Use of synthetic oligonucleotides for determination of HTLV-1 proviral load by real-time PCR: a helpful alternative approach in the clinical management

J Appl Microbiol. 2020 Sep;129(3):768-774. doi: 10.1111/jam.14646. Epub 2020 Apr 8.

Abstract

Aims: To evaluate the potential use of synthetic oligonucleotides as a standard curve for proviral load (PVL) of human T-cell leukaemia virus type 1 (HTLV-1) quantification in peripheral blood mononuclear cells (PBMC) of HTLV-1-infected individuals by quantitative real-time polymerase chain reaction (qPCR) analysis.

Methods and results: Synthetic oligonucleotides based on HTLV-1 genome were customized to use as a standard curve. Twelve anti-HTLV-1-positive samples with known HTLV-1 PVL, previously quantified by qPCR assay using TARL-2 cells as a conventional standard curve, were submitted to the new protocol. The proviral quantification levels had a high concordance with qPCR results using a conventional standard curve. The results demonstrate that the conventional standard curve can be replaced by a synthetic standard curve due to its ability to quantification based on the linearity and qPCR efficiency and similar results with a validated qPCR assay using a conventional standard curve.

Conclusions: Synthetic oligonucleotides standard curves could be a very useful tool on HTLV-1 diagnosis and absolute HTLV-1 PVL quantification.

Significance and impact of the study: HTLV-1 PVL determination using synthetic oligonucleotides standard curve by qPCR could be a helpful alternative for the laboratories that monitor infected patients as an important prognostic factor in HTLV-1-associated diseases progression. Also, it can decrease costs and overcome the biological limitations of the plasmid curve.

Keywords: HTLV; HTLV-1; HTLV-1 proviral load; qPCR; quantification; synthetic oligonucleotides standard curve.

MeSH terms

  • Adult
  • DNA, Viral / genetics
  • Disease Progression
  • Genome, Viral / genetics
  • HTLV-I Infections / blood
  • HTLV-I Infections / diagnosis*
  • HTLV-I Infections / virology
  • Human T-lymphotropic virus 1 / genetics
  • Human T-lymphotropic virus 1 / isolation & purification*
  • Humans
  • Leukocytes, Mononuclear / virology
  • Middle Aged
  • Oligonucleotides / chemical synthesis
  • Oligonucleotides / genetics
  • Prognosis
  • Proviruses / genetics
  • Proviruses / isolation & purification*
  • Real-Time Polymerase Chain Reaction / methods*
  • Real-Time Polymerase Chain Reaction / standards
  • Viral Load / methods*
  • Viral Load / standards

Substances

  • DNA, Viral
  • Oligonucleotides