scholarly journals Coinfections of Novel Polyomavirus, Anelloviruses and a Recombinant Strain of Myxoma Virus-MYXV-Tol Identified in Iberian Hares

Viruses ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 340 ◽  
Author(s):  
Ana Águeda-Pinto ◽  
Simona Kraberger ◽  
Michael C. Lund ◽  
Christian Gortázar ◽  
Grant McFadden ◽  
...  
Keyword(s):  
Recombinant Strain ◽  
Amino Acid Identity ◽  
T Antigen ◽  
Myxoma Virus ◽  
Large T Antigen ◽  
Dna Viruses ◽  
Putative Species ◽  
Recombinant Region ◽  
Genome Wide ◽  
Identity Based

Viruses are ubiquitous in nature; however, very few have been identified in the Leporid species. In the fall of 2018, an outbreak of myxomatosis in Iberian hares (Lepus granatensis) was reported in Spain and a novel recombinant myxoma virus strain (MYXV-Tol) was identified. To investigate variability within the recombinant region of the MYXV-Tol and identify any potential viral coinfections, samples (ear, eyelid or vaginal) of Iberian hares were collected from Spain and analyzed. The presence of the recombinant region of the MYXV-Tol was confirmed in six out of eleven samples analyzed. Additionally, a polyomavirus (family Polyomaviridae), representing a putative new species, and anelloviruses (family Anelloviridae) belonging to two putative species were identified, some as coinfection with the recombinant MYXV-Tol. The two polyomavirus genomes were identified in two hares and share >99% genome-wide identity. Based on the analysis of their large T-antigen, the new polyomavirus clusters in a distant clade from other mammals sharing <64% amino acid identity. A total of 14 anelloviruses were identified, which share 63–99% genome-wide identity. Overall, our results show a coinfection of different DNA viruses in the studied samples and raise awareness regarding the extensive unsampled diversity of viruses in hares.

scholarly journals SV40 Large T Antigen Is Not Responsible for the Loss of STING in 293T Cells but Can Inhibit cGAS-STING Interferon Induction

Viruses ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 137 ◽  
Author(s):  
Joshua B. Reus ◽  
Guillermo S. Trivino-Soto ◽  
Lily I. Wu ◽  
Kristiana Kokott ◽  
Efrem S. Lim
Keyword(s):  
T Antigen ◽  
Large T Antigen ◽  
Sv40 Large T Antigen ◽  
Dna Viruses ◽  
Antiviral Responses ◽  
Interferon Induction ◽  
Sv40 Origin ◽  
Immune Pathway ◽  
Sting Pathway ◽  
Lxcxe Motif

Several DNA viruses have evolved antagonists to inhibit the cyclic GMP–AMP synthase (cGAS)-stimulator of interferon genes (STING) DNA-sensing immune pathway. This includes DNA viral oncogenes that antagonize the cGAS-STING pathway by binding STING through the LxCxE motif. The 293T human cells are widely used in biology studies as they are highly transfectable. While parental 293 cells express high levels of STING, 293T cells lack STING and are unable to induce interferon antiviral responses to cytosolic DNA. Additionally, 293T cells express the SV40 polyomavirus large T antigen (LT) which enhances the replication of transfected DNA plasmids carrying the SV40 origin of replication. Since SV40 LT also encodes the LxCxE motif, the lack of STING expression in 293T cells is commonly assumed to be due to SV40 large T antigen. We find that SV40 LT does not alter exogenously expressed and endogenous levels of STING protein. We show that STING transcription is suppressed in 293T cells but is not driven by SV40. This study also revealed that SV40 LT does indeed inhibit cGAS-STING interferon induction, but through a mechanism distinct from other DNA virus oncogenes. Collectively, these results indicate that while SV40 LT can inhibit cGAS-STING interferon induction, it does so in an unanticipated manner.

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