<abstract xmlns="http://www.w3.org/1999/xhtml"><p> Multiple sclerosis (MS) is a neurological disease of unknown aetiology. Several research groups reported an increased level of human endogenous retroviruses HERV-W and HERV-H RNAs in cerebrospinal fluid, plasma and supernatants of cell cultures from MS individuals. To quantify the abundance of extracellular virion-associated HERV, RNAs in blood, plasma samples from Latvian MS patients, patients with other neurological diseases (OND), as well as blood donors (BD), were retrospectively studied by using both our previously published and newly developed quantitative Real-time reverse transcription PCR assays (QPCRs) targeting different polymerase (pol) gene regions of HERV-W and HERV-H. Unspecific signals due to incomplete removal of DNA were monitored by running the assays with and without reverse transcription (RT±) in parallel. According to our score, a few MS, OND and healthy controls gave borderline signals simultaneously with both newly developed HERV-H and HERV-W QPCRs, but the rest were negative. All borderline positive samples also had small amounts of non-retroviral cellular mRNA with possible origin from cell-free circulating RNA fragments, apoptotic bodies or exosomes, which can mimic the previously described virus-like particles. The results do not confirm the previous reports on prevalence of HERV-H or -W virion-associated RNA in plasma of MS patients.</p></abstract>

Multiple sclerosis (MS) is a neurological disease of unknown aetiology. Several research groups reported an increased level of human endogenous retroviruses HERV-W and HERV-H RNAs in cerebrospinal fluid, plasma and supernatants of cell cultures from MS individuals. To quantify the abundance of extracellular virion-associated HERV, RNAs in blood, plasma samples from Latvian MS patients, patients with other neurological diseases (OND), as well as blood donors (BD), were retrospectively studied by using both our previously published and newly developed quantitative Real-time reverse transcription PCR assays (QPCRs) targeting different polymerase (pol) gene regions of HERV-W and HERV-H. Unspecific signals due to incomplete removal of DNA were monitored by running the assays with and without reverse transcription (RT±) in parallel. According to our score, a few MS, OND and healthy controls gave borderline signals simultaneously with both newly developed HERV-H and HERV-W QPCRs, but the rest were negative. All borderline positive samples also had small amounts of non-retroviral cellular mRNA with possible origin from cell-free circulating RNA fragments, apoptotic bodies or exosomes, which can mimic the previously described virus-like particles. The results do not confirm the previous reports on prevalence of HERV-H or -W virion-associated RNA in plasma of MS patients.

No Definite Evidence for Human Endogenous Retroviral HERV-W and HERV-H RNAS in Plasma of Latvian Patients Suffering from Multiple Sclerosis and Other Neurological Diseases / Nav Apstiprinošu Pierādījumu Par Endogēno Retrovīrusu HERV-W Un HERV-H Rns Sastopamību Latvijas Pacientu Ar Multiplo Sklerozi Un Citām NeiroloĢiskām Slimībām Asins Plazmā

Department of Oncovirology, Augusts Kirhenšteins Institute of Microbiology and Virology, Rīga Stradiņš University, Rātsupītes iela 5, Rīga, LV-1067, LATVIA

Section of Clinical Virology, Department of Medical Sciences, Uppsala University Hospital, Dag Hammarskjölds väg 17, 751 85 Uppsala, Sweden

Department of Neurology and Neurosurgery, Rīga Stradiņš University, Pilsoņu iela 13-37, Rīga, LATVIA

Proceedings of the Latvian Academy of Sciences. Section B. Natural, Exact, and Applied Sciences.

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

Multiple sclerosis (MS) is a neurological disease of unknown aetiology. Several research groups reported an increased level of human endogenous retroviruses...

Published Online: Aug 04, 2016

Page range: 182 - 192

Received: Oct 26, 2015

DOI: https://doi.org/10.1515/prolas-2016-0029

Keywords
endogenous retrovirus, multiple sclerosis, plasma, real-time PCR, RNA.

© by Jonas Blomberg

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

Published Online: Aug 04, 2016

Page range: 182 - 192

Received: Oct 26, 2015

DOI: https://doi.org/10.1515/prolas-2016-0029

Keywordsendogenous retrovirus, multiple sclerosis, plasma, real-time PCR, RNA.

© by Jonas Blomberg

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

Keywords
endogenous retrovirus, multiple sclerosis, plasma, real-time PCR, RNA.