Monitoring of HTLV-1-associated diseases by proviral load quantification using multiplex real-time PCR

Author(s)

Rodrigues, Evandra Strazza ; Salustiano, Suellen ; Santos, Elaine Vieira ; Slavov, Svetoslav Nanev ; Picanco-Castro, Virginia ; Maconetto, Juliana Matos ; de Haes, Tissiana Marques ; Takayanagui, Osvaldo Massaiti ; Covas, Dimas Tadeu ; Kashima, Simone

• Document type: Journal article
• Source: JOURNAL OF NEUROVIROLOGY; v. 28, n. 1, p. 8-pg., 2022-01-13.

Abstract

Proviral load (PVL) is one of the determining factors for the pathogenesis and clinical progression of the human T-lymphotropic virus type I (HTLV-1) infection. In the present study, we optimized a sensitive multiplex real-time PCR for the simultaneous detection and quantification of HTLV-1 proviral load and beta-globin gene as endogenous control. The values obtained for HTLV-1 PVL were used to monitor the clinical evolution in HTLV-1-infected individuals. A vector containing cloned DNA targets of the real-time PCR for the beta-globin gene and the HTLV-1pol region was constructed. For the reaction validation, we compared the amplification efficiency of the constructed vector and MT-2 cell line containing HTLV-1. The analytical sensitivity of the reaction was evaluated by the application of a standard curve with a high order of magnitude. PVL assay was evaluated on DNA samples of HTLV-1 seropositive individuals. The construct showed adequate amplification for the beta-globin and HTLV-1 pol genes when evaluated as multiplex real-time PCR (slope = 3.23/3.26, Y-intercept = 40.18/40.73, correlation coefficient r(2) = 0.99/0.99, and efficiency = 103.98/102.78, respectively). The quantification of PVL using the MT-2 cell line was equivalent to the data obtained using the plasmidial curve (2.5 copies per cell). In HTLV-1-associatedmyelopathy/tropical spastic paraparesis patients, PVL was significantly higher (21315 +/- 2154 copies/10(5) PBMC) compared to asymptomatic individuals (1253 +/- 691 copies/10(5) PBMC). The obtained results indicate that the optimized HTLV-1 PVL assay using plasmidial curve can be applied for monitoring and follow-up of the progression of HTLV-1 disease. The use of a unique reference plasmid for both HTLV-1 and endogenous gene allows a robust and effective quantification of HTLV-1 PVL. In addition, the developed multiplex real-time PCR assay was efficient to be used as a tool to monitor HTLV-1-infected individuals. (AU)

• FAPESP's process: 13/08135-2 - CTC - Center for Cell-Based Therapy
• Grantee: Dimas Tadeu Covas
• Support Opportunities: Research Grants - Research, Innovation and Dissemination Centers - RIDC