The Role of Pulmonary Intravascular Macrophages in the Pathogenesis of African Horse Sickness

• Published in: Journal of comparative pathology 1999-07, Vol.121 (1), p.25-38
• Main Authors: Carrasco, L., Sánchez, C., Gómez-Villamandos, J.C., Laviada, M.D., Bautista, M.J., Martínez-Torrecuadrada, J., Sánchez-Vizcaíno, J.M., Sierra, M.A.
• Format: Article
• Language: English
• Subjects: African horse sickness; African Horse Sickness - pathology; African Horse Sickness - virology; African horse sickness virus; Animals; capillaries; Cytopathogenic Effect, Viral; edema; Endothelium, Vascular - pathology; Endothelium, Vascular - virology; experimental infections; Female; Horses; Lung - blood supply; Lung - pathology; lungs; macrophages; Macrophages, Alveolar - physiology; Macrophages, Alveolar - virology; Microscopy, Electron, Scanning Transmission; Orbivirus - isolation & purification; pathogenesis; ultrastructure; Virus Replication
• ISSN: 0021-9975; 1532-3129
• DOI: 10.1053/jcpa.1998.0293

African horse sickness (AHS) is a disease of equids, characterized by severe pulmonary oedema and caused by an orbivirus. To determine the role of pulmonary intravascular macrophages (PIMs) in the development of pulmonary microvascular changes in this disease, five horses were given an intravenous inoculation of 106TCID50of serotype 4 of AHS virus. Viral replication was detected in endothelial cells, PIMs, interstitial macrophages and fibroblasts. Alveolar and interstitial oedema, and changes in pulmonary microvasculature, consisting mainly of the sequestration of neutrophils and the formation of platelet aggregates and fibrinous microthrombi, were related to endothelial changes and to a high degree of PIM activation. This suggested that the PIMs, once activated, contributed to these vascular changes by releasing chemical inflammatory mediators.