Histophilus somni stimulates bovine monocyte-derived macrophages to release microparticles that increase fibrin clot formation in vitro.

Histophilus somni is a Gram-negative coccobacillus that causes diffuse vasculitis and intravascular thrombosis that can lead to multiple organ failure in cattle. Macrophages are important cellular mediators of fibrin deposition and removal at sites of inflammation. It has become evident that macrophages and other cells release microparticles (MPs) that have an array of biological activities, including pro-coagulant activity.

Procoagulant activity of bovine neutrophils incubated with conditioned media or extracellular vesicles from Histophilus somni stimulated bovine brain endothelial cells.

Histophilus somni is a Gram negative coccobacillus that causes respiratory, reproductive and central nervous system disease in cattle. The hallmark of H. somni infection is diffuse vasculitis and intravascular thrombosis that can lead to an acute central nervous system disease known as thrombotic meningoencephalitis (TME).

Interactions of Histophilus somni with Host Cells.

Histophilus somni resides as part of the normal microflora in the upper respiratory tract of healthy cattle. From this site, the organism can make its way into the lower respiratory tract, where it is one of the important bacterial agents of the respiratory disease complex. If H.

Histophilus somni causes extracellular trap formation by bovine neutrophils and macrophages.

Histophilus somni (formerly Haemophilus somnus) is a Gram-negative pleomorphic coccobacillus that causes respiratory, reproductive, cardiac and neuronal diseases in cattle. H. somni is a member of the bovine respiratory disease complex that causes severe bronchopneumonia in cattle.

Bovine herpesvirus type 1 infection of bovine bronchial epithelial cells increases neutrophil adhesion and activation.

Respiratory infection of cattle with bovine herpesvirus type 1 (BHV-1) predisposes cattle to secondary pneumonia with Mannheimia haemolytica as part of the bovine respiratory disease complex (BRD). One cell type that has received limited investigation for its role in the inflammation that accompanies BRD is the respiratory epithelial cell. In the present study we investigated mechanisms by which BHV-1 infection of respiratory epithelial cells contributes to the recruitment and activation of bovine polymorphonuclear neutrophils (PMNs) in vitro.