Ultrastructural changes in cultured cells under the effect of Vibrio Cholerae hemagglutinin/protease.

Electron microscopic study of changes in cultured cells caused by Vibrio cholerae recombinant hemagglutinin/protease (HA/P) showed significant structural changes, most pronounced in HeLa and L-929 cells not forming a compact monolayer with tight junctions between the cells: formation of numerous vesicles on the cell surface and clasmatosis, vacuolation of the cytoplasm, swelling of mitochondria, clarification of their matrix and crist distortions, and increase in the number of lysosomes. Cytoplasm vacuolation predominated in MDCK culture, while clasmatosis was less intense. Addition of HA/P to CaCo2 cells forming a differentiated polarized monolayer, led to extension of cell-cell spaces not impairing tight junctions, swelling of mitochondria, cytoplasm vacuolation, and clasmatosis on the apical surface. These changes virtually completely coincided with those caused by the so-called NMDCY factor (non-membrane-damaging cytotoxin), described as new Vibrio cholerae toxin. These findings confirm our previous hypothesis about the identity of these factors.

Ultrastructural changes in the small intestine of suckling mice, caused by vibrio cholerae hemagglutinin/protease.

Suckling mice aged 4-5 days were injected with Vibrio cholerae hemagglutinin/protease and ultrastructural changes in their small intestine were studied after 5 h. The preparation caused a statistically significant accumulation of fluid in the intestine, appearance of large gaps along cell-cell spaces in the villi and crypts, intense production and secretion of the mucus by goblet cells. The formation of interepithelial cavities was paralleled by vascular changes, supplemented by extravasal disorders caused by mast cell reaction. The role of enterochromaffin cells and lipofibroblasts, modulating the secretion in the intestine, is confirmed.

Ultrastructural changes in the nephron and renal protein cleaving function in suckling rabbits with experimental cholera.

Immature nephrons and the presence of a proteolytic system mediating extracellular protein digestion in the epithelium of proximal tubules are characteristic features of renal cortical ultrastructure in intact 10-12-day-old suckling rabbits. Cholera infection is accompanied by intensive cleavage of exogenous protein, which starts in podocytes and is completed in the cytoplasm of the proximal tubule epitheliocytes. Overload to nephron associated (in addition to urine production) with intensive extracellular hydrolysis impairs nephrothelium reactivity and increases its vulnerability to cholera exo- and endotoxins and their mediators.