Malignant catarrhal fever virus infectivity in rabbit macrophages and monocytes

1981 ◽  
Vol 5 (1) ◽  
pp. 51-56 ◽  
Author(s):  
E. Z. Mushi ◽  
F. R. Rurangirwa
1999 ◽  
Vol 80 (10) ◽  
pp. 2693-2697 ◽  
Author(s):  
J. G. Neilan ◽  
M. V. Borca ◽  
Z. Lu ◽  
G. F. Kutish ◽  
S. B. Kleiboeker ◽  
...  

An African swine fever virus (ASFV) ORF, 8CR, with similarity to the C-type lectin family of adhesion proteins has been described in the pathogenic isolate Malawi Lil-20/1. The similarity of 8CR to cellular and poxvirus genes associated with cell adhesion, cell recognition and virus infectivity suggested that 8CR may be of significance to ASFV–host cell interactions. Sequence analysis of the 8CR ORF from additional pathogenic ASFV isolates demonstrated conservation among isolates from both pig and tick sources. Northern blot analysis demonstrated 8CR mRNA transcription late in the virus replication cycle. A Malawi Lil-20/1 8CR deletion mutant (Δ8CR) was constructed to analyse 8CR function further. The growth characteristics in vitro of Δ8CR in porcine macrophage cell cultures were identical to those observed for parental virus. In domestic swine, Δ8CR exhibited an unaltered parental Malawi Lil- 20/1 disease and virulence phenotype. Thus, although well conserved among pathogenic ASFV field isolates, 8CR is non-essential for growth in porcine macrophages in vitro and for virus virulence in domestic swine.


2001 ◽  
Vol 75 (15) ◽  
pp. 6758-6768 ◽  
Author(s):  
Germán Andrés ◽  
Ramón Garcı́a-Escudero ◽  
Eladio Viñuela ◽  
Marı́a L. Salas ◽  
Javier M. Rodrı́guez

ABSTRACT This report examines the role of African swine fever virus (ASFV) structural protein pE120R in virus replication. Immunoelectron microscopy revealed that protein pE120R localizes at the surface of the intracellular virions. Consistent with this, coimmunoprecipitation assays showed that protein pE120R binds to the major capsid protein p72. Moreover, it was found that, in cells infected with an ASFV recombinant that inducibly expresses protein p72, the incorporation of pE120R into the virus particle is dependent on p72 expression. Protein pE120R was also studied using an ASFV recombinant in which E120R gene expression is regulated by the Escherichia coli lacrepressor-operator system. In the absence of inducer, pE120R expression was reduced about 100-fold compared to that obtained with the parental virus or the recombinant virus grown under permissive conditions. One-step virus growth curves showed that, under conditions that repress pE120R expression, the titer of intracellular progeny was similar to the total virus yield obtained under permissive conditions, whereas the extracellular virus yield was about 100-fold lower than in control infections. Immunofluorescence and electron microscopy demonstrated that, under restrictive conditions, intracellular mature virions are properly assembled but remain confined to the replication areas. Altogether, these results indicate that pE120R is necessary for virus dissemination but not for virus infectivity. The data also suggest that protein pE120R might be involved in the microtubule-mediated transport of ASFV particles from the viral factories to the plasma membrane.


1996 ◽  
Vol 32 (3) ◽  
pp. 437-443 ◽  
Author(s):  
Hong Li ◽  
David T. Shen ◽  
David A. Jessup ◽  
Donald P. Knowles ◽  
John R. Gorham ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document