A HML6 endogenous retrovirus on chromosome 3 is upregulated in amyotrophic lateral sclerosis motor cortex

There is increasing evidence that endogenous retroviruses (ERVs) play a significant role in central nervous system diseases, including amyotrophic lateral sclerosis (ALS). Studies of ALS have consistently identified retroviral enzyme reverse transcriptase activity in patients. Evidence indicates that ERVs are the cause of reverse transcriptase activity in ALS, but it is currently unclear whether this is due to a specific ERV locus or a family of ERVs. We employed a combination of bioinformatic methods to identify whether specific ERVs or ERV families are associated with ALS. Using the largest post-mortem RNA-sequence datasets available we selectively identified ERVs that closely resembled full-length proviruses. In the discovery dataset there was one ERV locus (HML6_3p21.31c) that showed significant increased expression in post-mortem motor cortex tissue after multiple-testing correction. Using six replication post-mortem datasets we found HML6_3p21.31c was consistently upregulated in ALS in motor cortex and cerebellum tissue. In addition, HML6_3p21.31c showed significant co-expression with cytokine binding and genes involved in EBV, HTLV-1 and HIV type-1 infections. There were no significant differences in ERV family expression between ALS and controls. Our results support the hypothesis that specific ERV loci are involved in ALS pathology.

One enzyme reverse transcription qPCR using Taq DNA polymerase

ABSTRACTTaq DNA polymerase, one of the first thermostable DNA polymerases to be discovered, has been typecast as a DNA-dependent DNA polymerase commonly employed for PCR. However, Taq polymerase belongs to the same DNA polymerase superfamily as the Molony murine leukemia virus reverse transcriptase and has in the past been shown to possess reverse transcriptase activity. We report optimized buffer and salt compositions that promote the reverse transcriptase activity of Taq DNA polymerase, and thereby allow it to be used as the sole enzyme in TaqMan RT-qPCR reactions. We demonstrate the utility of Taq-alone RT-qPCR reactions by executing CDC SARS-CoV-2 N1, N2, and N3 TaqMan RT-qPCR assays that could detect as few as 2 copies/µL of input viral genomic RNA.

Discovery of the First Human Retro-Giant Virus: Description of its morphology, retroviral kinase and ability to induce tumours in mice

BackgroundThe study of retroviruses dates back to the early 1900s during investigations on neoplastic diseases in chickens. Subsequently, Robert Gallo reported the first human retrovirus HLTV in 1980. What we report here is not an archetypal retrovirus, but the discovery of an oncogenic giant microbial agent with a mega-genome, where the transforming retroviral nature co-exists with multiple archaeal oncogenes.MethodsAfter their isolation from human T cells Leukaemia, these organisms were examined at electron microscopy, tested for reverse transcriptase activity, fully sequenced, used for transformation tests on NIH-3T3 cells in vitro and tumours formation in mice. Same type of particles were also isolated from Canine Transmissible Venereal Tumour (CTVT), the oldest contagious cancer in nature.ResultsEM showed the presence of giant viral particles displaying retroviral antigens. These microbial entities harbour in their mega-genome a transforming retroviral kinase, cell-based oncogenes and have reverse transcriptase activity. The purified viral particles transformed NIH-3T3 cells and induced metastatic tumours in nude mice, three weeks post infection. Ruling out the possible presence of filterable retroviruses, a filtered supernatant did not display RT activity and did not transforms.ConclusionsWe discovered an ancestral microbial agent, acutely transforming. For its giant dimensions, the ability to retain the Gram stain, the presence of a mega-genome and its retroviral nature, we tentatively named the agent Retro-Giant-Virus (RGV). However, distinct from amoeba giant Mimiviruses, this transforming human agent has a different nature and does not require for its isolation amoeba co-culture, since amoeba is not its natural host.The morphology, biology and genetic features allocate this mammalian giant microbe halfway in between a classic oncogenic virus and an infectious cancer cell. Its transforming nature goes with its constant ability to induce tumours formation in mice.