Fowlpox Virus Infection Research Articles

An alteration in the kinetic properties of a cholesterogenic enzyme in fowlpox virus infection

Cholesterogenesis in the chorioallantoic membrane (CAM) of the chick embryo during fowlpox virus infection has been studied by a variety of techniques. Analysis of the sterol content of the CAM epithelium revealed an elevation in the sterol content on the fourth day postinfection, but not on the third day. The increase was due primarily to the accumulation of sterol ester. That the increased level of sterols is due to an increase in synthetic rate is suggested by the observation that the activity of the enzyme usually considered to be rate limiting in cholesterogenesis, 3-hydroxy,3-methylglutaryl coenzyme A (HMG-CoA) reductase, becomes elevated above control values at about this same time period, i.e., between 3 and 4 days postinfection. The ability to synthesize sterol from labeled mevalonate is lower in the infected tissue than in the control. These data indicate that the HMG-CoA reductase reaction may be a primary site of action in the stimulation of cholesterogenesis in fowlpox virus infection. An examination of the kinetic properties of the HMG-CoA reductase from infected CAM epithelium suggested that two forms of the enzyme are present in infected cells, one form identical to the control enzyme- and an altered form. This conclusion was based on the biphasic nature of the saturation curve of the enzyme for HMG-CoA. Other kinetic properties such as thermal denaturation and pH titration also revealed differences between the enzymes from control and infected tissues.

Role of Humoral and Cell-Mediated Immunity on the Recovery of Chickens from Fowlpox Virus Infection

Abstract The influence of thymectomy and bursectomy in chickens on the recovery from fowlpox virus infection was examined. It was found that the virus titer in the lesions the 2nd week after infection was well correlated with the migration inhibition test of splenic cells. Healing time after the infection also was correlated with the migration inhibition test of splenic cells. These findings suggest that cell-mediated immunity plays a more important role in the recovery than does humoral immunity. However, the mechanism of humoral immunity was not excluded since the mortality was significantly higher in bursectomized-thymectomized chickens than in thymectomized chickens.

COMPOSITION OF FOWLPOX VIRUS AND INCLUSION MATRIX.

Randall, Charles C. (University of Mississippi School of Medicine, Jackson), Lanelle G. Gafford, Robert W. Darlington, and James M. Hyde. Composition of fowlpox virus and inclusion matrix. J. Bacteriol. 87:939-944. 1964.-Inclusion bodies of fowlpox virus infection are especially favorable starting material for the isolation of virus and inclusion matrix. Electron micrographs of viral particles and matrix indicated a high degree of purification. Density-gradient centrifugation of virus in cesium chloride and potassium tartrate was unsatisfactory because of inactivation, and clumping or disintegration. Chemical analyses of virus and matrix revealed significant amounts of lipid, protein, and deoxyribonucleic acid, but no ribonucleic acid or carbohydrate. Approximately 47% of the weight of the virus and 83% of the matrix were extractable in chloroform-methanol. The lipid partitions of the petroleum ether extracts were similar, except that the phospholipid content of the matrix was 2.2 times that of the virus. Viral particles were sensitive to diethyl ether and chloroform.