacterial agglutinating activity of saliva is mainly dependent upon a calcium-dependent non-immunoglobulin agglutinin. Furthermore, an experiment employing fluorescent antibody on isolated SMGs showed no reaction with the SMGs, only with bacterial contaminants {Rolla.…”

Cloning and expression of a Streptococcus sanguis surface antigen that interacts with a human salivary agglutinin

“…After chromatography on Sepharose 4B (2.0 by 120 cm), active fractions were pooled, lyophilized, and stored at -20°C. Some preparations of agglutinin were purified as described by Rundegren and Arnold (45).…”

Differential distribution of salivary agglutinin and amylase in the Golgi apparatus and secretory granules of human salivary gland acinar cells

“…This agglutinin has been isolated from both parotid and submandibular saliva of humans, and shown to be distinct from secretory IgA and mucins (Williams and Gibbons, 1975;Malamud, 1985). The agglutinin has been purified by both column chromatography (Demuth et al, 1988) and bacterial affinity (Rundegren and Arnold, 1987). The isolated glycoprotein is approximately 40% carbohydrate and 60% protein (Ericson and Rundegren, 1983).…”