Porcine Endogenous Retrovirus (PERV) Infection of HEK-293 Cell Line Alters Expression of Human Endogenous Retrovirus (HERV-W) Sequences

Machnik, Grzegorz; Klimacka-Nawrot, E.; Sypniewski, D.; Matczyńska, D.; Gałka, S.; Bednarek, I.; Okopień, B.

doi:10.14712/fb2014060010035

Folia Biologica > Archive > 2014, Vol. 60 > Issue 1 > Porcine Endogenous Retrovirus (PERV)…

Fol. Biol. 2014, 60, 35-46

https://doi.org/10.14712/fb2014060010035

Porcine Endogenous Retrovirus (PERV) Infection of HEK-293 Cell Line Alters Expression of Human Endogenous Retrovirus (HERV-W) Sequences

Grzegorz Machnik¹, E. Klimacka-Nawrot², D. Sypniewski³, D. Matczyńska³, S. Gałka³, I. Bednarek³, B. Okopień¹

¹Department of Pharmacology, Medical University of Silesia, Katowice, Poland
²Department of Basic Biomedical Sciences, Medical University of Silesia, Katowice, Poland
³Department of Biotechnology and Genetic Engineering, Medical University of Silesia, Katowice, Poland

Received May 2013
Accepted November 2013

The risk of infections of human recipients after xenotransplantations is now mainly represented by porcine endogenous retroviruses (PERVs) as these particles are part of the porcine genome. As in all vertebrates, human genome harbours its own numerous genetic sequences of retroviral origin; it is estimated that they comprise about 8 % of the human genome. Because some of them play an important role in human physiology, it is valuable to estimate whether the presence of PERVs in human cells influences homeostasis of the human endogenous retrovirus (HERV) expression pattern. The aim of the study was to evaluate whether the expression profile of HERV-W genes changes after infection of cells by porcine endogenous retroviruses. In the experimental settings, human embryonic kidney cell line (HEK-293) was infected by PERV particles and cultivated up to 22th passage after infection. HERV-W gag, pol and env, as well as env from locus 7q21.2 gene expression was monitored by means of realtime reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and Western blot techniques. We found that the expression level of HERV-W genes differs in PERV-infected HEK-293 cell cultures in comparison with that from non-infected cultures. Relative HERV-W gene expression also differed significantly between particular passages (P < 0.05). Moreover, we have noticed a high correlation between the HERV-W Env(7q21.2) mRNA and protein level (Spearman rank r = 0.65; P < 0.05) during the course of the experiment. As previously hypothesized, human genomic sequences of retroviral origin may be changed by the presence of porcine endogenous retroviruses.